Treesearch

The hemlock woolly adelgid (Adelges tsugae Annand) (HWA) was first found on the eastern hemlock (Tsuga canadensis (L.) Carriere) in the early 1950s and has been recognized as a significant pest of eastern hemlock since the mid-1980s.

Following an outbreak of spring hemlock looper in 1991, ten hemlocks in each of fifteen study plots were monitored annually through 1999. Although some mortality occurred within two years after defoliation, and additional mortality occurred in plots which were subsequently disturbed by logging, most defoliated trees recovered. Twenty-four percent of the trees with 90% defoliation and 43% with 100% defoliation were dead by 1999. Trunk and root collar wounds were more common on dead or unhealthy trees. Overall, tree crown condition improved. In the spring of 1993, only 14% of trees in...

Over the past decade hemlock stands in southern Connecticut have undergone significant decline coincident with the arrival in 1985 of an exotic insect pest, the hemlock woolly adelgid (Adelges tsugae Annand). The objective of this study was to evaluate image enhancement techniques for rating the health of hemlocks at the landscape level using remotely sensed data.

Eastern hemlock (Tsuga canadensis (L.) Carriere), is an important component of ecosystems in the northeastern United States and is the primary coniferous species in southern Connecticut. Hemlocks play a unique role in the region by providing spatial and structural habitat diversity that supports many wildlife and fish populations. Widespread damage to this species would have significant impact on water quality, wildlife, and recreational opportunities in the region.

Eastern hemlock (Tsuga canadensis (L.) Carr.) occurs in old-growth stands sometimes over 400 years old, throughout its principal range from Nova Scotia to Wisconsin. Studies based on aging as well as diameter distributions indicate a stand structure often dominated by an initial multi-decade post-disturbance pulse of seedling establishment, followed after a century or more by one or more subsequent pulses of seedlings and saplings. Over 400 years these new stems tend to produce a truly all-aged forest. The seedling and sapling layers are eliminated when white-tailed deer populations exceed...

Eastern hemlock lumber is manufactured for use in the construction industry. A brief history from the mid-1970s to the present, production challenges, and marketing issues were presented.

The forest stand composition within the terrestrial watershed of a small lake on the southern Precambrian Shield was assessed. Total phosphorus inputs from the terrestrial watersheds were obtained for two sub inflows by measuring flow rates and phosphorus concentrations. Direct aerial phosphorus fallout was estimated from nearby sites sampled by the Ontario Ministry of the Environment. Pollen fallout on the 88 ha lake surface was measured during the growing season with a series of floating pollen traps. Detailed microscopic examination was made of the slides prepared from the trapped...

Although it is an important component of the northern forest, eastern hemlock (Tsuga canadensis (L.) Carr.) is a secondary species in its regions' markets. In this paper, we examine the markets for hemlock, analyze price trends for stumpage, and suggest implications of market forces for management of forests containing hemlock. The characteristics of hemlock wood limit its use to relatively low-grade products, such as structural lumber, pulpwood, and pallets, although higher value niche markets exist, such as post and beam house frames. Analysis of trends for sawlog and pulpwood stumpage...

Ring shake is a barrier to improved utilization of eastern hemlock, an important component of the total softwood timber resource in the Eastern United States and Canada. Ring shake is the lengthwise separation of wood that occurs between and parallel to growth rings, diminishing lumber yields and values. Evaluating the potential for ring shake is essential to improving estimates of tree and stand volume and value, and identifying forest management practices that could minimize the occurrence of ring shake. To assess the incidence and extent of ring shake in eastern hemlock, we sampled 377...

Contains 31 papers and 20 poster presentations addressing hemlock silviculture, ecology, forest health, wildlife relationships, and marketing and utilization.