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Neotropical seasonal dry forest (NSDF) is one of the most threatened ecosystems under global climate change (GCC) predictions, with likely species losses and uneven modification of diversity patterns all through its distribution. Nonetheless, few studies have evaluated the GCC impacts on the diversity patterns of NSDF plants. The lack of continental-scale approaches restricts our understanding of GCC consequences in the high beta-diverse NSDF. We showed some potential impacts of GCC on the distributions of over 1000 species of the NSDF, species richness patterns, and species composition of assemblages (beta diversity). We focus on five representative plant families that are abundant, dominant, and have a high endemism rate within the NSDF. These families were Cactaceae, Capparaceae, Fabaceae, Malvaceae, and Zygophyllacea. We reconstructed potential species distributions in the present and future scenarios (2040–2080) considering an intermediate Shared Socio-economic Pathway scenario and two dispersal ability assumptions on the taxa. We correlated climate-induced changes in the species distribution ranges with drought tolerance. We found that, even under a favorable dispersal scenario, species distribution and richness showed significant declines in the future across sites where temperatures are predicted to increase in the future. In Fabaceae, we observed a negative correlation between drought tolerance and changes in species distribution ranges in the future. Our results suggested biotic homogenization across the NSDF, but biotic heterogenization is the likely outcome at the continental scale under dispersal limitations. This information is critical for further planning of conservation actions as it can help to assess the current and future value of NSDF-protected areas and define new areas worth protecting.

There is extensive knowledge about the visual system and the implications of the evolution of trichromatic color vision in howler monkeys (genus Alouatta) related to food selection; however, information about the other sensory systems is limited. In this study we assessed the use of touch, sniffing, and taste in fruit evaluation by 20 adult mantled howler monkeys (Alouatta palliata) on Agaltepec Island, Mexico. During 9 months of observation, we recorded the frequency that each monkey used touch, sniffing, and taste in evaluating cryptic fruits (that remain green during their ripening process) and conspicuous fruits (with red, yellow, or orange colorations when they are ripe). Sucrose content and hardness measurements were made to establish the degree of ripeness of the fruits. We found that mantled howler monkeys used long behavioral sequences during conspicuous fruit investigations. Sniffing was used infrequently, but significantly more often in the evaluation of conspicuous-ripe and unripe fruits compared to cryptic-ripe and unripe fruits. During the evaluation of cryptic-ripe fruits, mantled howler monkeys increased the use of touch compared to evaluating cryptic-unripe fruits. We did not find significant differences in the use of taste in the evaluation of cryptic and conspicuous fruits (both ripe and unripe). Our results suggest that the non-visual senses play an essential role in fruit selection by howler monkeys, with differences in the behavioral strategy according to the fruit's conspicuity. The multimodal signals of ripe and unripe fruits allow the howler monkeys to assess their palatability before being consumed.

Made available in DSpace on 2022-05-01T12:09:42Z (GMT). No. of bitstreams: 0 Previous issue date: 2022-01-01 Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Top-down control by large herbivores is a well-known driver of plant diversity structure and productivity. Yet, for forest ecosystems the sign and magnitude of herbivore control across resource gradients is not well understood. We conducted a series of replicated large herbivore exclusion experiments in defaunated and non-defaunated Atlantic forests of Brazil to evaluate the effects of large herbivores on tropical plant communities. We hypothesized that the top-down impact of large herbivores on seedling recruitment, species richness, diversity and productivity would change across a natural gradient in the density of a key plant resource, the palm Euterpe edulis, which is thought to act as a foundation species. We found both positive (agonistic) and negative (antagonistic) spatially-structured effects of large herbivores on plant communities driven by an interaction between large herbivores and palm density on non-defaunated sites, but not on defaunated sites. Indeed, through its interaction with large herbivores, palm trees were able to regulate the spatial structure of seedling communities. In the non-defaunated forest, the negative impact of large herbivores on plant recruitment and species richness decreased substantially as palms became more abundant and canopy cover decreased. Furthermore, large herbivores caused a 185% increase but a 194% decrease in aboveground seedling productivity in areas of high and low palm density, respectively. In contrast, in the defaunated forest we did not find any consistent large herbivore impacts on plant recruitment or species richness across the gradient of palm density, and herbivore activity consistently had negative effects on seedling productivity. Analyses using camera trap data indicate that white-lipped peccaries (Tayassu peccari) played a key role in modulating recruitment and seedling productivity, while tapirs (Tapirus terrestris) contributed significantly to an increase in plant diversity, hence playing a functionally complementary role. Our results demonstrate that a key interaction between large forest-dwelling tropical herbivores and their palm resource results in landscape-scale modulation of plant communities through positive and negative spatially-structured feedbacks, and support the view that palms might act as foundation species in tropical forests. Anthropogenic pressures posed by defaunation and illegal palm harvesting in the Neotropics might lead to the functional loss of this interaction and the collapse of the spatial structure along palm density gradients, with cascading effects on the dynamics and productivity of tropical forests. Instituto de Biociências Departamento de Biodiversidade Universidade Estadual Paulista (UNESP), SP Department of Aquatic Ecology Netherlands Institute of Ecology, P.O. Box 50 Instituto de Ecología A.C. Red de Biología Evolutiva, Carretera Antigua a Coatepec 351, El Haya Instituto Neotropical CP 19009, PR Department of Biology University of Miami Instituto de Biociências Departamento de Biodiversidade Universidade Estadual Paulista (UNESP), SP FAPESP: 2007/03392-6 FAPESP: 2014/01986-0

How ecological interactions vary across spatial and environmental gradients has received increasing attention in recent years, contributing to the revelation of the drivers of biodiversity. However, it is still unclear how the structure of ecological interactions varies across large spatial scales and which climatic factors are associated with such variation. Here, specific predictions were derived and tested to evaluate how climatic factors and latitude are associated with the structure of bat-fruit interaction networks throughout the Neotropical region. For each study site (n = 44 sites, encompassing 48 degrees of latitude), four metrics were used to describe the network structure (i.e., network size, connectance, modularity, and nestedness). In general, an increase in modularity and a decrease in connectance and nestedness was observed towards lower latitudes and in sites with lower precipitation seasonality. Moreover, plant richness within networks increased towards lower latitudes and in sites with higher annual precipitation, whereas bat richness increased at lower latitudes and in sites with lower precipitation seasonality. These findings partially confirm both energy and seasonality hypotheses and suggest that fruit-bearing plant richness and fruit availability associated with annual precipitation and precipitation seasonality can be important correlates shaping the structure of ecological interactions throughout the Neotropical region.

