Ground Layer Plant Species Turnover and Beta Diversity in Southern-European Old-Growth Forests

摘要: Different assembly processes may simultaneously affect local-scale variation of species composition in temperate old-growth forests. Ground layer diversity reflects chance colonization and persistence low-dispersal species, as well fine-scale environmental heterogeneity. The latter depends on both purely abiotic factors, such soil properties topography, factors primarily determined by overstorey structure, light availability. Understanding the degree to which plant forests is associated with structural heterogeneity and/or dispersal limitation will help assessing effectiveness silvicultural practices that recreate patterns structures for conservation or restoration diversity. We used a nested sampling design assess turnover, i.e. proportion changes among units, across 11 beech-dominated Southern Europe. For each stand, we also measured wide range variables might explain ground turnover. Our aim was quantify relative importance comparison stand while controlling other sources this purpose, multiple regression distance matrices at within-stand extent, mixed effect models extent whole dataset. Species turnover best predicted heterogeneity, especially differences availability topsoil nutrient concentration texture. Spatial distances were significant only four out eleven stands relatively low explanatory power. This suggests more important driver than southern European beech