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Global declines in wild and managed bee populations represent a major concern for the agricultural industry. Such declines result, in part, from the loss of natural and semi-natural habitats in and around agricultural ecosystems. However, remaining forest patches in heavily modified landscapes represent nesting habitats that may be crucial to preserving wild bees and their services. Because wild bees are the main pollinators of fruit crops, preserving potential nesting habitats might be particularly important for the crops’ yield and profitability. Here, we assessed whether the abundance and richness of visiting wild bees in blueberry crops relates to the amount of surrounding forest cover and if so, whether those relationships varied with spatial scale. Specifically, we sampled wild bee communities in 18 blueberry fields during the blooming period in Montérégie, Quebec, Canada, where sampling consisted of pan trap triplets and direct observation of flower visitors on blueberry bushes. Then, we quantified the proportion of forest in radii of 0.5 km, 1 km, and 2 km around each field. Wild bee abundance was positively related to the proportion of forest habitat surrounding the crop field, but the relationship for wild bee richness was less clear. Moreover, these relationships were strongest at 1 and 2 km radii of measured land cover. Overall, pollinator diversity was highest when at least 30% of the surrounding landscape consisted of forest patches, representing a total area of at least 1 km2. Our results suggest that preserving large habitat patches in agricultural landscapes can help prevent further decline in wild bee diversity while maximizing pollination services to fruit crops.

Forestry management can shape the structure of habitat types and have important biological consequences on the composition of biodiversity. This study focused on Momotus lessonii and Eumomota superciliosa, two potential bioindicators of local and wide scale tropical forest alterations. The study took place in the Karen Mogensen Wildlife Refuge (Costa Rica), a protected area characterized by two main forest habitats where the two species coexist, i.e., primary moist and second-growth dry forest. A distance sampling method was used to obtain density estimates for each species. A spot mapping approach showed an apparent partitioning of the two species at the site. The Kilometric Abundance Index (KAI) and statistical analyses revealed significant differences between the two habitats, i.e., E. superciliosa tended to be more abundant and preferred the dry forest, whilst M. lessonii favored moist environments. The development of arid and semi-arid environments characterized by open areas will probably lead to a numerical increase in E. superciliosa with a consequent expansion, while the decline of moister and homogeneously forested environments will likely affect negatively M. lessonii. We argue that these birds will act as bioindicators of local and global environmental changes, and their monitoring will enable appropriate forest management decisions for conservation purposes.

Fragmentation is one of the major threats to biodiversity. In a fragmented landscape, forest specialists are losing suitable forest habitats with specific site and microclimate conditions, which results in their local extinction. Conversely, the invasion of alien species is facilitated by open forest areas and increased boundaries between forest fragments and adjacent land. We studied the effect of fragmentation in terms of fragment size impact on overall plant species richness and on selected ecologically important groups' richness, composition, and diversity. We surveyed vegetation in the interior of 47 fragments of various sizes and one unfragmented reference forest. Our results reveal that the effect of fragmentation is complex and differs for studied plant groups. Decreasing fragment size negatively affects the overall plant richness and richness of native and ancient forest indicator plants as well as their diversity, while the effect is positive for alien plants. The highest proportion of ancient forest indicator plant species and the lowest proportion of alien plants in the unfragmented forest underline the great conservation value of forest fragments. At the same time, our results reveal that large and diverse forest ecosystems are susceptible to biological invasions as well. Nasl. z nasl. zaslona. Opis vira z dne 8. 12. 2022. Št. članka: 3392. Bibliografija: str. 12-13. Abstract. ARRS, Programi, SI, Računsko intenzivni kompleksni sistemi ARRS, Projekti, SI, Fazni prehodi proti koordinaciji v večplastnih omrežjih ARRS, Programi, SI, Gozdna biologija, ekologija in tehnologija Projekt GoForMura

Introduction: Although wildlife crossing structures have proven successful at reducing wildlife-vehicle collisions and linking fragmented habitat, their ability to prevent electrocutions of arboreal wildlife has not been closely examined. Objective: To evaluate the effectiveness of aerial rope bridges in restoring habitat connectivity for arboreal species in Manuel Antonio, Costa Rica, while preventing electrocutions by determining 1) what species are using the rope bridges and 2) whether wildlife prefer to use rope bridges instead of other hazardous structures that cross the roads (such as telephone cables, which are often in close proximity to electric wires). Methods: From January to May 2016, nine rope bridges along the highly-trafficked main road that extends from Quepos to Manuel Antonio, Costa Rica, were monitored using camera traps, and ten rope bridges were observed directly along a paved side road off the main road. Results: A total of 11 species were seen using the bridges, and 1 540 crossings were witnessed via camera traps and observations (1 234 via camera traps, 306 during observations). Results from a paired t-test showed no significant difference in the average number of individuals crossing the road via rope bridges versus telephone cables (t(8) = 1.027, P = 0.334). Conclusions: Rope bridges are used by a variety of arboreal wildlife species with a high degree of frequency; however, due to the equally high usage of telephone cables by arboreal wildlife, they are insufficient to prevent wildlife electrocutions on their own. Rope bridges should be installed in tandem with other methods to prevent electrocutions, such as insulating electric wires, to facilitate the safe passage of wildlife over roads. Resumen Introducción: Aunque los pasos de fauna han demostrado ser exitosos para reducir las colisiones entre vehículos y vida silvestre y vincular el hábitat fragmentado, su capacidad para prevenir electrocuciones de la vida silvestre arbórea no se ha examinado a fondo. Objetivo: Evaluar la efectividad de los puentes aéreos de cuerdas para restaurar la conectividad del hábitat de las especies arbóreas en Manuel Antonio, Costa Rica y al mismo tiempo prevenir las electrocuciones al determinar 1) qué especies están usando los puentes de cuerda y 2) si la vida silvestre prefiere usar puentes de cuerda en lugar de otras estructuras peligrosas que cruzan las carreteras (como cables telefónicos, que frecuentemente están muy cerca de cables eléctricos). Métodos: De enero a mayo de 2016, se monitorearon nueve puentes de cuerda a lo largo de la carretera principal altamente transitada que se extiende desde Quepos a Manuel Antonio, Costa Rica, utilizando cámaras trampa y la observación directa en diez puentes de cuerda a lo largo de una carretera pavimentada más pequeña fuera de la carretera principal. Resultados: Se observaron un total de 11 especies utilizando los puentes y se presenciaron 1 540 cruces mediante cámaras trampa y observaciones (1 234 mediante cámaras trampa, 306 durante las observaciones). Los resultados de una prueba t pareada no mostraron diferencias significativas en el número promedio de individuos que cruzan la carretera a través de puentes de cuerda versus cables telefónicos, t (8) = 1.027, P = 0.334. Conclusiones: Los puentes de cuerdas son utilizados por una variedad de especies de vida silvestre arbóreas con un alto grado de frecuencia; sin embargo, debido al uso igualmente elevado de cables telefónicos por parte de la vida silvestre arbórea, se considera que son insuficientes para prevenir las electrocuciones de la vida silvestre por sí solas. Los puentes de cuerda deben instalarse junto con otros métodos para evitar electrocuciones, como cables eléctricos aislados, para facilitar el paso seguro de la vida silvestre por las carreteras.

Ecosystems are degrading world-wide, with severe ecological and economic consequences. Restoration is becoming an important tool to regain ecosystem services and preserve biodiversity. However, in harsh ecosystems dominated by habitat-modifying organisms, restoration is often expensive and failure prone. Establishment of such habitat modifiers often hinges on self-facilitation feedbacks generated by traits that emerge when individuals aggregate, causing density- or patch size-dependent establishment thresholds. To overcome these thresholds, adult or juvenile habitat-forming species are often transplanted in clumped designs, or stress-mitigating structures are deployed. However, current restoration approaches focus on introducing or facilitating a single life stage, while many habitat modifiers experience multiple bottlenecks throughout their life as they transition through sequential life stages. Here, we define and experimentally test ‘life cycle informed restoration’, a restoration concept that focuses on overcoming multiple bottlenecks throughout the target species’ lifetime. To provide proof of concept, and show its general applicability, we carried out complementary experiments in intertidal soft-sediment systems in Florida and the Netherlands where oysters and mussels act as reef-building habitat modifiers. We used biodegradable structures designed to facilitate bivalve reef recovery by both stimulating settlement with hard and fibrous substrates and post-settlement survival by reducing predation. Our trans-Atlantic experiments demonstrate that these structures enabled bivalve reef formation by: (a) facilitating larval recruitment via species-specific settlement substrates, and (b) enhancing post-settlement survival by lowering predation. In the Netherlands, structures with coir rope most strongly facilitated mussels by providing fibrous settlement substrate, and predation-lowering spatially complex hard attachment substrate. In Florida, oysters were greatly facilitated by hard substrates, while coir rope proved unbeneficial. Synthesis and applications. Our findings demonstrate that artificial biodegradable reefs can enhance bivalve reef restoration across the Atlantic by mimicking emergent traits that ameliorate multiple bottlenecks over the reef-forming organism’ life cycle. This highlights the potential of our approach as a cost-effective and practical tool for nature managers to restore systems dominated by habitat modifiers whose natural recovery is hampered by multiple life stage-dependent bottlenecks. Therefore, investment in understanding how to achieve life cycle informed restoration on larger scales and whether the method it is applicable to restore other ecosystems is now required.

Human land use is a driving force of habitat loss and modification globally, with consequences for wildlife species. The American marten (Martes americana) and fisher (Pekania pennanti) are forest-dependent carnivores native to North America. Both species suffered population declines due to loss of forested habitat and overharvest for furs, and continued habitat modification is an ongoing threat. Furthermore, the smaller marten may be susceptible to intraguild exclusion where the larger fisher are abundant, and both habitat modification and climate change may reduce spatial refugia available to marten. A detailed understanding of co-occurrence patterns of marten and fisher in landscapes subjected to intense forest disturbance represents a key knowledge gap for wildlife ecology and management. Maine, in the northeastern United States, supports populations of both these species. It is an extensively forested state, and the vast majority is managed as commercial timberland. We designed a large-scale field study to understand the relative importance of three sets of predictions for marten and fisher occupancy patterns where commercial silviculture is widespread: (1) The intensity of forest disturbance primarily determined both marten and fisher occupancy rates, (2) fisher occupancy was limited to areas of shallower snow and marten limited by fisher presence, or (3) both species responded to the composition of tree species within forested habitat. We collected data to test these nonmutually exclusive hypotheses via camera-trap surveys, using an experimental design balanced across a gradient of forest disturbance intensity. We deployed 197 camera stations in both summer and winter over 3 years (2017–2020). We tagged over 800,000 images and found marten at 124 (63%) and fisher at 168 (85%) of the stations. By fitting multiseason occupancy models to the data, we found that the degree of habitat disturbance negatively influenced detection, occupancy, and temporal turnover for both species. Contrary to our expectations, however, we found no evidence of interspecific competition and instead support for positive associations with detection probabilities both spatially and temporally. Both species were positively associated with forest stands containing deciduous trees. Our findings further illustrate the impact that land use has on the occupancy dynamics for these forest-dependent carnivores.

Field research and surveys from the past century have provided a valuable resource for documenting amphibian population declines and investigating their possible causes. In Yellowstone National Park, research from the 1950s provided us with an extraordinary opportunity to investigate a Columbia Spotted Frog population’s decline over time in an area modified by increasing human occupation. Herpetologist F.B. Turner’s investigation (1953–1956) of a Columbia Spotted Frog (Rana luteiventris) population set the foundation for decades of study. In the 1990s, acting on Turner’s observation of an apparently sharp reduction in the number of frogs, we replicated his 1950s mark-recapture study with the goals of determining the extent of the decline and examining its possible causes. We continued annual monitoring through 2020. The population declined by nearly 80% between the mid-1950s and mid-1990s. The number of active breeding sites fell from 3 sites in 1950s, to 2 and then 1 in the 1990s, and none after 2007. The decline was accompanied by significant changes in the 28-hectare study area: a road constructed in the 1970s bisected the study area, headwater springs were developed, and facilities were built in and around the study area to support expanding human uses. Changes in spatial characteristics of the remnant frog population are thought to indicate the impacts of local habitat fragmentation, modification and loss. Here we focus on how the activity ranges and patterns of frog dispersal within the study area shrank to a zone upstream of the highway, prior to the eventual extirpation of the local breeding population. Multiple direct and indirect human-caused changes negatively influenced habitat that supported reproduction, survival, and recruitment. Climate change was not found to provide an adequate explanation of the observed changes. While a breeding population of Columbia Spotted Frogs has persisted next to the historical study area, it has experienced large fluctuations in egg mass production and repeated disease outbreaks in the last 15 years. This long-term case study provides a cautionary tale about shifting baselines and how land use may affect amphibian populations even in protected areas. We recommend extended monitoring for amphibians in developed zones of Yellowstone National Park, as visitation grows and conditions are further altered by infrastructure upgrades as well as by climate change.