Habitat specialists are particularly vulnerable to extinction when habitat conditions are altered. Information on the habitat use of such species is thus important because it provides insight into factors that influence distribution and abundance, which is crucial for conservation. Here, we aimed to identify factors that influence the patterns of presence and abundance of the Endangered volcano rabbit Romerolagus diazi, a rare leporid with a patchy distribution. Through exhaustive sampling of its range in the Sierra Chichinautzin and Sierra Nevada volcanic fields, Mexico, and using generalized linear models, we found that the probability of patch occupancy was higher where bunchgrass cover exceeded 75%, rock cover exceeded 5%, no cattle grazing was observed and human settlements were at least 7 km away. Patches with greater relative abundance were those with similar characteristics, but located at elevations > 3,600 m, and with rock cover < 15%. Cattle grazing was identified as a major threat to local populations of the volcano rabbit, particularly in the Sierra Chichinautzin. Because of the significance of bunchgrasses for this species, the protection of the mountain grasslands is required in both volcanic fields.

Background: Although pollen morphology has always been an important tool in plant systematics, the possibility of distinguishing between related taxa is still debated. A difficult case is the cycads, where their morphology and small size is very similar. Pollen morphology has been important in plant systematics and determination at the species level is possible depending on the group. Controversial cases are the cycads, where their small pollen and smooth sculpture when observed under light microscopy present few useful characters for separation at the species level. Question: Will cycad pollen morphometry be useful to distinguish taxa? Study species: 15 species within the genera Ceratozamia, Dioon and Zamia were investigated with five species of each genus. Methods: Pollen was obtained from both live specimens from the Clavijero Botanic Garden of the Instituto de Ecología, A.C., as well as herbarium specimens. Acetolyzed pollen was used for descriptions and morphometry, and non-acetolyzed pollen for SEM images. Results: The thickness of the exine and pollen sculpture of Dioon differed from that of Ceratozamia and Zamia thus allowing its identification. The pollen morphology of Ceratozamia and Zamia is very similar and therefore difficult to distinguish between species. Conclusions: The thicker exine of Dioon allows its pollen to be distinguished from the other two genera. Morphometric methods must be applied to distinguish pollen between species of Ceratozamia and Zamia.

Nestedness is widely observed in natural metacommunities, but its underlying mechanisms are still poorly understood. The distribution of habitats in the landscape and differences in dispersal rates of distinct insect taxa can determine the nestedness of the metacommunity. Here, we evaluated how species habitat specialization contributes to metacommunity nestedness in insect groups with different dispersal capacities in a mountaintop landscape in south-eastern Brazil. We sampled ants, butterflies and dung beetles in two main habitats, naturally fragmented forest islands and a grassland matrix (campo rupestre), during both dry and rainy seasons. We classified species according to their degree of habitat specialization (generalists or specialists) based on the relative frequencies and abundances between these two contrasting habitats. Forty of 211 species were classified as habitat specialists, seven as habitat generalists. It was not possible to classify the remaining species. The metacommunity was nested in structure, with habitat generalist species contributing more to nestedness than habitat specialists. Nonetheless, habitat distribution in the landscape did not affect the nestedness of the metacommunity. Our findings reveal that species sorting (for habitat specialists) and mass effects (for habitat generalists) are concurrent processes in the mountaintop forest–grassland mosaic. Our study helps to advance our understanding of the differences in the distribution of generalist and specialist species in a tropical mountaintop landscape and improves our ability to predict and manage the increasingly adverse effects of changes in land use and climate on metacommunities and ecosystem functions.

Butterfly species often synchronize their life cycles to seasonality, as increasing temperature and rainfall act as clues of resource availability. Nevertheless, human-made forest edges cause major changes in the microclimatic conditions that may jeopardize the synchrony between insects and favorable conditions for their emergence, conversely to natural ecotones. Here, the distribution of fruit-feeding butterflies was studied over one year in three different habitats (forest interior, forest ecotone, forest edge) to examine if: (i) species richness and abundance varies among habitats and subfamily/tribe over the year; (ii) temperature and rainfall affect the abundance and temporal distribution of species richness; and (iii) the beta diversity and its monthly partition are similar among habitats. The present study was carried out in the Rio Doce State Park, Brazil, a 36,000 ha forest reserve. In total, 11,594 individuals representing 98 butterfly species were collected. The butterflies presented a nonuniform distribution of abundance in all habitats, with greater abundance, richness and species diversity during the wet season. Butterfly abundance increased with high temperatures in all habitats. The contribution of species turnover and nestedness varied over the months, overlapping with the seasonal changes. Understanding how rates of species turnover vary over time in different habitats can help explain the vulnerability of species to environmental changes, allowing comparison of assemblages over time.

Coastal erosion is a natural process, whose intensity and occurrence have increased due to natural and anthropogenic factors. To protect the coasts, the use of hard infrastructure is a widespread practice that can be effective, mostly at a local scale. However, recent evidence also shows that downstream erosion can be accelerated in adjacent zones. Because of this, natural barriers such as coastal dunes and their plant cover have gained attention, but there is a general lack of information about the role that different species (and combinations of species) play in coastal protection. The aim of this study was to explore if the functional richness of plant species helps reduce wave erosion on embryo coastal dunes. In a wave flume, we set up a 1:1 scale artificial dune covered with different combinations of plant species (Ipomoeae pes-caprae, Sesuvium portulacastrum, and Sporobolus virginicus) and exposed it to simulated “storm waves”. We found that erosion was reduced in dunes covered by plants, but such protection was species-specific and the effectiveness of protection varied over time. Ipomoea was the most effective specie for protection. Differences between species and combinations of species were associated with their physical attributes such as growth form and plant architecture. Although we found that there are species that offer little or no protection from hydrodynamic forces, they may still be important for coastal protection through their ability to build embryo dunes through eolian processes. Indeed, nature-based coastal protection is likely to be an effective alternative to engineered solutions at many sites, but the protection provided is species-specific.

