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 agriculture. 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 principally 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 approaches that mimic past agricultural practices in order to maintain and restore important sand‐plain habitats. Corresponding Editor: M. G. Turner

Land-use history and topographic gradients as driving factors of subalpine Larix decidua forests

“…The understanding of past land use should be integrated into ecological models used to advise the management of biological reserves (Eberhardt et al 2003;Gimmi et al 2008). Reliable quantitative estimates of biomass output due to traditional forest uses provides the potential to incorporate these practices into ecological models and assess the impact on biogeochemical cycles and vegetation changes (Gimmi et al 2008).…”

The Importance of Land-Use Legacies to Ecology and Conservation

“…Studies by Harvard Forest researchers across coastal to inland sites (Motzkin et al 1996, 1999a, 1999b, 2002, Eberhardt et al 2003, and including extensive comparison with European woodlands, indicate that these compositional imprints are most apparent between continuously wooded sites (i.e., ancient woodlands and primary woodlands) and adjoining forests that were once cleared (secondary woodlands; figure 3). Although these floristic differences may be driven by site differences that predate the land use or arise from it, studies on environmentally homogeneous sites across which history varies indicate that the patterns are often controlled by land use alone (Motzkin et al 1996, Donohue et al 1999.…”

“…Although these floristic differences may be driven by site differences that predate the land use or arise from it, studies on environmentally homogeneous sites across which history varies indicate that the patterns are often controlled by land use alone (Motzkin et al 1996, Donohue et al 1999. At least two mechanisms are operative: (1) Intensive land use may act as an editor, removing native species that vary in their ability to disperse and reestablish when the intensity of use declines; (2) the site may be colonized by opportunistic species that may persist for considerable time once established (Motzkin et al 1996, Eberhardt et al 2003. Similarly, in Puerto Rico, localized impacts such as charcoal production have created distinctive forest patches that add to landscape-scale heterogeneity (Thompson et al 2002).…”

“…Of equal significance is the persistence of landuse legacies through several episodes of disturbance. This finding is critical, because scientists who are investigating disturbance-prone landscapes often incorrectly describe postdisturbance responses and conditions as "natural" in the sense that natural processes were the proximate cause of the pattern of disturbance and ecosystem response (Eberhardt et al 2003). The longevity of land-use legacies also belies a common assumption that natural processes and conditions may be restored on human-modified landscapes simply by applying historically relevant disturbances like prescribed fire (Stephenson 1999).…”

Shifting Baselines in a California Oak Savanna: Nineteenth Century Data to Inform Restoration Scenarios

“…Historical reconstruction of long-term land use history and associated ecological change is essential to understanding modern ecological patterns and processes MacDougall et al 2004) and for developing realistic conservation and restoration targets (Swetnam et al 1999;Eberhardt et al 2003;Grossinger et al 2007). …”