Treesearch

The emerald ash borer, Agrilus planipennis Fairmaire (Coleoptera: Buprestidae), is an important invasive pest of ash (Fraxinus) trees in North America. Two larval parasitoid species, Tetrastichus planipennisi Yang (Hymenoptera: Eulophidae) and Spathius agrili Yang (Hymenoptera: Braconidae), and 1 egg parasitoid species, Oobius agrili Zhang and Huang (Hymenoptera: Encyrtidae), were introduced into the United States in 2007 as part of a classical biological control program. We conducted field studies to assess the flight phenology of introduced and native parasitoids of emerald ash borer in...

The conventional approach to LiDAR-based forest inventory modeling depends on field sample data from fixed-radius plots (FRP). Because FRP sampling is cost intensive, combining variable-radius plot (VRP) sampling and LiDAR data has the potential to improve inventory efficiency. The overarching goal of this study was to evaluate the integration of LiDAR and VRP data. FRP and VRP plots using different basal-area factors (BAF) were co-located in 6 conifer stands near Alberta, Michigan, in the United States. A suite of LiDAR metrics was developed for 24 different resolutions at each plot...

Information needs associated with sustainable forest management are evolving rapidly as the forest sector works to satisfy an increasingly complex set of economic, environmental, and social policy goals. A barrier to the sustainable management of forests and the provision of ecosystem goods and services under these new pressures is a lack of up-to-date and detailed information with regard to the number and characteristics of forest resources. Accurate inventory systems are required that spatially quantify timber and other nontimber goods and services at multiple scales in order to inform...

Fire is a key earth-system and Anthropocene process (Bowman et al. 2009; Smith et al. 2016a). Fire impacts on the global carbon (C) cycle from both anthropogenic and natural sources, with 1350-3400 Tg C emitted from land-use changes, agricultural practices and residential uses, and 2750-4600 Tg C emitted in wildfire events, which exhibit high interannual variability (Westerling et al. 2006; van der Werf et al. 2010; Wotton et al. 2010; Balch et al. 2013; Lannom et al. 2014; Smith et al. 2016a). Biomass burning emissions can be determined from top-down assessments such as the Global Fire...

Following typical forest inventory protocols, individual tree volume estimates are generally derived via diameter-at-breast-height (DBH)-based allometry. Although effective, measurement of DBH is time consuming and potentially a costly element in forest inventories. The capacity of airborne light detection and ranging (LiDAR) to provide individual tree-level information poses options for estimating tree-level attributes to enhance the information content of forest inventories. LiDAR provides excellent height measurements and, given the physiologic scaling connection of plant height and...

Forests deliver a number of important ecosystem services, including clean water. When forests are disturbed by wildfire, the timing, quantity and quality of runoff are altered. A modelling study was conducted in a forested watershed in California, USA, to determine the risk of wildfire, and the potential post-fire sediment delivery from ~4-ha hillslope polygons within a 1500-km2 basin following a wildfire event. Wildfire intensity was estimated with fire spread models. The estimation of soil burn severity was based on predicted flame length. Sediment delivery was estimated from each...

In 1996 there was a meeting in Tucson of hydrologists from every Forest Service region, as well as Forest Service research scientists engaged in watershed-related activities. This meeting was organized by the Stream Team (which has since been enveloped by the National Stream and Aquatic Ecology Center). The focus of the meeting was to identify tools that needed to be developed to support watershed management. One of the suggested tools was a GIS-based application that could run on the internet. At that time, federal websites were in their infancy, and the development of GIS tools for...

Soil erosion is strongly related to soil hydraulic properties. Understanding how surface coal mining affects these properties is therefore important in developing effective management practices to control erosion during reclamation. To determine the impact of mining activities on soil hydraulic properties, soils from undisturbed areas, areas of roughly graded mine spoil, areas with replaced topsoil before seeding, and revegetated areas at the Rosebud Mine in Eastern Montana were evaluated. Field and laboratory studies were conducted to determine the soil hydraulic properties of the four...

Being prepared for an emergency is important. Every year wildfires threaten homes and lives, but danger persists even after the flames are extinguished. Post-fire flooding and erosion (Figure 1) can threaten lives, property, and natural resources. To respond to this threat, interdisciplinary Burned Area Emergency Response (BAER) teams assess potential erosion and flood risks, and if deemed necessary, develop remediation plans to protect lives and natural resources. BAER teams operate under tight deadlines - typically burn scars must be assessed and treatments recommended within two weeks...

Post-wildfire flooding and erosion can threaten lives, property and natural resources. Increased peak flows and sediment delivery due to the loss of surface vegetation cover and fire-induced changes in soil properties are of great concern to public safety. Burn severity maps derived from remote sensing data reflect fire-induced changes in vegetative cover and soil properties. Slope, soils, land cover and climate are also important factors that require consideration. Many modelling tools and datasets have been developed to assist remediation teams, but process-based and spatially explicit...