Arbuscular-mycorrhizal (AM) fungi affect individual plants and the diversity of plant communities. AM interactions are sensitive to the physical properties and nutrient availability of soil. In contrast to the comprehensive knowledge of AM fungi's diversity in many mainland ecosystems, there is a considerable gap in the understanding of the communities of AM fungi on oceanic islands. We surveyed the community of AM fungi in the wet forests of Socorro Island (above an elevation of 600 m). Because of the influence of northerly winds, the island's windward side is presumably more humid than the leeward side, although, above 600 m elevation, fog is common on both sides of the island. Forty-six percent of AM fungi species occurred on only one side of the island. Also, four species common to both sides showed marked differences in abundance, and the abundances of the AM fungi correlated with the abundance of plant life-forms. Beta diversity was similar in the southern and northern forests. However, the contribution of nestedness to beta diversity was three-fold greater in the southern forests than in the northern forests. Root colonization by AM fungi was higher in the northern forests, where phosphorous content was also high. The prevalence of nestedness in beta diversity and the lower mycorrhizal colonization of roots in the southern forests could reflect known perturbations in the southern forests.

In this chapter we examine how the current patterns of anthropogenic impact on biodiversity are engendering a pulse of animal life loss – defaunation – with emphasis on the decline and massive extinction of populations of mammals. Given that many species of this group operate as herbivores and, due to their local abundance in some regions and ecosystems of the world, have the potential to affect plant performance and survival, their decline or outright local extinction significantly disrupt the patterns of mammalian herbivory, in some cases causing the local extinction of this critical interaction affecting the structure and composition of communities and ecosystems. Our chapter, addressing a different group of herbivores than that examined in the other chapters of the volume, as well as addressing species interactions in defaunated systems, includes an analysis of mammalian herbivores in the context of insect herbivores, a historical account of the development and evolution of defaunation science, and a discussion of the methods available to document defaunation. (We hope that the inclusion of such contextual analysis and historical and methodological accounts will be of some use for the readers who are not familiar with this field.) This is followed by a brief expose of the disruption of mammalian herbivory and its consequences at the community and ecosystem levels.

Functional diversity is a key concept to understand how plants respond to selective pressures and how they influence ecosystem processes. Although there is empirical information about the variation of the functional traits of plants in environmental gradients, their use to understand their biotic interactions has been little explored. Currently, novel proposals for the analysis of the plant-herbivore interactions integrating the study of functional traits have been put forward. This approach can help to generate projection models about the effect of herbivory on ecosystem processes under different environmental scenarios. In this chapter we present a review of the concept of functional diversity in plants and their application in herbivory studies, through the use of syndromes and their ecological and evolutionary implications. In addition, we propose some lines of research that can help build a comprehensive framework to relate the functional responses of plants and defense theories, as well as determine the biotic and abiotic factors that regulate herbivory and its impacts on ecosystem processes.

Organic agriculture is increasingly used as an alternative to conventional agriculture due to its positive impact on the health of ecosystems and agroecosystems. However, the outcome of organic agriculture in terms of the production of various crops remains uncertain due to the influence of many variables, rising questions about its advantages over conventional agriculture. This study assessed the impacts of organic agricultural system on arbuscular mycorrhizal (AM) fungi diversity in soil and green tomato (Physalis ixocarpa Brot. ex Horn) crop production. A field experiment was conducted using a random block design with five repetitions of the following treatments: a) Control (no fertilization, NF); b) Vermicompost use (OTV); c) OTV with vermicompost leaching (OTH); and d) Inorganic fertilization (CST). Throughout the crop cycle, soil samples were analyzed chemically, the relative growth rate (RGR) of the plants was measured, and the colonization and diversity of AM fungi were quantified in roots and soil; finally, above-ground, root biomass, and fruit production were measured. Organic fertilization (OTV, OTH) increased (p 0.05). It is concluded that organic agriculture management is essential to promote a greater AM fungi diversity and fungi root colonization. Plant-AM fungi interaction increases growth rates and it allows a similar tomato production compared with conventional agriculture.

Riparian systems have been included as a key component in ecosystem management because of their role in buffering the impact of land-use activities on fluvial systems. Riparian knowledge can be enhanced with a typology that reflects the multiple relationships occurring throughout the landscape. We propose a hierarchical procedure based on biophysical aspects for building local to regional typologies for guiding research and management, using the Cuitzmala River Basin as a case study. The variables involved were obtained from geospatial databases, water balances, and topographic profiles. The levels and variables are context (altitude, geoform [mountains/hills/plains], and runoff coefficient), structure (stream order, longitudinal slope, hydroperiod, and segment length), and microstructure (lateral slope, bankfull width, and length-to-width ratio). We consider humidity and functional gradient along the basin to identify groups of streams and fluvial networks. Inside each network, we described struc...

Background. In arid environments plants face aridity and herbivory, therefore it has been proposed that both are convergent selective forces. However the drivers of insect herbivory in these ecosystems remain poorly understood. Question. Does insect herbivory vary in two plant associations subject to different levels of aridity? To what extent differences in herbivory are determined either by foliar traits, or predation by birds? Study species. Citharexylum tetramerum, Viguiera pinnatilobata, and Solanum tridynamum. Study site. We compared two-plant associations: the mezquital with a closed canopy and wettest conditions and the tetechera a dry place with an open canopy at the Zapotitlán Valley, México. Methods. We evaluated leaf traits (N, C, water content, leaf strength and trichomes), herbivore insects abundance and the effects on herbivory when some predators are excluded. Results. Herbivory was higher in the drier site (tetechera) than in the more humid one (mezquital) in one year but not in the second one. In both plant associations herbivory increased when predators of herbivores were excluded. Plants in mezquital had more water and nitrogen content than plants in tetechera. The later had higher carbon concentration and carbon:nitrogen ratio, leaf strength and density of trichomes. Abundance of herbivore insects and insect predation were higher in the most arid site. Conclusions. Our results show that insect herbivory increases in the most arid site and that predation by birds plays a role as a driver of herbivory, while resistance to aridity seems to be the main driver of leaf structural characteristics.

