Plant Ecology & Biodiversity: Mission Statement

Our mission is to understand the regulation of plant biodiversity, developing a theoretical framework to analyse mechanistic interactions between plants across a hierarchy of scales.

To successfully embark on this task two basic points have to be understood from the start:

1. Plants have evolved in competition with neighbours for resources and recruitment opportunities. This competitive setting puts constraints on the functional morphology and physiology of plants and consequently on their demography.
2. Evolution (selection pressure) does not require plants to maximize their performance in order to win the competition from their neighbours. They just have to do better than their neighbours. Therefore, in stead of simple optimization models, game-theoretical approaches are needed.

We study the dynamics in the performance of individual plants, grown in a competitive setting, in response to environmental factors and we assess how this performance affects the success of genotypes, populations and species. We reveal the mechanisms of how plants grow and structure a stand of vegetation, how plants manage to competitively exclude their neighbours or manage to co-exist with them. We evaluate the impact of seed production, seed dispersal, seedling establishment, and adult survival on dynamics and genetic variation in local populations and metapopulations. In this way we reveal how local biodiversity is built-up and regulated. We use this insight in combination with phylogeographical data and huge datasets on large-scale temporal and spatial dynamics to explain the historical component of biodiversity patterns and evolutionary radiation.

We pursue our mission through climate-room and field experiments, demographic field studies, and molecular analyses, in close combination with mechanistic, game theoretical and demographic modelling. We conduct our research in a wide range of climates and ecosystems, both in the Netherlands and abroad.

Examples of our recent work:

- Plant communities are less productive than their maximum potential because 'cheaters' of the rules always win the competition: Vegetation stands with optimal characteristics for maximum productivity do not appear to be evolutionarily stable. They can be successfully invaded by mutants that over invest in resource harvesting structures (leaves, stem height and roots) (e.g. Schieving & Poorter (1999) {pdf 197Kb); Anten (2005) {pdf 168 Kb}).

- Tropical rain forest trees are younger than previously thought: Tree ring analysis revealed that individuals in favourable microsites have persistently higher growth rates than their conspecific neighbours. As a consequence, tree age estimates based on average diameter growth strongly overestimate true age. (e.g. Brienen & Zuidema (2006): {pdf 462 Kb}; Brienen & Zuidema (2007) {pdf 257Kb}).

- The higher the local wood density, the lower the biodiversity: We revealed that regions in the Amazon basin that lacked regular large-scale disturbances have a poorer tree flora but their trees have a much higher wood density and heavier fruits (e.g. ter Steege et al (2003) {pdf 6Mb}; ter Steege et al. (2006) {pdf 371Kb}).

- New polders act as giant seed traps: New polders in the IJsselmeer, the Netherlands, provide new windows of opportunity for dispersal and establishment. This leads to strongly different patterns of invasion and genetic diversity for plant groups of different breeding strategy (mosses, ferns, phanerogams) (e.g. Verburg, Maas & During (2000) {pdf 241Kb} 646-652; During (2007) {pdf}).

- Obviously, our research frequently also has applied spin-offs, leading to advices for nature conservation, forest management and carbon sequestration (e.g. Peres, Baider, Zuidema et al. (2003) {pdf 690Kb} Selaya et al. (2007) {pdf 297Kb}; Van Staalduinen et al. (2007) {pdf 377Kb}; Zuidema et al. (2007): {pdf 257Kb}).