Treesearch

Background: Locating terrestrial sources and sinks of carbon (C) will be critical to developing strategies that contribute to the climate change mitigation goals of the Paris Agreement. Here we present spatially resolved estimates of net C change across United States (US) forest lands between 2006 and 2010 and attribute them to natural and anthropogenic processes. Results: Forests in the conterminous US sequestered −460 ± 48 Tg C year−1, while C losses from disturbance averaged 191 ± 10 Tg C year−1. Combining estimates of net C losses and gains results in net carbon change of −269 ± 49 Tg...

Wildfire can damage headwater wetlands, yet the value of post-fire restoration treatments in channels has been contested. Staff from the White Mountain Apache Tribe, students from the local Cibecue Community School, and researchers from the U.S. Forest Service collaboratively recorded channel responses over 13 years at two headwater wetlands lying within watersheds that were severely burned by the Rodeo-Chediski wildfire (Arizona, U.S.) in 2002. One site, Turkey Spring, was left largely untreated for 11 years following the fire, while the second site, Swamp Spring, was treated in 2005 by...

Among the many threats posed by invasions of nonnative species is introgressive hybridization, which can lead to the genomic extinction of native taxa. This phenomenon is regarded as common and perhaps inevitable among native cutthroat trout and introduced rainbow trout in western North America, despite that these taxa naturally co-occur in some locations. We conducted a synthetic analysis of 13,315 genotyped fish from 558 sites by building logistic regression models using data from geospatial stream databases and from 12 published studies of hybridization to assess whether environmental...

White-nose syndrome (WNS) is an emerging fungal disease of bats caused by Pseudogymnoascus destructans. Since it was first detected near Albany, NY, in 2006, the fungus has spread across eastern North America, killing unprecedented numbers of hibernating bats. The devastating impacts of WNS on Nearctic bat species are attributed to the likely introduction of P. destructans from Eurasia to naive host populations in eastern North America. Since 2006, the disease has spread in a gradual wavelike pattern consistent with introduction of the pathogen at a single location. Here, we describe the...

Persian walnut (Juglans regia L.) is the world's most widely grown nut crop, but large-scale assessments and comparisons of the genetic diversity of the crop are notably lacking. To guide the conservation and utilization of Persian walnut genetic resources, genotypes (n = 189) from 25 different regions in 14 countries on three continents were sampled to investigate their genetic relationships and diversity using ten microsatellite (SSR) loci. The SSRs amplified from 3 to 25 alleles per locus, with a mean value of 11.5 alleles per locus. The mean values of observed and expected heterozygosit...

This report provides a strategic approach developed by a Western Association of Fish and Wildlife Agencies interagency working group for conservation of sagebrush ecosystems, Greater sage-grouse, and Gunnison sage-grouse. It uses information on (1) factors that influence sagebrush ecosystem resilience to disturbance and resistance to nonnative invasive annual grasses and (2) distribution and relative abundance of sage-grouse populations to address persistent ecosystem threats, such as invasive annual grasses and wildfire, and land use and development threats, such as oil and gas development...

Resource utilization by earthworms affects soil C and N dynamics and further colonization of invasive earthworms. By applying 13C-labeled Tabebuia heterophylla leaves and 15N-labeled Andropogon glomeratus grass, we investigated resource utilization by three earthworm species (invasive endogeic Pontoscolex corethrurus, native anecic Estherella sp, and native endogeic Onychochaeta borincana) and their effects on soil C and N dynamics in Puerto Rican soils in a 22-day laboratory experiment. Changes of 13C/C and 15N/N in soils, earthworms, and microbial populations were analyzed to evaluate...

The Update to the 2010 Resources Planning Act (RPA) Assessment summarizes findings about the status, trends, and projected future of forests, rangelands, wildlife, biodiversity, water, outdoor recreation, and urban forests, as well as the effects of climate change upon these resources. Varying assumptions about population and economic growth, land use change, and global climate change from 2010 to 2060 largely influence the outlook for U.S. renewable resources. The key themes from the 2010 RPA Assessment remain relevant. Land development, climate change, and natural disturbances continue...

Heirs’ property is inherited land or real estate owned by two or more people as tenants in common. The property is typically passed to heirs without a will or with “clouded title” outside the formal probate process. This type of land tenure presents problems to its owners because it is very difficult for heirs to leverage such assets to enhance property values—for example, to use these assets as collateral to secure home improvement loans. Heirs’ property ownership also restricts landowner engagement with land improvement programs offered by State and Federal governments, again because of...

The 80 official experimental forests and ranges (EFR) administered by the U.S. Forest Service have provided a remarkable collection of research findings over the last 100 years, helping the agency address information needs related to forest and rangeland management. Long-term data sets are one of the most significant contributions of the EFR system, in particular, the ongoing, long-term studies of the effects of a changing climate on natural resources, streamflow, vegetation, and biogeochemistry from experimental watersheds. These data are crucial for examining ecosystem services from...