Recovery planning is an important global conservation strategy for threatened species. Despite the existence of international standards for recovery planning, deficiencies and anomalies have been detected in several jurisdictions. This study evaluated the quality of recovery plans based on internal consistency as a measurement of coherent planning. We analyzed 236 plans developed by the Australian Government (1992–2006) using three criteria: (a) consistency of gaps in scientific information with prescribed research actions, (b) consistency of identified threats with prescribed threat abatement actions and (c) consistency of established plan objectives with performance evaluation criteria. These criteria were aggregated in order to calculate an index of plan consistency. We tested two hypotheses: (1) plans made for single-species would exhibit better consistency than those for multi-species; and (2) plans made under the amended legislation of the Environment Protection and Biodiversity Conservation Act (EPBCA) would exhibit better consistency than those under the rescinded Endangered Species Protection Act (ESPA). In total, over 85% of the plans consistently addressed the research needs. However, the plans addressed threats poorly (66% of all plans exhibited inconsistencies). Moreover, nearly 50% of all plans established inconsistent performance evaluation criteria. Under the ESPA, single- and multi-species plans exhibited equal consistency, but under the EPBCA, single-species plans clearly exhibited higher consistency. Our major contribution is the assessment of attributes of consistency that are paramount for effective recovery planning. Evaluation of these attributes may provide knowledge of universal utility and relevance to other biodiversity conservation efforts.

Mexico is one of the most biodiverse countries in the world, with an important proportion of endemism mainly because of the convergence of the Nearctic and Neotropical biogeographic regions, which generate great diversity and species turnover at different spatial scales. However, most of our knowledge of the Mexican ant biota is limited to a few well-studied taxa, and we lack a comprehensive synthesis of ant biodiversity information. For instance, most of the knowledge available in the literature on Mexican ant fauna refers only to species lists by states, or is focused on only a few regions of the country, which prevents the study of several basic and applied aspects of ants, from diversity and distribution to conservation. Our aims in this data paper are therefore (1) to compile all the information available regarding ants across the Mexican territory, and (2) to identify major patterns in the gathered data set and geographic gaps in order to direct future sampling efforts. All records were obtained from raw data, including both unpublished and published information. After exhaustive filtering and updating information and synonyms, we compiled a total of 21,731 records for 887 ant species distributed throughout Mexico from 1894 to 2018. These records were concentrated mainly in the states of Chiapas (n = 6,902, 32.76%) and Veracruz de Ignacio de la Llave (n = 4,329, 19.92%), which together comprise half the records. The subfamily with the highest number of records was Myrmicinae (n = 10,458 records, 48.12%), followed by Formicinae (n = 3,284, 15.11%) and Ponerinae (n = 1,914, 8.8%). Most ant records were collected in the Neotropical region of the country (n = 12,646, 58.19%), followed by the Mexican transition zone (n = 5,237, 24.09%) and the Nearctic region (n = 3,848, 17.72%). Native species comprised 95.46% of the records (n = 20,745). To the best of our knowledge, this is the most complete data set available to date in the literature for the country. We hope that this compilation will encourage researchers to explore different aspects of the population and community research of ants at different spatial scales, and to aid in the establishment of conservation policies and actions. There are no copyright restrictions. Please cite this data paper when using its data for publications or teaching events.

International audience; The positive effect of earthworms on soil processes and plant growth has been extensively documented. The capacity of earthworms to decompose organic matter has been attributed to the microbial communities that inhabit their digestive track or the structures they build, which in turn contribute to make up the drilosphere, a hotspot for microbial activity. However, how earthworms modify the structure of soil microbial communities and how these changes affect soil microbial processes is still unclear. Do earthworms reduce microbial abundance and activity because they feed on microorganisms or do they select and stimulate specific microbial groups? We hypothesise that “the effect of earthworms on nutrient cycling and plant growth is not only a direct effect but is mainly mediated indirectly, via modifications of the microbial community.” The objective of this review is to synthesize the existing literature concerning the influence of earthworms on the structure and function of soil microbial communities, as well as to understand how earthworm-induced changes in the soil microbiota would in turn impact soil processes, particularly those occurring in the rhizosphere and involved in plant growth and health. Recent reports have shown that specific bacterial groups consistently increase in soils where earthworms are present, regardless of the earthworm functional group. The extent of this increase seems to be dependent upon the type of substrate under study. Our synthesis also reveals that endogeic and anecic earthworms regularly induce an increase in soil nutrients, whilst this positive effect is not as evident in the presence of epigeic earthworms. The effect of earthworms on nutrient cycling has been further investigated with microbial functional genes, although existing reports largely focus on nitrogen cycling. Earthworms seem to enhance denitrification, most likely through the increase in organic compounds due to organic matter decomposition. By enhancing soil nutrient availability, earthworms indirectly promote plant growth, which has also been attributed to the induction of signal molecules. However, no experiment to date has been able to prove a direct causal relationship between specific signal molecules, earthworms and plant growth promotion. Finally, we propose a framework for earthworm-microbiota interactions and recommend further research.

A set of species, not linked by close ancestry, with similar functional responses to selective pressures, is known as a functional group or response syndrome. Some studies have investigated antiherbivore plant defenses in the context of defense syndromes, with contrasting results. We analyze how the assembly of leaf-functional traits and wood density can explain insect herbivory in 69 woody species in a tropical rain forest in southern Mexico. In addition, we used a phylogenetic hypothesis to address whether the observed syndromes were at least in part driven by ancestry. Three functional groups of woody plants were detected and related to 1) low nutritional quality, 2) resistance, and 3) tolerance to herbivory. Herbivory tolerant species presented the highest damage by herbivores, which is concordant with theoretical expectations and other empirical observations. In contrast, herbivory in the defensive resistance and low nutrition syndromes were 35 % and 55 % lower than in herbivory tolerant species, respectively. Taxa in the defensive resistance syndrome were significantly clustered based on the net relatedness index (NRI) and the nearest taxon index (NTI). In contrast, in the other two syndromes, the NRI showed a random structure but opposed deviations from random expectations in the NTI. Taxa in the low nutritional quality syndrome were over-dispersed in the phylogeny, while tolerant species appeared clustered. This evidence suggests that the low nutritional quality syndrome may represent the ancestral antiherbivore defense of woody plants in the tropical rain forest. In contrast, the tolerance and defensive resistance syndromes included clades of recent diversification.

