Treesearch

Drought, ozone (O3), and nitrogen deposition (N) alter foliar pigments and tree crown structure that may be remotely detectable. Remote sensing tools are needed that pre-emptively identify trees susceptible to environmental stresses could inform forest managers in advance of tree mortality risk. Jeffrey pine, a component of the economically important and widespread western yellow pine in North America was investigated in the southern Sierra Nevada. Transpiration of mature trees differed by 20% between microsites with adequate (mesic (M)) vs. limited (xeric (X)) water availability as...

National Scenic Trails (NSTs) connect people with the natural and cultural heritage of the United States. These trails also provide important opportunities for agencies to engage partners in trail stewardship and sponsorship. Partnership engagement ultimately promotes trails that provide outdoor experiences and learning opportunities for visitors and trail users. In the founding legislation of the National Trails System Act of 1968, Congress acknowledged the integral role of volunteers and trail groups and set out “to encourage and assist volunteer citizen involvement in the planning,...

Conserving forests to provide ecosystem services and biodiversity will be a key environmental challenge as society strives to adapt to climate change. The ecosystem services and biodiversity that forests provide will be influenced by the behaviors of numerous individual private landowners as they alter their use of forests in response to climate change and any future carbon pricing policies that emerge. We evaluated the impact of forest landowners’ likely adaptation behaviors on potential habitat for 35 terrestrial, forest-dependent vertebrates across three U.S. Pacific states. In particula...

Although there is widespread support for diversity in natural resources, diversity is valued for different reasons. It is important to understand and critically examine these reasons, to ensure diversity efforts express clear thinking and appropriate motivations. We compiled recent (2000–2019) diversity literature in fisheries, forestry, range, and wildlife, and used a qualitative coding procedure to identify reasons articulated in support of diversity. We developed a subset of these reasons into formal arguments to assess their underlying beliefs and assumptions. Our analysis reveals a...

Fire exclusion has dramatically altered historically fire adapted forests across western North America. In response, forest managers reduce forest fuels with mechanical thinning and/or prescribed burning to alter fire behavior, with additional objectives of restoring forest composition, structure, and ecosystem processes. There has been extensive research on the effects of fuel reduction and restoration treatments on trees, fuels, regeneration, and fire behavior; but less is known about how these treatments influence understory vegetation, which contains the majority of vascular plant...

Questions: A recently introduced non-native annual grass, Ventenata dubia, is challenging previous conceptions of community resistance in forest mosaic communities in the Inland Northwest. However, little is known of the drivers and potential ecological impacts of this rapidly expanding species. Here we (1) identify abiotic and biotic habitat characteristics associated with the V. dubia invasion and examine how these differ between V. dubia and other problematic non-native annual grasses, Bromus tectorum and Taeniatherum caput-medusae; and (2) determine how burning influences relationships...

In 1994, a large-tree harvest standard known as the “21-inch rule” was applied to land and resource management plans of national forests in eastern Oregon and Washington (hereafter, the “east side”) to halt the loss of large, old, live, and dead trees and old forest patches. These trees and forest patches have distinct ecological, economic, and social values, as reflected in widespread fish and wildlife use, public support for protecting them, and commercial interest in harvesting them, thus they have been the topic of much discussion and debate. At the request of regional Forest Service...

Considerable resources have been invested in ecological restoration projects across the globe to restore ecosystem integrity. Restoration strategies are often diverse and have been met with mixed success. In this article, we describe the Chinook salmon (Oncorhynchus tshawytscha) decision-support models developed by the Central Valley Project Improvement Act Science Integration Team as part of a larger structured decision-making effort aimed at maximizing natural adult production of Chinook salmon in California’s Central Valley, the United States. We then describe the decision-analytic...

In interior Alaska’s 115 million acres of boreal forest, white and black spruce are the dominant tree species. Climate models suggest that the region is becoming warmer and drier, resulting in declining growth of black and white spruce, according to some researchers. These drier conditions also may lead to greater risk of stand-replacing wildfires, resulting in forests dominated by birch and aspen, which are early-successional tree species. To compare long-term growth trends of the dominant coniferous and deciduous tree species, a team of researchers with the USDA Forest Service Pacific...

In recent years, many forest managers have become interested in managing forests for a wider range of objectives than previously. As an initial or intermediate treatment, variable-density thinning (VDT) can help meet objectives such as improving wildlife and plant habitats, increasing structural and compositional diversity, and enhancing aesthetic values in stands that are currently lacking spatial variability. The “skips and gaps” method of VDT is flexible, allowing for the preservation of existing desirable features. Areas that are not thinned (“skips”) will protect existing features...