Treesearch

Context Mountain meadows occur in specific geomorphological conditions where low-gradient topography promotes fine sediment accumulation and high groundwater tables. Over 150 years of human-caused hydrological degradation of meadows along with fire suppression has resulted in decreased groundwater elevations and encroachment of upland vegetation, greatly diminishing the ecological value of meadows for water storage, baseflow, sediment capture, wildfire resistance, wildlife habitat, and carbon storage. Objectives We aimed to understand where and how frequently meadows historically occurred...

Due to the multiple ecosystem benefits that iconic large, old growth trees provide, forest managers are applying thinning treatments around these legacy trees to improve their vigor and reduce mortality, especially in the face of climate change and other forest health threats. One objectives of this study was to analyze sub-hourly stem fluctuations of legacy ponderosa (Pinus ponderosa Dougl. Ex P. & C. Laws) and sugar pines (Pinus lambertiana Dougl.) in the mixed-conifer forests of the Sierra Nevada in multiple different radius thinning treatments to assess the short-term effects of these...

Integrated pest management (IPM) is perhaps best described as “…the maintenance of destructive agents, including insects, at tolerable levels by the planned use of a variety of preventative, suppressive or regulatory tactics that are ecologically and economically efficient and socially acceptable. It is implicit that the actions taken are fully integrated into the total resource management process in both planning and operation” (Waters 1974). Another useful definition of IPM is “an ecosystem-based strategy that focuses on long-term prevention of pests or their damage through a combination...

Fungal pathogens of the genus Ceratocystisrecently introduced to the Island of Hawaiʻi have killed hundreds of thousands of native ‘Ōhiʻa trees, an ecologically and culturally important keystone species. Symptoms of the associated disease, Rapid ‘Ōhiʻa Death (ROD), have been found to be easily detectable with high resolution imaging spectroscopy. We used wall-to-wall maps of affected ‘Ōhiʻa canopy built in four consecutive years (2016–2019) to analyze how changes in the distribution and density of browning canopy detections over this time period corresponded to environmental drivers at two...

Historically, wildfire and tribal burning practices played important roles in shaping ecosystems throughout the Klamath Siskiyou Bioregion of northern California and southern Oregon. Over the past several decades, there has been increased interest in the application of fire for forest management through the implementation of prescribed fires within habitats that are used by a diversity of migrant and resident land birds. While many bird species may benefit from habitat enhancements associated with wildfires, cultural burning, and prescribed fire, individuals may face direct or indirect...

Julian Steward believed that single-leaf pinyon pine (“pinyon pine” hereafter; Pinus monophylla) was the most important long-term plant resource for Great Basin Shoshoneans, wherever it occurred. Assuming that pinyon pine reproductive ecology was constant across the Great Basin, Steward set the stage for generations of anthropologists to universally assume that the unpredictable cycling rendered pinyon a notoriously erratic resource throughout the Intermountain West. And because pine nut harvests were unpredictable, this uncertain food source prevented Great Basin family clusters from...

As the frequency and severity of large wildfires in the western United States have grown, impacts to private property and air quality have typically attracted the greatest attention; however, wildfires can also substantially affect water resources, altering watershed function and contaminating drinking water supplies. Although there is significant scientific literature describing impacts of wildfires on water resources, the literature on economic dimensions of these impacts is limited. In this article, we identify ways in which economic analyses can contribute to understanding and managing...

Mixed tree-species forest management can increase forest resilience by reducing the impacts of disturbances that disproportionately affect a single tree species or closely related groups of tree species. Beyond disturbance-risk reduction, tree-species diversification may foster functional-diversity effects (e.g., complementarity or facilitation) that alter the performance of a given tree species in mixed versus pure stands, potentially benefitting carbon sequestration and wildlife habitat. Tree species-mixture effects have been explored to only a limited degree in western US forests and,...

The Agaricomycete Heterobasidion annosumsensu lato (s.l.), a species complex of fungal pathogens, causes root and butt rot on conifers throughout the northern hemisphere, thereby shaping structure, composition, and evolution of vast and diverse forest ecosystems. We analyze forest change 48–49 years following Heterobasidion root disease emergence in 63 permanent plots first established in 1970–1972 and measured at least once every decade through 2020. We use this dataset to infer the long-term consequences of Heterobasidionroot disease in a set of common forest types that reflect some of...

When wildlife species exhibit unexpected associations with vegetation, replication of studies in different locales can illuminate whether patterns of use are consistent or divergent. Our objective was to describe fine-scale forest conditions used by Pacific martens (Martes caurina) at 2 study sites in northern California that differed in forest composition and past timber harvest. We identified denning and resting locations of radio-marked martens and sampled structure- and plot-level vegetation using standardized forest inventory methods between 2009–2021. Woody structures used by martens...