Seed dispersal by vertebrates in Madagascar’s forests: review and future directions

Madagascar’s highly diverse forests are critically threatened because of increasing deforestation, and those that remain are facing declines of vertebrate frugivores that disperse their seeds. Thus, understanding plant - frugivore interactions is of critical importance for the conservation and maintenance of plant diversity in Madagascar. This paper reviews observational and experimental studies of the multifaceted aspects of seed dispersal by vertebrates across Madagascar including the relative importance of different seed vectors, the patterns of seed deposition, and the post - dispersal fate of dispersed seeds. This also aims to lay a foundation for future studies by discussing understudied aspects that are crucial for the understanding of the role of frugivores on plant populations and communities in Malagasy forests. Such perspectives are important given the increasing threats to seed dispersers, the low richness of frugivore assemblages in Malagasy forests and the strong reliance of many plant species on frugivores for their dispersal. Understanding this ecosystem service can provide us insights on plant colonization, community structure, demography and invasion, as well as forest restoration and regeneration.RÉSUMÉLes forêts de Madagascar abritent des communautés de plantes vasculaires exceptionnellement diverses avec un taux d’endémisme s’élevant à 82 % . Malheureusement, hormis les continuelles dégradation et fragmentation menaçant ces forêts, la flore malgache est aussi menacée par l’insuffisance et le déclin des populations d’animaux frugivores qui jouent un rôle fondamental dans la dissémination des graines. La compréhension de ce mécanisme de dissémination des graines par des frugivores est importante pour savoir comment préserver la biodiversité et la régénération forestière ainsi que pour établir des stratégies de conservation des habitats fragmentés. Le présent article constitue une synthèse des publications scientifiques sur les recherches concernant ce mécanisme dans les forêts malgaches. Les informations disponibles sont plutôt limitées mais suggèrent que la majorité des plantes malgaches dépendent des vertébrés frugivores pour la dissémination de leurs graines. Ces études montrent également quelques aspects portant sur des modèles de dispersion des graines et des plantules. Plusieurs éléments relatifs à ce mécanisme sont encore inconnus et nécessitent des recherches approfondies. Les pressions menaçant les différents vecteurs de graines sont discutées, et plus particulièrement celles qui pourraient avoir des effets néfastes sur la démographie des populations de plantes. En outre, des recommandations sont formulées pour permettre l’intégration des interactions frugivore–plante dans la conservation des écosystèmes forestiers malgaches

Plio-Pleistocene climatic change had a major impact on the assembly and disassembly processes of Iberian rodent communities

Comprehension of changes in community composition through multiple spatio-temporal scales is a prime challenge in ecology and palaeobiology. However, assembly, structuring and disassembly of biotic metacommunities in deep-time is insufficiently known. To address this, we used the extensively sampled Iberian Plio-Pleistocene fossil record of rodent faunas as our model system to explore how global climatic events may alter metacommunity structure. Through factor analysis, we found five sets of genera, called faunal components, which co-vary in proportional diversity over time. These faunal components had different spatio-temporal distributions throughout the Plio-Pleistocene, resulting in non-random changes in species assemblages, particularly in response to the development of the Pleistocene glaciations. Three successive metacommunities with distinctive taxonomic structures were identified as a consequence of the differential responses of their members to global climatic change: (1) Ruscinian subtropical faunas (5.3–3.4 Ma) dominated by a faunal component that can be considered as a Miocene legacy; (2) transition faunas during the Villafranchian–Biharian (3.4–0.8 Ma) with a mixture of different faunal components; and (3) final dominance of the temperate Toringian faunas (0.8–0.01 Ma) that would lead to the modern Iberian assemblage. The influence of the cooling global temperature drove the reorganisation of these rodent metacommunities. Selective extinction processes due to this large-scale environmental disturbance progressively eliminated the subtropical specialist species from the early Pliocene metacommunity. This disassembly process was accompanied by the organisation of a diversified metacommunity with an increased importance of biome generalist species, and finally followed by the assembly during the middle–late Pleistocene of a new set of species specialised in the novel environments developed as a consequence of the glaciations

Environmental factors are stronger predictors of primate species’ distributions than basic biological traits

Understanding the neutral, biological and environmental processes driving species distributions is valuable in informing conservation efforts because it will help us predict how species will respond to changes in environmental conditions. Environmental processes affect species differently according to their biological traits, which determine how they interact with their environment. Therefore, functional, trait-based modelling approaches are considered important for predicting distributions and species responses to change but even for data-rich primate communities our understanding of the relationships between traits and environmental conditions is limited. Here we use a large-scale, high-resolution dataset of African diurnal primate distributions, biological traits and environmental conditions to investigate the role of biological traits and environmental trait filtering in primate distributions. We collected data from published sources for 354 sites, and 14 genera with 57 species across Sub-Saharan Africa. We then combined a three-table ordination method, RLQ, with the Fourth Corner approach to test relationships between environmental variables and biological traits and used a mapping approach to visually assess patterning in primate genus and species’ distributions. We found no significant relationships between any groups of environmental variables and biological traits, despite a clear role of environmental filtering in driving genus and species’ distributions. The most important environmental driver of species distributions was temperature seasonality, followed by rainfall. We conclude that the relative flexibility of many primate genera means that not any one particular set of traits drives their species-environment associations, despite the clear role of such associations in their distribution patterns

Editorial: Increasing women’s participation in community based conservation: Key to success?

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