.|  Baltimore Ecosystem Study
Vegetation Research Projects

Historical Changes in Forest Cover, Gwynns Falls Watershed
  • James Dyer, Ohio University

Traditionally, forest ecologists and biogeographers have sought to explain vegetation patterns in terms of climate, topography, soils, and other factors of the abiotic environment. It is becoming increasingly apparent, however, that past land use often imparts a stronger control on regional vegetation patterns. If we are to understand the distribution of organisms and ecosystem characteristics of a human-impacted landscape, we need to assess its land use history. Establishing "baseline" vegetation is also critical for restoration ecologists - to what are we restoring this modified landscape?

Several related projects are underway that examine forest change in the Gwynns Falls watershed since European settlement. The first seeks to construct baseline vegetation characteristics, by examining patents issued for lands transferred beginning in the early 18th century; since the surveyors frequently used "witness trees" to mark property boundaries, these documents in essence represent an initial survey of the forest vegetation before widespread alteration by Euro-Americans. A second project concentrates on changes in forest cover within the Gwynns Falls watershed in the 20th century, utilizing historic air photos (covering the period 1939-1971). Together, these studies can begin to tell us how not only historic land use decisions may have influenced present-day forest composition, but also how composition and structure have changed over the 350 years since settlement.

Historic Maryland Air Photographs - 1957 and 1971
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