Authors: Mari Lepik Jaan Liira Kristjan Zobel
Publish Date: 2005/06/28
Volume: 145, Issue: 3, Pages: 465-474
Abstract
Several theoretical considerations imply that high shoot morphological plasticity could increase competition symmetry and favour plant coexistence We tested whether mean plasticity across cooccurring species is a key trait for explaining ramet density and species richness in herbaceous vegetation We used three data sets to test the hypotheses a experimentally achieved estimates of plasticity to light availability for 35 herbaceous species b richness ramet density and canopy architecture data from 17 herbaceous communities c species richness data from a 5year permanentplot study in a calcareous grassland In herbaceous communities containing species with relatively higher shoot plasticity ramet density was significantly higher Consequently relatively more species were growing per unit area—a greater proportion of the community species pool was represented on 1 m2 In the permanent plot study speciesrichness was higher in those 40×40 cm quadrats where species with high shoot plasticity prevailed—there was a positive regression of richness on the mean plasticity of species This relationship was highly significant in five consecutive years Our results suggest that shoot plasticity to light availability is evidently one of the key traits in processes that alter the density of coexisting plants and therefore species diversity in herbaceous communitiesWe are grateful to Jacob Weiner for useful discussion Many thanks to Tõnu Möls and members of the working group who helped with the experiments The work was supported by ESF 5535 and Tartu University 2540 The experiments comply with the current laws of the Republic of Estonia
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