Treesearch

The 170 National Forests and Grasslands (NFs) in the conterminous United States are public lands that provide important ecosystem services such as clean water and timber supply to the American people. This study investigates the potential impacts of climate change on two key ecosystem functions (i.e., water yield and ecosystem productivity) using the most recent climate projections derived from 20 Global Climate Models (GCMs) of the Coupled Model Intercomparison Project phase 5 (CMIP5). We find that future climate change may result in a significant reduction in water yield but an increase...

The Aquatic Conservation Strategy (ACS) of the Northwest Forest Plan guides management of riparian and aquatic ecosystems on federal lands in western Oregon, western Washington, and northern California. We applied new scientific findings and tools to evaluate two potential options, A and B, for refining interim riparian reserves to meet ACS goals and likely challenges of climate change while supporting other management goals, including timber production. Interim riparian reserves are retained in late-successional reserves and other special land designations in the options. In lands...

Disturbanceby non-native insect species can be an important ecological driver shaping long-term changes in vegetation and plant species composition. While impacts of gypsy moth (Lymatria dispar L.) outbreaks in North American forests have been extensively studied, the results are quite inconsistent, particularly with respect to the amount of tree mortality associated with defoliation. In this study, we integrate geographical data describing historical gypsy moth defoliation with forest inventory data collected by a national forest inventory programme to quantify regional impacts across...

Asian gypsy moth, Lymantria dispar L. (Lepidoptera: Erebidae), females are capable of flight, but little is known about what causes the variation in flight propensity that has been observed. The female flight propensity and capability of Asian gypsy moth from seven geographic populations (three from China, two from Russia, one from Japan, and one from Korea) were compared under all combinations of three light intensities (0.05, 0.10, and 0.40 lux) and during three time intervals after the start of scotophase. A total of 567 females were flight tested. Female flight propensity, time to...

Robust models of wildlife population size, spatial distribution, and habitat relationships are needed to more effectively monitor endangered species and prioritize habitat conservation efforts. Remotely sensed data such as airborne laser altimetry (LiDAR) and digital color infrared (CIR) aerial photography combined with well-designed field studies can help fill these information voids. We used point count-based distance sampling survey data and LiDAR-fused CIR aerial photography to model density of the Golden-cheeked Warbler (Setophaga chrysoparia), an endangered songbird, on the 10 000-ha...

The increasing importance and impacts of root diseases on the forested ecosystems across the United States are documented in this report. Root diseases have long-term impacts on the ecosystems where they reside due to their persistence onsite. As a group of agents, they are a primary contributor to overall risk of growth loss and mortality of trees in the lower 48 States. Root diseases kill trees, decay wood, slow tree growth, predispose trees to other mortality agents, and cause trees to fail or fall over. In this manner, these diseases reduce timber volume, alter forest composition and...

Timber harvesting can cause both short- and long-term changes in forest ecosystem functions, and scientists from USDA Forest Service (USDA FS) have been studying these processes for many years. Biomass and bioenergy markets alter the amount, type, and frequency at which material is harvested, which in turn has similar yet specific impacts on sustainable productivity. The nature of some biomass energy operations provides opportunities to ameliorate or amend forest soils to sustain or improve their productive capacity, and USDA FS scientists are leading the research into these applications....

This resource update provides an overview of forest resources in Michigan based on inventories conducted by the U.S. Forest Service, Forest Inventory and Analysis (FIA) program of the Northern Research Station. Estimates are based on field data collected using the FIA annualized sample design and are updated yearly. The annual inventory started in 1999. For the 2015 inventory, estimates for current variables such as area, volume, and biomass are based on 6,672 plot samples collected from 2010-2015. Change variables such as net growth, removals, and mortality are based on 6,094 samples...

This publication provides an overview of forest resources in Vermont based on inventories conducted by the U.S. Forest Service, Forest Inventory and Analysis (FIA) program of the Northern Research Station. For annual inventory years 2003-2013, the sample length was equal to 5 years. Beginning in 2014, the cycle length was changed to 7 years. For the 2015 inventory, estimates for current variables such as area, volume, and biomass are based on 1,101 plot samples collected from 2010-2015. Change variables, such as net growth, removals, and mortality, are based on 961 samples collected in...

Global climate models predict a future of increased severity of drought in many tropical forests. Soil microbes are central to the balance of these systems as sources or sinks of atmospheric carbon (C), yet how they respond metabolically to drought is not well-understood. We simulated drought in the typically aseasonal Luquillo Experimental Forest, Puerto Rico, by intercepting precipitation falling through the forest canopy. This approach reduced soil moisture by 13% and water potential by 0.14 MPa (from -0.2 to -0.34). Previous results from this experiment have demonstrated that the...