Treesearch

Fire has both positive and negative effects on insects. Bark beetle and defoliator epidemics have positive and negative effects on wildfires. Additional study of these relationships is warranted given the effects of climate change on forests and forest disturbances, recent declines in some pollinator species in North America, and interests in restoring fire-adapted forest ecosystems.

The National Agricultural Statistics Service, the statistical arm of the US Department of Agriculture, and the Multi-Resolution Land Characteristics Consortium, a group of the US federal agencies, collect and publish several land-use and land-cover data sets. The aim of this study is to analyze the consistency of forestland estimates based on two widely used, publicly available products: the National Land-Cover Database (NLCD) and Cropland Data Layer (CDL). Both remote sensing based products provide raster-formatted land-cover categorization at a spatial resolution of 30 m. Although the...

Emerald ash borer (EAB), Agrilus planipennis (Coleoptera: Buprestidae), was first detected infesting ash (Fraxinus spp.) trees in southeastern Michigan and nearby Ontario in 2002. Shortly after the discovery of EAB in North America, researchers began foreign exploration for natural enemies of this destructive beetle in northeastern Asia, where it is native. This activity led to development of a classical biological control program in 2003. In 2007, North American regulatory agencies approved the first environmental releases of three EAB hymenopteran parasitoid species from China to...

Sustainable management of forest ecosystems requires the use of reliable and easy to implement biodiversity and naturalness indicators. Tree-relatedmicrohabitats (TreMs) can fulfill these roles as they harbor specialized species that directly or indirectly depend on them, and are generally more abundant and diverse in natural forests or forests unmanaged for several decades. The TreM concept is however still recent, implying the existence of many knowledge gaps that can challenge its robustness and applicability. To evaluate the current state of knowledge on TreMs, we conducted a systematic...

As wildfires become larger and more severe across western North America, it grows increasingly important to understand how they will affect the biogeochemical processes influencing ecosystem recovery. Soil nitrogen (N) cycling is a key process constraining recovery rates. In addition to its direct responses to fire, N cycling can also respond to other post-fire transformations, including increases or decreases in microbial biomass, soil moisture, and pH. To examine the short-term effects of wildfire on belowground processes in the northern Sierra Nevada, we collected soil samples along a...

The conservation and sustainable management of forests across ownership groups of the conterminous USA was assessed using the Montréal Process Criteria and Indicators (C&I) framework using national forest inventory and other data. Sixty-one percent of the forest area in the USA is Privately owned (20% Corporate, 39% Family, and 2% Other Private), 37% is Public (28% Federal, 2% Local, and 7% State), and 2% is within Native American Tribal Reservation boundaries. There are many commonalities across ownership categories, but there are also important differences. A 1.1 million ha yr-1 decrease...

Human-assisted movement has allowed the Asian longhorned beetle (ALB, Anoplophora glabripennis (Motschulsky)) to spread beyond its native range and become a globally regulated invasive pest. Within its native range of China and the Korean peninsula, human-mediated dispersal has also caused cryptic translocation of insects, resulting in population structure complexity. Previous studies used genetic methods to detangle this complexity but were unable to clearly delimit native populations which is needed to develop downstream biosurveillance tools. We used genome-wide markers to define...

Background: Fire-dependent vegetation communities in the northeastern USA have undergone significant transitions since social and ecological disruptions associated with Euro-American colonization of North America. There is much interest, though little information available, about historical fire regimes of fire-adapted vegetation communities in the northeastern USA in pre-Columbian times (i.e., pre-1492 CE). We intensively investigated a red pine (Pinus resinosa Ait.)—oak (Quercus spp.) forested landscape in north-central Pennsylvania, USA, for exceptionally old red pine remnants (stumps,...

The Hyrcanian forest in northern Iran is threatened by human use and encroachment and has suffered degradation in some areas. The forest has been declared a World Heritage Site and management in the region is shifting from timber production to conservation. There is considerable interest in developing a greater understanding of these diverse forest communities to inform forest management and multiple use plans to maintain the diversity and resilience of these forests. The Hyrcanian forest is characterized by a complex topography of catenas ranging up mountain slopes. Topographic gradients...

A key aspect in understanding patterns in wood demand and harvesting activities is monitoring of timber products output by wood processing facilities. Estimation of change from year-to-year is necessary but is complicated due to shifts in the population as well as changing strata over time. Taking independent samples each year eases complexity, yet suffers from relatively large sampling error in comparison to other designs that take advantage of the covariance arising from correlated samples. In this study, a design intended to maximize the precision of the change estimate by retaining the...