Treesearch

Background: Remote sensing (RS) technologies provide unprecedented opportunities to assess forest structure at broad spatial scales. Light detection and ranging (LiDAR) is a powerful tool that offers detailed vertical information, but its consistent high-resolution coverage can be limited across vast areas and quantifying understory vegetation remains challenging due to occlusion. Conversely, while high-resolution RGB imagery is more accessible and valuable for large-scale analyses, it comes with higher uncertainty and only captures canopy-level information. Integrating RGB data with...

Since the 1960s, there has been an increasing trend in oak (Quercus spp.) dominated forests exhibiting poor oak regeneration and recruitment, and associated hickories (Carya spp.) are likely undergoing a similar trend. Additionally, American chestnut (Castanea dentata) responses to management have been poorly studied. Silvicultural treatments to increase oak regeneration include prescribed fires and stand thinning, but often show mixed results. One potential issue is grouping oaks and hickories when analyzing treatment responses. This may obscure species- or genus-specific responses,...

Soils are a critical component of forest ecosystems and the global terrestrial carbon cycle. They regulate the resources that limit plant and microbial activity, support biodiversity, serve as reservoirs of carbon, and influence forest health. Systematic soil data can help fill key knowledge gaps, such as the sensitivity of forest health and functioning to disturbances and agents of change and the capacity of soils to help mitigate climate change through carbon storage. Since 2000, the Nationwide Forest Inventory (NFI) conducted by the Forest Inventory and Analysis (FIA) program has...

Forest harvesting can lead to mercury (Hg) mobilization from soils to aquatic habitats and promote the transformation of inorganic Hg to highly neurotoxic and bioaccumulative methyl-Hg (MeHg). Multiple past studies reveal broad variation of stream water MeHg and total Hg (THg) concentration responses to forest harvesting, which has confounded messaging to forest and resource managers. To advance beyond divergent and sometimes contradictory findings, we synthesized information for 23 previously studied catchments in North America and Fennoscandia and compiled a uniform set of soil, landscape...

In recent years, much attention has focused on strategies to reverse the decline of social capital in the United States. Increased social capital, which includes both intergroup contact and civic engagement, has many important benefits. For low-income individuals, friendships with high-income individuals (“economic connectedness”, a measure of inter-group contact) are one of the strongest predictors of their ability to escape poverty and gain increased life opportunities. Volunteering, a measure of civic engagement, is hypothesized to be key in building trust among neighbors. Urban parks...

Urban tree cover (UTC) is a commonly used metric in policy and management activities, including urban forest resources assessment, equity and distribution, and ecosystem services modelling. Despite the well-established benefits associated with urban tree canopy, declining tree cover has catalysed many cities into setting UTC targets. In this short communication, we used an assessment of UTC targets set by 57 cities worldwide to discuss the merits and drawbacks of setting UTC targets and to inform recommendations for setting effective UTC targets. We found that UTC targets range in ambition,...

Changing climates are creating more intense and frequent high-temperature events that could disrupt forest communities. In temperate forests, we have a relatively limited understanding of how trees are impacted by heat events, hindering our ability to predict the impacts of future heat waves. We conducted a community-level assessment of thermal safety margins in 11 hardwood tree species native to eastern North America. We used chlorophyll fluorescence to determine the critical heat tolerance of photosystem II (PSII) across 2 years in central Tennessee, USA. We focus on the temperature at...

Social equity, and the related topic of social vulnerability, is an important issue that is impacting many facets of society, including forests. A substantial portion, 39 %, of forests in the United States are owned by families, individuals, trusts, estates, and family partnerships, collectively referred to as family forest owners. There are many programs and services intended to help family forest owners conserve and better manage their land, but participation rates are relatively low, the efficacy of many programs has been called into question, and the social equitability of access is...

Ecological theory predicts that consumers should be co-limited by resource quantity and quality, given widespread consumer-resource nutritional imbalances. We used 25 estimates of annual community secondary production (ACSP) of stream macroinvertebrates to assess the relative roles of basal resource quantity (leaf litter standing stock [LLSS]) and quality (% nitrogen and % phosphorus of leaf litter) in modulating patterns of production in forest streams. We also tested the effects of hypothesized indirect drivers (stream discharge and inorganic nutrient concentrations) on basal resource...

Climate change is reducing snowpack across temperate regions with negative consequences for human and natural systems. Because forest canopies create microclimates that preserve snowpack, managing forests to support snow refugia—defined here as areas that remain relatively buffered from contemporary climate change over time that sustain snow quality, quantity, and/or timing appropriate to the landscape—could reduce climate change impacts on snow cover, sustaining the benefits of snow. We review the current understanding of how forest canopies affect snow, finding that while closed-conifer...