Treesearch

We assessed density of emerald ash borer (Agrilus planipennis Fairmaire) (Coleoptera: Buprestidae) larvae over a 6-yr period by felling and sampling a total of 315 green ash (Fraxinus pennsylvanica Marsh.) trees that were left untreated or treated with imidacloprid, dinotefuran, or emamectin benzoate products at 1-yr, 2-yr, or 3-yr intervals. Our study, conducted across a 32-ha forested area, began soon after emerald ash borer became established and continued through the peak and eventual decline of the emerald ash borer population. Less than half of the 96 trees in the pretreatment sample...

This resource update provides an overview of forest resources in Georgia based on an inventory conducted by the U.S. Forest Service, Forest Inventory and Analysis (FIA) program, the Southern Research Station (SRS) in cooperation with the Georgia Forestry Commission. Estimates are based on field data collected using the FIA annualized sample design and are updated yearly. The estimates presented in this update are for the measurement year 2016 with comparisons made to data reported in 2015 and prior years.

Clemmys guttata is known to inhabit a wide variety of wetland types, such as shallow grassy marshes, forest swamps, ponds, and even bays of large lakes (Ernst 1976. J. Herpetol. 10:25–33; Litzgus and Brooks 2000. J. Herpetol. 34:178–185; Stevenson et. al. 2015. Chelon. Conserv. Biol. 14:136–142). C. guttata populations inhabiting wetland complexes often display seasonal shifts in habitat use (Ward et. al. 1976. Herpetologica 32:60–64; Beaudry et. al. 2009. J. Herpetol. 43:636–645). Individuals have also been documented moving among wetlands over short time intervals, sometimes remaining...

Pine wilt disease (PWD) invaded southern Japan in the early 1900s and has gradually expanded its range to northern Honshu (Japanese mainland). The disease is caused by a pathogenic North American nematode, which is transmitted by native pine sawyer beetles. Recently, the disease has invaded other portions of East Asia and Europe where extensive mortality of host pines is anticipated to resemble historical patterns seen in Japan. There is a critical need to identify the main drivers of PWD invasion spread so as to predict the future spread and evaluate containment strategies in newly...

This resource update provides an overview of timber product output (TPO) and use in Nebraska based on questionnaires designed to determine the size and composition of the State's primary wood-using industry, its use of roundwood, and its generation and disposition of wood residues. This study was a cooperative effort between the Nebraska Forest Service (NFS) and the Forest Inventory and Analysis (FIA) program at the Northern Research Station (NRS) of the USDA Forest Service. The NFS surveyed all known primary wood-using mills and FIA processed and analyzed the survey responses. Mill...

Climate change is already resulting in changes in cold desert ecosystems, lending urgency to the need to understand climate change effects and develop effective adaptation strategies. In this review, we synthesize information on changes in climate and hydrologic processes during the past century for the Great Basin and Columbia Plateau and discuss future projections for the 21st century. We develop midcentury projections of temperature and climate for the Great Basin and Columbia Plateau at timescales relevant to managers (2020-2050) and discuss concepts and strategies for adapting to the...

The boundary between woodlands and shrublands delineates the distribution of the tree biome in many regions across the globe. Woodlands and shrublands interface at multiple spatial scales, and many ecological processes operate at different spatial scales to determine the position of the woodland-shrubland boundary. The overall objective of this dissertation was to examine processes affecting vegetation dynamics at the woodland-shrubland interface in the western United States, at spatial scales ranging from biomes to individual plants. In Chapter 1, I examined broad-scale drivers of the...

Diameter growth is seasonal in Douglasfir, the evergreen tree found in much of western Washington, Oregon, and northern California. Initiation and cessation of diameter growth are both triggered by environmental cues. The tree responds to these cues to improve its chances of growing under favorable conditions. As environmental conditions change, however, land managers want to know how warmer summers and falls may affect diameter growth in Douglas-fir. Forest Service scientists Connie Harrington, Brad St. Clair, and Kevin Ford conducted a study to examine the environmental cues that drive...

We investigated relationships between the spatial patterns of burn severity in Chinese boreal forests and weather parameters. Patch size, shape and arrangement differed between high-severity and low/moderate-severity patches.Wind speed and relative humidity were dominant weather parameters of spatial variation in burn severity. Patch size negatively correlated with relative humidity; patch complexity and aggregation positively correlated with wind speed.

Invasions of introduced species have homogenized ecological communities worldwide, leading to losses of native species and the services they provide. Some of these invaders substantially alter nutrient cycling, which changes conditions for all other organisms, but less is known about the potential influence of these species on nitrogen (N) trace gas emissions that affect atmospheric processes. We used a natural experiment to explore whether the establishment of an introduced nitrogen (N) fixing tree (Falcataria moluccana) and recent invasion of an amphibian predator, the Caribbean tree...