FOR891_sp11e invasibility

SP11e The interplay of herbaceous and woody species richness: impacts on invasibility and productivity in subtropical forests

This subproject studies the interactions between tree layer diversity, herb layer diversity and invasibility in subtropical China. In the first phase of BEF China we focused on characteristics of the herb layer (1) as response variable to tree layer characteristics and (2) as a predictor variable for invasion resistance towards exotic plant species. In the second phase, the project will continue with these tasks and, in addition, (3) take herb layer characteristics into account as predictor variable for feedback effects on the tree layer of young successional stages. In a monitoring approach, species richness and composition of the herb layer will be studied as a function of environmental variables (Ecoscape approach) and of planted tree diversity in a grid of permanent plots at site A and B of the Main Experiment. In return, the studied properties of the herb layer can later be used as covariates by other projects. We will use measurements of functional traits of herbaceous species and indices of functional diversity of the herb layer to predict invasibility by other plant species with particular functional traits and test if invasions will be complementary, i.e. increasing functional diversity in the herb layer. The impact of tree species richness on herb layer assembly and invasibility will be studied by herb removal and addition experiments. At the same time, we will use these treatments to quantify feedback effects of the herb layer on growth and survival of trees. The field work will be complemented with common garden experiments, factorially crossing functional diversity and species diversity of herbaceous plants. The Chinese partner project will disentangle effects of herb layer richness and evenness on productivity and invasibility.

2011-04-01

2019-12-17