Treesearch

An integrated management approach is needed to maintain eastern hemlock (Tsuga canadensis (L.) Carrière) in eastern North America and to minimize tree damage and mortality caused by the invasive hemlock woolly adelgid (Adelges tsugae Annand). This study examined the hypothesis that chemical control with low rates of insecticide and biological control can be combined in the same stand to impact adelgid populations, prolong crown health, and allow predator proliferation. Sixty T. canadensis trees in northern Georgia were individually treated via soil injection with 0%, 10%, or 25% of the...

There is a need to develop improved accelerated test methods for evaluating the leaching of wood preservatives from treated wood exposed to precipitation. In this study the effects of rate of rainfall and length of intervals between rainfall events on leaching was evaluated by exposing specimens to varying patterns of simulated rainfall under controlled laboratory conditions. Lumber specimens were pressure-treated with 0,5; 1 or 2,% solutions of chromated copper arsenate (CCA) and exposed to 762 mm of rainfall at rates of 2,5; 8 or 25 mm/h. Intervals between rainfall events were increased...

How does potential fire behavior differ in grass-invaded non-native forests vs open grasslands? How has land cover changed from 1950–2011 along two grassland/forest ecotones in Hawaii with repeated fires? A study on non-native forest with invasive grass understory and invasive grassland (Megathyrsus maximus) ecosystems on Oahu, Hawaii, USA was established. We quantified fuel load and moisture in non-native forest and grassland (Megathyrsus maximus) plots (n = 6) at Makua Military Reservation and Schofield Barracks, and used these field data to model potential fire behavior using the...

Understanding the effects of management on forest structure and function is increasingly important in light of projected increases in both natural and anthropogenic disturbance severity and frequency with global environmental change. We examined potential impacts of the procurement of forest-derived bioenergy, a change in land use that has been suggested as a climate change mitigation strategy, on the productivity and structural development of aspen-dominated ecosystems. Specifically, we tested the effects of two factors: organic matter removal (stem-only harvest, whole-tree harvest,...

Reductions of nitrogen (N) export from agricultural lands because of changes in specific N stocks andfluxes by incorporation of small amounts of prairie vegetation strips (PVS) are poorly understood. Theprimary objective of this study was to evaluate the effect of the presence and topographical position of PVSon soil and plant carbon (C) and N stocks relative to annual crop and native prairie vegetation. The studywas implemented within three small adjacent watersheds, treated with one of the following cover types:(1) 100% row-crop agriculture (CROP); (2) 20% prairie vegetation (PVS)...

Twenty species of corticioid Basidiomycota (Cantharellales, Corticiales, Hymenochaetales, Polyporales, Russulales, Thelephorales) are reported for the first time from Uruguay, extending the known species of this group of fungi to 130 in the country. In addition, Sistotrema biggsiae Hallenb., Peniophora guadelupensis Boidin & Lanq., Phanerochaete cryptocystidiata Nakasone, and Phlebia weldeniana Nakasone & Burds. are new reports for South America. Brief descriptions are provided for Hyphoderma granuliferum P. Roberts, P. guadelupensis, P. cryptocystidiata, Phanerochaete incrustans Parmasto,...

We examine U.S. exports and imports of hardwood products from 1990 to 2013. These products include logs, lumber, veneer, chips, molding, cooperage, plywood, and flooring. The values of hardwood products exported and imported have fluctuated over the years but have generally inceased. More substantial changs have occurred with the countries and regions receiving U.S. exports, as well as with those importing into the United States. The primary region receiving U.S. hardwood log and lumber in 1990 was Western Europe,but today China is the most important market. East Asia has been the most...

Isolations from the granulate ambrosia beetle, Xylosandrus crassiusculus (Coleoptera: Curculionidae: Scolytinae: Xyleborini), collected in Georgia, South Carolina, Missouri and Ohio, yielded an undescribed species of Ambrosiella in thousands of colony-forming units (CFU) per individual female. Partial sequences of ITS and 28S rDNA regions distinguished this species from other Ambrosiella spp., which are asexual symbionts of ambrosia beetles and closely related to Ceratocystis spp. Ambrosiella roeperi sp. nov. produces sporodochia of branching conidiophores with disarticulating swollen...

Composition of diets selected by tame but free-ranging deer in a natural forest environment was studied throughout a 24-month period and summarized by mean monthly percentage composition on the basis of dry-matter intake. A modifi cation of the standard bite-count method of diet determination was used. All forages were identifi ed by species and plant part (leaf, twig). Major forages comprising the diet were identifi ed seasonally and considered in relation to their role in the nutritional ecology of the deer. Overall, a simple but consistent pattern was evident in the data. When green,...