Sensitivity of Functional Traits to Environmental factors in a Karst
Plant Community
Abstract
In this study, the plant communities at five succession stages (herbage,
herbage-shrub, shrub, tree-shrub, and tree) in the Zhenning Karst
Plateau area of Guizhou were examined. The changes of plant functional
characteristics in different succession stages were analyzed, as was the
relationship between functional traits and environmental factors. The
main results include the following. (1) During the succes-sion process,
plant height, leaf dry matter mass, leaf area, leaf nitrogen content,
and leaf phosphorus content gradually increased, whereas leaf thickness
and specific leaf area decreased, and leaf C:P ratio and leaf N:P ratios
did not change significantly. (2) Soil organic matter, soil total
nitrogen, soil total phosphorus, soil C:N, soil C:P, and soil C:K
increased at first and then decreased, reaching a peak at the tree-shrub
stage. Soil total potassium fluctuated and soil bulk density gradually
decreased and reached the lowest value at the tree-shrub stage. (3)
Redundancy analysis (RDA) showed that the plant community shifted from a
nutri-ent-poor soil environment to a nutrient-rich environment. Soil
total phosphorus, soil C:K, soil organic mat-ter, soil C:N, and soil
bulk density were the key environmental factors affecting the change of
functional traits. (4) Structural equation modeling suggests that that
specific leaf area and leaf nitrogen content had more sensitive
responses to soil nutrient resources and environmental factors,
respectively.