Preparing for hemlock woolly adelgid in Ohio: Communities associated with hemlock-dominated ravines of Ohio's unglaciated Allegheny Plateau

Abstract

Hemlock woolly adelgid (HWA) is an invasive insect causing widespread mortality in eastern hemlock (Tsuga canadensis [L.] Carr; hereafter "hemlock") throughout eastern forests. Hemlock is a foundation species, regulating ecosystem structure and function (e.g., microclimate, nutrient cycling). Across the central and southern Appalachians, hemlock tends to dominate ravine and riparian forests; thus its loss will have dramatic effects across ecosystem boundaries. Prior to invasion by HWA, we are collecting data on hemlock in southeastern Ohio. We found hemlock associated with short, steep slopes regardless of aspect. Hemlock is dominant at lower slope positions adjacent to streams, where few other woody species are found in either the overstory or sapling layers. At upper slope positions, increases in diversity indices are small. Nonmetric multi-dimensional scaling analyses indicate additional species (deciduous hardwoods) form predicable associations along environmental gradients within ravines. Thus, at upper slope positions, communities of oaks and other deciduous hardwoods similar to other ecosystems of the region may develop should widespread hemlock mortality occur. At the same time, riparian forests will experience nearly complete shifts in species composition and, thus, function. Hemlock mortality remains a serious challenge for the Central Hardwoods region, where hemlock-dominated ravine systems are important recreation and tourism sites.

Parent Publication

• Proceedings, 17th Central Hardwood Forest Conference

Citation

Martin, Katherine L.; Goebel, P. Charles. 2011. Preparing for hemlock woolly adelgid in Ohio: Communities associated with hemlock-dominated ravines of Ohio's unglaciated Allegheny Plateau. In: Fei, Songlin; Lhotka, John M.; Stringer, Jeffrey W.; Gottschalk, Kurt W.; Miller, Gary W., eds. Proceedings, 17th central hardwood forest conference; 2010 April 5-7; Lexington, KY; Gen. Tech. Rep. NRS-P-78. Newtown Square, PA: U.S. Department of Agriculture, Forest Service, Northern Research Station:436-446.