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Mauldin et al. (2014) examined 103 woodrats collected in 1988 from a putative contact zone located in Major County, Oklahoma, and provided evidence for a substantial level of hybridization between Neotoma floridana and N. micropus. This site was resampled in 2010, with 42 woodrats collected, and again in 2011, when an additional 88 woodrats were collected from 11 localities along a transect extending northwest to southeast of the center of the hybrid zone. These specimens were examined to: 1) serve as independent data sets, separated by 22 years, for a temporal comparison of hybrid zone characteristics and 2) determine the geographic extent of genetic introgression between the two species. All individuals were genotyped at 11 genetic markers (eight microsatellite loci, one mitochondrial gene—Cytochrome b, and two nuclear introns—intron 2 of the vertebrate alcohol dehydrogenase gene and intron 7 of the beta-fibrinogen gene) that were shown to be informative in the original study. Levels of allelic introgression were assessed at 12 localities (11 new localities, as well as the previously sampled putative contact zone) to determine size and continuity of the hybrid zone. Expanded geographic sampling revealed evidence of genetic introgression at 11 of 12 localities, although only two localities were determined to be active areas of hybridization in 2011. The temporal comparison revealed that characteristics of the hybrid zone (i.e., frequency of hybridization, directionality, location of the zone, and ratios of hybrid classes) remained similar between sampling events. These findings suggest hybridization between these species is ongoing but is intermittent and potentially ephemeral in this region.

The population of the New Forest burnet moth, Zygaena viciae, at its only UK site in western Scotland, was assessed between 1990 and 2019, using direct counts, standard transect counts and Mark/Release/Recapture (MRR). Data from eleven of these years, when reliable comparative transect counts and MRR population estimates were available, were analysed to answer the question as to whether the more economical transect counts provided a reliable estimate of the population size. Lin's Concordance Coefficient showed conclusively that transect counts do have a consistent relationship with the MRR population estimates. However, it was found that transect counts consistently under-estimate the MRR derived population estimates and that the scaling factor between them is best valued at ×5 (see Results). It can be concluded that, when resources are too limited to allow a full MRR population analysis, the more economical transect counts can trusted to indicate the relative size of the moth population.

Coral reefs are unique ecosystems and only occur in the tropics area. One of the coral reef distribution in Indonesia is Lombok Island. The coral reefs in Lombok Island under degradation conditions caused by natural and human activities. The purpose of this study was to provide an overview of the benthic profile and substrate of coral reefs in the Labuhan Pandan waters, Eastern Lombok. Observations were conducted in March 2019 at 5 stations using the Underwater Photo Transect (UPT) method. The results showed that in general benthic coral reefs were dominated by Acropora Branching (35.40%) then followed by Soft Coral (20.89%), DCA (14.08%), Coral Foliose (11.07%), Rubble (7.36%) and Halimeda (2.77%). The highest percentage of Acropora Branching were found at KND_01 station (63.33%) followed by PTG_01 (49.13%), PTG_02 (31.18%), BDR_01 (21.73%), and PTG_03 (11.00%). The highest DCA percentage was found at BDR_01 station (29.27%) while Soft Coral was found dominant at PTG_02 (47.67%). Halimeda was only found in PTG_02 (1.87%) and PTG_03 (12.00%). Differences in the composition of benthic and substrate may be caused by differences in water conditions at each station.

Line transect survey methodology is a commonly used method for estimating the population abundance. Despite recent advances in this regard, parametric models are still widely used among biometricia...

Supercolonial ants are among the largest cooperative units in nature, attaining extremely high densities. How these densities feed back into their population growth rates and how abundance and extrinsic factors interact to affect their population dynamics remain open questions. We studied how local worker abundance and extrinsic factors (rain, tree density) affect population growth rate and spread in the invasive big-headed ant, which is disrupting a keystone mutualism between acacia trees and native ants in parts of East Africa. We measured temporal changes in big-headed ant (BHA) abundance and rates of spread over 20 months along eight transects, extending from areas behind the front with high BHA abundances to areas at the invasion front with low BHA abundances. We used models that account for negative density dependence and incorporated extrinsic factors to determine what variables best explain variation in local population growth rates. Population growth rates declined with abundance, however, the strength of density dependence decreased with abundance. We suggest that weaker density dependence at higher ant abundances may be due to the beneficial effect of cooperative behavior that partially counteracts resource limitation. Rainfall and tree density had minor effects on ant population dynamics. BHA spread near 50 m/year, more than previous studies reported and comparable to rates of spread of other supercolonial ants. Although we did not detect declines in abundance in areas invaded a long time ago (> 10 years), continued monitoring of abundance at invaded sites may help to better understand the widespread collapse of many invasive ants.

Summary Microbial communities are essential for a healthy soil ecosystem. Metals and radionuclides can exert a persistent pressure on the soil microbial community. However, little is known on the effect of long‐term co‐contamination of metals and radionuclides on the microbial community structure and functionality. We investigated the impact of historical discharges of the phosphate and nuclear industry on the microbial community in the Grote Nete river basin in Belgium. Eight locations were sampled along a transect to the river edge and one location further in the field. Chemical analysis demonstrated a metal and radionuclide contamination gradient and revealed a distinct clustering of the locations based on all metadata. Moreover, a relation between the chemical parameters and the bacterial community structure was demonstrated. Although no difference in biomass was observed between locations, cultivation‐dependent experiments showed that communities from contaminated locations survived better on singular metals than communities from control locations. Furthermore, nitrification, a key soil ecosystem process seemed affected in contaminated locations when combining metadata with microbial profiling. These results indicate that long‐term metal and radionuclide pollution impacts the microbial community structure and functionality and provides important fundamental insights into microbial community dynamics in co‐metal‐radionuclide contaminated sites.