Fil: Villada Bedoya, Sebastián. Universidad de Caldas. Grupo de Investigación en Biodiversidad y Recursos Naturales; Colombia. Fil: Cultid Medina, Carlos Andrés. Universidad de Caldas. Grupo de Investigación en Biodiversidad y Recursos Naturales; Colombia. Fil: Cultid Medina, Carlos Andrés. Universidad del Valle. Grupo de Investigación en Biología, Ecología y Manejo de Hormigas; Colombia. Fil: Cultid Medina, Carlos Andrés. Wildlife Conservation Society; Colombia. Fil: Cultid Medina, Carlos Andrés. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Fil: Escobar, Federico. Consejo Nacional de Ciencia y Tecnología. Instituto de Ecología A. C.; México. Fil: Guevara, Roger. Consejo Nacional de Ciencia y Tecnología. Instituto de Ecología A. C.; México. Fil: Zurita, Gustavo Andrés. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico (Nordeste). Instituto de Biología Subtropical; Argentina. Fil: Zurita, Gustavo Andrés. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico (Nordeste). Instituto de Biología Subtropical. Nodo Puerto Iguazú; Argentina. Fil: Zurita, Gustavo Andrés. Universidad Nacional del Nordeste. Instituto de Biología Subtropical; Argentina. Fil: Zurita, Gustavo Andrés. Universidad Nacional del Nordeste. Instituto de Biología Subtropical. Nodo Puerto Iguazú; Argentina. In landscapes dominated by agriculture, conspicuous edges often occur between landscape elements. However, there is disagreement about the existence and intensity of edge effects, and information about species‐specific responses remains scarce. Studying such edge effects can help elucidate functional landscape connectivity and contribute to agricultural management. We, therefore, assessed whether sun‐grown coffee represents a barrier to dung beetles in an Andean agricultural landscape. We also evaluated whether the response to edge effects differs among species. We found that diversity and abundance tend to decrease from forest to sun‐grown coffee and that there are sharp increases in species turnover at the forest–coffee edge. We detected several different species‐specific responses to the forest–coffee edge, suggesting differences in the mobility of the species (or spillover) and in the degree of penetration that takes place from forest patches to sun‐grown coffee plantations. This study demonstrates that the sun‐grown coffee matrix constitutes a barrier to forest species and suggests that the forest–coffee ecotone is more complex than expected. Our results support the notion that the conservation value of native forest patches in agricultural scenarios depends on the functional connectivity of forest units in the landscape to maximize the opportunities species have to disperse through the agricultural matrix.

The study of morphological variation in heterogeneous environments provides evidence for understanding processes that determine the differences between species and interspecific adaptive strategies. In 14 populations of two closely related cycads from the genus Zamia (Zamia loddigesii and Z. prasina), the phenotypic variation was analyzed based on 17 morphological traits, and this variability was correlated with environmental conditions across the populations. Despite the significant inter-population variation observed in the two species, greater inter-specific differences were observed based on generalized linear models. Individuals of all populations except for the Macuspana (Tabasco) population of Z. prasina were separated into two discrete groups in a multivariate space (non-metric multidimensional scaling). Macuspana plants overlapped marginally with the multivariate space defined by plants in the four Z. loddigesii populations. Remarkably, Macuspana is geographically located at the distribution limits of both species that occur in close proximity expressing traits that resemble either of the two species. The heterogeneous environment seems to play a determining role in the phenotypic expression of both species. The variation found could be related to the local ecological adaptions that tend to maximize the populations adaptation.

Ecological invasions are a major issue worldwide, where successful invasion depends on traits that facilitate dispersion, establishment, and population growth. The nonnative succulent plant Kalanchoe pinnata, reported as invasive in some countries, is widespread in remnants of seasonally dry tropical forest on a volcanic outcrop with high conservation value in east‐central Mexico where we assessed its mating system and demographic growth and identified management strategies. To understand its local mating system, we conducted hand‐pollination treatments, germination, and survival experiments. Based on the experimental data, we constructed a life‐stage population matrix, identified the key traits for population growth, weighted the contributions of vegetative and sexual reproduction, and evaluated management scenarios. Hand‐pollination treatments had slight effects on fruit and seed setting, as well as on germination. With natural pollination treatment, the successful germination of seeds from only 2/39 fruit suggests occasional effective natural cross‐pollination. The ratios of the metrics for self‐ and cross‐pollinated flowers suggest that K. pinnata is partially self‐compatible. Most of the pollinated flowers developed into fruit, but the seed germination and seedling survival rates were low. Thus, vegetative propagation and juvenile survival are the main drivers of population growth. Simulations of a virtual K. pinnata population suggest that an intense and sustained weeding campaign will reduce the population within at least 10 years. Synthesis and applications. The study population is partially self‐compatible, but sexual reproduction by K. pinnata is limited at the study site, and population growth is supported by vegetative propagation and juvenile survival. Demographic modeling provides key insights and realistic forecasts on invasion process and therefore is useful to design management strategies.

Phylogenetic information provides insight into the ecological and evolutionary processes that organize species assemblages. We compared patterns of phylogenetic diversity among macromycete and woody plant communities along a steep elevational gradient in eastern Mexico to better understand the evolutionary processes that structure their communities. Macrofungi and trees were counted and identified in eight sites from 100 to 3500 m asl, and sequence data retrieved from GenBank for the same or closely related species were used to reconstruct their phylogenies. Patterns of species richness and phylogenetic diversity were similar for both macrofungi and trees, but macromycete richness and diversity peaked at mid-elevations, whereas woody plant richness and diversity did not show significant trends with elevation. Phylogenetic similarity among sites was low for both groups and decreased as elevational distance between sites increased. Macromycete communities displayed phylogenetic overdispersion at low elevations and phylogenetic clustering at high elevations; the latter is consistent with environmental filtering at high elevation sites. Woody plants generally exhibited phylogenetic clustering, consistent with the potential importance of environmental filtering throughout the elevational gradient.