Habitat loss is a serious issue threatening biodiversity across the planet, including coastal habitats that support important fish populations. Many coastal areas have been extensively modified by the construction of infrastructure such as ports, seawalls, docks, and armored shorelines. In addition, habitat restoration and enhancement projects often include constructed breakwaters or reefs. Such infrastructure may have incidental or intended habitat values for fish, yet their physical complexity makes quantitatively sampling these habitats with traditional gears challenging. We used a fleet of unbaited underwater video cameras to quantify fish communities across a variety of constructed and natural habitats in Perdido and Pensacola Bays in the central northern Gulf of Mexico. Between 2019 and 2021, we collected almost 350 replicate 10 min point census videos from rock jetty, seawall, commercial, public, and private docks, artificial reef, restored oyster reef, seagrass, and shallow sandy habitats. We extracted standard metrics of Frequency of Occurrence and MaxN, as well as more recently developed MeanCount for each taxon observed. Using a simple method to measure the visibility range at each sampling site, we calculated the area of the field of view to convert MeanCount to density estimates. Our data revealed abundant fish assemblages on constructed habitats, dominated by important fisheries species, including grey snapper Lutjanus griseus and sheepshead Archosargus probatocephalus. Our analyses suggest that density estimates may be obtained for larger fisheries species under suitable conditions. Although video is limited in more turbid estuarine areas, where conditions allow, it offers a tool to quantify fish communities in structurally complex habitats inaccessible to other quantitative gears.

Background Harvesting of forest products is a widespread driver of disturbance in developing nations, where policies are increasingly aimed at managing natural forests for sustainable use. There is thus need for research aimed at understanding the impact of resource use on forest habitats and concomitant effects on biodiversity. Afromontane forests in the Eastern Cape, South Africa are harvested informally for poles and medicinal bark and occur along elevational gradients of 800–1600 m above sea level. Patterns of spatial diversity and human disturbance are expected to be affected by elevation. Furthermore, species’ responses to disturbance are expected to vary depending on their level of habitat specialisation. Understanding harvest impacts on forest biodiversity thus requires disentangling the separate effects of elevation and disturbance, and considering forest-specialist and forest-generalist species separately. This study comprises two components. First, harvest activities, resultant harvest-mediated habitat heterogeneity, and avifaunal species richness, composition and beta-diversity were compared across two elevational zones in a harvested forest. Second, the role of harvest-mediated habitat heterogeneity in driving patterns of avifaunal diversity were assessed, while controlling for elevation, and considering forest-specialist and forest-generalist species separately. Results Harvest rates were higher, and activities more varied in the lower elevation zone, with significant impacts of harvesting on habitat features resulting in higher harvest-mediated habitat heterogeneity at lower elevations. Harvest-mediated increases in habitat heterogeneity positively affected forest-generalist species richness, while forest-specialist richness was negatively affected. While species composition of both groups differed across elevational zones, variation in harvest-mediated habitat heterogeneity did not fully account for this, suggesting that factors other than disturbance shape avifaunal communities along the elevation gradient. However, variation in harvest-mediated habitat heterogeneity accounted for the amount of beta-diversity attributed to species turnover in the forest-specialist assemblage, indicating that harvest disturbances affect the mechanisms driving beta-diversity of this group. Conclusion Spatial patterns of avifaunal diversity are affected by elevation over a 300-m gradient. Harvesting results in increased habitat heterogeneity, which variably affects avifaunal communities at the forest-scale, with positive effects for forest generalists and negative effects for forest-specialists.

Made available in DSpace on 2019-10-04T12:31:28Z (GMT). No. of bitstreams: 0 Previous issue date: 2018-10-18 Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Leishmaniasis is a vector-borne parasitic protozoan infection that affects mammals and involves a complex epidemiology. Although dogs are considered the main reservoir in zoonotic visceral leishmaniasis (VL), the possible presence of other mammalian species acting as reservoirs has been associated as a possible cause of lack of success in the control of human VL in many endemic areas. The knowledge about natural infections of some species is still scarce, such as nonhuman primates (NHP), especially from the genus Callithrix (marmosets). We investigated the infection by Leishmania (Leishmania) infantum, the agent of VL in the Americas, in 26 marmosets captured monthly, from April 2014 to March 2015, in an environmentally protected area (EPA) in Southeastern Brazil. The EPA has undergone significant environmental changes and has a transmission focus of canine VL since 2009. Serology was performed through the direct agglutination test, which detected low antibody titers in seven marmosets (7/26; 26.9%, 95% confidence interval 9.9-44.0), being five Callithrix penicillata (black-tufted-ear marmoset) and two Callithrix jacchus (white-tufted-ear marmoset). The presence of the DNA of Leishmania was investigated in blood and skin samples by PCR and genetic sequencing. This is the first report of the detection of L. (L.) infantum in the skin of a marmoset, which was verified in a sample from one C. penicillata. The results demonstrate the natural infection of marmosets by L. (L.) infantum and may suggest the participation of these animals as hosts in the parasite's transmission cycle in the EPA. However, more comprehensive studies are needed to elucidate their role on the VL epidemiology in this area and also in different endemic areas, especially because these NHP are increasingly in contact with humans and domestic animals, particularly due to environmental changes. Univ Estadual Campinas, Dept Publ Hlth, Fac Med Sci, Campinas, SP, Brazil Adolfo Lutz Inst, Ctr Syst Parasit Dis, Sao Paulo, Brazil Adolfo Lutz Inst, Bauru Ctr Reg Labs 2, Bauru, Brazil Sao Paulo State Univ, Sch Vet Med & Anim Sci, Dept Vet Hyg & Publ Hlth, Botucatu, SP, Brazil Sao Paulo State Univ, Sch Vet Med & Anim Sci, Dept Vet Hyg & Publ Hlth, Botucatu, SP, Brazil FAPESP: 2014/27212-0 FAPESP: 2014/13049-0 FAPESP: 2016/02572-0

In biogeomorphic landscapes, plant traits can steer landscape development through plant‐mediated feedback interactions. Interspecific differences in clonal expansion strategy can therefore lead to the emergence of different landscape organisations. Yet, whether landscape‐forming plants adopt different clonal expansion strategies depending on their physical environment remains to be tested. Here, we use a field survey and a complementary mesocosm approach to investigate whether sediment deposition affects the clonal expansion strategy employed by dune‐building marram grass individuals. Our results reveal a consistent shift in expansion pattern from more clumped, Brownian‐like, movement in sediment‐poor conditions, to patchier, Lévy‐like, movement under high sediment supply rates. Additional model simulations illustrate that the sediment‐dependent shift in movement strategies induces a shift in optimisation of the cost–benefit relation between landscape engineering (i.e. dune formation) and expansion. Plasticity in expansion strategy may therefore allow landscape‐forming plants to optimise their engineering ability depending on their physical landscape., Clonal dune grasses can express different movement strategies that determine their ecosystem engineering ability. Here we show that dune grasses can switch between local movement patterns – indicating low engineering strength – to multi‐scale movement patterns – signifying high engineering efficiency – when sediment deposition is low or high respectively. This environment‐dependent trait expression has important consequences for our understanding of coastal landscape formation and resilience under global change.

Organisms that are part of complex ecosystems interact not only with other organisms but also with their environment, affecting ecosystem functions. In aquatic ecosystems filter feeders affect ecosystem functioning by transferring energy and nutrients from the water to the benthos. The filter-feeding unionoid mussels can have strong effects on nutrient release and biodeposition in streams, affecting primary and secondary production. In a 90-day field cage experiment during winter 2019-2020, effects of the critically endangered freshwater pearl mussel (Margaritifera margaritifera) and leaf litter on benthic macroinvertebrate communities were tested using a factorial study design. Benthic macroinvertebrates were collected from the cages and examined in the lab. No significant effects of mussels, leaf litter or their interaction on the abundance and diversity of invertebrates were found for most groups. The abundance of Simulidae was however lower in cages with mussels compared to cages without mussels. The presence of mussels in streams may therefore affect ecosystem function, here shown as a possible effect on the interspecific competition for food sources between filter feeders. Organismer i komplexa ekosystem interagerar inte bara med andra organismer utan också med sin miljö, samt påverkar ekosystemfunktioner. I akvatiska ekosystem påverkar filtrerare ekosystemfunktioner genom att överföra energi och näringsämnen från vattnet till det bentiska samhället. De filtrerande unionoida musslorna kan ha stora effekter på närsalter och biodeposition i vattendrag, vilket påverkar primär- och sekundärproduktionen. I ett 90-dagars fältbursförsök under vintern 2019-2020 testades effekterna av den starkt hotade sötvattenspärlemusslan (Margaritifera margaritifera) och löv på bentiska samhällen. Makroevertebrater provtogs i burarna och undersöktes på lab. Det fanns inga signifikanta effekter av musslor, löv eller deras interaktion på makroevertebraters tätheter och diversitet för de flesta grupper. Tätheter av Simulidae var dock lägre i burar med musslor jämfört med burar utan musslor. Förekomsten av musslor i vattendrag kan därför påverka ekosystemets funktion, här visat som en möjlig effekt på mellanartskonkurrens mellan filtrerare.

Wheat is one of the major crops throughout the Balkan peninsula of Europe. Specific harvest and binning dates can vary depending on the specific geographic region. Grain aeration, wherein ambient air is used at low-volume airflow rates to cool a grain mass to levels that will suppress insect population development, is an under-utilized component of pest management plans for stored wheat. The successful use of aeration can potentially reduce fumigation of stored wheat, which will contribute to the amelioration of increasingly prevalent phosphine resistance. Historical weather data were used from 19 sites in the Balkan region to predict how quickly grains could be cooled through the use of aeration, using a web-based aeration model, and three different starting dates, including 1, 15, and 30 July. The model was used to predict population growth and development of Sitophilus oryzae, the rice weevil, with and without the use of aeration. Results show that, in the northern regions of the Balkans, aeration implemented at the start of binning reduced insect populations far below pest levels in unaerated wheat, and may potentially eliminate the need for fumigations. In more southerly regions, additional chemical inputs, such as fumigation or grain protectants, may be necessary in conjunction with aeration. Results provide guidelines for the increased potential of using aeration for the management of wheat produced and stored in the Balkan peninsula.

The Eastern Cape Province harbours 46% of South Africa’s remaining indigenous forest cover, and is one of the country’s poorest and least developed provinces. Forest resources thus represent a vital component of rural livelihoods in this region. Consequently, forest management policies aim to balance the needs of resource users with the ecological integrity of forest ecosystems. In a recent study, forest bird ranges were shown to have declined in the Eastern Cape over the past 20 years, despite increases in forest cover over the same time period, indicating that habitat degradation may be driving forest bird losses. Given that harvesting of forest products represents the primary human disturbance in forests in the Eastern Cape today, insight is needed regarding the link between resource use and habitat modification. We report on effects of harvesting of three key forest products – poles, timber and medicinal bark – on habitat structure at the ground, understorey and canopy layers in indigenous forests in the province. Harvest activities had considerable impacts on habitat structure, depending on the nature and extent of harvesting. Bark and timber harvesting resulted in canopy gaps, whereas pole harvesting reduced tree density, resulting in understorey gaps. Overall, harvest activities increased the frequency of canopy disturbance, and density of understorey layer foliage. Unsustainable bark harvesting practices increased the mortality rate of canopy trees, thereby increasing dead wood availability. By providing insight into human-mediated habitat modification in forests of the Eastern Cape, this study contributes to the development of ecologically informed sustainable resource management policies. Significance: Unregulated harvesting of forest products in state-managed indigenous forests of the Eastern Cape results in habitat modification. The nature and extent of habitat modification is dependent on the type and intensity of resource use, indicating that resource use may be sustainably managed. Timber and medicinal bark harvesting activities result in canopy disturbances, thereby altering natural canopy gap dynamics, with concomitant impacts on understorey habitat structure. Changes in forest habitat structure associated with high levels of resource use are likely to have ramifying effects on forest biodiversity.

