Treesearch

Larger and more frequent disturbances are motivating efforts to accelerate recovery of foundational perennial species by focusing efforts into establishing island patches to sustain keystone species and facilitate recovery of the surrounding plant community. Evaluating the variability in abiotic and biotic factors that contribute to differences in survival and establishment can provide useful insight into the relative importance of these factors. In the western United States, severe degradation of the sagebrush steppe has motivated substantial efforts to restore native perennial cover, but...

The focus of investigation in this study was to consider the potential of arthropods in the dissemination of the bacterium involved in drippy blight disease, Lonsdalea quercina. Arthropod specimens were collected and tested for the presence of the bacterium with molecular markers. The bacteriumL. quercina was confirmed on 12 different insect samples fromthree orders (Coleoptera, Hemiptera, and Hymenoptera) and eight families (Buprestidae, Coccinellidae, Dermestidae, Coreidae, Pentatomidae and/or Miridae, Apidae, Formicidae, and Vespidae). Approximately half of the insects found to carry...

Insect and disease infestations pose major threats to several North American forest tree species. Scientists and managers from throughout the United States Forest Service developed a conservation priority-setting framework for forest tree species at risk from insects and disease and other threats. The Project CAPTURE (Conservation Assessment and Prioritization of Forest Trees Under Risk of Extirpation) framework is data-driven and guided by expert opinion, allowing the quantitative grouping of species into vulnerability classes that may require different management and conservation...

Diseases and insects, particularly those that are non-native and invasive, arguably pose the most destructive threat to North American forests. Currently, both exotic and native insects and diseases are producing extensive ecological damage and economic impacts. As part of an effort to identify United States tree species and forests most vulnerable to these epidemics, we compiled a list of the most serious insect and disease threats for 419 native tree species and assigned a severity rating for each of the 1378 combinations between mature tree hosts and 339 distinct insect and disease...

Formulations of entomopathogenic (insect-killing) fungi represent alternatives to synthetic insecticides in the management of forest and shade tree insects. We evaluated bark spray applications of the entomopathogen Beauveria bassiana (Balsamo) Vuillemin (Hypocreales: Cordycipitaceae) strain GHA (BotaniGardES), permethrin insecticide (Astro), and water (control) on colonization of black walnut (Juglans nigra L.) (Fagales: Juglandaceae) bolts by the walnut twig beetle (Pityophthorus juglandis Blackman) (Coleoptera: Curculionidae), vector of the fungus that causes thousand cankers disease....

Shifts in streamflow, due to future climate and land use change, may pose risks to nearby human communities. Projecting the spatial distribution and impacts of these risks requires consideration of biophysical and socioeconomic factors. Models like the Soil and Water Assessment Tool (SWAT) can project spatial distributions of hydrologic risk due to shifting biophysical factors like climate and land use, but cannot account for socioeconomic factors influencing a community’s capacity to adapt to future streamflow changes. To address this limitation, we used a risk matrix to classify subbasins...

The development of appropriate strategies towards the sustainable management of tropical second-growth forests is essential for human well-being and climate change mitigation. The well-documented process of forest recovery in Puerto Rico offers a unique opportunity to evaluate the potential of second-growth tropical forests for forestry. Here, we combined 10 years of forest inventory data with ethnobotanical information to determine trends in forest cover, stand structure, and timber volume, as well as the suitability of useful tree species for timber and non-timber forest products. We...

Melanerpes erythrocephalus (Red-headed Woodpecker) has experienced sharp declines in portions of its range. Knowledge of how birds use their nesting habitats, particularly what foods they exploit, may be important in determining causes of population declines, but no modern quantitative study exists on diets of nestling Red-headed Woodpeckers. Our objectives were to identify diets of nestling Red-headed Woodpeckers and quantify variability in food types over time and between roles of males and females in provisioning their young. We conducted observations of nests on the Savannah River...

Land use change (LUC), disturbances, and their interactions play an important role in regional forest carbon (C) dynamics. Here we quantified how these activities and events may influence future aboveground biomass (AGB) dynamics in forests using national forest inventory (NFI) and Landsat time series data in the Northern United States (US). Total forest AGB predictions were based on simulations of diameter growth, mortality, and recruitment using matrix growth models under varying levels of LUC and disturbance severity (low (L), medium (M), and high (H)) every five years from 2018 to...

Plant-plant interactions are important drivers of ecosystem structure and function, yet predicting interaction outcomes across environmental gradients remains challenging. Understanding how interactions are affected by ontogenetic shifts in plant characteristics can provide insight into the drivers of interactions and improve our ability to anticipate ecosystem responses to environmental change. We developed a conceptual framework of nurse shrub facilitation of tree establishment. We used a combination of field experiments and environmental measurements to test the framework with a shrub...