Stand Dynamics and Disturbance History of Champlain Valley Clayplain Forests

Studies of stand dynamics can explain how species interactions and disturbances drive forest structure and recruitment patterns of tree species. It is difficult to generate an understanding of stand dynamics and successional trends of forests in areas that have a long history of intense land use such as the Champlain Valley of Vermont, where over 230 years of agricultural activity has acutely and permanently influenced the landscape. The valley clayplain forest, a rare natural community containing endangered herbaceous plants and overstory tree species assemblages that are rare in Vermont, has been fragmented by agricultural use of the Champlain Valley. This study used dendroecological methods and assessments of forest structural conditions to describe the tree recruitment history and structural dynamics of two old-growth valley clayplain forest patches. Our results indicate that the valley clayplain forest has a species composition and recruitment history that has been heavily influenced by human land use throughout at least the past 230 years. We found that Quercus spp., typically considered characteristic of the valley clayplain forest, are being replaced by late-successional species such as Tsuga canadensis. Additionally, other human influences such as invasive species threaten to further alter the composition and dynamics of valley clayplain forests in the near future

High temperature coatings for gas bearings

Aluminum oxide and nickel-chrome bonded chrome carbide coatings enhance the performance of gas bearings at temperatures up to 1400 degrees F. A plasma-sprayed aluminum-oxide coating is applied to the bearing surface and a plasma- sprayed 25 percent nickel-chrome bonded chrome carbide coating is applied to the journal surface

When co-management fails: a review of theory and lessons learned from reservoir fisheries in dry-zone of Sri Lanka

Over recent decades co-management has become an increasingly popular form of governance reform in many developing countries. Viewed as a means of promoting sustainable and equitable management of natural resources, it has seen wide application in small-scale inland fisheries. However, perhaps because of its worthy credentials, there has been insufficient critical assessment of the results. This paper commences with a review of underlying theory which is then used to explore the reasons for failure of a co-management initiative in Sri Lankan reservoir fisheries between 2001 and 2002.Reservoir fisheries, Fishery management