International audience; Spatial heterogeneity plays a crucial role in the coexistence of species. Despite recogni- tion of the importance of self-organization in creating environmental heterogeneity in otherwise uni- form landscapes, the effects of such self-organized pattern formation in promoting coexistence through facilitation are still unknown. In this study, we investigated the effects of pattern formation on species interactions and community spatial structure in ecosystems with limited underlying envi- ronmental heterogeneity, using self-organized patchiness of the aquatic macrophyte Callitriche platy- carpa in streams as a model system. Our theoretical model predicted that pattern formation in aquatic vegetation – due to feedback interactions between plant growth, water flow and sedimentation pro- cesses – could promote species coexistence, by creating heterogeneous flow conditions inside and around the plant patches. The spatial plant patterns predicted by our model agreed with field observa- tions at the reach scale in naturally vegetated rivers, where we found a significant spatial aggregation of two macrophyte species around C. platycarpa. Field transplantation experiments showed that C. platycarpa had a positive effect on the growth of both beneficiary species, and the intensity of this facilitative effect was correlated with the heterogeneous hydrodynamic conditions created within and around C. platycarpa patches. Our results emphasize the importance of self-organized patchiness in promoting species coexistence by creating a landscape of facilitation, where new niches and facilitative effects arise in different locations. Understanding the interplay between competition and facilitation is therefore essential for successful management of biodiversity in many ecosystems.

Abiotic factors, climatic factors (such as temperature and rainfall) and biotic factors (such as population density and the structure of host communities and reservoirs) are essential variables in the transmission of infectious or parasitic agents.

Conflict between conservation objectives and human livelihoods is ubiquitous and can be highly damaging, but the processes generating it are poorly understood. Ecological elements are central to conservation conflict, and changes in their dynamics — for instance due to anthropogenic environmental change — are likely to influence the emergence of serious human–wildlife impacts and, consequently, social conflict. We used mixed-effects models to examine the drivers of historic spatio-temporal dynamics in numbers of Greenland barnacle geese (Branta leucopsis) on the Scottish island of Islay to identify the ecological processes that have shaped the environment in which conflict between goose conservation and agriculture has been triggered. Barnacle goose numbers on Islay increased from 20,000 to 43,000 between 1987 and 2016. Over the same period, the area of improved grassland increased, the number of sheep decreased and the climate warmed. Goose population growth was strongly linked to the increasing area of improved grassland, which provided geese with more high quality forage. Changing climatic conditions, particularly warming temperatures on Islay and breeding grounds in Greenland, have also boosted goose numbers. As the goose population has grown, farms have supported geese more frequently and in larger numbers, with subsequent damaging effects on grassland. The creation of high-quality grassland appears to have largely driven the problem of serious economic damage by geese. Our analysis also reveals the drivers of spatial variation in goose impacts: geese were more likely to occur on farms closer to roosts and those with more improved grassland. However, as geese numbers have increased they have spread to previously less favoured farms. Synthesis and applications. Our study demonstrates the primary role of habitat modification in the emergence of conflict between goose conservation and agriculture, alongside a secondary role of climate change. Our research illustrates the value of exploring socio-ecological history to understand the processes leading to conservation conflict. In doing so, we identify those elements that are more controllable, such as local habitat management, and less controllable, such as climate change, but which both need to be taken into account when managing conservation conflict.

Grasslands are among the most critically endangered ecosystems in the tropics, but they are often treated as wastelands and conservation efforts are seldom directed towards these landscapes. The Blackbuck Antilope cervicapra is a large wild herbivore found in most grassland ecosystems across India. Despite their critical role in their trophic web, there are no reliable estimates of Blackbuck populations from their geographic range that takes detection probability into consideration. In this study, we conducted field surveys to estimate Blackbuck density in Basur Amruth Mahal Kaval Conservation (BAMKCR) with an area of 7.36km2 in southern India. We surveyed Blackbucks for a week in July 2014 along straight line transects between 09:00–12:00 hr and used the distance sampling approach to address the imperfect detection. A total of three transect lines of lengths 3.01km, 2.4km and 1.2km were sampled for seven temporal replicates. With an effort of 46.27km, 56 sightings of Blackbucks were recorded that was analyzed using the program DISTANCE. With a detection probability of 0.58 (0.053 SD) the estimated density of Blackbuck was 26.23 (6 SD) individuals/km2. The derived abundance estimate was 193 (c. 148–238) individuals in the study area. Our results show implications of a statistically robust design that accounts for imperfect detection. It provides an insight into a resident population of Blackbucks in a dynamic and fragile habitat. Blackbuck density estimate from this study sets the background for periodic monitoring of their populations, examination of the impacts of habitat modifications and gauge long-term viability of the grassland habitat in BAMKCR.

Highlights: • Mussel beds increase benthic microalgae biomass and productivity on intertidal flats. • Ecosystem engineers facilitate coastal production. • Biological control is important for the functioning of sedimentary systems. Abstract: Intertidal flats are highly productive areas that support large numbers of invertebrates, fish, and birds. Benthic diatoms are essential for the function of tidal flats. They fuel the benthic food web by forming a thin photosynthesizing compartment in the top-layer of the sediment that stretches over the vast sediment flats during low tide. However, the abundance and function of the diatom film is not homogenously distributed. Recently, we have realized the importance of bivalve reefs for structuring intertidal ecosystems; by creating structures on the intertidal flats they provide habitat, reduce hydrodynamic stress and modify the surrounding sediment conditions, which promote the abundance of associated organisms. Accordingly, field studies show that high chlorophyll a concentration in the sediment co-vary with the presence of mussel beds. Here we present conclusive evidence by a manipulative experiment that mussels increase the local biomass of benthic microalgae; and relate this to increasing biomass of microalgae as well as productivity of the biofilm across a nearby mussel bed. Our results show that the ecosystem engineering properties of mussel beds transform them into hot spots for primary production on tidal flats, highlighting the importance of biological control of sedimentary systems.

Management of coastal wetlands is increasingly difficult because of increasing pressure arising from anthropogenic causes. These include sea level and climate change as well as coastline development caused by population growth and demographic shifts, for example, amenity migration where people move to coastal communities for lifestyle reasons. Management of mangroves and salt marshes is especially difficult because maintaining ecosystem values, including the goods and services provided, is countered by the potential of enhancing or even creating ecosystem disservices, such as unpleasant odour and mosquito hazards. Here we present, explain and apply a conceptual model aimed at improving understanding of management choices that primarily focus on mitigation of disservice while enabling improvement in ecosystem services. The model was developed after more than 30 years of habitat management following modification of a salt marsh to control mosquito production. We discuss the application of the model in a mangrove forest known to produce mosquitoes and outline the benefits arising from using the model.

Land‐use and climate change are two of the primary drivers of the current biodiversity crisis. However, we lack understanding of how single‐species and multispecies associations are affected by interactions between multiple environmental stressors.We address this gap by examining how environmental degradation interacts with daily stochastic temperature variation to affect individual life history and population dynamics in a host–parasitoid trophic interaction, using the Indian meal moth, Plodia interpunctella, and its parasitoid wasp Venturia canescens.We carried out a single‐generation individual life‐history experiment and a multigeneration microcosm experiment during which individuals and microcosms were maintained at a mean temperature of 26°C that was either kept constant or varied stochastically, at four levels of host resource degradation, in the presence or absence of parasitoids.At the individual level, resource degradation increased juvenile development time and decreased adult body size in both species. Parasitoids were more sensitive to temperature variation than their hosts, with a shorter juvenile stage duration than in constant temperatures and a longer adult life span in moderately degraded environments. Resource degradation also altered the host's response to temperature variation, leading to a longer juvenile development time at high resource degradation. At the population level, moderate resource degradation amplified the effects of temperature variation on host and parasitoid populations compared with no or high resource degradation and parasitoid overall abundance was lower in fluctuating temperatures. Top‐down regulation by the parasitoid and bottom‐up regulation driven by resource degradation contributed to more than 50% of host and parasitoid population responses to temperature variation.Our results demonstrate that environmental degradation can strongly affect how species in a trophic interaction respond to short‐term temperature fluctuations through direct and indirect trait‐mediated effects. These effects are driven by species differences in sensitivity to environmental conditions and modulate top‐down (parasitism) and bottom‐up (resource) regulation. This study highlights the need to account for differences in the sensitivity of species’ traits to environmental stressors to understand how interacting species will respond to simultaneous anthropogenic changes., Species are often exposed simultaneously to multiple anthropogenic stressors, but their impacts have mainly been studied independently and in single species. The authors demonstrate that environmental degradation amplifies species’ responses to fluctuating temperatures by directly altering individual life‐history traits and by indirectly affecting top‐down and bottom‐up regulations in a host‐parasitoid trophic interaction.

Contains fulltext : 207180.pdf (Publisher’s version ) (Open Access) Abstract Coastal exploitation and human-mediated modifications have markedly altered the community composition and functioning of coastal wetlands worldwide. Although recent work has shown that harnessing positive density-dependent feedbacks can greatly enhance the recovery of habitat-modifying species in degraded wetlands, the role of these intraspecific feedbacks in explaining the persistence of altered, unfavorable plant communities remains largely unexplored. Here, we experimentally tested whether intraspecific facilitation may explain the persistence of common reed (Phragmites australis) in human-modified coastal wetlands. We performed a full-factorial mesocosm experiment crossing low-density pioneer versus high-density established development stages with saline (20 psu) versus freshwater conditions. Results showed a clear shift in plant growth response from intraspecific competition under freshwater conditions to self-facilitation in saline treatments. We identified two positive feedback mechanisms enabling the established treatment to overcome salinity stress: (1) Enhanced root oxygenation of the sediment at higher plant density decreased accumulation and intrusion of phytotoxic sulfide, and (2) density-dependent rainwater infiltration into the soil lowered salinity in the dense root mat, preventing salt stress. Our study demonstrates that intraspecific facilitation can be an important factor in explaining the persistence of Phragmites australis in coastal wetlands. We emphasize the importance of integrating positive interactions in coastal restoration but argue that they should either be harnessed when restoring vegetation or broken when eradication of nontarget species is the management objective.

In the present study, we inventoried gall-inducing arthropod species and evaluated the effects of habitat anthropization, vegetation structure and seasonality on this group in areas of deciduous seasonal forest of Parque da Sapucaia, Montes Claros, MG, Brazil. The gall-inducing fauna was sampled between April 2017 and February 2018 from 20 plots distributed in anthropized and preserved habitats. A total of 29 morphospecies of gall-inducing arthropods and 21 species of host plants were recorded. The Fabaceae plant family had the highest number of gall morphospecies (n = 10), while the Cecidomyiidae (Diptera) insect family induced the most galls (41.3%). Mean gall richness did not differ between preserved and anthropized plots, but was negatively affected by mean vegetation height and density. The total number of gall morphospecies recorded during each sampling did not differ between dry and rainy seasons, but the mean richness of galls per plot was higher in the rainy season. In conclusion, natural factors, such as vegetation structure and seasonality, were more important for the distribution of gall-inducing species than anthropic factors, such as vegetation anthropization level.

