Aim: Species’ environmental requirements and large-scale spatial and evolutionary processes are known to determine the structure and composition of local communities. However, ecological interactions and historical processes also have major effects on community assembly at landscape and local scales. In this work we evaluate whether two xerophytic shrub communities follow fixed ecological assembly dynamics throughout large geographical extents, or their composition is rather driven by species individualistic responses to environmental and macroecological constraints. Location: SW Iberian Peninsula (Portugal and Spain) Taxa: Stauracanthus genistoides agg. and Ulex australis agg (Fabaceae). Methods:Inland dune xerophytic shrub communities were sampled in 95 plots distributed within their potential area of occurrence. Then, we described the main gradients of vegetation composition and assess the relevance of biotic interactions. We also characterized the habitat suitability of the dominant species, S. genistoides and U. australis, to map the potential distribution of the xerophytic shrub communities. Finally, to identify the relative importance of each factor driving changes in community composition, we examined the relationships between the vegetation gradients and a broad set of explanatory variables. Results: Our results show that xerophytic shrubs follow uniform successional patterns throughout the whole geographical area, but also that these communities respond differently to the main environmental gradients in each region. Soil organic matter is the main determinant of community variations in the northern regions, Setúbal Peninsula and Comporta, while in the South/South-Western region most of the variation between both types of communities is explained by temperature seasonality. Main conclusions: The relative importance of the main factors causing community-level responses varies according to regional processes and the suitability of the environmental conditions for the dominant species in these communities. These responses are also determined by intrinsic community mechanisms that result in a high degree of similarity in the gradient-driven community stages in different regions.

Approaching the consequences of climate change demands understanding how temperature controls species' responses across key biological aspects, as well as the coordination of thermal responses across these aspects. We study the role of temperature in determining the species' diel, seasonal, and geographical occurrence, using dung beetles as a model system. We found that temperature has relatively low --but not negligible-- effects in the three studied species' aspects, once accounting for alternative factors. More importantly, the estimated thermal niches were largely incongruent across aspects. This shows that species have multidimensional thermal niches, entailing that adjustments to fulfil temperature requirements for one biological aspect, such as seasonal ontogenetic cycles, may result in detrimental effects on other aspects, like diel activity. Paradoxically, the relatively weak effects of temperature we found may have serious consequences for species' responses to warming if temperature regulates essential aspects of species' biology in divergent ways.

Studies focused on the drivers of change in species composition often fail to integrate several aspects of beta diversity and scale. Here, we assess the impact of species pool, environmental gradients, geographic distance, and spatial scale on the diversity of epiphytic bryophytes. We identify biogeographic modules of co-occurring species using network analyses. For each biogeographic unit we study the effects of environment, abundance structure of the community and geographic distance on beta diversity. We analyse two aspects of beta diversity related to different scales of analysis: between-forests dissimilarity in species composition and within-forests heterogeneity in species composition. We show that the structuring of the communities is a by-product of niche-related and stochastic processes. The balance of these processes changes with biogeographic region and scale, neutral stochastic effects are more significant in the most favourable regions and for small-scale within-forest heterogeneity