Coastline changes are caused by sea-level rise, erosion and anthropogenic activities, and have important consequences on coastal ecosystems and communities. In this study, shore line changes during the last 40 years near the Mahi estuarine belt in the Gulf of Khambhat region have been monitored using multi-temporal Landsat data from 1978 to 2018. Multi-date Landsat digital data with 10-year interval from 1978 to 2018 was downloaded from the website https://earthexplorer.usgs.gov/ . The Landsat data covering the study area with 15-km buffer was extracted and analyzed for monitoring the changes in the shoreline. The Normalized Difference Water Index (NDWI) images were also generated for delineation of the shoreline. The data was analyzed using the Digital Shoreline Analysis System in ArcGIS software, which provides a set of tools permitting transects-based calculation of shoreline displacement. A total number of 10 transects from the centre of the village up to the coast line were marked on the multi-date Landsat digital data. The changes in the shoreline from the centre of the village were calculated using the End Point Rate (EPR) and temporal linear regression model to predict future shoreline position. The decadal shoreline change indicated that shoreline has continuously increased from 113.9 to 831.4 m during the 40-year period from 1978 to 2018, respectively. This indicates that total migration of shoreline towards the land area of the study village during the last 40 years (1978 to 2018) was 1590.5 m with an alarming annual rate of change of 39.76 m year−1, which is very remarkably high and alarming which may lead to any future disaster for the study village. The coastline was not significantly changing until 1988; however, change in coastline is exponentially faster from 1989 to 2018. The linear regression method was adopted for predicting the shoreline change rates over the entire period of the study from 1978 to 2018 and from 2018 to 2028 and 2038. The results of shoreline change prediction for future 10 years (2028) and 20 years (2038) indicate the average predicted transect length of 1908 m and 1543 m, respectively. With the projected estimates of shoreline change during next 20 years at the rate of almost 120 m/year, it appears that the Chokari village may get submerged in the sea water. The analysis of change in the land surface area of the Chokari village indicated that it has decreased from 12.45 to 9.63 km2, which indicates that area reduced by 2.8 km2 may be due to the erosion along the river-bed which is the result of change in the shoreline during the last 40 years. Based on these results of shoreline change analysis, it is recommended that the Government of Gujarat needs to take immediate steps to protect the Chokari village from submergence by adopting Integrated Coastal Zone management strategies.

In this study, we investigated the links between peat carbon accumulation and past ecological and hydrological conditions in three peatlands (Bouleau, Mista, Auassat) which developed along a South-North transect within a watershed encompassing the boreal and subarctic domain in Eastern Canada. Peatland development and long-term apparent rates of carbon accumulation (LORCA) were asynchronous in the watershed, suggesting an influence of both latitude and topography (altitude) on the length of the growing season (GGD0). Results show that peat initiation within the three peatlands (respectively ca. 9070, 8400, and 6270 cal BP) was delayed after the deglaciation and that LORCA (respectively 35.5, 15.4, and 9.0 g C m−2 yr−1) decreased from South to North. Peatland development and fen to bog transitions were found to be almost synchronous for the two southernmost sites. The fen to bog transition in the northernmost subarctic site was delayed until the 20th century, owing to the less favorable climatic conditions. This suggests that recent warming has extended the length of the growing season and increased Sphagnum growth enough to potentially influence an ecosystem state-shift as observed in other Subarctic regions of eastern Canada.

To determine whether mangrove soil accretion can keep up with increasing rates of sea level rise, we modeled the theoretical, steady-state (i.e., excluding hurricane impacts) limits to vertical soil accretion in riverine mangrove forests on the southwest coast of Florida, USA. We measured dry bulk density (BD) and loss on ignition (LOI) from mangrove soils collected over a period of 12 years along an estuarine transect of the Shark River. The plotted relationship between BD and LOI was fit to an idealized mixing model equation that provided estimates of organic and inorganic packing densities in the soils. We used these estimates in combination with measures of root production and mineral deposition to calculate their combined contribution to steady-state, vertical soil accretion. On average, the modeled rates of accretion (0.9 to 2.4 mm year−1) were lower than other measured rates of soil accretion at these sites and far less than a recent estimate of sea level rise in south Florida (7.7 mm year−1). To date, however, no evidence of mangrove “drowning” has been observed in this region of the Everglades, indicating that assumptions of the linear accretion model are invalid and/or other contributions to soil accretion (e.g., additional sources of organic matter; feedbacks between physical sedimentation processes and biological responses to short-term environmental change) make up the accretion deficit. This exercise highlights the potential positive impacts of hurricanes on non-steady-state soil accretion that contribute to the persistence of neotropical mangroves in regions of high disturbance frequency such as the Gulf of Mexico and the Caribbean region.

The present study proposed a novel approach to investigate variability in the acoustic behavior of a number of deciduous tree-dominated narrow and long urban parks in Isfahan city, central Iran, between winter leaf fall and summer foliage. Noise levels (Lq30 in dB) were measured along two adjacent sides of the parks: along the road-adjacent side (Ro transect) and the relatively calmer river-adjacent side of the parks (Ri transect) during 4–17 January 2018 and 7–14 August 2019. Using Sentinel-2 images, two NDVI maps were also produced for these two periods to determine how changes in green biomass were associated with changes in noise levels. Using ANOVA, a significant difference was found in Ri-Lq30 and NDVI maps between winter and summer (p = 0.0), while the difference was insignificant for Ri-Lq30 (p = 0.1). We also developed two multiple linear regressions, one for each season, to assess the dependency of Ri-Lq30 to the intensity of vegetation and Ro-Lq30 and compare the two seasons by performing a t test analysis on the intercept and slope of the models, with results suggesting there is a significant difference in the association of green biomass and noise levels measured inside the parks between leaf fall and foliage time (p = 0.04). Our results indicated the temporal variability of park characteristics in providing calmer urban landscapes throughout the year.

The positive ecological interaction between gap formation and natural regeneration has been examined but little research has been carried out on the effects of gaps on natural regeneration in forests under different intensities of disturbance. This study evaluates the composition, diversity, regeneration density and abundance of natural regeneration of tree species in gaps in undisturbed, intermittently disturbed, and disturbed forest sites. Bia Tano Forest Reserve in Ghana was the study area and three gaps each were selected in the three forest site categories. Ten circular subsampling areas of 1 m2 were delineated at 2 m spacing along north, south, east, and west transects within individual gaps. Data on natural regeneration

The vegetation communities within semi-permanent or ephemeral montane marshes colloquially known as lagoons are an under investigated wetland type of the New England Tablelands Bioregion (NETB) yet they are listed (Upland Wetlands) on both state and federal acts as endangered. Lack of survey and analysis of plot data has meant that the variation in vegetation due to zonation, seasonality and unpredictable wetting and drying cycles are poorly understood. Here, 317 full floristic 2 × 2-m plots were placed across 13 lagoons. The plot data were classified to allow description of native and novel vegetation types using the hierarchical EcoVeg schema. The updated classification includes one Division and Macrogroup with 15 Alliances and 47 Associations. Permanent 50-m transects with a 1 × 1-m plot at every 5 m (10 per transect) were placed within lagoons. Five lagoons were resurveyed annually for 3 years. Within transects, each plot was assigned an Association after each survey period. Approximately one third of transect plots changed in vegetation type each year, often at the Alliance level. Over the 3-year period the number of Associations reduced by ~30% across transects associated with increasing drought and drying out of the wetlands. Transitional environments with the greatest level of hydrological periodicity had the greatest variety of Associations recorded. Highly dynamic systems with increased temporal turnover are likely to require increased sampling effort both spatially and temporally than more stable vegetated systems. The constant changing nature of these communities poses significant issues for management and conservation planning, including benchmarking and offsetting, which may require novel solutions.