Macroinvertebrates assemblages in Croatian section of the Drava River have been drastically changed by habitat modification for the purpose of hydropower plants (construction of reservoirs and artificial channels) as well as alien invasive species. In this study we investigated macroinvertebrate assemblages structure at the upstream distribution front of the alien invasive amphipod Dikerogammarus villosus in the Drava: differences between the derivation channel and the old river course of the Drava between the Ormož and the Čakovec reservoirs were examined. Benthos samples were collected on different types of microhabitats (macrophytes, stony substrate) with hand net (25×25 cm, mesh size 500 μm) in summer of 2018 at five locations in the derivation channel and seven locations in the old course of the Drava. Non-metric multidimensional scaling analysis revealed a complete separation of sites in the derivation channel and the old course. The average number of taxa were significantly higher in the old course (20.1) than in the derivation channel (11.6), while Oligochaeta, Ephemeroptera, Coleoptera and Trichoptera had significantly higher densities in the old course. Invasive species Dreissena polymorpha had much higher densities in the derivation channel, while D. villosus in low abundance inhabited only sites close to the downstream reservoir Čakovec. Observed differences between the old course and the derivation channel, as well as between microhabitats (macrophytes and gravel) in the derivation channel, were due to a higher level of hydrological disturbance in the derivation channel which is exposed to hydropeaking, while almost constant low flow is present in the old course.

Foundation species host diverse associated communities by ameliorating environmental stress. The strength of this facilitative effect can be highly dependent on the underlying biotic and abiotic context. We investigated community level patterns of macrofauna associated with and adjacent to the marine foundation species eelgrass (Zostera marina) along a hydrodynamic stress gradient. We could demonstrate that the relative importance of this foundation species for its infaunal community increases with environmental variables associated with increasing hydrodynamic stress (depth, sand ripples formation, sediment grain size and organic content). Faunal assemblages in proximity to the Zostera patch edges, however, showed no (infauna) or negative (epifauna) response to hydrodynamic stress. Our study highlights that the facilitative outcome of a foundation species is conditional to the faunal assemblage in question and can be highly variable even between positions within the habitat.

Background Haemosporidian parasites of the genera Plasmodium and Haemoproteus can have detrimental effects on individual birds and populations. Despite recent investigations into the distribution and richness of these parasites and their vertebrate hosts, little is known about their dipteran vectors. The Neotropics has the highest diversity of mosquitoes in the world, but few studies have tried to identify vectors in this area, hampering the understanding of the ecology of avian malaria in the highly diverse Neotropical environments. Methods Shannon traps and active collection were used to capture 27,110 mosquitoes in a Seasonally Dry Tropical Forest in southeastern Brazil, a highly endangered ecosystem. Results We screened 17,619 mosquito abdomens from 12 different species and several unidentified specimens of Culex, grouped into 1,913 pools, for the presence of haemosporidians. Two pools (out of 459) of the mosquito Mansonia titillans and one pool (out of 29) of Mansonia pseudotitillans were positive for Plasmodium parasites, with the detection of a new parasite lineage in the former species. Detected Plasmodium lineages were distributed in three different clades within the phylogenetic tree revealing that Mansonia mosquitoes are potential vectors of genetically distant parasites. Two pools of Culex spp. (out of 43) were positive for Plasmodium gallinaceum and closely related lineages. We found a higher abundance of these putative vectors in pasture areas, but they were also distributed in areas at intermediate and late successional stages. One pool of the mosquito Psorophora discrucians (out of 173) was positive for Haemoproteus. Conclusions The occurrence of different Plasmodium lineages in Mansonia mosquitoes indicates that this genus encompasses potential vectors of avian malaria parasites in Brazil, even though we did not find positive thoraces among the samples tested. Additional evidence is required to assign the role of Mansonia mosquitoes in avian malaria transmission and further studies will add information about evolutionary and ecological aspects of avian haemosporidia and untangle the diversity of their vectors in Brazil.

The pike population in the Løpsjøen reservoir and the accessible 21 km section of the inflowing RiverRena was investigated from 2003 to 2013. Telemetry and mark-recapture with Floy tags demonstratedthat most fish had an annual home range of less than 2 km, while some fish performed quite extensivemigrations (up to 14.4 km). Of fish radio-tagged in the reservoir, 57% were positioned in the river atleast once. The population of pike ≥25 cm was estimated at 1002 fish, or 3.9 fish (3.17 kg) ha−1. Meanlength at age was significantly larger for pike caught in the river than in the reservoir for almost all agegroups. CPUE during boat electro-fishing indicated significantly lower population densities and a lowerproportion of juvenile fish in the river than in the reservoir. Diet analysis revealed that almost all availableprey fish species were taken by pike, and that there was a clear diet differentiation between pike sizeclasses, and between fish from the river and reservoir habitats. Small pike (50 cm) in the reservoir had taken brown trout as well as a number of other prey fish, while river pike ofthis size had taken burbot (Lota lota), lamprey and brown trout. Species like perch (Perca fluviatilis), roach(Rutilus rutilus) and in particular grayling (Thymallus thymallus) were rarely found in pike stomachs. Theconstruction of the reservoir in a fast-flowing river caused the establishment of a healthy pike populationand additional predation pressure on the rheophilic salmonids in the system, both in the reservoir andin the inflowing river.© 2015 Elsevier B.V. All rights reserved. River fragmentation, Predation, Habitat utilization, Habitat modification, Northern pike

RESUMEN Entre 2007 y 2008 evaluamos la riqueza, abundancia y diversidad estacional de aves en la Reserva Nacional isla Mocha, sur de Chile. Las aves fueron registradas en puntos de conteo (radio = 50 m, duración = 10 min) en cinco tipo de hábitats: borde costero, pastizal, pradera arbolada, ecotono bosque-pradera y bosque valdiviano. Para determinar mejor la riqueza de especies también incluimos registros ocasionales fuera de los puntos de conteo. La riqueza avifaunística en la isla alcanzó 70 especies. El hábitat más rico en especies fue el pastizal (29 especies), seguido del ecotono bosque-pradera y el borde costero (25 especies, respectivamente), la pradera arbolada (21 especies), y del bosque valdiviano (17 especies). No detectamos ningún patrón estacional al comparar las riquezas de especies entre hábitats. En todos los hábitats la distribución de abundancia entre las especies mostró el patrón típico de muchos organismos: pocas especies fueron muy abundantes o poco abundantes, y varias fueron medianamente abundante. Sin embargo, la dominancia numérica entre las especies cambió estacionalmente. Las especies más regulares fueron la gaviota dominicana en el borde costero y el pastizal, el queltehue en el pastizal, el jilguero en la pradera arbolada, la torcaza, el chucao y el rayadito en el ecotono bosque-pradera, y el chucao, rayadito y picaflor chico en el bosque valdiviano. Todas estas especies tuvieron fluctuaciones numéricas temporales notorias causadas posiblemente por el reclutamiento de individuos juveniles, migraciones, congregación reproductiva, y/o variación en la disponibilidad de alimento. Todos los hábitats tuvieron diversidades altas debido a que fueron ricos en especies y hubo una alta equitatividad entre especies respecto de su abundancia. En términos avifaunísticos la isla Mocha representa una “trozo” continental del sur de Chile, ya que la similitud en la diversidad de hábitats de esta isla con el continente resulta en ensambles similares de aves. ABSTRACT Between 2007 and 2008, we evaluated the seasonal richness, abundance and diversity of bird species in the Isla Mocha National Reserve, southern Chile. We recorded birds in point-count stations (radius = 50 m, length = 10 min) in five habitat types: coastline, pastureland, prairie with trees, forest-prairie ecotone, and Valdivian forest. We also include occasional records outside count points to determine species richness. In total, we recorded 70 species on the island. The habitat with higher species richness was the pastureland (29 species), followed by the forest-prairie ecotone, coastline (25 species, respectively), prairie with trees (21 species), and Valdivian forest (17 species). We did not detect seasonal patterns when we compared species richness among habitats. In all habitats, the abundance distribution among species showed the typical pattern of many organisms: few species were very or few abundant, and several had an intermediate abundance. However, the numerical dominance between species changed seasonally. The most regular species were Kelp Gull in the costline and pastureland, Chilean Lapwing in the pastureland, Black-chinned Siskin in the prairie with trees, Chilean Pigeon, Chucao Tapaculo and Thorn-tailed Rayadito in the forest-prairie ecotone, and Chucao Tapaculo, Thorn-tailed Rayadito, and Green- backed Firecrown in the Valdivian forest. All these species showed noticeable seasonal numerical fluctuations possibly caused by the recruitment of juveniles, reproductive congregation and/or variation in food availability. All habitats had a high diversity because they were rich in species and had high evenness among species regarding abundance. Avifaunally, the island Mocha represents a continental “slice” of southern Chile as the similarity in habitat diversity of this island to the mainland result in similar bird assemblages.

The importance of ecosystem engineering and biogeomorphic processes in shaping many aquatic and semiaquatic landscapes is increasingly acknowledged. Ecosystem engineering and biogeomorphic landscape formation involves two critical processes: (1) species establishment, and (2) scale-dependent feedbacks, meaning that organisms improve their living conditions on a local scale but at the same time worsen them at larger scales. However, the influence of organism traits in combination with physical factors (e.g. hydrodynamics, sediments) on early establishment and successive development due to scale-dependent feedbacks is still unclear. As a model system, this was tested for salt marsh pioneer plants by conducting flume experiments: i) on the influence of species-specific traits (such as stiffness) of two contrasting dominant pioneer species (Spartina alterniflora and Schpus mariqueter) to withstand current-induced stress during establishment; and ii) to study the impact of species-specific traits (stiffness) and physical forcing (water level, current stress) on the large-scale negative feedback at established tussocks (induced scour at tussock edges) of the two model species. The results indicate that, not only do species-specific plant traits, such as stiffness, exert a major control on species establishment thresholds, but also potentially physiologically triggered plant properties, such as adapted root morphology due to sediment properties. Moreover, the results show a clear relation between species-specific plant traits, abiotics (i.e. sediment, currents) and the magnitude of the large-scale negative scale-dependent feedback. These findings suggest that the ecosystem engineering ability, resulting from physical plant properties can be disadvantageous for plant survival through promoted dislodgement (stem stiffness increases the amount of drag experienced at the root system), underlying the importance of scale-dependent feedbacks on landscape development. (C) 2015 Elsevier B.V. All rights reserved.

Locusts and grasshoppers are major economic pests in China and are controlled by a strategy of preventive management where about 1.5 million ha are treated each year. The preventive management system aims to keep locusts and grasshoppers at lower densities, so that the dense swarms seen in the past are no longer common and crop and pasture damage minimized. There is substantial cultural control, including conservation of natural enemies and reducing the area of favorable habitats through habitat modification. Even with substantial cultural control, locust and grasshopper infestations are still widespread, with 127 field stations having more than 2000 technicians involved in monitoring and control. These officers monitor and treat locust and grasshopper infestations and the data collected are integrated into a national computer-based platform. These data are analyzed and news bulletins are issued on where and when the densest infestations are likely to be so that extra resources can be provided when needed as part of coordinating an effective locust and grasshopper management program. In the past, treatments were by chemical pesticides, but in recent years there has been an increasing use of bio pesticides: namely, the naturally occurring fungus Metarhizium acridum and the microsporidian Paranosema locustae. While such products were used in only 5% of treatments during 2004, their use has increased to over 30% in recent years, which amounts to over 100,000 ha per year sprayed. These applications of bio pesticides against locusts and grasshoppers are more than all of the rest of the world combined.

In conservation strategies of marine ecosystems, priority is given to habitat-structuring foundation species (e.g. seagrasses, mangroves and reef-building corals, shellfish) with the implicit goal to protect or restore associated communities and their interactions. However, the number and accuracy of community level metrics to measure the success of these strategies are limited. Using intertidal shellfish reefs as a model, we tested to what extent foundation species alter community and food web structure, and explored whether basic metrics of food web structure are useful indicators of ecosystem complexity compared to other often-used indices. We found that shellfish reefs strongly modified community and food web structure by modifying habitat conditions (e.g. hydrodynamics, sediment grain size). Stable isotope-based food web reconstruction captured important differences between communities from bare mudflat and shellfish reefs that did not emerge from classic abundance or diversity measures. On shellfish reefs, link density and the number of top predators were consistently higher, while both connectance and the richness of intermediate species was lower. Species richness (+ 42%), species density (+ 79%) and total biomass of benthos, fish and birds (+ 41%) was also higher on shellfish reefs, but this did not affect the Shannon diversity or Evenness. Hence, our results showed that basic food web metrics such as link density and number of top consumers and intermediate species combined with traditional measures of species richness can provide a robust tool to measure conservation and restoration success. We therefore suggest that these metrics are included as Essential Biodiversity Variables (EBV), and implemented as ecosystem health indicators in legislative frameworks such as the Marine Strategy Framework Directive (MSFD).

