The Vegetation of the Ravines of the Southern Finger Lakes, New York, Region

Abstract

The vegetation pattern of the forested ravines found in the southern Finger Lakes region of New York State was analyzed, using several approaches, including community-type and agglomerative classifications, direct gradient analysis (composite transects and weighted averages), and Bray and Curtis ordination. These tended to converge upon a single interpretation, although there were variations depending upon the method. The most important axis of vegetational variation was along the ravine-side gradient from bottom to top. The bottomlands were dominated by sugar maple and beech with basswood and elm, and sometimes bitternut hickory. Low-slope trees were primarily sugar maple, beech and basswood. Hemlock became more important going upslope, dominating almost completely on middle to upper-middle-slope stands. Oak-hemlock stands characterized the uppermost ravine slopes. Understory shrubs and herbs were most dense and diverse on lower to middle slopes. Lower-slope understory species included Taxus baccata, Viburnum alnifolium, Ribes cynosbati, Solidago flexicaulis, Caulophyllum thalictroides, Actaea alba and Viola spp. Maianthemum canadense, Medeola virginiana and Aralia nudicaulis were common under hemlock. On the upper slopes, in the more open oak stands, the understory was richer than in the hemlock stands. Upper-slope understory species included Viburnum acerifolium, Phryma leptostachya, Sanicula spp. and Osmorhiza claytoni, as well as some of the common lower-slope species. Certain structural features were associated with the ravine-side gradient as well. This pattern bears some similarity to those found in other New York ravines, and in the eastern deciduous forest in general. However, there are several differences, depending upon size of the ravine, aspect and geography. The relative merits of the methods used are briefly discussed. It is concluded that direct gradient analysis provides the most accurate pattern of ravine vegetation, but simple intuitive community classification can often be used for general purposes. INTRODUCTION Numerous steep ravines and vertical gorges provide one of the most striking and beautiful physiographic features of the southern Finger Lakes region of New York State. The ravines support well-developed forest vegetation which varies in composition with different ravine environments. Perhaps because of the general disturbance of natural communities throughout the whole region, there have been no quantitative ecological studies of the southern Finger Lakes vegetation. The more inaccessible ravines, however, are relatively undisturbed and, therefore, amenable to ecological analysis. This research was undertaken to examine the pattern of plant communities in these ravines. Of the many different approaches to vegetation study, no single one is entirely adequate for all kinds of vegetation. A clearer and more understandable picture of the vegetation is