Changes in the Forests of the Jockey Hollow Unit of Morristown National Historical Park over the Last 5-15 years

Russell Southgate, Emily

The forests of Morristown National Historical Park (Morris County, NJ) constitute a major element of the cultural as well as the natural landscape of the park (Russell 2001). The forested vegetation of the park is not homogeneous; rather it includes older mature stands of varied species composition and a variety of younger stands that have replaced fields abandoned in the last century or more (Ehrenfeld 1977). These forest stands are undergoing changes today, in a complex interplay between the natural dynamics of forest vegetation and the consequences of human activities. These changes are consistent with park objectives when they result in a continued healthy, ecologically integrated forest. On the other hand, if the changes are tending toward an ecologically impoverished forest, with little resemblance to the vegetation of the le century, it may be necessary to intervene to reverse these trends. I have proposed several approaches to monitoring change in the forests of Morristown National Historical Park (Russell 2001) to provide a scientific basis for making decisions about possible management actions. Here I report on preliminary results from implementing this monitoring; integrating it with results from other studies initiated in the last 15 years. The small size of the existing data sets precludes rigorous statistical analysis, which would require a very large study. Because the plots have been sited randomly or at least haphazardly, however, they do provide a reasonably unbiased estimate of change, which can suggest potential problems with forest regeneration. These data can be interpreted in terms of consistent trends or very marked differences. The function of statistics is to indicate whether small differences are real or are attributable to sampling procedures, random variation, etc. When the differences are striking, it is not necessary to use statistics to provide support for the conclusions. However, lack of obvious differences does not prove lack of subtler but statistically significant differences.