Treesearch

Drought is an important stressor affecting forests and is commonly defined as a period of moisture deficit resulting from below-average precipitation, high temperatures, or both (Clark and others 2016). Alone or in combination with other disturbances, drought can reduce forest productivity, cause shifts in forest types, affect the ability of forests to regenerate, and diminish the capacity of forests to provide ecosystem services (Brodribb and others 2020, Vose and others 2016). As climate warms and many parts of the world become drier, droughts are expected to become more widespread,...

This work developed a precipitation-based forest exposure indicator that identified warm season (May-Sept.) changed conditions between the multidecadal wet cycle from 1940s-1999 and dry cycle from 2000-2021 for the conterminous USA. Changed moisture conditions were validated for disturbance connection by assessing bark beetle and wildfire disturbance spatial records by severity of dry exposure. Results indicated 2-fold increase in wildfire and bark beetle disturbances from 2017-2022, respectively, for western U.S. locations with highest dry exposure classes vs. where dry exposure was...

Invasive omnivores may have profound impacts on ecological communities through diet selection, particularly when their functional roles differ from those in their native range. While the threat of feral pigs (Sus scrofa) to native plant communities in Hawai‘i is well known, their trophic dynamics and the drivers of variation in their diet remain understudied. We investigated the feral pig trophic niche on Hawai‘i Island using stable isotopes (13C and 15N) and Bayesian mixing models to identify drivers of variation in resource use. We also reconstructed intra-individual variability for six...

Wood–plastic composites are composite materials consisting of wood particles, thermoplastic polymer, and small amounts of other performance additives to increase performance in exterior construction applications such as decking and siding. Three best-performing fire retardants, determined from a previous study, which were brominated, magnesium hydroxide, and ammonium polyphosphate, were selected for this weathering study and more detailed analysis with color analysis, thermogravimetric analysis/differential scanning calorimetry, and the cone calorimeter. With the rapid surface heating...

Urban forests—trees within an urban area—provide substantial environmental and economic benefits, such as air purification, temperature regulation and energy savings, water absorption, and improved public health. However, these forests face multiple and overlapping threats that could reduce their capacity to deliver these benefits. Understanding threats to urban forests is critical for planning and implementing strategies that sustain urban forest health.

Forests and woodlands cover an extensive area of the United States, 333 million ha or approximately 36 percent of the Nation’s land area (Oswalt and others 2019). These forests provide a broad range of goods and services for current and future generations, safeguard biological diversity, and contribute to the resilience of ecosystems, societies, and economies (McGinley and others 2023). Their socioeconomic benefits include wood products, nontimber goods, reduction of air pollutants, moderation of city temperatures, recreational opportunities, and natural beauty. Their ecological roles...

The management of biodiversity on arid landscapes can be challenging: Arid landscapes are often highly vulnerable to environmental and land-use changes. Moreover, these landscapes are home to rare and endemic species which are difficult to monitor. Environmental DNA sampling - the inference of species presence from genetic material in the environment - using high-throughput quantitative PCR (HT-qPCR) panels may be an efficient, cost-effective monitoring tool when multiple, taxonomically diverse taxa are of conservation concern. We validated and applied a HT-qPCR panel to detect ten native,...

Understanding how species distributions and associated habitat are impacted by natural and anthropogenic disturbance is central for the conservation of rare forest carnivores dependent on subalpine forests. Canada lynx at their range periphery occupy subalpine forests that are structured by large-scale fire and insect outbreaks that increase with climate change. In addition, the Southern Rocky Mountains of the western United States is a destination for winter recreationists worldwide with an associated high degree of urbanization and resort development. We modeled habitat for a reintroduced...

Long‐distance acoustic signals mediate important social interactions between animals, and the structure of the environment can influence sound transmission to affect communication distance. Anthropogenic disturbances such as fire suppression alter forest structure and can potentially affect acoustic interactions by altering sound attenuation patterns. In the spruce‐fir and mixed‐conifer forests of the Pinaleño Mountains, Arizona, USA, that harbor endangered Mount Graham red squirrels (Tamiasciurus fremonti grahamensis), numerous historical anthropogenic disturbances have altered forest...

Accurate taxonomy is fundamental to the study and conservation of biodiversity. Because of their morphological similarities, most brook and river lampreys in western North America have been placed in the genus Lampetra along with lampreys from Eurasia and eastern North America. However, molecular-based phylogenetic studies dating back several decades indicate that lampreys from Pacific drainages are genetically distinct from Atlantic Lampetra. Reviewing previous phylogenetic analysis of two mitochondrial and two nuclear genes for Northern Hemisphere lampreys, we assign these western North...