Birds optimize fruit size consumed near their geographic range limits.

Animals can adjust their diet to maximize energy or nutritional intake. For example, birds often target fruits that match their beak size because those fruits can be consumed more efficiently. We hypothesized that pressure to optimize diet-measured as matching between fruit and beak size-increases under stressful environments, such as those that determine species' range edges.

Global and regional ecological boundaries explain abrupt spatial discontinuities in avian frugivory interactions.

Species interactions can propagate disturbances across space via direct and indirect effects, potentially connecting species at a global scale. However, ecological and biogeographic boundaries may mitigate this spread by demarcating the limits of ecological networks. We tested whether large-scale ecological boundaries (ecoregions and biomes) and human disturbance gradients increase dissimilarity among plant-frugivore networks, while accounting for background spatial and elevational gradients and differences in network sampling.

Metatranscriptomics reveals contrasting effects of elevation on the activity of bacteria and bacterial viruses in soil.

Soil microbial diversity affects ecosystem functioning and global biogeochemical cycles. Soil bacterial communities catalyse a diversity of biogeochemical reactions and have thus sparked considerable scientific interest. One driver of bacterial community dynamics in natural ecosystems has so far been largely neglected: the predator-prey interactions between bacterial viruses (bacteriophages) and bacteria.

Scatter-hoarding birds disperse seeds to sites unfavorable for plant regeneration.

Scatter-hoarding birds provide effective long-distance seed dispersal for plants. Transporting seeds far promotes population spread, colonization of new areas, and connectivity between populations. However, whether seeds transported over long distances are deposited in habitats favorable to plant regeneration has rarely been investigated, mainly due to methodological constraints.

Speciation and population divergence in a mutualistic seed dispersing bird.

Bird-mediated seed dispersal is crucial for the regeneration and viability of ecosystems, often resulting in complex mutualistic species networks. Yet, how this mutualism drives the evolution of seed dispersing birds is still poorly understood. In the present study we combine whole genome re-sequencing analyses and morphometric data to assess the evolutionary processes that shaped the diversification of the Eurasian nutcracker (Nucifraga), a seed disperser known for its mutualism with pines (Pinus).

Biodiversity and ecosystem functions depend on environmental conditions and resources rather than the geodiversity of a tropical biodiversity hotspot.

Biodiversity and ecosystem functions are highly threatened by global change. It has been proposed that geodiversity can be used as an easy-to-measure surrogate of biodiversity to guide conservation management. However, so far, there is mixed evidence to what extent geodiversity can predict biodiversity and ecosystem functions at the regional scale relevant for conservation planning.

Direct and plant-mediated effects of climate on bird diversity in tropical mountains.

Aim: Although patterns of biodiversity across the globe are well studied, there is still a controversial debate about the underlying mechanisms and their generality across biogeographic scales. In particular, it is unclear to what extent diversity patterns along environmental gradients are directly driven by abiotic factors, such as climate, or indirectly mediated through biotic factors, such as resource effects on consumers.

Location: Andes, Southern Ecuador; Mt.

Environmental context determines the limiting demographic processes for plant recruitment across a species' elevational range.

Plant recruitment is a multi-stage process determining population dynamics and species distributions. Still, we have limited understanding of how the successive demographic processes depend on the environmental context across species' distributional ranges. We conducted a large-scale transplant experiment to study recruitment of Pinus cembra over six years.

Downsizing of animal communities triggers stronger functional than structural decay in seed-dispersal networks.

Downsizing of animal communities due to defaunation is prevalent in many ecosystems. Yet, we know little about its consequences for ecosystem functions such as seed dispersal. Here, we use eight seed-dispersal networks sampled across the Andes and simulate how downsizing of avian frugivores impacts structural network robustness and seed dispersal.

Trait-Based Assessments of Climate-Change Impacts on Interacting Species.

Plant-animal interactions are fundamentally important in ecosystems, but have often been ignored by studies of climate-change impacts on biodiversity. Here, we present a trait-based framework for predicting the responses of interacting plants and animals to climate change. We distinguish three pathways along which climate change can impact interacting species in ecological communities: (i) spatial and temporal mismatches in the occurrence and abundance of species, (ii) the formation of novel interactions and secondary extinctions, and (iii) alterations of the dispersal ability of plants.

Direct and indirect effects of plant and frugivore diversity on structural and functional components of fruit removal by birds.

Seed dispersal is an important ecosystem function, but it is contentious how structural and functional diversity of plant and bird communities are associated with seed-dispersal functions. We used structural equation models to test how structural (i.e.

Different responses of taxonomic and functional bird diversity to forest fragmentation across an elevational gradient.

Many studies have investigated how habitat fragmentation affects the taxonomic and functional diversity of species assemblages. However, the joint effects of habitat fragmentation and environmental conditions on taxonomic and functional diversity, for instance across elevational gradients, have largely been neglected so far. In this study, we compare whether taxonomic and functional indicators show similar or distinct responses to forest fragmentation across an elevational gradient.

Spatio-temporal variation in bird assemblages is associated with fluctuations in temperature and precipitation along a tropical elevational gradient.

Understanding the spatial and temporal dynamics of species assemblages is a main challenge in ecology. The mechanisms that shape species assemblages and their temporal fluctuations along tropical elevational gradients are particularly poorly understood. Here, we examined the spatio-temporal dynamics of bird assemblages along an elevational gradient in Ecuador.

Pollination and seed dispersal are the most threatened processes of plant regeneration.

Plant regeneration is essential for maintaining forest biodiversity and ecosystem functioning, which are globally threatened by human disturbance. Here we present the first integrative meta-analysis on how forest disturbance affects multiple ecological processes of plant regeneration including pollination, seed dispersal, seed predation, recruitment and herbivory. We analysed 408 pairwise comparisons of these processes between near-natural and disturbed forests.

Contrasting taxonomic and phylogenetic diversity responses to forest modifications: comparisons of taxa and successive plant life stages in South African scarp forest.

The degradation of natural forests to modified forests threatens subtropical and tropical biodiversity worldwide. Yet, species responses to forest modification vary considerably. Furthermore, effects of forest modification can differ, whether with respect to diversity components (taxonomic or phylogenetic) or to local (α-diversity) and regional (β-diversity) spatial scales.

Seed perishability determines the caching behaviour of a food-hoarding bird.

Many animals hoard seeds for later consumption and establish seed caches that are often located at sites with specific environmental characteristics. One explanation for the selection of non-random caching locations is the avoidance of pilferage by other animals. Another possible hypothesis is that animals choose locations that hamper the perishability of stored food, allowing the consumption of unspoiled food items over long time periods.

Constant properties of plant-frugivore networks despite fluctuations in fruit and bird communities in space and time.

Human-induced changes in anthropogenic landscapes are a predominant threat to biodiversity and have been documented to affect mutualistic interactions between plants and animals, such as avian seed dispersal. Interactions between fleshy-fruited plants and frugivorous birds are highly seasonal in temperate ecosystems. Nevertheless, combined effects of landscape modification and seasonal variation on plant-frugivore interactions have never been assessed from a network perspective.