Treesearch

Literature describing the effectiveness of best management practices (BMPs) applicable to forest roads is reviewed and synthesized. Effectiveness is considered from the perspective of protecting water quality and water resources. Both paved and unpaved forest roads are considered, but BMPs that involve substantial engineering are not considered. Some of the BMPs included are commonly used on roads; others are used less often. The synthesis focuses on quantitative BMP effectiveness and descriptions of processes or characteristics that influenced the effectiveness. Qualitative results and...

A demographic approach based on a size-structured version of the McKendrick-Von Foerster equation is used to demonstrate a theoretical link between the population size distribution and the underlying vital rates (recruitment, mortality and diameter growth) for the population of individuals whose diameter distribution is negative exponential. This model supports the conclusion that the negative exponential distribution as applied to balanced natural uneven-aged stands is a stable equilibrium model under appropriate assumptions. These assumptions include constant recruitment of stems into...

The uneven provisioning of ecosystem services has important policy implications; yet the spatial heterogeneity of tree canopy remains understudied. Private residential lands are important to the future of Philadelphia’s urban forest because a majority of the existing and possible tree canopy is located on residential land uses. This article examines the spatial distribution of tree canopy in Philadelphia, PA and its social correlates. How are existing tree canopy and opportunities for additional tree canopy distributed across the city of Philadelphia and with respect to three explanations:...

In recent years, the Alabama shad (Alosa alabamae) has experienced dramatic declines and extirpations from portions of its native range. Habitat degradation and barriers to migration are considered contributing factors to contraction in the distributional range this species. To identify conditions during successful spawning, river temperatures and discharges in 2 drainages of the northern Gulf of Mexico (the Apalachicola and Pascagoula rivers) were characterized during successful hatching “windows.” Sampling during 2005–2009 yielded 400 juvenile Alabama shad of which 261 were aged from...

The spread of white nose syndrome raises serious concerns about the long-term viability of affected bat species. Here we examine the geographic distribution of genetic variation, levels of population connectivity that may influence the spatial spread of WNS, and the likelihood that recent population declines in regions affected by WNS have led to the loss of unique genetic variation for the endangered Indiana bat (Myotis sodalis). We amplified a fragment of the mitochondrial control region for 375 individuals and genotyped 445 individuals at 10 microsatellite loci from 18 sampling sites...

Field-based public natural resource managers in the Lake States (MI, MN, WI) were surveyed for theirperspectives on various aspects of private forest land parcelization. This includes their perceptions ofrecent changes in parcelization activity, drivers and impacts, mitigation strategies, and ability to influenceparcelization. Their perspectives on the implications private forest land parcelization has on public landmanagement were also sought. Across the Lake States, most public natural resource managers havewitnessed an increasing frequency of forest land parcelization. They consider...

Natural forest disturbances, which drive succession and development, differ in extent, severity, and return interval and range from frequent, gap-scale disturbances, to infrequent stand-replacing events. Most studies have focused on natural disturbances near the ends of the disturbance severity gradient and relatively little quantitative information is available on intermediate-severity disturbance. On 20 April 2011, an EF1 tornado tracked 5 km through the Sipsey Wilderness in Alabama and resulted in a patchwork mosaic of disturbed areas. To analyze the effects of the intermediate-severity...

PREMISE OF THE STUDY: Molecular genetic evidence can help delineate taxa in species complexes that lack diagnostic morphological characters. Pinus ponderosa (Pinaceae; subsection Ponderosae ) is recognized as a problematic taxon: plastid phylogenies of exemplars were paraphyletic, and mitochondrial phylogeography suggested at least four subdivisions of P. ponderosa. These patterns have not been examined in the context of other Ponderosae species. We hypothesized that putative intraspecific subdivisions might each represent a separate taxon. METHODS: We genotyped six highly variable plastid...

Efforts to manage and eradicate invasive species can benefit from an improved understanding of the physiology, biology, and behavior of the target species, and ongoing efforts to eradicate the Asian longhorned beetle (Anoplophora glabripennis Motschulsky) highlight the roles this information may play. Here, we present a climate-driven phenology model for A. glabripennis that provides simulated life-tables for populations of individual beetles under variable climatic conditions that takes into account the variable number of instars beetles may undergo as larvae. Phenology parameters in the...

Studies of historical fire and vegetation conditions in dry conifer forests have demonstrated a high degree of heterogeneity across landscapes. However, there is a limit to the amount of inference that can be drawn from historical fire reconstructions. Contemporary "reference" landscapes may be able to provide information that is not available from historical reconstructions. In this study, we characterized variability in vegetation structure and composition across two Sierra Nevada landscapes with long-established fire restoration programs. We used tree, shrub, and surface fuel data from...