Restoring drastically disturbed sites within the pygmy pine-oak forests of southern New Jersey's Pinelands National Reserve.

摘要

The Pinelands National Reserve and UNESCO Biosphere encompass a large portion of southern New Jersey's Pine Barrens. Within the core preservation zone of these Reserves lies the Warren Grove Weapons Range, a military installation where exercises during the past 50 years have devastated portions of the indigenous pygmy pine-oak forest. In 1987, restoration efforts were initiated to identify materials and techniques that would promote a diverse and productive native plant community atop drastically disturbed portions of the Range. Trial plantings were designed to examine fertilizer and sewage compost fertility amendments; the response of plant mixtures incorporating the local flora, including the dwarfed race of pitch pine (Pinus rigida); the influence of the ectomycorrhizal fungus Pisolithus tinctorius on the growth of pines and associated species; mulch applications to conserve moisture and add organic matter; and, the interaction of pitch pine and the N{dollar}sb2{dollar}-fixing shrub bayberry (Myrica pensylvanica). Studies involved both field plots and greenhouse experiments.; Following two growing seasons, test plantings exhibited 25% of the vegetation biomass found in surrounding pine-oak communities, 50% canopy closure, and levels of diversity comparable to those occurring in the surrounding reference areas. Greatest vegetation responses were achieved following the application of 16 Mg/ha compost and the establishment of pitch pine seedlings. Amendments of seeded grasses, P. tinctorius, and mulch, failed to enhance plant establishment and growth. Finally, a greenhouse study examining the interactions among pitch pine, bayberry, and their respective symbionts P. tinctorius and Frankia, demonstrated competitive rather than complementary associations. Plants expressed differences in productivity, biomass partitioning, and nutrient concentrations in response to intra- and inter-specific plantings. No evidence exists to conclude nitrogen fixed in the nodules of bayberry reached adjacent pine seedlings during the two years of the study.; Guidelines for restoring drastically disturbed sites in the Pine Plains are presented. Considerations for the application of these techniques to other sites in the Pine Barrens, as well as additional activities warranting future research, are briefly discussed.