Concurrent interactions and the availability of resources (e.g., light) affect the cost/benefit balance during mutualistic and antagonistic interactions, as well as plant resource allocation patterns. Mycorrhizal interactions and herbivory concur in most plants, where mycorrhizae can enhance the uptake of soil nutrients by plants as well as consuming a large fraction of the plant's carbon, and defoliation usually reduces light interception and photosynthesis, thereby causing direct losses to the hosts of mycorrhizal fungi. Both types of interactions affect the carbon budget of their host plants and thus we predict that the relative costs of herbivory and mycorrhizal colonization will increase when photosynthesis is reduced, for instance in light limited environments. We conducted a greenhouse experiment using Datura stramonium to investigate the effects of defoliation and mycorrhizal inoculation on the resource allocation patterns in two different light environments. Defoliated plants overcompensated in terms of leaf mass in both light environments, but total seed mass per fruit was negatively affected by defoliation in both light environments. Mycorrhizal inoculation had a positive effect on vegetative growth and the leaf nitrogen content, but defoliation negates the benefit of mycorrhizal interactions in terms of the leaf nitrogen content. In general, D. stramonium compensated for the relative costs of concurrent mycorrhizal interactions and defoliation; plants that lacked both interactions exhibited the same performance as plants with both types of interactions.

While arbuscular mycorrhizal fungi improve plant performance they demand large shares of the plant's assimilated carbon, therefore resource allocation trade-offs may drive the commonly observed sexual dimorphism in mycorrhizal colonization in dioecious species. Here we looked for evidence of the evolutionary reduction of mycorrhizal colonization in males of 15 tropical rain forest plants including palms (Chamaedorea) and trees, light-demanding and shade-tolerant species. For none of the analyzed species there was evidence of spatial segregation of the sexes. Most of the tree species had no seasonal variability in mycorrhizal colonization and males had lower mycorrhizal colonization than females in over 70% of the tree species. In contrast, there were no differences between the sexes of the Chamaedorea species. Chamaedorea species had ticker roots and lower specific root length than trees, and seasonal patterns of mycorrhizal colonization correlated with the life-histories of the plants. Based on phylogenetically independent contrast, mycorrhizal colonization of male trees correlated negatively with a metric of sexual differentiation of mycorrhizal colonization between sexes. Our results suggest an evolutionary reduction in the intensity of mycorrhizal interactions in male plants, presumably driven by resource allocation trade-offs as the origen of sexual dimorphs in mycorrhizal colonization.

Rodents are known to perform post-dispersal seed predation in tropical rain forest, but there is little information on the identity of these seed predators and how they select their seeds. Using cafeteria experiments, we found that seed mass, rodent body mass, and the ratio of seed/rodent mass were determinants of seed consumption.

Modelling geographic patterns of abundance/density of species is an important step forward in ecological niche modelling, with implications for theoretical and applied ecology. The distance to the niche centroid approach (DNC) is a methodological development toward better understanding how the internal structure of species’ ecological niches is related to geographic patterns of abundance. We evaluated this approach under combinations of three sampling scenarios and three sampling intensities for a hypothetical species for which abundance patterns were ideal and strictly controlled. Our results indicate that predictive ability of the DNC approach increased with sample intensity, particularly under a strict random sampling scheme. Model performance under a sampling scenario biased by species' density fell slightly, but was importantly reduced when the source of the biases were attractor sites unrelated with species’ traits. We conclude that the DNC approach is only suitable to model species’ abundances/densities under particular conditions. First because it is necessary fulfill some assumptions (discussed in this paper), and second because its performance strongly depends on sampling characteristics that are unusual in most biodiversity data.

Leaf traits of tropical tree species are known to operate as intrinsic determinants of insect herbivory. However, we know little about how habitat fragmentation affects these traits and what, if any, are the consequences of this process on herbivory. We tested the effects of forest fragmentation on the leaf traits of sapling of four light-demanding species: Acalypha diversifolia, Hampea nutricia, Myriocarpa longipes, Siparuna thecaphora, and two shade-tolerant species: Pseudolmedia glabrata and Garcinia intermedia, in Los Tuxtlas, Mexico. We also conducted an acceptability assay with a generalist herbivore Spodoptera frugiperda. Plant traits did not change with forest fragmentation, but did with plant regeneration mode and species identity. Light-demanding species had significantly higher water content, nitrogen concentration and specific leaf area than shade-tolerant species. The latter had significantly higher leaf strength, carbon concentration and carbon:nitrogen ratio. Acceptability was affected by fragmentation but only in P. glabrata; plant tissue from forest fragments was consumed 2.6 times more than that from continuous forest. We conclude that forest fragmentation did not affect leaf traits in this site.

Species that are strong interactors play disproportionately important roles in the dynamics of natural ecosystems. It has been proposed that their presence is necessary for positively shaping the structure and functioning of ecosystems. We evaluated this hypothesis using the case of the world's largest parrotfish (Bolbometopon muricatum), a globally imperiled species. We used direct observation, animal tracking, and computer simulations to examine the diverse routes through which B. muricatum affects the diversity, dis- persal, relative abundance, and survival of the corals that comprise the foundation of reef ecosystems. Our results suggest that this species can influence reef building corals in both positive and negative ways. Field observation and simulation outputs indicated that B. muricatum reduced the abundance of macroalgae that can outcompete corals, but they also feed directly on corals, decreasing coral abundance, diversity, and colony size. B. muricatum appeared to facilitate coral advancement by mechanically dispersing coral fragments and opening up bare space for coral settlement, but they also damaged adult corals and remobilized a large volume of potentially stressful carbonate sediment. The impacts this species has on reefs appears to be regulated in part by its abundance—the effects of B. muricatum were more intense in simulation scenarios populated with high densities of these fish. Observations conducted in regions with high and low predator (e.g., sharks) abundance generated results that are consistent with the hypothesis that these predators of B. muricatum may play a role in governing their abundance; thus, predation may modulate the intensity of the effects they have on reef dynamics. Overall our results illustrate that functionally unique and threatened species may not have universally positive impacts on ecosystems and that it may be necessary for environmental managers to consider the diverse effects of such species and the forces that mediate the strength of their influence.

