B3 Trait-dependent effects of abiotic and biotic filters on plant regeneration in mountain dry forest and mountain rain forest. [funded by DFG]

PI(s) for this project:

Dr. Eike-Lena Neuschulz
PD Dr. Matthias Schleuning
Prof. Katrin Boehning-Gaese


In our project, we use trait-based approaches to investigate how abiotic and biotic filters shape plant trait diversity, seed rain and plant regeneration in natural and anthropogenic replacement systems of tropical forests. In the first phase of the project, we have used a combination of observations and experiments to identify mechanisms that underlie processes of plant regeneration in mountain rain forest (MRF). In particular, we measured functional fruit and seed traits of fleshy-fruited plant species, recorded seed rain in forest and pasture habitats, conducted a multi-species seed-sowing experiment in forest and pastures, and recorded natural recruitment in the forest. In the second phase of the project, we will transfer our approach to the mountain dry forest (MDF) to identify the limiting factors of plant regeneration and compare the abiotic and biotic filters of plant regeneration between forest types. The very large climatic gradient in our study area will offer an unprecedented opportunity to gain a mechanistic understanding of how abiotic and biotic filters shape plant regeneration in distinct environmental contexts. In the first work package, we seek to measure fruit and seed traits of woody plants to quantify the functional trait diversity of plant communities along the abiotic and biotic gradients in MDF and MRF. In the second work package, we seek to quantify the abundance and diversity of seed rain along the abiotic and biotic gradients in MDF (by collecting new data) and MRF (based on seed rain data collected in the first project phase). In the third WP, we aim at experimentally disentangling the relevance of abiotic filters (in particular water) versus biotic filters (in particular litter cover) for seedling establishment in forest and agroforest systems in MDF. In the fourth work package, we will quantify seedling recruitment under natural conditions in forest and agroforest in the MDF. This will allow us to compare the functional diversity of seedling communities between MDF and MRF and to test how changes in the trait diversity of plant and avian frugivore communities translate into changes in seedling communities. Our project will identify response and effect traits for plant regeneration in different tropical forest ecosystems and thereby contribute to the conceptual development and testing of the response-effect framework for the study region. The data generated in this project will further feed into the HUMBOL-TD model to parameterize the plant establishment module of the LSMBio and will be key for testing the stability and resistance of ecosystem functions under future scenarios of land-use and climate change.