The influence of grazing and mining on arbuscular mycorrhizal fungi (AMF) species in grassland were studied around the opencast coal mine pit. The two sampling transects had been designed which was located in the grazing area and in the non-grazing area in the grassland on the north side of the opencast coal mining area. Besides, two control points with the direct distance of 8 km to the opencast coal mining area have been designed. The two points are located in the inside grassland station and outside the grassland station. We collected 3 replicate rhizosphere soil in every point which is from the two transects. We analyzed the genetic diversity of AMF, measured the chemical properties and enzyme of rhizosphere soil of Cleistogenes squarrosa, and explored their correlations using redundancy analysis. And we identified the factors affecting species diversity of AMF around the mining area. Our results showed that grazing on the grassland around the opencast coal mine will aggravate soil degradation and reduce the species richness and diversity of arbuscular mycorrhizal fungi in rhizosphere soil, which can be a theoretical basis for the scientific management of the grassland around the opencast mining area.

Community structure and distribution of chaetognaths were investigated along the upwelled and non-upwelled waters of Southeastern Arabian Sea (SEAS) from the coastal, shelf and open ocean regions. With the onset of monsoon, intense upwelling along the southern part of SEAS (8° 28′ N) and a weak coastal upwelling along the northern counterpart (15° 30′ N) was evident. Zooplankton biomass was observed to be high in the upwelled waters with the dominance of copepods. Chaetognaths were also observed in significant numbers all along the SEAS, however maximum numerical abundance was observed in the southern upwelled waters. Chaetognaths belonging to 10 genera were identified of which genus Flaccisagitta (54%) made the most dominant group along the entire study area followed, in order of abundance, by Serratosagitta (20%), Mesosagitta (18.2%), Sagitta (12.3%), Ferosagitta (11%) and Krohnitta (6.4%). Flaccisagitta were observed to be abundant in the upwelled waters along with Pterosagitta, Serratosagitta, Sagitta, Krohnitta and Ferosagitta whereas genus Mesosagitta dominated the non-upwelled waters of northern transects.

Carbon (C) and nitrogen (N) soil profiles are influenced by several environmental factors. However, the contents and distributions of these elements in deep soils and sediments are largely underestimated. We aimed to estimate the stocks, patterns, and driving factors of deep soil C and N on the Chinese Loess Plateau (CLP) after large-scale ecological restoration projects. Soil organic carbon (SOC) and total nitrogen (TN) contents in different soil layers were measured directly at 86 sites along a regional transect across the CLP. SOC and TN contents ranged from 1.97 to 6.83 g C kg−1 and 0.24 to 0.72 g N kg−1, respectively, as the soil depth varied from 0 to 5 m. The mean contents and degrees of variability of SOC and TN decreased with the increasing of soil depth. Based on SOC and TN content patterns, we divided the 0–5-m soil profile into layers of 0–0.1, 0.1–0.4, 0.4–1, and 1–5 m. In the 1–5-m soil layer, approximately 70% of the mean SOC stock (14.97 kg C m−2) and 71% of the mean TN stock (1.75 kg N m−2) were stored. A partial least square regression model showed satisfactory predictive performance, with R2 and Q2 > 0.5 for SOC and TN stocks in the 0.1–0.4-m soil layer. Climatic factors, soil water content (SWC), and field capacity strongly affected SOC and TN stocks in all soil layers. The significance of clay content, SWC, and normalized difference vegetation index varied with soil depth and became the strongest in the 1–5-m soil layer. The highest proportion of SOC and TN stocks for this soil layer were found in grassland and in 450–550 mm rainfall zone. Considerable amounts of SOC and TN stocks were stored in the 1–5-m-deep soils. Land-use types and rainfall zones can significantly affect the SOC and TN stocks. This information is helpful for identifying local land uses associated with high SOC and TN stocks and is essential for accurately estimating and predicting regional C and N stocks and cycles in terrestrial ecosystems.

As spatially fine-scale foraging decisions are intrinsic to browsing herbivores such as deer, the search and selection of individual plants may be shaped by the density of neighbouring plants. However, how such neighbourhood effects may modify herbivore foraging decisions at different spatial scales is largely unexplored. Our main goal was to examine deer foraging preferences for tree species and seedling sizes, and to ask whether the spatial relationship of unbrowsed and browsed seedlings was indicative of different neighbourhood effects at the spatial scale of seedling neighbourhoods. We used two data sets from an old-growth temperate forest: (1) a seedling inventory and (2) fully mapped transect data, and applied a generalized linear mixed model and spatial point pattern analyses, respectively. We found that neighbourhood effects modified deer foraging behaviour depending on the proximity, density and species identity of neighbours, which, in turn, determined the strength and spatial extent of browsing impacts on tree seedlings. While sycamore maple seedlings experienced the highest levels of deer selectivity, deer were selective for European beech seedlings only within short distances. Beyond these distances, beech seedlings were browsed only opportunistically, as conspecific neighbours ceased to modify deer selectivity. Beech seedlings were also more susceptible to browsing within short distances from silver fir seedlings, indicating an associational susceptibility. As fir seedlings experienced strong and extensive density-dependent deer selectivity both near conspecific and beech neighbours, using such neighbourhood effects may not be a promising tool to prevent deer browsing on tree seedlings at the spatial scale of seedling neighbourhoods.