Wind energy development is the most recent of many pressures on upland bird communities and their habitats. Studies of birds in relation to wind energy development have focused on effects of direct mortality, but the importance of indirect effects (e.g., displacement, habitat loss) on avian community diversity and stability is increasingly being recognized. We used a control-impact study in combination with a gradient design to assess the effects of wind farms on upland bird densities and on bird species grouped by habitat association (forest and open-habitat species). We conducted 506 point count surveys at 12 wind-farm and 12 control sites in Ireland during 2 breeding seasons (2012 and 2013). Total bird densities were lower at wind farms than at control sites, and the greatest differences occurred close to turbines. Densities of forest species were significantly lower within 100 m of turbines than at greater distances, and this difference was mediated by habitat modifications associated with wind-farm development. In particular, reductions in forest cover adjacent to turbines was linked to the observed decrease in densities of forest species. Open-habitat species' densities were lower at wind farms but were not related to distance from turbines and were negatively related to size of the wind farm. This suggests that, for these species, wind-farm effects may occur at a landscape scale. Our findings indicate that the scale and intensity of the displacement effects of wind farms on upland birds depends on bird species' habitat associations and that the observed effects are mediated by changes in land use associated with wind-farm construction. This highlights the importance of construction effects and siting of turbines, tracks, and other infrastructure in understanding the impacts of wind farms on biodiversity.Efectos del Desarrollo de la Energía Eólica y los Cambios Asociados al Uso de Suelo sobre las Densidades de Aves en Tierras Altas Resumen El desarrollo de la energía eólica es la más reciente de muchas presiones ejercidas sobre las comunidades de aves de tierras altas y sus hábitats. Los estudios sobre aves en relación con el desarrollo de la energía eólica se han enfocado en los efectos de la mortalidad directa, pero la importancia de los efectos indirectos (p. ej.: desplazamiento, pérdida de hábitat) sobre la diversidad y estabilidad de las comunidades aviares cada vez se reconoce más. Usamos un estudio de control-impacto combinado con un diseño de gradiente para evaluar los efectos de los campos eólicos sobre las densidades de aves de tierras altas y sobre las especies de aves agrupadas por asociación de hábitat (especies de bosque y de hábitat abierto). Realizamos 506 censos de conteo por puntos en 12 sitios de campos eólicos y 12 sitios control en Irlanda durante dos temporadas de reproducción (2012 y 2013). Las densidades de aves totales fueron más bajas en los campos eólicos que en los sitios control, con las diferencias más importantes ocurriendo cerca de las turbinas. Las densidades de las especies de bosque fueron significativamente más bajas a 100 m de las turbinas que a distancias mayores y esta diferencia estuvo mediada por modificaciones asociadas con el desarrollo de campos eólicos. De manera particular, las reducciones en la cobertura de bosque adyacente a las turbinas estuvieron vinculadas con la disminución observada en las densidades de las especies de bosque. Las densidades de las especies de hábitat abierto fueron más bajas en los campos eólicos pero no estuvieron relacionadas con la distancia a las turbinas y tuvieron una relación negativa con el tamaño del campo eólico. Lo anterior sugiere que, para estas especies, los efectos del campo eólico pueden ocurrir a la escala de paisaje. Nuestros hallazgos indican que la escala y la intensidad de los efectos de desplazamiento de los campos eólicos sobre las aves de tierras altas dependen de las asociaciones de hábitat de las especies de aves y que los efectos observados están mediados por cambios en el uso de suelo asociados con la construcción de campos eólicos. Esto remarca la importancia de los efectos de construcción y el sitiado de las turbinas, pistas y demás infraestructura en el entendimiento de los impactos que tienen los campos eólicos sobre la biodiversidad.风能的开发是山地鸟类群落面临的许多压力中最近出现的一种。关于鸟类与风能开发有关的研究主要集中于其直接导致鸟类死亡的影响, 但人们也逐渐认识到其对鸟类群落多样性和稳定性的间接影响 (如被迫迁徙、生境丧失) 的重要性。我们用控制-影响研究, 结合梯度设计, 来评估风电场对山地鸟类密度和按生境相关性分类的鸟类物种 (森林和开放生境的物种) 的影响。我们在 2012 年和 2013 年的两个繁殖季对爱尔兰 12 个风电场和 12 个对照位点对 506 个样点进行计数调查。结果显示, 风电场的鸟类总密度比对照位点低, 且差异最大的位置在涡轮机附近。在涡轮机附近 100 米内森林鸟类的密度显著低于离涡轮机更远的位置, 这一差异受到风电场建设相关生境改造的调控。特别是与观察到的森林鸟类密度下降与涡轮机附近森林覆盖的减少有关。风电场开放生境的物种密度也较低, 但这与距离涡轮机的远近无关, 而与风电场的大小呈负相关。这说明风电场对这些物种的影响可能发生在景观尺度上。我们的结果表明, 风电场导致山地鸟类被迫迁徙的影响尺度和强度取决于物种的生境相关性, 观察到的影响是由风电场建设相关的土地利用变化介导的。这强调了涡轮机、轨道和其它基础设施的施工效应及选址对于理解风电场对生物多样性影响的重要性。 【翻译: 胡怡思; 审校: 聂永刚】.

Extinctions of large mammals characterize the Late Quaternary, spanning from the Late Pleistocene to the Anthropocene. As their causes, apart from climate change, researchers have proposed anthropogenic factors with focus on roles of early foraging behaviors (e.g. hunting and using fire) and industrial development in mammal range contractions and final extinctions. However, much less is known about how such events have unfolded in agricultural societies that lie evolutionarily between Paleolithic ones and modern ones. To fill the gap, using spatiotemporal data derived from historical records in ancient China over the past two millennia, we analyzed the patterns of mammal range contractions and their associations with historical climate change and agricultural population dynamics. We found that it was the long-term upslope spread of agricultural population that consistently contracted the mammal distributions in China during the study period, while periodic warming and cooling may have contributed to temporary range fluctuations. Our study provides direct evidence that biotic interactions can overshadow climate in terms of driving species distributions even at large spatiotemporal scales and suggests that humans may have long been reshaping species distributions and the biosphere progressively in times of agriculture. Better understanding of the processes that have led to current species distribution patterns has great implications for future conservation strategies in the Anthropocene.

Ecosystem engineering research has recently demonstrated the fundamental importance of non-trophic interactions for food-web structure. Particularly, by creating benign conditions in stressful environments, ecosystem engineers create hot beds of elevated levels of recruitment, growth, and survival of associated organisms; this should fuel food webs and promote production on the ecosystem scale. However, there is still limited empirical evidence of the influence of non-trophic interactions on the classical food-web processes that determine energy transfer, that is, consumer-resource interactions. On the basis of a biomanipulation experiment covering 600 m2 of an intertidal flat, we show that ecosystem engineers influence resource uptake efficiency and the accumulation of algae following nutrient enrichment in a soft-sediment food web. Nutrient additions increased chlorophyll a concentrations in the sediment by 90%, but only in plots where we also introduced high densities (2000 per m2) of a burrowing bivalve, the common cockle Cerastoderma edule. The artificial cockle beds increased the nutrient uptake efficiency of the biofilm and promoted sediment accumulation, which suggests that the cockles facilitated the sediment-living algae by increasing sediment stability. This indicates that ecological interactions, rather than the availability of nutrients per se, set the limits for production in this coastal ecosystem. Our results emphasize the need to include facilitation theory and recognize that positive interactions between species are key to understand, manage, and restore ecosystems under human influence.

The Segura River Basin is one of the most arid and regulated zones in the Mediterranean as well as Europe that includes four hydrologic river types, according to their natural flow regime: main stem rivers, stable streams, seasonal streams and temporary streams. The relationships between flow regime and fluvial and riparian habitats were studied at reference and hydrologically altered sites for each of the four types. Flow regime alteration was assessed using two procedures: (1) an indirect index, derived from variables associated with the main hydrologic pressures in the basin, and (2) reference and altered flow series analyses using the Indicators of Hydrologic Alteration (IHA) and the Indicators of Hydrologic Alteration in Rivers (IAHRIS). Habitats were characterized using the River Habitat Survey (RHS) and its derived Habitat Quality Assessment (HQA) score, whereas riparian condition was assessed using the Riparian Quality Index (RQI) and an inventory of riparian native/exotic species. Flow stability and magnitude were identified as the main hydrologic drivers of the stream habitats in the Segura Basin. Hydrologic alterations were similar to those described in other Mediterranean arid and semiarid areas where dams have reduced flow magnitude and variability and produced the inversion of seasonal patterns. Additionally, the Segura Basin presented two general trends: an increase in flow torrentiality in main stems and an increase in temporality in seasonal and temporary streams. With the indirect alteration index, main stems presented the highest degree of hydrologic alteration, which resulted in larger channel dimensions and less macrophytes and mesohabitats. However, according to the hydrologic analyses, the seasonal streams presented the greatest alteration, which was supported by the numerous changes in habitat features. These changes were associated with a larger proportion of uniform banktop vegetation as well as reduced riparian native plant richness and mesohabitat density. Both stream types presented consequent reductions in habitat and riparian quality as the degree of alteration increased. However, stable streams, those least impacted in the basin, and temporary streams, which are subject to great hydrologic stress in reference conditions, showed fewer changes in physical habitat due to hydrologic alteration. This study clarifies the relationships between hydrologic regime and physical habitat in Mediterranean basins. The hydrologic and habitat indicators that respond to human pressures and the thresholds that imply relevant changes in habitat and riparian quality presented here will play a fundamental role in the use of holistic frameworks when developing environmental flows on a regional scale, We wish to thank the University of Murcia for the predoctoral grant to Oscar Belmar and the Ministry for Education, Culture and Sport for the predoctoral grant to Daniel Bruno. We also thank Jose Antonio Carbonell and Simone Guareschi for their support during the fieldwork. Finally, we are also grateful to Melissa Crim and Javier Lloret for double-checking the English.

Summary: Beta diversity is the compositional heterogeneity of biotic assemblages among sites, and biotic homogenization is the decrease in beta diversity, facilitated by an increase in similarity of biotic communities over time. Environmental harshness decreases the importance of stochastic processes in structuring assemblages, resulting in a homogenization of the biota. We investigated if increasing nutrient enrichment, land-use pressure, and within-lake habitat alteration would decrease the beta diversity of macroinvertebrates in 46 lakes across Europe. Beta diversity was calculated using global multivariate dispersion. We utilized a structural equation modelling approach to account for hierarchical interdependence between potential impacts, that is the direct effects and correlations among the different impacts. We found clear indications that European macroinvertebrate communities are being homogenized by ongoing lake shore development. Increasing land-use pressure in the form of residential and commercial development had a direct negative effect on beta diversity (standardized coefficient = -0·40), as did roadways, albeit indirectly through an increase in engineering structures (standardized coefficient = -0·31). Increasing within-lake silt levels also homogenized macroinvertebrate communities (standardized coefficient = -0·18), independent of near shore land use. Our results indicate the negative effect of both the near shore land-use pressure and the within-lake habitat alteration on macroinvertebrate beta diversity, with significant interactions between these pressures. Habitat protection should take a more holistic approach to assessing lake development pressure, over a range of scales, as a solely site specific approach is not always biologically meaningful. Thus, future management plans should carefully control and mitigate ongoing development pressure if lake ecosystem health and resilience is to be maintained. Synthesis and applications. This study is the first of its kind to demonstrate European-wide homogenization of littoral macroinvertebrate lake communities with increasing habitat alteration and land-use pressure. Significant interactions occur between different habitat scales, with no one scale entirely accounting for the homogenization effect. To avoid further biotic homogenization, development pressure must be carefully managed at multiple scales, and where possible, minimized. This presents a challenge, as globally there is an increasing expansion of the human population and a consequent increase in anthropogenic pressure across all habitats. This study is the first of its kind to demonstrate European-wide homogenization of littoral macroinvertebrate lake communities with increasing habitat alteration and land-use pressure. Significant interactions occur between different habitat scales, with no one scale entirely accounting for the homogenization effect. To avoid further biotic homogenization, development pressure must be carefully managed at multiple scales, and where possible, minimized. This presents a challenge, as globally there is an increasing expansion of the human population and a consequent increase in anthropogenic pressure across all habitats.

