Treesearch

Recent, widespread tree mortality in the western U.S. resulting from changes in climate, pathogens, insect activity, and forest management practices has led to concerns for many ecologically and culturally important species. Within conifers, resin-based defenses have long been recognized as a primary defense mechanism against a variety of insects and pathogens. Oleoresin produced by trees contain complex mixtures of terpenoids that have numerous insecticidal and fungicidal properties. Research has also identified links between resin duct characteristics and increased probability of...

After fire, bark beetles pose a significant threat to trees. Resin duct characteristics in trees can increase resistance to bark beetles. However, little is known about how intra- and interspecific variations in resin ducts due to tree characteristics, fire-caused tree injury and life history traits contribute to resistance. In fall 2013, a mixed-stand of Pinus sylvestris and P. nigra was underburned, with some trees subsequently attacked and killed by bark beetles (Ips sexdentatus) during the following two years. We investigated whether inter- or intraspecific differences in constitutive...

The dead foliage of scorched crowns is one of the most conspicuous signatures of wildland fires. Globally, crown scorch from fires in savannas, woodlands and forests causes tree stress and death across diverse taxa. The term crown scorch, however, is inconsistently and ambiguously defined in the literature, causing confusion and conflicting interpretation of results. Furthermore, the underlying mechanisms causing foliage death from fire are poorly understood. The consequences of crown scorch – alterations in physiological, biogeochemical and ecological processes and ecosystem recovery...

We compared precipitation intensity-duration-frequency (PIDF) curves developed for four small forested watersheds to spatially interpolated estimates from the National Oceanic and Atmospheric Administration’s (NOAA) Atlas-14. We also evaluated the Rational Method (RM) using on-site PIDFs and USGS Regional Regression Equations by comparing their estimated design discharges with a given exceedance probability p (Qp) to values computed from on-site data fitted to the Log-Pearson (LPIII) distribution. Overall, NOAA’s PIDF estimates were not substantially different from the on-site PIDFs. The...

Sensitivity of bats to land use change depends on their foraging ecology, which varies among species based on ecomorphological traits. Additionally, because prey availability, vegetative clutter, and temperature change throughout the year, some species may display seasonal shifts in their nocturnal habitat use. In the Coastal Plain of South Carolina, USA, the northern long‐eared bat (Myotis septentrionalis), southeastern myotis (Myotis austroriparius), tri‐colored bat (Perimyotis subflavus), and northern yellow bat (Lasiurus intermedius) are species of conservation concern that are threatene...

Mixedwood stands are composed of hardwoods and softwoods, with neither comprising greater than 75%–80% of basal area or aboveground biomass. By conferring associational resistance and greater resilience to forests when stressed or disturbed, the more diverse composition of mixedwood stands contributes to forest health. We analyzed three examples where mixedwood stands are more resistant to insect infestations in eastern North America. In balsam fir (Abies balsamea L. Mill.) and spruce (Picea spp.) forests, susceptibility and vulnerability to spruce budworm infestations is reduced with...

Aims. Slow decomposition and isolation from groundwater mean that ombrotrophic peatlands store a large amount of soil carbon (C) but have low availability of nitrogen (N) and phosphorus (P). To better understand the role these limiting nutrients play in determining the C balance of peatland ecosystems, we compile comprehensive N and P budgets for a forested bog in northern Minnesota, USA. Methods. N and P within plants, soils, and water are quantified based on field measurements. The resulting empirical dataset are then compared to modern-day, site-level simulations from the peatland land...

Wildland-urban interface residents, who occupy the areas where wildlands meet and mix with human development, are both contributors to and recipients of the disastrous effects of wildland fires. They contribute through fire starts, flammable homes, unmitigated properties, opposition to mitigation on nearby public lands, and land use planning efforts. We argue that successful, sustainable wildland fire solutions are only possible if the WUI residents are engaged. In this article, we describe an evidence-based quantitative social science model to illustrate how to put people at the center of...

The Collaborative Forest Landscape Restoration Partnership (CFLRP), focused on land managed at the national level (the National Forest System) by the US Forest Service, is a prominent public approach to FLR; whereas notable private sector programmes have been organized around specific forest types, for example the Longleaf Pine Initiative (ALRI, 2020), or bottomland hardwoods in the Lower Mississippi Alluvial Valley (NWFW, 2019). Major conservation organizations, including The Nature Conservancy, National Wildlife Federation, and American Forest Foundation, are financing restoration...

Background: A new variance estimator is derived and tested for big BAF (Basal Area Factor) sampling which is a forest inventory system that utilizes Bitterlich sampling (point sampling) with two BAF sizes, a small BAF for tree counts and a larger BAF on which tree measurements are made usually including DBHs and heights needed for volume estimation. Methods: The new estimator is derived using the Delta method from an existing formulation of the big BAF estimator as consisting of three sample means. The new formula is compared to existing big BAF estimators including a popular estimator...