Vegetation ecologists are interested in the ecology of plant communities, their species composition, diversity, and environmental factors that are driving differences between individual sites. In Vegetation Ecology Lab, we work in the field (vegetation survey), in the lab (sample measurement and data analysis), and also in the greenhouse (experiments). We also spend considerable time discussing and interpreting our findings and putting them into a broader context of what we already know. Recently we focus on the vegetation of the Taiwanese cloud forest and aim to understand how fog density affects their taxonomic and functional species composition and diversity.

Find more about our lab at https://www.davidzeleny.net/veglab/doku.php 

Current Research Topics

　Effect of cloud on diversity and species composition of forest vegetation in Taiwan. Taiwan, as a subtropical island exposed to the East- Asian monsoon system, offers a unique opportunity to study vegetation along fog frequency, a peculiar ecological factor, that has a remarkable ecological effect on vegetation and requires species to develop unique adaptations. We use cloud forest as a model system and apply various approaches, from purely descriptive (vegetation–environment association) to more mechanical (trait-based community assembly). 

　The trait-based approach in vegetation ecology. Different species have different strategies for how they adapt to the environment they are living in, and functional traits are one way how to quantify these strategies. For example, if nutrient availability is not a problem, species may grow fast, build thin and cheap leaves and softer wood, to use as many resources as quickly as possible (“live fast, die young”). We measure various traits on trees and ferns and ask which of them are essential for plants to grow where they do. This, in turn, helps us to understand the mechanisms behind the ecological requirements of individual species and potentially also predict what happens with species in a community if the environment changes.

　Diversity pattern of vegetation along important environmental gradients and effect of spatial scale. Why there are more species over there and fewer here? Is it because the environment is different, or is it simply a result of random events like dispersal limitation and ecological drift? We study patterns of alpha diversity (species richness) at fine- to broad-scale spatial level, changes in beta-diversity along environmental and spatial gradients, and diversity of vegetation types at the landscape level (vegetation classification). We use both real and simulated community data to test our hypotheses. Although not perfect, diversity is a useful indicator of processes acting in nature, and as such, it deserves detailed research attention.

　Methodological aspects of analyzing community-ecology data. It is always good to try new methods to analyze our data, but at the same time, it is essential to critically ask whether these methods are really doing what we suppose they do. Modern community ecology cannot exist without advanced numerical methods able to handle large and complex community datasets, but we need to be aware that even the most advanced of them have certain limitations. In the lab, we focus on exploring and improving several methods that are commonly used by vegetation ecologists and that seem to suffer from severe limitations (community-weighted mean analysis, the effect of undersampling, beta diversity analysis).