Treesearch

Forests across much of the United States are becoming denser. Trees growing in denser stands experience more competition for essential resources, which can make them more vulnerable to disturbances. Forest density can be expressed in terms of basal area, a metric that has been used to assess vulnerability of some forests to damage by certain insects or pathogens. A raster map of total tree basal area (TBA) for the conterminous United States was compared with annual (2000–2019) survey maps of forest damage due to insects and pathogens. Across each of four regions, median TBA was significantl...

Contemporary restoration and management of sagebrush-dominated (Artemisia spp.) ecosystems across the intermountain west of the United States increasingly involves the removal of expanding conifer, particularly juniper (Juniperus spp.) and pinyon pine ( Pinus edulis, P. monophylla). The impetus behind much of this management has been the demonstrated population benefits of sagebrush restoration via conifer removal to greater sage-grouse (Centrocercus urophasianus), a species of conservation concern. One of the challenges with scaling up from a focal-species approach to a community-level...

Anticipating consequences of disturbance interactions on ecosystem structure and function is a critical management priority as disturbance activity increases with warming climate. Across the Northern Hemisphere, extensive tree mortality from recent bark beetle outbreaks raises concerns about potential fire behavior and post-fire forest function. Silvicultural treatments (that is, partial or complete cutting of forest stands) may reduce outbreak severity and subsequent fuel loads, but longevity of pre-outbreak treatment effects on outbreak severity and post-outbreak fuel profiles remains...

Climate change is shifting the phenological timing, duration, and temporal overlap of interacting species in natural communities, reshaping temporal interaction networks worldwide. Despite much recent progress in documenting these phenological shifts, little is known about how the phenologies of species interactions are tracked across different life history stages. Here we analyze four key phenological traits and the pairwise interaction potential of nine amphibian species for the adult (calling/breeding) and subsequent larval (tadpole) stage at eight different sites over six years. We...

The 3rd Mass Timber Research Needs Assessment was held on September 20–22, 2022, at a location nearby the USDA Forest Service, Forest Products Laboratory. The workshop was co-sponsored by the Forest Products Lab and WoodWorks. The purpose of the workshop was to gather a diverse group of people with expertise in mass timber, in particular cross-laminated timber, to discuss and prioritize the research needed to move the mass timber industry forward in North America. The workshop was attended by more than 130 design professionals, researchers, manufacturers, industry leaders, and government...

Concerned about air quality in southcentral Seattle’s Duwamish Valley, community leaders collaborated with USDA Forest Service Pacific Northwest (PNW) Research Station to implement a study similar to one in Portland, Oregon, in 2015 that found that urban tree moss indicated the presence of airborne toxic metals.Together, PNW Research Station scientists and community leaders designed a study that not only collected moss samples from this heavily polluted area but also engaged 55 community members, including 25 members of the Duwamish Valley Youth Corps, to do so. The youth corps members...

A diverse, representative workforce is both beneficial and legally mandated for U.S. federal agencies. While previous research documents overall diversity within public agencies, like the USDA Forest Service, little is known about career outcomes and trajectories within these agencies. In this work, we look at individual-level career metrics which reveal patterns in employee retention, advancement, and termination. Using employment data for over 25,000 USDA Forest Service employees, we found that race/ethnicity, gender, and the interaction of these variables significantly related to each...

The long-term effects of harvesting on stand carbon (C) pools were assessed in a dry, interior pine-dominated forest at the Blacks Mountain Experimental Forest in northeastern California. Six 8-hectacre plots, established in 1938–1943, were treated as either an uncut control or a heavy-cut harvest (three-quarters of the stand volume removed). Response variables included C pools in overstory tree and shrub, coarse woody debris (CWD), forest floor, mineral soil (to 30 cm depth), cubicle brown root fragments of wood, fine roots, and ectomycorrhizal root tips. CWD was further classified as...

Giant reed (Arundo donax) is a prevalent invasive plant in desert riparian ecosystems that threatens wildlife habitat. From 2008 to 2018, under a United States–Mexico partnership, prescribed burns and herbicide applications were used to remove giant reed and promote native revegetation along the Rio Grande— Río Bravo floodplain in west Texas, USA, and Mexico. Our goal was to explore the effects of the removal efforts on butterfly and bird communities and their habitat along the United States portion of the Rio Grande—Río Bravo floodplain in Big Bend National Park, Texas. During spring and...

Orchid bees are abundant and widespread in the Neotropics, where males are important pollinators of orchids they visit to collect fragrant chemicals later used to court females. Assemblages of orchid bees have been intensively surveyed in parts of Central America, but less so in Belize, where we studied them during the late-wet and early-dry seasons of 2015-2020.