The capacity of organisms to change their sex has evolved independently in several plant and animal lineages. Sex change has been widely studied, but research approaches have differed for plants and animals, and conclusions have often been taxon-specific. Although sex allocation theory provides a unifying framework for the study of sex change, this unity has not always been appreciated, especially in the botanical literature. Here, we review sex change with regard to its representation in relation to taxonomy and other sexual systems, with regard to its suggested adaptive benefits, and to the role of taxon-specific body architecture, such as modularity and gonadal structure. We highlight differences and similarities between plants and animals and suggest promising lines of future research.

El objetivo de este estudio consistió en identificar los factores familiares y socio-demográficos asociados al consumo de drogas lícitas e ilícitas en escolares de una institución escolar de la ciudad de Ica, distrito de La Tinguiña, departamento de Ica, Perú. La población en estudio estuvo integrada por 980 escolares, y la muestra se determinó en 416 adolescentes escolares, entre 11 y 18 años, de ambos sexos. La prevalencia de consumo de drogas lícitas se ubicó en 31,2%, y las variables asociadas fueron: la condición laboral y la estructura familiar; mientras que para el consumo de drogas ilícitas la prevalencia fue de 12,2% y las variables asociadas fueron la función familiar y la educación en valores.

We analyzed the influence of humidity, temperature, and temporal and elevational distribution on the composition, abundance, and richness of rove beetle assemblages captured with carrion traps in a Quercus L. forest, Cerro de Garcia, Jalisco, Mexico. Four sites with elevations ranging 2,100–2,700 m were surveyed. Beetles were captured monthly from September 2013 to August 2014. Three carrion traps were set at each sampling site, separated by 100 m distance. At each site, a data-logger was used to record temperature and humidity. In total, 18,054 rove beetles were captured, belonging to nine subfamilies, 11 tribes, 33 genera, and 75 species. The rove beetle assemblage showed the highest diversity during the rainy season (q = 0, 1 and 2) and the lowest during the dry season. The composition of the assemblage at 2,700 m elevation was mainly influenced by humidity and at 2,100 m by temperature. Beta diversity in the Quercus forest at different elevations and collecting periods was best explained by species replacements (shifts), and the interaction of humidity and temperature.

Oceanic islands are simplified ecosystems, which are very useful for understanding the processes related to the structuring of natural communities and for assessing cascade effects after perturbations. Socorro Island in the Pacific Ocean reaches up to 1040 m in elevation, and the northeastern side that faces trade winds is more humid than the leeward southwestern side. Apparently, the lack of freshwater throughout most of the island has prevented the spread of invasive cats and sheep to the north, but these species have severely impacted land bird communities on the southern side, where they have potentially disrupted functions such as the top-down control of herbivory. We tested the relative importance of bottom-up (soil and foliage nutrient availability) and top-down (predation of insect herbivores) drivers of herbivory in three endemic tree species. By experimentally excluding birds, we assessed changes in herbivory when top-down control was disrupted, and we also evaluated herbivore predation rates using artificial caterpillars. Our findings suggest that the herbivory patterns on Socorro Island are driven by the top-down control of herbivores by land birds, because their exclusion resulted in higher herbivory (12%) despite low nitrogen content (bottom-up control) of leaves on the north side, whereas the leaves were richer in nitrogen on the south side but no change in herbivory was observed when birds were excluded, and overall, herbivory was 30% higher than in the north, suggesting release of herbivores from top down control on the south side, probably due to effects of invasive predators (cats) or sheep, which may have reduced suitable bird habitats. A better understanding of how drivers of ecological interactions operate on Socorro Island may increase the likelihood of success of future restoration programs.

Overhunting has caused severe decline or local extinction in many large-bodied mammals with direct consequences on plant regeneration, yet little is known about indirect impacts of selective defaunation on commensal species. Cascading effects of species extinction across dependent species groups are likely to occur in coprophagous beetles, because these invertebrates rely on mammal dung for food and nesting material. Both mammals and dung beetles provide important ecosystem services and cascading effects are likely to lead to rapid functional losses. In this study, we described changes in dung beetle communities across a gradient of selective defaunation in continuous Brazilian Atlantic rain forest. We compared the dung beetle assemblages in seven sites with different mammalian biomass and composition. The reduction in the mammalian biomass had a major effect on dung beetle communities by (1) increasing dung beetle abundance with decreasing overall mammal, primate and large mammal biomasses, (2) decreasing dung beetle species richness with decreasing overall mammal biomass and (3) decreasing dung beetle size with decreasing large mammal biomass. Moreover, our study demonstrated the importance of the composition of mammal communities in structuring dung beetle communities. This study documented how selective changes in mammalian biomass and composition affect dung beetle species communities, which in turn may have cascading consequences for the ecosystem. Since most of tropical ecosystems are facing dramatic changes in mammalian composition, it is urgent to evaluate the functional losses associated with such co-extinctions.

One of the most intriguing questions in ecology is how to identify which and how many species will be able to inhabit human-modified landscapes. Large-bodied mammals structure plant communities by trampling, herbivory, seed dispersal and predation, and their local extinction may have pervasive consequences in plant communities due to the breakdown of key interactions. Although much attention has been given to understanding the effects of defaunation on plant communities, information on the potential impacts on plant functional groups (seed dispersal, seed size and seedling leaves defense) inhabiting continuous forests after defaunation is scarce. We conducted mammal surveys (line transects and camera trapping) to determine the defaunation status of a continuous Atlantic forest in Brazil. Then, we evaluated the effects of defaunation on seedling diversity, richness and abundance of functional groups using 15 plot-pairs (each pair with one open and one exclusion plot) monitored over 36 months. We found that the studied area is partially defaunated because it exhibits high abundance of primates, while terrestrial mammals, such as large rodents and ungulates, are rare. We found no significant changes in either seedling richness and diversity or in the seedling composition of plant functional groups in response to mammal exclosure. Seedling mortality and recruitment were similar between plot types. Our findings suggest that at semi-defaunated areas, where arboreal species are still present, terrestrial mammals have low impacts on the plant community reassembly.

