Format: ORAL

Teresa Morn-Lpez (3,4), Jess Lpez-Angulo(1-2), David Snchez Pescador(1,5), Adrin Escudero(1)

(1) Área de Biodiversidad y Conservación, Universidad Rey Juan Carlos, Madrid, Spain (2) Institute of Agricultural Sciences, ETH Zurich, Zurich, Switzerland (3) Departamento Biología de Organismos y Sistemas (Universidad de Oviedo) e Instituto Mixto de Investigación en Biodiversidad (IMIB CSIC-Universidad de Oviedo-Principado de Asturias), Oviedo, Spain. (4) Grupo de Ecología Cuantitativa, INIBIOMA, Universidad Nacional del Comahue, CONICET, Bariloche, Río Negro, Argentina (5) Departamento de Farmacología, Farmacognosia y Botánica, Facultad de Farmacia, Universidad Complutense de Madrid, 28040, Madrid, Spain.

Unravelling assembly processes that explain the composition and abundance of coexisting species is a backbone of community ecology. Local communities emerge from the filtering of species present in the regional pool in response to assembly processes such as the suitability of environmental conditions. Understanding how plant communities with distinct levels of turnover respond to their environment is crucial for comprehending these species-environment relationships. The regional pool limits the amount of functional variation among species, and hence, their ability to cope with contrasting environments. However, we often lack information about niche requirements of all species present in the community, especially for rare ones. To shed some light on this regard, we analysed the distribution of plant species across two mountain ranges with contrasting levels of regional richness (63 and 159 species, Mediterranean and Temperate respectively). We applied Hierarchical Modelling of Species Communities (HMSC) to quantify species-specific environmental responses (to elevation, soil fertility and radiation) and how they are affected by 3 functional traits (vegetative height, LDMC, leaf thickness). Despite differences in species turnover between communities, we detected common signals of filtering with plant height and leaf harness (LDMC, thickness) modulating the effects of environmental stress (elevation and radiation). Contrary to our expectations, functional responses of species were more diverse in the species-poor Mediterranean region. We found positive and negative responses to elevation, whereas in the Temperate area negative responses prevailed. In addition, in the Mediterranean area, species also responded to soil fertility according to their growth strategies (height and leaf thickness). Taken together these findings highlight the importance of functional traits related to growth strategies and leaf economic spectrum in shaping species environmental responses in high mountain contexts. Also, they suggest that contrasting environmental stress (drought in summer and cold in winter) may trigger diverse functional responses in species poor Mountains