Treesearch

The international workshop on monitoring forest degradation in Southeast Asia provided a forum for discussion of the technical, social and political challenges and successes that have occurred during recent work in sub-national forest degradation monitoring. The 2012 workshop, held in Bangkok, Thailand, followed recent US Forest Service/LEAF (USAID's Lowering Emissions in Asia's Forests) forest degradation monitoring options assessments that took place in Cambodia, Lao PDR and Viet Nam. Forest degradation can play a significant role in decreasing forest carbon, and therefore should be...

Emerald ash borer, Agrilus planipennis Fairmaire (Coleoptera: Buprestidae), is an invasive insect that has caused significant ash (Fraxinus spp.) mortality in North America. Three Chinese parasitoids have been approved for release as part of a classical biological control program for A. planipennis in the United States: Spathius agrili Yang (Hymenoptera: Braconidae), Tetrastichus planipennisi Yang (Hymenoptera: Eulophidae), and Oobius agrili Zhang and Huang (Hymenoptera: Encyrtidae). This study was designed to measure the cold tolerance of the overwintering stage for each parasitoid...

Many demographic parameters of imperiled fishers (Martes pennanti) in the Pacific Northwest remain poorly understood but are necessary to develop conservation strategies; herein we report on fisher reproduction, recruitment, and dispersal on the Hoopa Valley Indian Reservation, California, to help fill key knowledge gaps. Forty radiocollared, breeding-age females exhibited denning behavior on 80 (87%) of 92 opportunities between 2005 and 2011. Twenty-eight female fishers weaned offspring in 55 (65%) of 85 adequately monitored denning opportunities. Two-year-old female fishers were less...

In August 2010, a mycelial fan (isolate AZ32F) of Armillaria sp. was collected from the root collar of a living Douglas-fir tree on the Mogollon Rim within the Coconino National Forest (approximate location 34°25′31.26″N, 111°20′41.04″W, elevation 2,293 m) in central Arizona. Mycelial fans under the bark of living trees are a sign of pathogenicity, and symptoms of the diseased tree included resinosis, sloughing bark, and thinning crown. The infected tree was located on a south-facing slope with approximately 30% tree cover, dominated by ponderosa pine (Pinus ponderosa), with lesser...

We examined reassembly of winning and losing tree species, species traits including shade and fire tolerance, and associated disturbance filters and forest ecosystem types due to rapid forest change in the Great Lakes region since 1850. We identified winning and losing species by changes in composition, distribution, and site factors between historical and current surveys in Minnesota’s mixed and broadleaf forests. In the Laurentian Mixed Forest, shade-intolerant aspen replaced shade-intolerant tamarack as the most dominant tree species. Fire-tolerant white pine and jack pine decreased,...

La Reserva Natural Datanlí-El Diablo, es un complejo mosaico de hábitats dentro de la zona de vida del bosque nuboso, ubicado en Jinotega. Datanlí, es un vocablo de la lengua indígena “Matagalpa”, y significa por donde bajan las aguas, expresión más que correcta para definir el complejo de riachuelos y ríos que nacen en esta zona, y que desembocan en el lago artificial de Apanás, una de las principales fuentes de generación de energía eléctrica en Nicaragua, y además de esto, forma parte de la cuenca 69 o cuenca del Río San Juan, lo cual nos da una idea de la importancia de estos bosques...

This paper deals with 3D numerical simulations of two fires fronts (head and backfire) propagating simultaneously through a grassland fuel. The simulations were carried out using a “fully” physical and three-dimensional fire model (namely WFDS). One of the objectives of this work, was to evaluate the potential for fully physical fire model to simulate the interactions between two fire fronts (a head fire and a backfire), in conditions similar to those encountered during suppression fire operations. A set of numerical simulations was first carried out for standalone head fires propagating...

The eastern spruce gall adelgid, Adelges abietis (Linneaus 1758) (Hemiptera: Adelgidae) is an invasive pest of spruce trees, Picea (Pinaceae), that was introduced to North America from Europe prior to the 20th century (Drooz 1985). The preferred host of A. abietis is Norway spruce, P. abies (Linneaus) H. Karst, but the insect also infests white (P. glauca (Moench) Voss), red (P. rubens Sargent) and blue spruces (P. pungens Engelmann). The adelgid is established in eastern North America (southeastern Canada and the northeastern United States down to Tennessee), the Great Lakes region (Drooz...

Biodiversity has been described as the diversity of life on earth within species, among species, and among ecosystems. The rate of biodiversity loss due to human activity in the last 50 years has beenmore rapid than at any other time in human history, and many of the drivers of biodiversity loss are increasing, including habitat loss, overexploitation, invasive species, climate change, and pollution, including pollution from reactive nitrogen (Nr). Of these stressors, climate change and Nr from anthropogenic activities are causing some of the most rapid changes. Climate change is causing...

The Forest Service, U.S. Department of Agriculture, considers a species to be invasive if it meets the following criteria: (1) the species must be nonnative to the ecosystem under consideration, and (2) the species’ introduction must cause or be likely to cause economic or environmental harm or harm to human health (Executive Order No. 13112, Federal Register/Vol. 64, No. 25/February 8, 1999). Indeed, Pimentel and others (2005) last estimated the cost of prevention and eradication of invasive plant species in crop, pasture, and forest settings at approximately $27 billion every year. In...