My goal is to investigate global patterns in the structure of interaction networks of insect herbivores and their host plants. Specifically, I seek to determine whether intensification of land use and the dominance of exotic host plant species influence the structure and robustness (i.e., resistance to co-extinctions) of interaction networks of insect herbivores and host plants. I also ask whether latitude has an influence on the structure and robustness of these interactions. I compiled 90 local plant-herbivore networks distributed worldwide, spanning different taxonomic groups of plants and insects and several herbivore guilds. My results showed that intensification of land use was associated with dominance of exotic plant species and can impoverish the species richness and taxonomic diversity of insect herbivores in the networks. Moreover, land use intensification surprisingly increases network specialization by decreasing connectance and nestedness, and increases modularity; while the increase in the proportion of exotic hosts had opposite effects. These changes in the network structure may be due to the proportionately greater loss of generalist herbivores relative to specialists. Land use intensification also decreases the robustness of plant-herbivore networks, while the proportion of exotic host plant species increases, which is an intriguing result that contradicts previous studies. Controlling for anthropic effects that can act on the networks, my results show that plant–herbivore networks are structured independently of latitude, suggesting that the factors that influence the interactions between host plants and insect herbivores are latitudinally invariant.

Pollution can affect wildlife directly through toxicity and indirectly through changes in biotic and abiotic factors, however, how these mechanisms interact in affecting free‐ranging animals remains poorly understood. By examining effects on individual fitness proxies, we aimed to determine the mechanisms behind documented amphibian and reptile declines in barren landscapes where vegetation was nearly decimated due to atmospheric metal and sulfur deposition from smelting operations in Sudbury, Ontario, Canada. We examined individual characteristics of snakes (Thamnophis sirtalis, Storeria occipitomaculata) and frogs (Lithobates clamitans, L. pipiens, L. septentrionalis) in replicated barren and reference sites, including standard metabolic rates (in snakes), body condition (all species), female reproductive status (snakes), limb deformity (frogs), and fluctuating asymmetry (all species). Frogs in barren sites (except L. septentrionalis) were in poor body condition, and all but one case of limb deformities in frogs were found in barren sites. However, neither frogs nor snakes exhibited elevated frequency of fluctuating asymmetry in barren sites. Standard metabolic rates (SMR) were not elevated in either snake species, suggesting that metal toxicity does not present an energetic burden. Instead, female T. sirtalis from barren sites exhibited lower SMR and were in poor body condition, which is a predicted response to reduced food intake. By contrast, SMR and body condition of S. occipitomaculata were not different between barren and reference sites. While physiological responses differed between T. sirtalis and S. occipitomaculata, both species exhibited lower reproductive rates (proportion of pregnant females) in barren sites compared to reference sites. Thus, energy deficiency may explain reduced reproduction in T. sirtalis while reduced availability of suitable gestation microhabitat may be a limiting factor for S. occipitomaculata. Populations in smelting‐impacted habitats include individuals with potentially compromised fitness. The low values of our measured fitness proxies appear to have resulted from pollution‐induced changes in biotic and abiotic factors, in addition to (for frogs) or rather than (for snakes) from the direct toxicity. These results suggest that impact assessment based solely on toxicological data and species distributions can underestimate the full impacts of pollution, highlighting the need for integrated examination at multiple levels of biological organization.

Mestrado Management and Conservation of Natural Resources - Instituto Superior de Agronomia - UL / Universidade de Évora Seagrass beds provide higher biomass, abundance, diversity and productivity of ichthyofaunal communities than non-vegetated substrata. During 2008, the seagrass beds of Zostera noltii located in the lower Mira estuary (SW Portugal) disappeared completely. However, during 2009, slight symptoms of natural recovery were observed, a process which has since evolved intermittently. The main goal of this study was to investigate the temporal and spatial distribution patterns of the composition and structure of the ichthyofaunal communities under two distinct habitat ecological conditions: “before” the collapse, characterized by mature vegetation of the seagrass beds, and “after” recovery, corresponding to natural habitat recovery process of the seagrass beds. The following hypotheses were tested: there would be significant differences of the fish communities between i) the period “before” the habitat loss and “after”, during the natural recovery; and ii) seagrass beds and main channel under both ecological conditions. The temporal and spatial distribution patterns of the fish species composition and abundance were clearly different before the habitat loss and after, during the natural recovery. “Before” the collapse the main channel and seagrass beds showed significant differences between the habitats, on the contrary, during the natural recovery it was not possible to distinguish both communities, which were much similar to those of the non-vegetated areas in the 1980s. Generally, fish communities of Z. noltii seagrass beds in the 1980s were more rich and diverse and with higher abundance of individuals. Apparently, disappearance of Z. noltii seagrass beds led to the disappearance or decrease in abundance of resident fish species in that habitat, which have not return to the system or recover the respective populations even after the beginning of the recovery of Z. noltii seagrass beds. This study also revealed that this system has registered an increased colonization from species with subtropical affinity, which might be related to gradual temperature increase at a global scale. However, modifications due to the collapse and recovery of the Z. noltii seagrass beds seemed to surpass the effects resulting from climate changes N/A

PhD (Zoology), North-West University, Potchefstroom Campus, 2016. The focus of the Department of Water and Sanitation (DWS) has changed from one which addresses the quality and quantity of water resources in isolation to one which integrates these attributes with that of aquatic ecosystem integrity. The right to water for basic human needs as well as to ensure a functioning ecosystem is entrenched in the National Water Act (Act 36 of 1998) through the setting of the Reserve (Rowlston 2011). The Ecological Reserve is defined as the quality and quantity of water required for protecting aquatic ecosystems in order to secure ecologically sustainable development and use of the relevant water resource. Although macroinvertebrates are used to set environmental flows in South Africa and abroad, very limited information is available about their flow requirements (Brunke et al. 2001, Schael 2002, Jowett 2002a, Cassin et al. 2004, Clifford et al. 2004, Hanquet et al. 2004, Kleynhans and Louw 2007). In southern Africa some information is available on certain Ephemeroptera in the Inkomati System (Matthew 1968) and some species occurring in the Lesotho Highlands (Skoroszewski and de Moor 1999). A structured approach is required to determine macroinvertebrate environmental requirements taking into account the different life stages, ecoregions, seasonality and substratum The purpose of this study was to determine the habitat requirements of selected riverine macroinvertebrate taxa. The main aim was to determine the preferred ranges of water depth, velocity and temperature, as well as the substratum types required by Ephemeroptera, Trichoptera, Coleoptera and Diptera. In order to determine the habitat requirements for the selected riverine macroinvertebrates, 266 quantitative samples were collected at 52 sites between July 2005 and February 2009. Samples were taken with a Surber sampler and hand net at a number of localities at each site to cover all substratum types, velocity and depth groupings. Basic in situ water measurements (temperature, dissolved oxygen, pH and Electric Conductivity) were also collected at each site. The macroinvertebrates were preserved in 80% ethanol and identified to family. The water velocity was also measured at 5 – 10 cm intervals at each locality from as close to the bottom as possible to the water surface. No comprehensive study has been done on the distribution of aquatic macroinvertebrates in South Africa. The only distribution maps available are those of selected insect families drawn mostly from existing museum and literature records (Picker et al. 2003, Griffiths et al. 2015). The geographical distribution of 10 Ephemeropteran, 16 Trichopteran, 10 Coleopteran and 14 Dipteran families were determined using data collected from this study as well as archived datafrom the National Rivers Database, the Biobase and the National Freshwater Invertebrate Collection housed at the Albany Museum in Grahamstown. The distribution ranges for each of the insect families were then compared to distribution ranges in the literature. The distribution of each of the families was also associated with Level I Ecoregion, geomorphological zone and altitude range. The range extension in a number of taxa such as the Calamoceratidae (Trichoptera) and the Ptilodactylidae (Coleoptera) as well as the identification of questionable distribution records for a number of mostly south-western Cape endemics such as Barbarochthonidae, Sericostomatidae and Glossosomatidae was highlighted. The need to archive voucher specimens, not only for new or unidentified taxa, but also to validate the range distributions of known taxa is emphasised. The scarcity of distribution records for a number of families, most notably that of the Hydrosalpingidae (Trichoptera), Ptilodactylidae, Limnichidae (Coleoptera) and Ephemeridae (Ephemeroptera) is also noted. Redundancy analysis (RDA) was done using Canoco 5.04 (ter Braak and Šmilauer 2012) to determine the environmental factors contributing most to the distribution of the different invertebrate families. Results from the RDA were then used to draw response curves for the selected families using the Species Response Curve function in Canoco 5.04 (ter Braak and Šmilauer 2012). A Generalised Additive Model (GAM) with Poisson distribution and log link function (family as the response and depth, velocity at 60% of depth and substratum category as predictors) were used with stepwise selection using the Akaike Information Criterion (AIC) and two degrees of freedom (2 DF) factor to smooth the curves. Significance of relationships was regarded as p < 0.05. The concept of Habitat Suitability Curves (HSCs) was developed as part of the Instream Flow Incremental Methodology (IFIM) and the Physical Habitat Simulation System (PHABSIM) in the 1980s by researchers at the United States Fish and Wildlife Service (Bovee 1982, Bovee 1986). Habitat Suitability Curves (HSCs) were determined for the selected taxa using the methods described in Bovee (1986) and Jowett et al. (2008). Separate univariate curves were developed for frequency and abundance and the average of the two curves was then used to derive the final HSC. A second order polynomial regression was performed for the depth and velocity curves using Excel 2010. No regression was done on the substratum curves as they represent discrete categories rather than a range of values. Based on the reasoning of Jowett et al. (2008), only families with at least twenty individuals and that were present in at least ten samples were selected for the HSCs. Environmental factors such as velocity, pH, temperature, latitude and longitude, as well as Ecoregion, geomorphological zone and substratum type were determining factors in the distribution patterns of the insect families under consideration. Not all of the factors were important for all of the families. While certain common families (e.g. Baetidae, Chironomidae) showed no preference for any of the environmental factors under consideration, others (e.g. Simuliidae, Blephariceridae) are associated with very fast flowing water over cobbles, the Caenidae with the GSM biotope and Dytiscidae with vegetation. The distribution of taxa with a more limited geographical range such as the more subtropical Calamoceratidae and the burrowing mayflies (Ephemeridae and Polymitarcyidae) are associated with Ecoregion as well as latitude and longitude while the distribution of the southwestern Cape endemic mayflies (Teloganodidae) and cased caddisflies (Sericostomatidae, Glossosomatidae) are also associated with low pH values. The importance of noting the developmental stage of insects such as larva, pupa and adult is highlighted most notably by the different environmental requirements of the beetles where the larval and adult stages sometimes have different requirements. These results provide a first step in setting habitat requirements for selected families of Ephemeroptera, Trichoptera, Coleoptera and Diptera, and the need for more data on certain families (Prosopistomatidae, Sericostomatidae, Glossosomatidae, Haliplidae, Ephydridae, and Syrphidae) is pointed out. Although depth does not appear to be a determining factor in the occurrence of the macroinvertebrate families investigated here, there is still a requirement for investigating the effect of particularly shallower depths as there might be a threshold value below which the macroinvertebrates could potentially be affected. There is a real danger of damaging the riverine macroinvertebrate communities if depth is ignored and the focus is solely placed on substratum and velocity as there can still be water of a suitable velocity but the depth might be too shallow to enable long-term survival of the resident macroinvertebrates. The Macroinvertebrate Response Assessment Index (MIRAI) was developed as part of a suite of EcoStatus indices to be used in the Ecological Classification Process (Thirion 2007). The MIRAI is based on the principle that macroinvertebrates integrate the effect of the modification of drivers (hydrology, geomorphology and physico-chemical conditions). The degree of change from natural is rated on a scale of 0 (no change) to 5 (maximum change) for a variety of metrics. Each metric is weighted in terms of its importance to determining the Ecological Category under natural conditions for the specific locality. The main aim of the Ecological Classification process is to acquire a better understanding of the reasons for the system’s deviation from the natural or reference condition. The distribution of an aquatic macroinvertebrate assemblage is determined by the tolerance of the individuals in the population to an array of environmental factors. It is therefore essential that all habitat features are considered when evaluating the suitability of habitat for aquatic macroinvertebrates. The approach followed in assessing macroinvertebrate response to driver characteristics is based on a qualitative combination of information gained by field surveys, the available habitat as a result of driver conditions, and the traits of the macroinvertebrates present (Lamaroux et al. 2004, Horta et al. 2009). The Habitat Suitability Curves (HSCs) were converted to values out of 5 and rounded to the nearest 0.5 to fit in with the system used in the suite of EcoStatus models. Where no or not enough data were available, information from the literature was used to assign the preference values to each taxon. Teresa and Casatti (2013) suggested that values greater than 0.7 can be regarded as preferred conditions. It was therefore decided to use preference values greater than 3.5 to indicate a strong preference for a certain habitat feature. No changes were made to the physico-chemical (water quality) metric group as these ratings are based on the sensitivity values (QVs) used in the South African Scoring System (SASS) version 5 (Dickens and Graham 2002). The preference values in MIRAI v1 were then updated to reflect these new values. This new version (MIRAI v2) was then tested by running it for 44 sites covering a large geographical range and ecological conditions. The results from the two different versions of MIRAI were compared using a one-way analysis of variance (ANOVA) and a linear regression analysis done using Excel 2010. The changes to the velocity and substratum preference ratings in the MIRAI model resulted in only small changes to the total MIRAI score. The MIRAI category generally remained the same or at most changed by half a category. The largest percentage change was 5.7% at the Sterkstroom (Site A2STER-MAMOG) that remained in a D Category, and 5.3% at the Jukskei River (Site A2JUKS-DIENR) that changed from a DE category to an E category for MIRAI v2. The relatively small changes in MIRAI, together with the high correlation values (>0.9) means that the results from the two versions should be compatible and no adjustments will be needed to the results obtained from the original MIRAIs. The impact of the larger changes to the Flow modification and Habitat modification metric group will however need to be investigated. The following three hypotheses were tested in this study;  The macroinvertebrate assemblage structure can be differentiated based on Ecoregion delineation and geomorphological zonation. The results indicated that this is true for certain taxa while other taxa have a countrywide distribution and have been recorded from most geomorphological zones. However, the macroinvertebrate assemblage structure as a whole can be differentiated based on Ecoregion and geomorphological zone. This hypothesis is thus accepted.  The macroinvertebrate assemblage structure can be differentiated based on environmental factors such as substratum, depth and velocity as well as physico-chemical parameters. The results indicated that this is true for certain taxa but not for others. It is also clear that some of the environmental factors play a role in the distribution of certain taxa but not others (e.g. temperature is a determining factor for Blephariceridae, but not for Simuliidae). Depth was not a significant factor in determining the distribution of the insect families under consideration. However, the macroinvertebrate assemblage structure as a whole can be differentiated based on a combination of environmental factors. This hypothesis is therefore accepted.  The different habitat requirements of the macroinvertebrate taxa in terms of velocity and substratum type can be used to refine the macroinvertebrate taxa’s preference values in the Macroinvertebrate Response Assessment Index (MIRAI), to assess the ecological condition of the macroinvertebrate assemblage. The preference ratings, based on the HSCs as well as information from the literature and personal experience, were successfully used in MIRAI v2 to determine the ecological condition of the macroinvertebrate assemblage at 44 sites spanning a range of conditions. The high correlation values (>0.9) for the different MIRAI metrics tested clearly indicates that the hypothesis can be accepted. The following recommendations were made:  Information collected post January 2014 should be used to update the distribution ranges. The updated distribution maps and associated KML files should be placed on the RQIS website.  Gaps identified should be filled by actively targeting areas with limited or no data and a concerted effort made to collect information on the distribution of taxa with limited records.  A sampling programme should be designed and implemented to include the water surface as a possible habitat and the study area expanded to include polluted sites as well.  HSCs and preference ratings should be developed for taxa not included in this study.  Specimens should be identified to genus or species level and HSCs and preference ratings for these genera or species determined where possible.  A wider range of depths should be included in order to determine if there is a minimum depth requirement that should be used when determining Environmental Water Requirements.  Information obtained should be included in the RHAMM and FIFHA models.  A list of possible reference taxa per Level II Ecoregion, geomorphological zone and altitude range should be compiled based on information obtained during this study. These lists should be included in MIRAI v2 as well as the RHAMM model. This will enable a user to compile a reasonable reference condition for a site, based not only on the list but also on the natural characteristics of the site. Ideally these reference conditions should be placed in a central location such as the RQIS websites where other researches can access it.  The effects of the changes in the flow modification and habitat modification metric group results between the two MIRAI versions should be investigated and the following questions answered: o Does it have an impact on the explanation for the Ecological condition/ impacts at the site? o Does it explain the impacts more realistically than the information obtained using MIRAI v1? Doctoral