The concept of the transect is derived from a scientific method of investigating a sequence of environments by sampling geographical cross-sections of the target region. Many environmental theorists, including Patrick Geddes and Ian McHarg, have adopted the transect to pursue an ideal relationship between nature and human settlement. Transect planning provides an essential perspective on and transdisciplinary platform for mitigating today's urban problems and social changes. Transects have been especially widely used in urban resilience projects designed to prepare for future uncertainties stemming from climate change. In this context, this study reveals the strengths of the transect method for urban resilience and landscape sustainability in the current era. This study first examines the theoretical background of the transect as evidenced in the history of environmental planning, including in the work of Patrick Geddes and Ian McHarg, as well as the study of contemporary urbanism. Additionally, this work describes the distinctive characteristics of the transect method through an analysis of recent urban resilience projects. Historically, transect use has furthered the pursuit of a synergistic relationship between nature and human beings. Leading theorists have adopted different perspectives on the environment and pursued various philosophies of urban planning. Many urban and landscape projects have actively taken advantage of the transect method and its foundation in ecological thinking. Through an examination of certain contemporary urban resilience projects, the main characteristics of the transect method can be deduced, including: (1) multiscale and multidirectional analysis, (2) spatiotemporal design, and (3) heterogeneous patterning. This method-oriented research offers new insights into the current study of landscape ecology, landscape architecture, and environmental planning, and reveals the potential of the transect method for resilient design.

Termites are globally dominant and functionally important soil organisms. While their role in ecosystems is being increasingly recognised and understood, methods that adequately sample termite communities across habitats can be challenging and have not advanced at the same pace as studies of termite ecology. Moreover, the appropriateness of sampling methods varies with habitat and biogeographic region due to differences in termite communities. Focusing largely on tropical systems where the majority of termites occur, we review currently available termite sampling methods and provide recommendations for sampling across different biomes and biogeographic regions. Active searching transects are most effective in rainforest habitats, whereas reduced transects, baiting and mound surveys are more appropriate in grassy systems and seasonally dry forests. Baiting is recommended for deserts. Recent advances in termite sampling, such as the use of remote sensing and DNA metabarcoding, and outstanding challenges, such as sampling episodic grass-feeding termites, are also discussed. Improved use of standardised termite sampling methods, as we recommend, should lead to increased knowledge of the patterns and drivers of termite diversity, which will, in turn, facilitate the quantification of the influence termites have on ecosystems and lead to new insights into the functioning of tropical systems.

FOOD: Bigger than the Plate served up a slice of everyday life, and showed the multiple elements and interactions that make up and transect the world of food. Through a series of interdisciplinary ...

The layer cake of Ian McHarg. Catherine Mosbach and a mouldy glass of sangria. Roland Gustavsson and the forest-time transects. The eidetic collages of Anton James and the spare motations of Lawren...

Brick making is one of the major small-scale industries in Sironga which has been expanding due to the growing demand for urban expansion. Due to the increasing population pressure, brick-making is competing for the wetland resources. Sironga wetland is threatened with serious degradation and probable loss of plant diversity. Conversion of this wetland for economic uses such as brick making has resulted in its loss. The objective of the study was to assess the effects of brick making on plant diversity in Sironga wetland. Nyamira County, Kenya. A one metre by one metre quadrat frame was laid down and perpendicularly recorded the percent cover for each species found inside the quadrant plus the percentage area covered by the bare ground litter. From each transect lines “diagonally” detailed vegetation under study was then done. The plant species were recorded and classified into three life-forms; herbs, sedges and grasses. The study revealed that grasses had the highest diversity H = 1.144. Diversity for herbs was H = 0.987 and H = 0.899 for reeds respectively. The study concluded that brick-making activities affected the plant diversity in Sironga wetland. This may be attributed partly to the limited information and awareness campaigns to the surrounding communities on the values and benefits of wetland ecosystem services and the lack of alternative livelihood sources. The study recommends that alternative livelihoods are provided and awareness campaigns on the values and benefits of wetlands to the residents are done by the relevant agencies.

portuguesO comportamento de Apismelliferaem areas urbanas tem causado acidentes com seres humanos e animais domesticos. Acoes que visem minimizar o problema, como a captura, sao essenciais. Assim, o presente trabalho buscou compreender a dinâmica de nidificacao e a variacao anual das ocorrencias de enxames e colonias, as suas relacoes com a precipitacao pluviometrica e a floracao apicola.O trabalho foi realizadono Sertao Pernambucano, em Serra Talhada, principalmente, e em cidades vizinhas. As ocorrencias foram registradasno periodo de2014 a 2015. Colonias e enxames foram capturados e levados para oapiario da Unidade Academica de Serra Talhada, ou doados paraumacomunidade de assentados. Dados pluviometricosforam coletados, eo levantamento do pasto apicola emSerra Talhada, atraves de transectos aleatorios de 1.500m a partir do referido apiario. Foram registradas115 ocorrencias, sendo65% em areas urbanas e35% emareasrurais.Desse total, 76% foram de colonias nidificadas e 24% de enxamesprovisorios. Em relacao ao tamanho, 62%foram considerados grandes,22% de porte medio e 16% pequeno. O maior numero de ocorrenciasfoi verificadoentre os mesesde marcoe abril, coincidindo com o periodo de maior precipitacao acumulada e as floradas. Desta forma, as abelhas capturadas possibilitaram uma reducao de riscos a sociedade, contribuiram para uma renda extra dosassentados e aulas praticas universitarias.A dinâmica de nidificacao de A.mellifera, na area de estudo, mostrou estar relacionada ao periodo com maior volume de chuvas e tambem de maior disponibilidade de recursos florais. EnglishThe behavior of Apis melliferain urban areas has caused accidents with humans and domestic animals. Actions that aim to minimize the problem, such as capture, are essential. Thus, the present work sought to understand the nesting dynamics and the annual variation of the occurrences of swarms and colonies, their relationship with rainfall and bee flowering. The work was carried out in the Sertao Pernambucano, in Serra Talhada, mainly, and in neighboring cities. The occurrences were registered in the period from 2014 to 2015. Colonies and swarms were captured and taken to the apiary of the Serra Talhada Academic Unit, or donated to a settlement community. Rainfall data were collected, and the survey of beepasture in Serra Talhada, through random transects of 1,500mfrom the said apiary. 115 occurrences were recorded, 65% in urban areas and 35% in rural areas. Of this total, 76% were from nesting colonies and 24% from provisional swarms. Regarding size, 62%were considered large, 22% medium and 16% small. The highestnumber of occurrences was observed between the months of March and April, coinciding with the period of greatest accumulated precipitation and flowering. In this way, the captured bees enabled areduction of risks to society, contributed to an extra income for settlers and practical university classes. The nesting dynamics of A. mellifera, in the study area, proved to be related to the period with the highest rainfall volume and also the greatestavailability of floral resources.

