OVERVIEW
Present patterns in natural systems often cannot be understood without knowledge of past events. Many of the forces affecting ecosystems are too slow-acting or too rare to be observed on human time scales, yet they may have important implications for ecological processes, response to global change, and management or restoration of ecosystems. Our research group studies how ecosystems respond to environmental changes. We use methods from ecology and paleoecology to understand how changes in climate and disturbance regimes influence spatial and temporal dynamics of ecosystems.
Our current projects include studies of climate history, vegetation history, disturbance, species invasion, and ecosystem development.
Fire, climate, and landscape-scale vegetation patterns: with Randy Calcote (U of Minnesota), Beth Lynch (Luther College), and David Mladenoff (UW-Madison). We are investigating the response of landscape-scale vegetation patterns to changes in disturbance frequency and climate on the Northwest Wisconsin Sand Plain and nearby till soils.
Drought as a trigger for rapid state shifts in kettlehole ecosystems: with Robert K. Booth (Lehigh University). We are studying the effect of multidecadal droughts on rates of carbon storage in kettlehole ecosystems across gradients of elevation and peatland establishment (Jeffrey Meyer, Cassandra Kaplon).
Edge effects at Sylvania Wilderness Area: with Kristin Michels (UMN-Twin Cities). We are studying the contemporary and historical effects of the land use boundary around Sylvania Wilderness Area, Michigan, on vegetation inside and outside the wilderness management area.
Fire in forested peatlands of the Upper Great Lakes region: with Colleen Sutheimer (UW-Madison), Jed Meunier (Wisconsin DNR), and Volker Radeloff (UW-Madison). We are reconstructing fire history at three forested peatlands using fire scars and lake sediment charcoal records.
Historical perspectives on Hawaiian montane ecosystems: We are using vegetation re-surveys and paleoecological methods to reconstruct the history of vegetation, invasive species, dust deposition, peatland ecology, and relative moisture in Hawaiian montane ecosystems on a variety of timescales covering the last 40,000 years (Michael Peyton, Soo Kim, Kevin Barrett, Rachel Brunner, Shelley Crausbay).
Ecosystem effects of Sphagnum: with Peter Vitousek (Stanford University). We are studying the ecosystem effects of Sphagnum palustre in Hawaiian wet forests over the past few decades (Lisa Schomaker, Kevin Barrett, Sara Hotchkiss).
Hawaiian ecosystems, soils, and society: with Patrick Kirch (U.C. Berkeley), Peter Vitousek and Shripad Tuljapurkar (Stanford University), Oliver Chadwick (U.C. Santa Barbara), Thegn Ladefoged (Aukland), Michael Graves and Kaeo Duarte (U.H. Manoa), we are investigating the development and intensification of agriculture over 1000 years in Hawaii, focusing on interactions between human societies and the ecosystems they lived in. Our current research in this long-term collaboration focuses on reconstructing the history of drought and on changes in vegetation in the Kohala Field System over time.
Fire regimes and succession in Hawaiian dry forests: with Kealohanuiopuna Kinney and Christian Giardina (USFS Pacific Island Ecosystem Research Center, Hilo). Our lab is developing methods to use phytoliths and charcoal analysis to shed light on Hawaiian species that have coexisted with fire over thousands of years, contributing information on change over time to a dry forest succession study based on space-for-time substitution (Marjeta Jeraj, Kevin Barrett, and Tom Thein).