Jg. Ehrenfeld et al., ABOVEGROUND AND BELOWGROUND CHARACTERISTICS OF PERSISTENT FOREST OPENINGS IN THE NEW-JERSEY PINELANDS, Bulletin of the Torrey Botanical Club, 122(4), 1995, pp. 298-305
Openings in the pitch pine (Pinus rigida Mill.) forests of southern Ne
w Jersey may persist for decades. In five such openings, ranging in si
ze from 22 to 223 m(2), and their surrounding forest matrix, we charac
terized the vegetation, the forest floor, root biomass, soil chemistry
and soil fungi. There was a much greater disparity between the openin
gs and the forest matrix in the density of small ericad shrubs than in
the number or basal area of the canopy trees, and this disparity was
mirrored in the thickness of the litter and organic horizons, and in t
he total small root biomass. The matrix:gap ratios of total root bioma
ss and of total soil fungal length were similar to the ratios for tree
and large shrub densities. Extractable NH4-N, Bray-P, pH, and soil mo
isture did not differ between the openings and matrix, but extractable
NO3-N was higher in the openings than the intact forest. We suggest t
hat the shrubs may be an important factor in maintaining the differenc
es between the openings and the matrix, by trapping litter, maintainin
g high root biomasses, and inhibiting decomposition. If the organic ho
rizon is destroyed in a locally intense disturbance, the slow rate of
invasion and growth of the shrubs into mineral soil may help perpetuat
e the opening for long periods of time.