A multitude of recent studies have detailed microplastic concentrations in aquatic and terrestrial environments, although questions remain over their ultimate fate. At present, few studies have detailed microplastic characteristics and abundance along a freshwater–marine interface, and considerable uncertainties remain over the modelled contribution of terrestrial and riverine microplastic to the world’s oceans. In this article, for the first time, we detail sedimentary microplastic concentrations along a River–Sea transect from the lower reaches of a major continental river, the River Danube, through the Danube Delta, the Black Sea coast to the Romanian and Bulgarian inner shelf of the Black Sea. Our results indicate that isolated areas of the Danube Delta are still relatively pristine, with few microplastic particles in some of the sediments sampled.

The objective of this study is to characterize and assess the risk of collapse of woody plant formations in the Fathala forest. In recent years, this forest has suffered a sharp reduction in its plant cover to the point of compromising the survival of populations of certain animal species such as the Red colobuses. The methods used are respectively constituted by the transect method, the dendrometric statements method and that of establishing the red list of ecosystems of the IUCN. The specific richness comprises 56 species divided into 47 genera and 22 families. The density is higher in the unfenced area (369 ind/ha in clear forest and 53 ind/ha in gallery forest) compared to the fenced area (160 ind/ha in clear forest versus 48 ind/ha in gallery forest). A study of the plant formations shows a strong degradation of the ecosystems passing from a clear and dry Sudanese forest to a wooded savannah. The cover rate in the fenced area is 20% in gallery forests and 25% in clear forests; in the unfenced area, it is 19% and 23% in gallery forests and clear forests, respectively. The application of the IUCN criteria shows an annual rate of collapse is -6 ind/ha in gallery forests and -4 ind/ha in clear forests. The annual rate of cover collapse would be -3.75% and -2.9% for gallery forests and clear forests, respectively. These results classify the forest in the Critically Endangered category. The main factors responsible for this degradation are, among others, anthropogenic actions and climatic pejoration. These results could constitute a basic tool for undertaking an improvement in the management of this forest, which is a living environment for an animal species.

Anthropogenic soils known as Amazonian Dark Earths (ADEs) have long been known as a key component of subsistence systems for various pre-Columbian Amazonian populations. Often treated as a single category, ADE systems consist of two broad anthrosols (human-modified soils): the darker ADE (traditionally known as terra preta) and a lighter brown Amazonian Brown Earth (ABE; traditionally known as terra mulata). Data on the characteristics and spatial distribution of these anthrosols are severely lacking. Transects of soil test pits at the Triunfo and Versalles archaeological sites in the Iténez Forest, in the Bolivian Amazon, show variability in the distribution of soil types, revealing aspects of settlement organisation and resource management. Geochemical, isotopic and archaeobotanical data from an ADE, ABE and control soil profile from the Triunfo site, established ca. 500 cal?BCE, characterise the two anthrosols as distinct components of a polyculture agroforestry subsistence system that combines anthropogenic soil fertilisation, closed-canopy forest enrichment, limited forest clearance for crop cultivation and low-severity fire management.

Free-roaming horses (Equus ferus caballus) occur throughout arid and semiarid regions of the western United States, where they can decrease plant biomass and diversity, impair water quality, and reduce forage available to native wildlife and domestic livestock. Management of free-roaming horses on Bureau of Land Management (BLM) and US Forest Service lands is determined by protections and population targets established by law, but these do not apply to other federal or Tribal Lands, where relatively little is known about the abundance and distribution of free-roaming horses. To address this information gap, we conducted the first comprehensive survey of free-roaming horses within the Navajo Nation, which is the largest Tribal Land holding in the contiguous United States and covers portions of the states of Arizona, New Mexico, and Utah. We used stratified random sampling and double-observer distance methods to produce estimates of horse abundance corrected for detection bias. During the summer of 2016, we used fixed-wing aircraft to survey 4 975 km of transects across our 67 089-km2 study area. We observed 4 290 horses distributed among 527 groups and estimated 38 223 horses lived within the study area during the survey period (standard of error [SE]: 6 052, 90% confidence interval: 29 365–47 080), with 29 394 horses in open areas (SE: 5 511, 90% confidence interval [CI]: 21 328–37 460) and 8 829 horses in forested areas (SE: 2 331, 90% CI: 5 417–12 240). Overall density of 0.570 horses/km2 (SE: 0.090, 90% CI: 0.438–0.702) was 23% higher than density of horses and burros (Equus asinus) in all BLM herd management areas (HMAs) in 2016 and exceeded by 17% the density in Nevada, the only state with an HMA of comparable size to the Navajo Nation. Our results will inform management of a free-roaming horse population that this study has revealed to be the among the largest in the United States.

The article considers the role of GPR in solving problems of soil science, as well as the accuracy of tracking soil horizons using the example of field data. The study of the current state of the issue has shown that there is significant variability in the electrophysical properties of different types of soil. In this case, the dielectric constant of the soil horizons can both increase and decrease with depth. This fact determines the need for parameterization of the soil profile in GPR studies to prevent errors. Based on a generalizing analysis of practical examples, it has been established that the error in determining individual soil horizons by a GPR is on average 2–10 cm, depending on the frequency of the GPR antenna and the structural features of the soil. Experimental and methodological work to substantiate the main conclusions was carried out to trace the soil horizons by the GPR method using the example of typical entic podzol located on the Zaonezhsky Peninsula (Republic of Karelia), the structure and composition of which were described in detail earlier. The survey was carried out by a georadar OKO-2 (Logis-Geotech, Russia) with an antenna unit with a central frequency of 400 MHz. Fieldwork on the study site was carried out along separate transects, according to the reference soil profile. A detailed analysis of the radargrams provided, first of all, tracking the base of the BC horizon. The results obtained showed that the thickness of the soil within the profile varies from 23 to 32 cm, and the average observation error was ± 3 cm. Besides, the influence on the recording of shungite shale fragments and the differentiation of moisture content in the soil horizons was revealed. The presence of shungite shale leads to the formation of diffracted waves and an increase in the amplitudes of the reflected signal, while an increase in humidity is characterized by a decrease in the velocities of the electromagnetic wave.

