Research - Dr. Robert van Hulst
Dr. Robert van Hulst
Department of Biology
Dr. van Hulst's primary research deals with vegetation dynamics. This area of study focuses on changes in the plants that dominate an area. Whether left to itself or actively managed, vegetation changes over time. This is most obvious where the existing vegetation has been removed by humans or by natural events like landslides, forest fires, and erosion. The area thus denuded will typically become revegetated on its own, and in most cases it will eventually attain a semblance of its former self. Dr. van Hulst is concerned with constructing a minimal model of such vegetation change after a disturbance. How much (or rather: how little) do we need to know about the area, the plants that can reach the site, and the disturbance in order to effectively predict what will happen? It turns out that rather simple models can effectively predict what kind of species will be present, when, and in what numbers. This can be useful in practical forest and land management, because of the length of time it takes for forest regrowth.
Another area of research that concerns Dr. van Hulst is the population dynamics of annual plants. Annuals predominate in disturbed areas but perennials will soon take over. For some annual species, however, it takes little in the way of disturbance to guarantee a spot in the sunlight, and such annuals often find themselves surrounded by perennials. To study what factors are specifically responsible for the maintenance of two annual species amidst perennials in grassland communities, he has conducted a series of experiments involving seeding annuals in artificially created gaps to investigate their reproductive fitness. The conclusions that are starting to emerge from this work are that annuals walk a tightrope between competitive exclusion by surrounding perennials (if the environment stabilizes) and extinction through environmental change (if it does not). Different annual species appear to have adopted different solutions to this conundrum.
