No abstract

Regeneration and assembly of a plant community after a large-scale natural disturbance are affected by many factors. The relative importance of abiotic factors represented by the external environment and the biological factors inside the plant community during this process is still unexplored. This work investigated the regions affected by the Wenchuan earthquake, focusing on areas with the highest intensity (XI degrees) of this earthquake, and the process of community assembly through functional traits on landslides. The aim of this study was to understand the importance of factors influencing community assembly from the perspective of functional traits. The main conclusion is presented as follows: after the regeneration of large earthquake-induced landslides, community-level functional traits covering many plant organs, such as roots, stems, leaves and seeds, are obviously different from those unaffected by landslides. Functional traits do not show strong phylogenetic conservatism. Overall, community traits are divergent or random, and the degree of divergence among the different traits varies. Species composition and alpha diversity have minimal effect on community functional traits during the process of landslide restoration. Landslide scale and altitude significantly affected community-level functional traits in the process of community assembly. All the findings suggested that the functional traits of regenerating vegetation after the earthquake changed significantly and that the functional traits depended more on abiotic regulation than on evolutionary and species-specific factors.

Functional traits are important indicators for examining ecological processes and after-effects of plant community restoration after large-scale geological disturbance. Sample sites with and without landslides in typical forest ecosystems within the region that experienced the highest intensity of the Wenchuan 8.0 earthquake in China were selected in this study, and the characteristics, variations, relationships and influencing factors of woody plant traits at the species, individual and functional type scales were studied. The total interspecific and intraspecific variation of woody plant functional traits was 62.02% and 14.86%, respectively. Differences in woody plant traits were observed at multiple ecological scales on landslides compared with those on nonlandslides. The differentiation of functional traits of recovering communities significantly decreased among woody plant functional types (WFTs) on landslides after the earthquake, indicating disruption and reorganization of the original functional structure. Woody plants on landslides adapted to the new environment by adjusting their leaf traits to improve light use efficiency and adopting rapid ecological strategies. In contrast, woody plants on nonlandslides were more inclined to accumulate material and support structures. Leaf thickness was sensitive to earthquakes. Leaf traits showed a high degree of synergy in their environmental response.