On cruise 76 in 2019, the R/V Akademik Mstislav Keldysh completed the Gulf of Ob–Kara Sea slope transect. Samples of bottom water and two sediment layers 1 cm thick were obtained with a multicorer. The silicon, mineral and total phosphorus, and organic nitrogen concentrations were measured in them. The magnitude of fluxes of these nutrients at the water–bottom boundary along the transect was calculated; they are all positive, i.e., directed from sediment to water. Comparison of silicon and phosphates fluxes obtained in the transect in 2019 with fluxes measured on a similar transect in 2007 showed good agreement. Silicon fluxes along the transect vary little (less than two times), including the frontal river–sea mixing zone. Mineral phosphorus fluxes have two maxima: in pure river waters and on the slope of the Kara Sea. In the area of the lens of freshened waters, phosphorus fluxes can have an alternating character, depending on season, the state of production, and destructive processes. A method is proposed for comparing fluxes of different nutrients in order to establish the nature of their variability along the transect and to identify measurement errors.

Many studies of Mediterranean ecosystems have analyzed vegetation recovery after a wildfire based on fieldwork or remote sensing; however, only a few have adopted a multi-approach assessment. The aim of this study is to determine the viability of a multi-approach using vegetation and remote sensing to observe vegetation recovery time in areas with different wildfire severity. The study area is located in a Mediterranean forest of North-east Spain. After a wildfire, low-, medium- and high- severities with an unburned control were delimited and inventoried at short-, medium- and long-terms using a 20-m transect; measurements were taken in a 1-m width. In each area, vegetal richness (S), diversity (H') and density (D) were measured using fieldwork. The differenced Normalized Burnt Ratio (dNBR) and Mean Decrease Accuracy (%incMSE) were calculated and quantified. Both methods result to be accurate in studying plant density. The dNBR index decreases over time as an effect of the disappearance of fire disturbance. Topographic and vegetation variables help explain the fire severity at very-short and short-terms, while at medium- and long-terms any explanatory power is virtually lost. Partial dependence allowed us to identify those areas that suffered higher fire severity and vegetal evolution over time., Muchos estudios de los ecosistemas mediterráneos han analizado la recuperación de la vegetación después de un incendio forestal, basándose en el trabajo de campo o en la teledetección; sin embargo, solo unos pocos han adoptado una evaluación con ambos enfoques. El objetivo de este estudio es determinar la viabilidad de un enfoque múltiple que utilice el trabajo en terreno y la teledetección para observar el tiempo de recuperación de la vegetación en zonas con diferente severidad tras un incendio forestal. La zona de estudio está situada en un bosque Mediterráneo del noreste de España. Después de un incendio forestal, se delimitaron e inventariaron las severidades bajas, medias y altas con un control sin quemar a corto, medio y largo plazo, utilizando un transecto de 20 m tomando las medidas en un ancho de 1 m. En cada zona se midió la riqueza (S), la diversidad (H') y la densidad (D) vegetal mediante trabajo de campo. Se calculó y cuantificó la diferencia entre el índice normalizado de quemado (dNBR) y la precisión de la disminución media (%incMSE). Ambos métodos resultan ser muy exhaustivos en el estudio de la densidad vegetal. El índice dNBR disminuye con el tiempo como efecto de la desaparición de la perturbación por incendio. Las variables topográficas y de vegetación ayudan a explicar la severidad del fuego a muy corto y corto plazo, mientras que a medio y largo plazo prácticamente se pierde toda capacidad explicativa. La dependencia parcial permitió identificar aquellas áreas que sufrieron una mayor severidad del fuego y la evolución vegetal a lo largo del tiempo.

The Chinese Pangolin (Manis pentadactyla) is a “Critically Endangered” insectivorous mammal. There is a lack of information on the ecology, distribution and behavior of this species in Nepal, even though community forests in the Midhills Region of Nepal are considered to be prime habitats for the species. We conducted an ecological assessment of the habitat use of this species in nine community forests covering an area of 170.69 ha in Balthali village in Kavrepalanchok district, Nepal. We divided each forest into 50 × 50 m grids and searched for Chinese Pangolin burrows along 50 m transects in each grid. We categorized burrows into two types, new and old burrows, and recorded 10 environmental variables for each burrow. We found a total of 542 burrows, including 323 old burrows and 219 new burrows. The average width and height of a burrow opening was 21.66 ± 3.94 cm (n = 542) and 22.42 ± 5.02 cm (n = 542). The total density of burrows in the study area was 3.1 ha−1, with new burrows density of 1.2 ha−1 and old burrows density of 1.8 ha−1. We found most burrows in sites with an elevation range of 1400 - 1500 m above sea level, gentle slopes, brown colored soil, high density of tree crown cover and undergrowth vegetation, southern exposure, within 150 m from a water source and less than 200 m from a human settlement. Our study has generated baseline data on the habitat use of Chinese Pangolin, which we hope will help in designing site-specific action plans for Chinese Pangolin conservation in Kavrepalanchok district, Nepal.

A first estimate of the energy potential in the tidal streams on the Faroe Shelf is derived from a barotropic numerical model with 100 m resolution. A total of 13 sites are identified as potential candidates for the harvest of the tidal stream energy with a total available mean energy flux in transects through these locations exceeding 2 GW . Of this 214–886 MW is in areas with depths larger than 40 m and peak velocities above 2.5 m s − 1 , where the lower estimate is for the mean tide and the higher estimate is with 8 constituents included in the assessment. Lowering the criteria for the peak velocities expands the potential areas significantly. A relatively large diversity of tidal phasing between the sites is identified suggesting good opportunities to construct a network of production units with a low ebb/flood variability.

