Land cover change

LC changeThe earth’s ecosystems are being transformed by human activities. The resultant loss of wild lands is the leading threat to biodiversity. I use large- and small-scale experiments, observational studies, and mathematical modeling to understand the consequences of habitat loss for biodiversity and ecosystem function and to find ways to mitigate loss through sustainable land use.

Optimizing ecological sustainability and crop production in Wisconsin enhances a suite of ecosystem services (multifunctionality) relative to the current land cover and use.

Agricultural intensification is eroding ecosystem services such as pollination, pest suppression, and carbon sequestration. Transforming corn- and soybean-dominated landscapes to include greater areas of perennial bioenergy crops like native grasslands may help preserve ecosystem services, while supplying renewable energy. However, gains in ecological sustainability are not without an economic cost. Taking advantage of differences in the biology and ecology of different crops may allow us to strategically design landscapes that optimize sustainability and crop production. I’m working in collaboration with the Gratton lab, Tim Meehan, and GLBRC to model how a suite of ecosystem services responds to different landscape design scenarios that emphasize annual crop production, perennial crops, or a “smart” optimization of the two. See a bit more detail on this project here.

microcosm setup 05-22-2007a
Landscape microcosms

I’m using microcosms – miniature landscapes – made from patches of different types of leaf litter to study how landscape structure effects biodiversity and ecosystem function. The idea that biodiversity increases with greater areas of natural habitat and decreases as patches become more isolated has become a guiding principle in ecology and conservation. But because area and isolation are correlated, debate persists on the relative importance of the two. Whats more, the habitat between patches (the landscape matrix) can mediate area and isolation effects. Results of this study show that matrix quality and isolation can have independent and unexpected results on bacterial diversity and ecosystem function that suggest interspecific interactions mediate simple dispersal dynamics (Spiesman et al. 2018).

model landscapes
Predator and prey populations depend on movement over a temporally variable resource landscape.

Many species need food resources continuously throughout the growing season. Temporal gaps in resource availability can limit survival and population growth. I am using predator-prey metapopulation models to explore how resource asynchrony allows mobile predators to persist by tracking resources across a landscape as they become available at different times in different locations. A better understanding how temporal variation in resources affects, for example, beneficial insect populations may help us sustainably manage agroecosystems. Rather than planting landscapes in a single crop type, planting a diversity of crops that provide resources at complementary times of the season may enhance beneficial insect populations and the ecosystem services that they provide. This idea has formed the basis for a large-scale empirical study that was recently funded by the USDA. Check back for updates.