Enhancement of summer habitat could improve survival and reproduction by bats recovering from white-nose syndrome (WNS). We found that captive little brown bats (Myotis lucifugus) recovering from WNS preferentially selected heated bat houses and we calculated a dramatic reduction in energy costs for bats in heated roosts., Habitat modification can improve outcomes for imperilled wildlife. Insectivorous bats in North America face a range of conservation threats, including habitat loss and white-nose syndrome (WNS). Even healthy bats face energetic constraints during spring, but enhancement of roosting habitat could reduce energetic costs, increase survival and enhance recovery from WNS. We tested the potential of artificial heating of bat roosts as a management tool for threatened bat populations. We predicted that: (i) after hibernation, captive bats would be more likely to select a roost maintained at a temperature near their thermoneutral zone; (ii) bats recovering from WNS at the end of hibernation would show a stronger preference for heated roosts compared with healthy bats; and (iii) heated roosts would result in biologically significant energy savings. We housed two groups of bats (WNS-positive and control) in separate flight cages following hibernation. Over 7.5 weeks, we quantified the presence of individuals in heated vs. unheated bat houses within each cage. We then used a series of bioenergetic models to quantify thermoregulatory costs in each type of roost under a number of scenarios. Bats preferentially selected heated bat houses, but WNS-affected bats were much more likely to use the heated bat house compared with control animals. Our model predicted energy savings of up to 81.2% for bats in artificially heated roosts if roost temperature was allowed to cool at night to facilitate short bouts of torpor. Our results are consistent with research highlighting the importance of roost microclimate and suggest that protection and enhancement of high-quality, natural roosting environments should be a priority response to a range of threats, including WNS. Our findings also suggest the potential of artificially heated bat houses to help populations recover from WNS, but more work is needed before these might be implemented on a large scale.

International audience; Today, we are witnessing changes in the spatial distribution and abundance of many species, including ticks and their associated pathogens. Evidence that these changes are primarily due to climate change, habitat modifications, and the globalisation of human activities are accumulating. Changes in the distribution of ticks and their invasion into new regions can have numerous consequences including modifications in their ecological characteristics and those of endemic species, impacts on the dynamics of local host populations and the emergence of human and livestock disease. Here, we review the principal causes for distributional shifts in tick populations and their consequences in terms of the ecological attributes of the species in question (i.e. phenotypic and genetic responses), pathogen transmission and disease epidemiology. We also describe different methodological approaches currently used to assess and predict such changes and their consequences. We finish with a discussion of new research avenues to develop in order to improve our understanding of these host-vector-pathogen interactions in the context of a changing world.

The construction of dams causes major impacts on fauna by changing or eliminating irreversibly their habitats. The resulting changes lead to deep potential modifications on reproductive biology and population structure of lizards, snakes and amphisbaenas. The reservoir in the Multiple Use Area of Manso (APM-Manso) is located near to Chapada dos Guimarães National Park, in Mato Grosso State. We analyzed comparatively the male gonads of Anolis meridionalis, Colobosaura modesta, Cercosaura ocellata, Cnemidophorus ocellifer, Hoplocercus spinosus, Bachia bresslaui, Mabuya frenata, Micrablepharus atticolus and Tropidurus oreadicus, from APM-Manso, aiming to verify possible changes in the reproductive success according to environmental changes. Before the impoundment A. meridionalis, Colobosaura modesta, Cercosaura ocellata, M. atticolus and T. oreadicus showed up reproductive. However, during the impoundment period they presented changes in seminiferous tubules, evidenced by the absence of spermatids and spermatozoids. B. bresslaui and M. frenata had no differences in the seminiferous tubules before and after the impoundment, being reproductive in both moments. The damming and the formation of the lake of Manso reservoir may have interfered on the reproduction of some lizards species, especially if the reproductive cycle is regulated by the rainfall of the habitat.A construção de barragens tem ocasionado grandes impactos sobre a fauna ao alterar ou eliminar seus habitats de forma irreversível. Alterações decorrentes exercem profundas modificações potenciais na biologia reprodutiva e na estrutura populacional de lagartos, serpentes e anfisbenas. O reservatório da Área de Aproveitamento Múltiplo de Manso (APM-Manso) localiza-se próximo ao Parque Nacional da Chapada dos Guimarães, em Mato Grosso. Foram analisadas comparativamente as gônadas masculinas de Anolis meridionalis, Colobosaura modesta, Cercosaura ocellata, Cnemidophorus ocellifer, Hoplocercus spinosus, Bachia bresslaui, Mabuya frenata, Micrablepharus atticolus e Tropidurus oreadicus, da APM-Manso com o objetivo de verificar se houve alterações no sucesso reprodutivo das mesmas de acordo com as modificações ocorridas no ambiente. Antes do represamento A. meridionalis, Colobosaura modesta, Cercosaura ocellata, M. atticolus e T. oreadicus apresentavam-se reprodutivas. No entanto, durante o período de represamento apresentaram alterações nos túbulos seminíferos evidenciadas pela ausência de espermátides e espermatozóides. B. bresslaui e M. frenata não apresentaram diferenças em seus túbulos seminíferos antes ou depois do represamento, estando reprodutivas em ambos os momentos. O represamento e a formação do lago do Manso pode ter interferido na reprodução de algumas espécies de lagartos, principalmente se o ciclo reprodutivo for regulado a partir da pluviosidade do habitat.

Gregarious flowering of bamboo species impacts ecosystem properties and conservation, but documentation of these periodic events is difficult. Here, we compare the characteristics of flowering sites and un-flowered patches of an arrow bamboo (Fargesia qinlingensis) in the Qinling Mountains, China, over a five-year period (2003-2007) after a mast flowering event (2003). We examined flowering culm and seedling characteristics in relation to questions regarding the evolution of delayed flowering. Density of live culms decreased over the five years in both flowering sites and un-flowered patches. New shoots regenerated only in un-flowered patches. Chemical constituent allocation varied among culm parts (stems, branches, and leaves). Crude protein and extract ether in branches and leaves were less in flowering culms than in un-flowered culms. Seedling density was lower than expected based on floret counts, suggesting predation of seeds. Seedling density was significantly greater in flowering sites than in un-flowered patches and decreased over time. Seedlings performed better in flowering sites than in un-flowered patches based on their height, leaf number per seedling, and average leaf length, while fertilization on flowering sites had no significant effect on seedling growth, suggesting a saturation of resources. This study suggested that the characteristics of bamboos and bamboo stands were dramatically altered during this flowering event, enhancing seedling establishment and growth, and supporting mostly the habitat modification hypothesis of delayed reproduction.