Sustaining agriculture and civilizations requires protecting topsoil from erosion. Residue on the soil surface dissipates energy in raindrops, runoff, and wind, reducing detachment and transport of soil particles. Our objective was to contrast transect residue estimates based on (1) in-field evaluation of 100 evenly spaced points along a 15 m tape; (2) evaluation of imagery of the same tapes obtained at two ground sampling distances: 0.014 and 0.06 cm pixel−; and (3) a 100 point grid analysis of 50 contiguous 0.3 × 0.2 m images (0.014 cm pixel−) adjacent to the tape. Data were collected from May through early July of 2018 in row-crop fields in four Missouri counties: Audrain, Boone, Callaway, and Cooper. We used data from 60 15.2 m transects in 20 fields. Residue estimates based on field readings of the transect tape ranged from 6% to 99%. Reading images of tapes resulted in a mean decrease of 2.5 percentage points of residue. The bullseye grid point method documented tremendous variability along the transect (mean transect sd = 12.4) and a substantially lower estimate of residue cover compared to field tape readings (mean difference −10.3 percentage points). Consistent with a systematic bias to overestimate residue with the tape transect method, the difference increased with increasing residue for residue

Soil magnetism provides valuable information about soil-landscape relationships and soil evolution. However, only limited number of studies on the relationship between soil magnetic properties and soil forming factors and processes, especially in arid and semi-arid regions, are available. The aim of this study was to determine vertical distribution of soil magnetic susceptibility and selected pedoenvironmental parameters and to interpret them in terms of the soil evolution. Eight representative soil profiles were selected on different geomorphic surfaces including alluvial fan, piedmont plain and flood plain. Soil samples were collected from different diagnostic horizons and analyzed for routine physico-chemical properties, different iron forms and magnetic susceptibility. The average values of magnetic susceptibility (χlf) and relative frequency-dependent magnetic susceptibility in the studied soils are 53.1 × 10−8 m3 kg−1 and 2.62%, respectively, with the latter ranging from 0 to 6.88%. The negative significant correlation (with correlation coefficient R = −0.48 and statistical significance p < 0.01) between soil evolution index (ratio of acid oxalate soluble and free Fe oxides — Feo/Fed) and χlf values indicated that χlf increased with soil evolution. A positive significant correlation between χlf and Fed (and Fed — Feo) values, and a negative significant correlation between χlf and CaCO3 values were observed. The vertical distribution of χlf along the studied profiles showed different patterns (uniform, non-uniform, ascending and descending) with depth. Overall, the results indicated that the χlf distribution along the soil profiles was affected by topography, distribution of different iron forms, soil evolution, and weathering rate in different soil layers.

Most cities around the world, including Abuja Municipal are being faced with an undesirable increased in air temperature. This is indicated by an increase in non-porous, non-evaporating, highly thermal conductive surfaces such as concrete and asphalt, which has replaced the vegetation biomass resulting to the formation of urban heat island. There is an increasing need for studies on the changing trend of UHI intensity in cities. This research employed geospatial techniques to determine the urban heat island intensity in Abuja Municipal. Temperature characteristics over twenty selected rural and urban locations in Abuja, FCT were derived from the satellite image of 1986, 2001 and 2016 using the “Extract Multi Values to Point” tool in ArcGIS 10.4. These transects pass over various landscapes with different environmental settings, with the aim of understanding the factors shaping the city’s thermal landscape. The intervals of +15 years were deliberately chosen to ensure uniformity between the datasets. The results of this analysis indicate that UHII has been increasing, from 1986-2016, giving credence to the results of the spatial and temporal analysis of the land surface temperature, indicating the development phases had hit full stride. The different periods under study (1986, 2001 and 2016) were also tested using the student “t” test to determine the significant difference in the land surface temperature values to acknowledge the presence of a substantial urban heat island within the study area. The result reveals the calculated “t” values of 2.50, 3.34, 5.57 of 1986, 2001 and 2016 respectively, are higher than the critical value of “t” at 0.05 being 1.73, thus, revealing the temperature differences between the urban and rural stations to be highly significant, indicating the presence of a strong urban heat island. Also, a slide difference in the temperature was observed with the Rubuchi and Karmajiji rural areas having higher temperature readings than their counterparts in the urban areas, Asokoro and Garki, with readings of −0.4°C and −1.3°C. Since effectiveness of a surface in reducing daytime urban air temperatures depends strongly on the amount of heating avoided, the study recommends preserving and replicating greenery, light coloured facades as measures to reduce the effects of urban heat island.

Anthropogenic cadmium (Cd) in alpine soils is mainly from long-range atmospheric transport. Because of the high toxicity and mobility, whether the accumulation of Cd in the soils threats to ecosystem safety remains unclear. The fractions of soil Cd along three altitudinal transects on Gongga Mountain were analyzed to decipher the drivers on its mobility, and its contamination and health risk were assessed. The concentrations of Cd in the organic (O) and mineral (A) horizons were significantly higher on the eastern and southern transects than the western transect. The Cd fractions in the two horizons dominated by acid-soluble and reducible Cd. Soil organic matter and pH modulated the mobilization of soil Cd. Cadmium reached a moderate contamination level on the eastern and southern transects, but no or slight contamination on the western transect. The soil Cd had a low non-carcinogenic risk and no carcinogenic risk despite of adults or children.

Urban Heat Island (UHI) has the potential to directly influence the health and welfare of urban residents. The study employed a traditional method called “paired measurement program” to analyze the effects of four land use/land- cover patterns on intra-urban air temperature variations in the Douala Metropolis, Cameroon under different atmospheric conditions. This study also investigated the possible adaptation measures employed by the inhabitants to combat the urban heat island effects. The result revealed a variation in the temperature of the selected transects. There was a mix of cool and heat islands by day, especially during rainy seasons. The daytime variations were strongly correlated to the amount of tree shading. It was also observed that the temperature gradient was formed at the Central Business District (CBD) and progressively lowered to the suburbs. The thermal comfort classification for the area ranges between 25.4°C and 27°C, which is a class where over 50% of the population feels stressed; and the range of 32°C and above, where most of the population suffers discomfort. In order to investigate the possible adaptation measures employed by the inhabitants of Douala, two hundred and fifty questionnaires were distributed and analyzed using descriptive statistics. The result revealed that the inhabitants use various coping strategies in order to adapt to UHI effects. The strategies identified include; stay indoors, drink plenty of water, wear light clothing, go to an A/C location, take a cool shower, avoid outdoors, and wear a hat or cover head. The widely used coping strategy identified is drinking plenty of water. The expensive nature of A/C makes it the least used coping strategy.

