Subproject 2: Plant growth and demography
Individual plant growth and plant demography as a function of species richness and composition
PI: Härdtle, Werner, Prof. Dr. (University of Lüneburg)
Co-PI: von Oheimb, Goddert, Dr. (University of Lüneburg)
Summary
This subproject addresses the influence of tree and shrub species richness on aboveground plant growth and competition on the individual- and population-level.
This subproject addresses the influence of tree and shrub species richness on aboveground plant growth and competition on the individual- and population-level.
Specific objectives are:
1. To quantify the impact of experimentally manipulated plant species diversity on individual tree growth and mortality within and among species;
2. To relate patterns of variation in individual growth rates of different tree species to underlaying variation in branch demography and functional traits;
3. To analyse local neighbour interactions in terms of branch demography and growth rates and to test whether diversity reduces competition;
4. To evaluate soil feed-backs on individual tree growth and stand architecture.
The results of this subproject will contribute to a better understanding of mechanisms underlying the coexistence of woody species in relation to different levels of species richness. Moreover, the measurements will help to quantify short- and long-term developments of stand architecture and timber production and will improve our still limited knowledge on growth of woody species and their functional significance in subtropical forest ecosystems.
Objectives
In this subproject, the influence of tree and shrub species richness on individual tree growth and neighbourhood competition will be analysed.
Overall objectives of this subproject are:
1. To quantify within-plot variation in individual tree growth and mortality within and among species as a function of species richness;
2. To relate individual growth rates of the different tree species to branch demography and functional traits;
3. To analyse local neighbour interactions in terms of branch demography and individual tree growth and to test whether diversity reduces competition;
4. To analyse soil feed-backs (mycorrhiza, soil fauna, pedogenetic processes, soil chemistry and nutrient cycle) on individual tree growth and stand architecture.
Specific objectives of the first phase of this subproject are:
5. To quantify height–diameter–age relationships of individuals of different tree species (sampled in the experimental plots) and to relate them to functional groups (such as successional position of tree species, architectural traits, evergreen/deciduous, light/shade tolerance) and neighbourhood competition indices;
6. To analyse branch demography and crown architecture of individuals of different tree species (sampled in the experimental plots) in relation to functional groups and competition indices;
7. To study growth rates and mortality of tree individuals in the comparative study plots in relation to successional stages, species richness, functional diversity, and competition.