Different sexual morphs of dimorphic and trimorphic populations of plants have different demands for resources correlating with phenotypic and ecological dissimilarities among morphs. Few studies have investigated the variations in mycorrhizal symbiosis across the sexual morphs of trimorphic plant populations. Here, we report seasonal variations in the mycorrhizal colonization of the roots of female, male and hermaphroditic trees of Jacaratia mexicana under field conditions in central Mexico. Mycorrhizal colonization was low in the rainy season, when J. mexicana bears only leaves, but high in the dry season when it flowers and fruits. In the dry season, the mycorrhizal colonization of female and male trees was over twofold higher than that of the hermaphroditic trees, and all three morphs had low mycorrhizal colonization in the rainy season. The lack of seasonal variation in the mycorrhizal colonization of hermaphroditic trees, together with other available evidence, supports the idea that hermaphroditic trees of J. mexicana might have some physiological disadvantages compared with male and female trees.

Positive density-dependent seed and seedling predation, where herbivores selectively eat seeds or seedlings of common species, is thought to play a major role in creating and maintaining plant community diversity. However, many herbivores and seed predators are known to exhibit preferences for rare foods, which could lead to negative density-dependent predation. In this study, we first demonstrate the occurrence of increased predation of locally rare tree species by a widespread group of insular seed and seedling predators, land crabs. We then build computer simulations based on these empirical data to examine the effects of such predation on diversity patterns. Simulations show that herbivore preferences for locally rare species are likely to drive scale-dependent effects on plant community diversity: at small scales these foraging patterns decrease plant community diversity via the selective consumption of rare plant species, while at the landscape level they should increase diversity, at least for short periods, by promoting clustered local dominance of a variety of species. Finally, we compared observed patterns of plant diversity at the site to those obtained via computer simulations, and found that diversity patterns generated under simulations were highly consistent with observed diversity patterns. We posit that preference for rare species by herbivores may be prevalent in low- or moderate-diversity systems, and that these effects may help explain diversity patterns across different spatial scales in such ecosystems.

Las interacciones troficas representan importantes costos a las plantas afectando sus patrones de asignacion de recursos. Ademas las relaciones entre hospederos y sus interactuantes son afectadas por la disponibilidad de recursos, por ejemplo, nutrientes del suelo. En este estudio, exploramos la relacion entre las interacciones troficas micorriza-planta-herbivoro en poblaciones naturales de Datura stramonium, y su correlacion con la concentracion de fosforo, nitrogeno y carbono en el suelo. Se estimo la masa vegetativa y reproductiva de las plantas, el nivel de colonizacion por micorrizas arbusculares en sus raices, asi como el nivel de herbivoria en ocho poblaciones de D. stramonium. La abundancia local de D. stramonium estuvo relacionada negativamente con el contenido de fosforo en el suelo. Por otra parte, la concentracion de carbono afecto positivamente la masa vegetativa y reproductiva de las plantas, aunque tuvo un efecto negativo en el area foliar especifica (AFE). De las interacciones troficas, solo la herbivoria estuvo relacionada significativamente con el AFE y no se detecto relacion entre ambos tipos de interaccion. La falta de respuesta significativa de las micorrizas a la concentracion de nutrientes, al desempeno de las plantas y a la herbivoria puede ser consecuencia de la estocasticidad en la disponibilidad de inoculo micorrizogeno (identidad y abundancia) en las poblaciones estudiadas o bien con la epoca de muestreo de las plantas

The effectiveness of seed dispersal by vertebrates has been analysed by examining both quantitative and qualitative components (Jordano & Schupp 2000, Schupp et al. 2010). While the quantitative component is relatively easily assessed in the field (e.g. visitation rate, number of fruits eaten per visit), the qualitative component (e.g. fate of dispersed seeds, seed treatment in the digestive system of the disperser) is rarely studied under natural conditions, because it is difficult to measure the effects on seeds once ingested by the dispersers (Cortes et al. 2009).

Gradient analysis is rarely used in studies of fungal communities. Data on macromycetes from eight sites along an elevation gradient in central Veracruz, Mexico, were used to demonstrate methods for gradient analysis that can be applied to studies of communities of fungi. Selected sites from 100 to 3,500 m altitude represent tropical dry forest, tropical montane cloud forest, conifer forest, and their ecotones. From May to October 2010, macromycetes were collected monthly within ten 10 × 10 m permanent plots per site. In total, 672 individuals of 213 species of macromycetes were recorded. Models for richness and diversity for all macromycete and ectomycorrhizal communities displayed peaks in the mid-part of the gradient, and a tendency to increase with elevation, whereas xylophagous fungi displayed a peak in the mid-lower part but tended to decrease with elevation. Cluster and Maximum Likelihood analyses distinguished four communities for both macromycetes and trees, but plant and fungal communities were only partly concordant. Canonical correspondence analysis indicated that macromycete distribution along the gradient is related to slope, relative humidity, soil temperature, soil water content, canopy openness, and litter depth. Spearman’s correlation and regression trees suggested that air and soil temperature, relative humidity, soil water content, canopy openness, vegetation structure and tree species richness were most strongly related to macrofungal functional groups, but these environmental variables were often correlated to the forest type and may not be causal. Variation in the environment along the elevation gradient differentially affected macromycete functional groups. Results from the different methods used in this work were concordant and showed significant patterns.

Heterogeneous distribution of resources in most plant populations results in a mosaic of plant physiological responses tending to maximize plant fitness. This includes plant responses to trophic interactions such as herbivory and mycorrhizal symbiosis which are concurrent in most plants. We explored fitness costs of 50% manual defoliation and mycorrhizal inoculation in Datura stramonium at different light availability and soil fertility environments in a greenhouse experiment. Overall, we showed that non-inoculated and mycorrhiza-inoculated plants did not suffer from 50% manual defoliation in all the tested combinations of light availability and soil fertility treatments, while soil nutrients and light availability predominately affected plant responses to the mycorrhizal inoculation. Fifty percent defoliation had a direct negative effect on reproductive traits whereas mycorrhiza-inoculated plants produced larger flowers than non-inoculated plants when light was not a limiting factor. Although D. stramonium is a facultative selfing species, other investigations had shown clear advantages of cross-pollination in this species; therefore, the effects of mycorrhizal inoculation on flower size observed in this study open new lines of inquiry for our understanding of plant responses to trophic interactions. Also in this study, we detected shifts in the limiting resources affecting plant responses to trophic interactions.