Riparian zones are valuable ecosystems. They act as the ecological engineers that improve river health by delivering a range of ecosystem functions. They play a significant role in river health and provide various ecosystem goods and services for human well-being. Currently, riparian areas are under threat due to intensive human activities such as agriculture and urbanization, which alter riparian ecosystem structure and composition. The main objective of this study was to determine the effect of adjacent land use on the structure and diversity of the riparian vegetation in the Njoro and Kamweti Rivers. Along each river, three sampling sites were selected within the major land use categories which were; forest, agricultural and built-up areas. At each site, three 70 m long transects were established perpendicular to the river. The three plots were systematically established, separated by a 5 m distance along each transect. Forest canopy cover was estimated in percentage. Njoro River riparian vegetation recorded a total of 145 plant species from 40 families where trees and shrubs were dominant in the forest area, and herbs dominated the agricultural and built-up areas. In Kamweti River riparian area, a total of 110 species from 45 families were encountered, in which trees dominated the forest area. A similar trend to the Njoro River was observed, in which herbs were dominant in the agricultural and built-up areas. In Njoro River, the Shannon diversity (H’) values ranged between 2.73 and 3.08 whereas Kamweti River riparian area values ranged from 2.59 to 3.40. At the level of P ≤ 0.05, T-Test revealed that there was no significant difference in plant abundance and diversity between the two rivers, with F = 0.53; P = 0.51 and F = 2.71; P = 0.17. Human-centered disturbances along the Njoro and Kamweti River riparian areas have affected the riparian vegetation as shown by the decrease in plant species diversities, and the change in vegetation composition and distribution across the land uses. Due to the present and probable future scenarios of the changes in riparian vegetation observed, there is a pressing need for an integrated approach for the management of riparian zones based on various components such as riparian condition assessment, policy framework, stakeholder’s participation, management practices, legislation, and awareness.

In this article we present results from transect walks and participatory mapping done in Burkina Faso. Since the Sahelian drought of the 1970s, researchers have continued to depict the Sahelian region of West Africa as an environment experiencing severe degradation; a narrative that persists over time. Recently, however, analyses of satellite imagery have identified remarkable patterns of greening across the Sahel. The causes of this greening are hotly debated. Through this project we aim to inform these debates with on-the-ground perceptions of local farmers and pastoralists. The transect walk method is a community-based process that collects information on the land-use/land-cover (LULC) features across villages. Transects help triangulate data by combining high-resolution satellite imagery, firsthand observations, and local experiences of ecological processes. We describe the methodology behind transects and discuss how they contextualize an otherwise removed process of environmental analysis. We also describe the challenges that arise throughout the fieldwork process.

The appraisal of tree stand structure on parklands is crucial for sustainable agroforestry management decisions, particularly in the drylands of Nigeria. An assessment of tree species distribution in farm plots across the three driest Agroecological zones (AEZ) within Northern Nigeria was performed to determine diversity and abundance in a changing climate. The AEZ include Sudan savannah (SS), Northern Guinea savannah (NGS) and Southern Guinea savannah (SGS). In each AEZ, 3 transects were laid per village and a total of 4 sample plots were located along each transect. Tree bole diameter of all the sampled woody perennials with dbh ≥ 10 cm was measured and identified to species level. The measurement and computation include basal area, species relative density and dominance as well as the important value index (IVI). Results showed that across the AEZs, Parkia biglobosa trees had the highest IVI but reduces from the driest zone, SS (50.25%) through the transitional zone, NGS (38.45%) to the wettest AEZ, the SGS (35.43%). The lowest IVI recorded were in Gliricidia sepium (0.62%), Psidium guajava (2.89%) and Eucalyptus camaldulensis (1.83) in the SGS, NGS and SGS respectively. Parkia biglobosa and Mangifera indica dominated the landscapes and are classified as the landscapes’ habitat generalists. Despite the low organic matter content, Sudan savannah had more diverse species on its farm landscapes than the two other AEZ but with less tree popuplation density. The potential contribution of agroforestry parkland trees to agrobiodiversity in reducing drought and improving soil fertility is essential for sustainable agricultural productivity and landscape restoration.

Due to unabated anthropogenic exploitations, mangrove forests globally are constantly under pressure and degradation, which may result in the reduction of ecosystem functioning and biodiversity. Molluscan fauna, which is one of the main macroinvertebrates that play a major ecological role in nutrient dynamics in mangroves, are sensitive to the changes in their habitat. This survey aims to assess the impact of anthropogenic activities on the diversity of molluscs’ communities in the mangrove forest. Anthropogenic disturbances within 20 sampling sites were valued at six mangrove stands and patched scoring the degree of influence according to vegetation, structure, waste and trampling. Molluscs were caught by hand and counted within 1 × 1 m2 plots placed at three points distant of 50 m established using a straight line transect of 100 m. Upon the 20 sites investigated, five were slightly disturbed, eight moderately disturbed and seven sites were highly disturbed. The mean abundance of molluscs decreased from slightly disturbed areas (172.25 ± 73.09 Ind·m−2) to highly disturbed areas (100.57 ± 62.84 Ind·m−2). Highly disturbed areas have shown lower species richness (R = 1.09 ± 0.15) and diversity (H’ = 2.30 ± 0.31). Human activities in the mangrove forest could particularly have effects on the diversity of molluscs, however, feature potential conservation measures have to be in harmony with the needs of the local population.

This study investigates the bathymetry of three major lakes and the water quality of nine lakes at Ramaroshan Lake Complex Area (RLCA), Far-Western Nepal. Lakes were surveyed based on line transects using Echosounder (depth measuring gauge) and GPS to collect the data for bathymetry. Water samples were collected from 43 sites of nine lakes, considering the land use patterns, anthropogenic activities, inlets, and outlets. Twenty physico-chemical parameters were analyzed to know the water characteristics and pollution level. The bathymetry map showed that Jingale is the deepest lake (44 m), followed by Batula (15 m) and Mathillo Dhaune (9.5 m). There was no significant spatial variability in the concentration of physicochemical parameters among the sampling sites. The mean concentrations of cations and anions were in the order of Ca2+> Mg2+> Na+> K+, and HCO3-> Cl-> SO42-> PO42-> NO3-, respectively. Principal component analysis (PCA) and cluster analysis (CA) techniques were applied to assess the influence of pollution levels and their controlling mechanism. PCA showed 79.89 % of the cumulative variance with > 1.26 Eigenvalue. Similarly, CA showed that Jingale Lake (in cluster 2) sites were less polluted than other sampling sites. Piper diagram concluded that there was a dominance of mixed water type belonging to Ca-Mg-Cl compared to Ca-HCO3. Furthermore, the Water Quality Index (WQI) value of the lakes in the study area was 27 indicating good water quality (slightly polluted).