Pattern of Community Dynamics in the Sunken Forest: 1967 to 1985 and 1985 to 1986

Art, Henry

This report presents the results of 1985 and 1986 midsummer resurveys of 19 of the 34 permanent 100 sq.m. plots established in 1967 and a 600 sq.m. Ecosystem Analysis Plot established in 1968 in the Sunken Forest, Fire Island National Seashore, Fire Island, New York. In the period between 1967 and 1985, the deer population increased dramatically on the island but appeared to have had little effect on dominant species in the tree layer. However, deer appear to be a major cause of the reduction of subordinant tree layer species (e.g. Ilex glabra), the shrub layer, and herbaceous perennials. On 27 September 1985 Hurricane Gloria made landfall over the Sunken Forest. The hurricane appears to have been selective in its impacts on the Sunken Forest, breaking off branches and even uprooting mature trees in exposed sites. A comparison of the pre- and post-hurricane data, however, shows that the storm was far from devastating. In the 10 months following the hurricane, the tree layer in the Sunken forest had shown remarkable resiliency, with increases in basal area and density that compensated for the initial storm-induced mortality. The storm also appears to have stimulated growth in the shrub layer and recruitment of woody seedlings in the herbaceous layer as well.