Saturday, September 14, 2013

How The Northeastern American Forests Have Been Changed Over 400 Years


Four Centuries of Change in Northeastern United States Forests

Authors:

1. Jonathan R. Thompson mail,

Dunbar N. Carpenter,

Charles V. Cogbill,

David R. Foster

Affiliations:

a. Smithsonian Conservation Biology Institute, Smithsonian Institution Front Royal, Virginia, United States of America

b. Department of Forest and Wildlife Ecology, University of Wisconsin, Madison, Wisconsin, United States of America

c. Harvard Forest, Harvard University, Petersham, Massachusetts, United States of America

Abstract:

The northeastern United States is a predominately-forested region that, like most of the eastern U.S., has undergone a 400-year history of intense logging, land clearance for agriculture, and natural reforestation. This setting affords the opportunity to address a major ecological question: How similar are today's forests to those existing prior to European colonization? Working throughout a nine-state region spanning Maine to Pennsylvania, we assembled a comprehensive database of archival land-survey records describing the forests at the time of European colonization. We compared these records to modern forest inventory data and described: (1) the magnitude and attributes of forest compositional change, (2) the geography of change, and (3) the relationships between change and environmental factors and historical land use. We found that with few exceptions, notably the American chestnut, the same taxa that made up the pre-colonial forest still comprise the forest today, despite ample opportunities for species invasion and loss. Nonetheless, there have been dramatic shifts in the relative abundance of forest taxa. The magnitude of change is spatially clustered at local scales (<125 a="" additionally="" agricultural="" and="" as="" associated="" away="" beech="" been="" blockquote="" broad="" but="" change="" clearing.="" climatic="" composition="" compositional="" controls.="" coupled="" early-="" ecological="" evidence="" exhibits="" extent="" favor="" forest="" from="" gradients.="" has="" hemlock="" historical="" homogeneous="" in="" is="" km="" late="" less="" little="" local="" maple="" mid-successional="" modern="" more="" most="" of="" poplar.="" red="" region="" regional-scale="" shift="" strongly="" successional="" such="" taxa="" the="" there="" throughout="" to="" with="">

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