In this work, the Ictalurus punctatus species estimated available physical habitat is compared with the estimated physical habitat for the same but modified river reach, with the aim of creating a linear park, along a length of 5 500 m. To determine the effect of ecological park construction, on physical habitat of the Lerma river stretch of study, first, the available habitat for the Ictalurus punctatus species was estimated through the simulation of the physical habitat, by using surveying, hydraulics, and habitat information gotten at the river reach in its actual situation. Second, it was estimated the available habitat for the above species, upon the simulation of the physical habitat through the proposed modification for the ecological park creation. Third, it is presented a comparison between both scenarios in terms of available habitat estimated for Ictalurus punctatus species, concluding that in cases of adult and spawning life stages, changes in the channel to create an ecological park would produce a considerable loss of potentially usable habitat (PUH), while in the case of the juvenile life stage PUH remains virtually unchanged, and in the case of life stage fry the PUH would increase due to the presence of velocities and depths of lesser magnitude, due to the presence of minor flow rates and lower volume of the wet channel. It is expected that habitat modification for linear park construction may produce the lack of Ictalurus punktatus species conservation at the river reach of the study., {"references":["K. D. Bovee, B. L. Lamb, J. M. Bartholow, C.B. Stalnaker, J. Taylor &\nJ. Enriksen, Stream habitat analysis using the instream flow incremental\nmethodology. U.S. Geological Survey, Biological Resources Division\nInformation and Technology Report USGS/BRD-1998-0004. viii+131\npp, 1998.","K.D. Bovee, A guide to stream habitat analysis using the instream flow\nincremental methodology. Fort Collin, CO., U. S. Fish and Wildlife\nService. 251, 1992.","CONAGUA (Comision Nacional del Agua), Banco Nacional de Datos\nde Aguas Superficiales (BANDAS). México, D.F., 2010.","CONAGUA (Comisión Nacional del Agua), Cuencas hidrológicas con\nsu disponibilidad media anual de aguas superficiales publicada.\nhttp://www.conagua.gob.mx/Espaniol/TmpContenido.aspx?id=Documentos%20relacionados%20con:%20Instrumentos%20de%20Gesti%C3%\nB3n%20del%20Agua|Documentos%20relacionados%20con:%20Instrumentos%20de%20Gesti%C3%B3n%20del%20Agua|0|0|264|0|0. México. 2008, Web consulted october 25th 2009.","CONAGUA (Comisión Nacional del Agua), Ley de Aguas Nacionales y\nsu Reglamento. México. 2012, 209 p.","P. Correa, G., Atlas Geográfico del Estado de Michoacán. EDDISA,\nMorelia, México, 1978.","Florida Museum of Natural History, Taxonomic Information on Cat Fish\nhttp://www.flmnh.ufl.edu/catfish/. Consultada en junio de 2010.","E. E. Herricks, J. B. Stall, J.W. Eheart, A. B. Libby, S.F. Railback, &\nM.J. Sale, Instream flow needs analysis of the Little Wabash River\nBasin. Dept. Civil Eng., University of Illinois, Urbana, IL. . 1980, 150\npp.","Instituto de Ingeniería de la UNAM, Diagnostico Energético e\nHidráulico del Estado de Michoacán. Informe final de proyecto,\nMorelia, Michoacán. 2005, 211pp.\n[10] INE (Instituto Nacional de Ecología), Diagnóstico bio-físico y socioeconómico\nde la cuenca Lerma-Chapala. México. 2003, 285pp.\n[11] R.T. Milhous, Updike, & Schneider, D.M., Physical Habitat Simulation\nSystem Reference Manual - Version II. Instream Flow Information\nPaper No. 26. U.S. Fish and Wild. Serv. Biol. Rep. 89 (16). v.p. 1989.\n[12] R.T. Milhous, Wegner, D.L, y Waddle, T., Physical Habitat Simulation\nSystem User's Guide. Instream Flow Information Paper No. 11. U.S.\nFish and Wildlife Service. FWS/OBS-81/43. 1984.\n[13] W. S. Platts, , W. F. Megahan, & G. W. Minshall, Methods for\nevaluating stream riparian, and biotic conditions. USDA Forest Service,\nGeneral Tech. Report. INT-138. Ogden, UT. 1983, 70 pp.\n[14] R. A. Rueda Jasso, Pérez Munguía R., & Martínez Trujillo M., Informe\ndel análisis biológico de las poblaciones presentes y manejo ecológico\ndel meandro. Realizado dentro del Proyecto Fomix CONACYTGobierno\ndel Estado de Michoacán No, 73881. Morelia, Michoacán,\nMexico. 2010, 135pp.\n[15] C. Stalnaker, Lamb, B.L., Henriksen, J., Bovee K., And Bartholow, J.,\nThe Instream Flow Incremental Methodology, A primer for IFIM.\nBiological Report 29. U.S. Department of the Interior, National\nBiological Service. Washington, D.C., 1995, 44 pp.\n[16] R. E Tharme, A Global Perspective on Environmental Flow Assessment:\nEmerging Trends in the Development and Application of Environmental\nFlow Methodologies for Rivers. RIVER RESEARCH AND\nAPPLICATIONS 19: p. 397–441. 2003, Wiley InterScience.\n[17] L.C. Van Rijn, Principles of fluid flow and surface waves in rivers,\nstuaries, seas and oceans. Aqua publications, Amsterdam, The\nNetherlands, 1990.\n[18] T. J. Waddle, PHABSIM for Windows: user's manual and exercises.\nFort Collins, CO: U.S. Geological Survey. Open-File Report 01-340.\n2001, 288 p.\n[19] T. J. Waddle, Personal Communication, 2000.\n[20] E. García, Determinación de un Régimen de Caudales Ecológicos para\nel Cauce Natural (Meandro) del Río Lerma, que atraviesa la zona\nconurbada de La Piedad, Michoacán y Santa Ana Pacueco, Guanajuato.\nProyecto FOMIX CONACYT-Gobierno del Estado de Michoacán No.\n73881: Saneamiento del cauce natural (meandro) del Río Lerma e\nintegración del mismo a la dinámica urbana de La Piedad Michoacán.\nMorelia, México. 2011, 45 p."]}

Ecosystem engineers are organisms that strongly modify abiotic conditions and in the process alter associated communities. Different types of benthic ecosystem engineers have been suggested to facilitate different communities in otherwise similar marine environments, partly because they alter sediment conditions in contrasting ways. However, most studies testing this hypothesis have either not manipulated the presence of engineers, or have transplanted engineers into areas already dominated by other engineers, which limits the ability to assess the relative engineering effects. Here we combined a field survey and a field experiment to investigate if two contrasting ecosystem engineers - the sediment-stabilizing seagrass Zostera noltei and the bioturbating lugworm Arenicola marina - facilitate different macrofauna communities. The study was performed in a sheltered mudflat area of the eastern Dutch Wadden Sea, where seagrasses and lugworms form a mosaic of spatially alternating seagrass-dominated elevations (hummocks) and lugworm-dominated depressions (hollows). Results showed that seagrasses facilitated some organisms (mainly attached epifauna) while lugworms facilitated others (primarily burrowing infauna), generating distinctly different macrofauna communities in hummocks and hollows. However, seagrasses had a much stronger effect on the macrofauna communities than lugworms, and competitively excluded lugworms. This contrasts with results from similar studies in hydrodynamically more exposed sand flats, where lugworms instead dominate communities and exclude seagrass. We therefore propose that effects of ecosystem engineering (acting primarily on a local scale) and variation in abiotic conditions (acting on larger scales, e.g., hydrodynamic gradients along the Dutch coastline) strongly interact to dictate the distribution and fitness of engineering species, and indirectly, the diversity and structure of associated benthic communities. (C) 2015 Elsevier B.V. All rights reserved.

This paper reports on experimental restoration of mussel beds in the Wadden Sea and the processes that might limit successful restoration of this foundation species (i.e. substrate, predation, hydrodynamics). The importance of substrate, predation, hydrodynamic conditions and location on mussel restoration success was studied using artificially created mussel beds. Experimental beds established on a stable substrate (coir net) were compared with control beds established on sand, at three locations in the Wadden Sea. Their persistence was followed over time. The results revealed a near disappearance of all experimental beds in just over 7 months. Providing a stable substrate did not improve mussel survival. Predation could not explain the disappearance of the beds, as the maximal predation rate by birds was found to be insufficient to have a significant effect on mussel cover. Differences in wave conditions alone could also not explain the variation in decline of mussel cover between the locations. However, the gradual disappearance of mussels from the seaward side of the bed strongly suggested that hydrodynamic conditions (i.e. combined effects of waves and current) played an important role in the poor persistence of the artificial beds. Our results highlight the fact that restoration of mussel beds in dynamic areas cannot simply be implemented by mussel transplantation, particularly if additional measures to prevent wave losses are not taken, even when artificial substrate is provided to facilitate mussel adhesion. (C) 2015 Elsevier B.V. All rights reserved.

Author(s): Van Vuren, Dirk H.; Ordenana, Miguel A.; McGrann, Michael C. C.; Berentsen, Are R. | Abstract: Burrowing mammals such as ground squirrels are considered threats to levee integrity, and some authors have proposed that ground squirrel occurrence on levees might be reduced by habitat modification. We characterized the threat that California ground squirrels pose to levees by summarizing available information on burrow lengths and depths, and we reviewed available information about the efficacy of habitat modification to reduce squirrel occurrence on levees. Burrows of California ground squirrels averaged 8.2 m in length (range = 0.9-42.1 m) and 75 cm in greatest depth (range = 33-168 cm), indicating that most burrows are not long enough to transect most levees but nonetheless could contribute to “piping” of water through the levee and create voids that trigger collapses of levee soil. There is little evidence that managing for either short-stature grassland or shrubby vegetation on levees will reduce occurrence of ground squirrels, but further research is needed for both approaches. Managing for trees on levees likely will reduce the occurrence of ground squirrels, probably because tree-covered habitats create visual obstruction that is avoided by ground squirrels. The presence of nut and fruit crops adjacent to levees increases the occurrence of ground squirrels on the levee, probably because these crops provide a rich food resource.

The effect of deforestation and the introduction of exotic grasses on the population dynamics of Rhipi- cephalus (Boophilus) microplus in northern Argentina was analysed. Biological parameters that were mea- sured included proportion of females ovipositing, pre-oviposition period, incubation period of eggs, proportion of egg clusters hatching, larval longevity and total non-parasitic period. No significant differ- ences were observed in proportion of females ovipositing and in pre-oviposition period between forested and grassland areas. Regarding the other parameters, in the majority of the temporal series there were no significant differences. In the cases where differences with statistical significance were detected, they were not unidirectional. The replacement of native forest by grasses can potentially increase tick abun- dance not by the modification of microclimatic conditions, but by increasing the tick-host encounter rate due to a higher cattle density. The hypothesis that deforestation and introduction of exotic grasses affects the non-parasitic phase of R. microplus in northern Argentina was not supported. Fil: Nava, Santiago. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Santa Fe. Estación Experimental Agropecuaria - Rafaela; Argentina; Fil: Mastropaolo, Mariano. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Santa Fe. Estación Experimental Agropecuaria - Rafaela; Argentina; Fil: Guglielmone, Alberto Alejandro. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Santa Fe. Estación Experimental Agropecuaria - Rafaela; Argentina; Fil: Mangold, Atilio Jose. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Santa Fe. Estación Experimental Agropecuaria - Rafaela; Argentina

The primary objective of this study was to apply a multifaceted approach to understand the historical and contemporary aspects of hybridization between 2 species of ground squirrels (Ictidomys). Genetic and ecological data were used to determine the influence of historical biogeography on hybridization, the extent of contemporary hybridization, and the role the environment plays in determining locations of contact and potential hybridization. In Chapter I, the subject of hybridization and hybrid zones and its part in the speciation process was introduced. In addition, literature relevant to hybridization in mammals was discussed. Relevant to this dissertation, hybridization between the Rio Grande ground squirrel (I. parvidens) and the thirteen-lined ground squirrel (I. tridecemlineatus) was examined. In Chapter II, the historical contribution to hybridization between I. parvidens and I. tridecemlineatus was evaluated. Given the genetic data incorporated in this study, these species likely have undergone an ancient hybridization event, leading to mitochondrial capture in areas of previous sympatry. In Chapter III, the extent of hybridization at areas previously identified to have such was determined. By combining sequence data used in Chapter II with a genome-wide scan, hybridization was limited to small populations, with hybrids in a mosaic spatial pattern. In Chapter IV, the contributions of climate and anthropogenic changes to habitat were assessed. Through ecological niche modeling, it was determined that climate contributed the most to distributional patterns of both species. However, recent habitat modifications might have had an additive effect on both species’ distributions. Concluding remarks are provided in Chapter V.