CONSERVATION OF CHANGING LANDSCAPES: VEGETATION AND LAND-USE HISTORY OF CAPE COD NATIONAL SEASHORE

Abstract

The pervasive impact of historical land use is often underappreciated in the management and restoration of conservation areas and natural resources. We used historical and ecological approaches to determine the relative influences of past land use, fire, and site conditions on woodland vegetation patterns in Cape Cod National Seashore (CACO), the largest protected coastal landscape and area of sand-plain vegetation in New England. Coastal sand plains are the focus of intense conservation activity because they support uncommon plant and animal assemblages that are dynamic as a result of past disturbance and ongoing human impacts. CACO was predominantly wooded prior to extensive land clearance for historical ag- riculture. Historical maps and modern soil profiles indicate that by the mid-19th century, -44% of the area supporting sand-plain woodlands in CACO was plowed for crops or pasture, 42% was logged repeatedly but never cleared, and 14% was open and subjected to diverse uses. Relationships between modern vegetation and 19th-century land use are striking and largely independent of site conditions. Continuously wooded areas support pine-oak woodlands with abundant ericaceous shrubs, whereas previously plowed sites have less canopy oak, more pine, few ericaceous shrubs, and a distinct understory including the grass Deschampsia flexuosa and the shade-intolerant shrub Arctostaphylos uva-ursi. Current composition and historical sources suggest that past agriculture generated extensive heathland and grassland habitats, much of which has subsequently reforested. In contrast to many interpretations and management guidelines, the persistent influence of fire is prin- cipally on the canopy composition and structure of former woodlots. The results highlight a need (1) to integrate an understanding of past land use into ecological models underlying the management of biological reserves; and (2) to consider the use of management ap- proaches that mimic past agricultural practices in order to maintain and restore important sand-plain habitats.