Landscape dynamics and vegetation at multiple scales: A recent history of the northwest Wisconsin sand plain.
Grossmann, Emilie*,1, Mladenoff, David1, 1 University of Wisconsin-Madison, Madison, WI
ABSTRACT- Sandy glacial outwash soils in northwest Wisconsin have historically supported a unique, open, pine barrens vegetation type. Comparing presettlement (ca. 1830) land cover with today's landscape reveals a loss of open spaces (barrens), and an increasing oak component in the southern portion of the landscape. While the long-term trends are striking, analysis of recent history at several scales may better explain the landscape's form today. Using historic airphotos and a GIS, we describe 60 years of recent land cover history, at 20-year intervals. At local (30m2), landscape (16km2), and regional scales (1000km2), we illustrate the nature of recent land cover changes, characterize recent disturbances, and project future scenarios for land cover change through Markov analysis. Regional scale results show that the proportion of open space fluctuates: 13.4% in 1938, 17.7% in 1960, 20.4% in 1980, and 13.7% in 1997. Additionally, the proportion of evergreen forest cover has increased consistently: 13.1% in 1938, and 30.2% in 1997. Analysis at the landscape scale shows spatial variability in these general trends. Local descriptors of land cover dynamics are also variable. Some locales are fairly static while others are quite dynamic. It is important to note that while pine barrens vegetation depends on open spaces, not all open spaces support barrens. Because of this, we show local relationships between landscape history, soils and plant community composition using field data from a subset of our study blocks. We discuss our results in the context of pine barrens conservation. Landscape composition, especially with respect to open space in the sand plain, can enhance or inhibit a diverse native plant community. Understanding land cover history throughout the sand plain and at multiple scales, can help us identify places likely to support native pine barrens vegetation today.
Key words: landscape history, pine barrens, Wisconsin, vegetation
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