Deadwood abundance in recently harvested and old Nova Scotia hardwood forests

Abstract

Deadwood – consisting of dead standing trees (snags), woody debris (WD; downed deadwood), buried wood and stumps – is an important yet poorly documented component of forest structure. Deadwood is important to carbon cycles (e.g. Kurz and Apps, 1993), provides growing and breeding habitat for a range of species, including saproxylic plants, fungi and animals (Kruys and Jonsson, 1999; Harmon et al., 2004; Norden et al., 2004). Deadwood is also an important habitat for southern flying squirrels (Glaucomys volans Linnaeus), which are endangered in Nova Scotia (Stabb, 1987). However, deadwood dynamics in northeastern North American hardwood forests have not received the same attention as other forest ecosystems and there is a dearth of information for Nova Scotia hardwood forests. Hence, forest dynamics of the northeastern USA and inland Canada are implied to apply to the whole of the Acadian Forest Region (Rowe, 1972), which includes Nova Scotia (e.g. Mosseler et al., 2003). Forests dominated by sugar maple (Acer saccharum L.), yellow birch (Betula alleghaniensis Britton), American beech (Fagus grandifolia Ehrh), white birch (Betula papyrifera Marsh) and red maple (Acer rubum L.) are common from the coast of New England, USA and Maritime Canada inland to southern Ontario and Quebec, Canada, Minnesota and Wisconsin, USA. Forests dominated by these species grow at their northeastern limit in Nova Scotia, which is more influenced by a maritime climate resulting in high winds, more frequent ice storms and cooler summers than most of their range. Thus, yields and tree dimensions of Nova Scotia’s hardwood forests are potentially lower than southern and inland hardwood forests, likely producing less deadwood consisting of smaller pieces that are less persistent on the landscape. Hardwood forests dominated by sugar maple, yellow birch and beech constitute 23 per cent of the potential late successional forests of Nova Scotia. Mixed woods composed of softwood, maple, birch and beech represent a further 11 per cent of the potential climax forests of Nova Scotia (Stewart et al., 2003). While the area of Nova Scotia dominated by the above species is unknown, Nova Scotia is estimated to contain a total merchantable volume of 132.1 million m3 of hardwood, consisting of 57.6, 19.4, Deadwood abundance in recently harvested and old Nova Scotia hardwood forests