Treesearch

Prescribed fire is an increasingly important tool in restoring ecological conditions and reducing uncontrolled wildfire. Prescribed burn techniques could reduce public health impacts associated with wildfire smoke exposure. However, there have been few assessments of the health impacts of prescribed burning, and potential vulnerabilities among populations exposed to smoke from prescribed fires. Our study area focused on counties in and near U.S. National Forests – a set of lands distributed across the U.S. In county-level analyses, we compared the sociodemographic and health characteristics...

Heat-related mortality is one of the leading causes of weather-related deaths in the United States. With changing climates and an aging population, effective adaptive strategies to address public health and environmental justice issues associated with extreme heat will be increasingly important. One effective adaptive strategy for reducing heat-related mortality is increasing tree cover. Designing such a strategy requires decision-support tools that provide spatial and temporal information about impacts. We apply such a tool to estimate spatially and temporally explicit reductions in...

Fire severity is a key driver shaping the ecological structure and function of North American boreal ecosystems, a biome dominated by large, high-intensity wildfires. Satellite-derived burn severity maps have been an important tool in these remote landscapes for both fire and resource management. The conventional methodology to produce satellite-inferred fire severity maps generally involves comparing imagery from 1 year before and 1 year after a fire, yet environmental conditions unique to the boreal have limited the accuracy of resulting products. We introduce an alternative method - the...

Context. Many forest tree species are composed of a gradient of populations adapted to different environmental segments, especially to temperature gradients. Therefore, populations are likely to respond differently to climate change compared to the entire species. Objectives. Using Pinus strobus as an example, we model geographic patterns of growth potential and habitat suitability to understand how intraspecific genetic variation affects its response under climate change, and facilitate management. Methods. We model populations' growth potential based on data from provenance tests and...

Water supply impairment from increased contaminant mobilization and transport after wildfire is a major concern for communities that rely on surface water from fire-prone watersheds. In this article we present a Monte Carlo simulation method to quantify the likelihood of wildfire impairing water supplies by combining stochastic representations of annual wildfire and rainfall activity. Water quality impairment was evaluated in terms of turbidity limits for treatment by modeling wildfire burn severity, postfire erosion, sediment transport, and suspended sediment dilution in receiving...

Many plant-sap-feeding insects have maintained a single, obligate, nutritional symbiont over the long history of their lineage. This senior symbiont may be joined by one or more junior symbionts that compensate for gaps in function incurred through genomedegradative forces. Adelgids are sap-sucking insects that feed solely on conifer trees and follow complex life cycles in which the diet fluctuates in nutrient levels. Adelgids are unusual in that both senior and junior symbionts appear to have been replaced repeatedly over their evolutionary history. Genomes can provide clues to understandi...

Ecological restoration commonly emphasizes reestablishing native plant communities. Implicit in this approach is the assumption that actively restoring plant communities can passively restore structure and function of other community components like wildlife. However, this assumption is rarely tested. We evaluated how plant restoration in grasslands of the northwestern Unites States affected the structure (composition and relative abundance) of native small mammal communities and the important functional role they play as seed predators. We quantified vegetation, small mammal community...

Unmaintained vacant land in urban areas is associated with a number of negative outcomes for residents of urban areas, including mental and physical health, safety, and quality of life. Community programs which promote land parcel maintenance in urban neighborhoods have been found to reverse some of the effects that unmaintained land has on nearby residents. We explored how land parcel maintenance is associated with mental health outcomes using data collected in Flint, MI in 2017–2018. Trained observers assessed the maintenance of approximately 7200 land parcels and surveyed 691 residents...

Pyrodiversity is the spatial or temporal variability in fire effects across a landscape. Multiple ecological hypotheses, when applied to the context of post-fire systems, suggest that high pyrodiversity will lead to high biodiversity. This resultant “pyrodiversity-biodiversity” hypothesis has grown popular but has received mixed support by recent empirical research. In this paper, we sought to review the existing pyrodiversity literature, appraise support for the pyrodiversity-biodiversity hypothesis, examine potential mechanisms underlying the hypothesis and identify outstanding questions...

The heating of a fuel element representing a vertically oriented living manzanita leaf was computationally investigated. The computational conditions resembled a previous experimental setup where manzanita leaves were exposed to an upward stream of hot gases supplying the convective heating and a radiant panel providing the radiative heating. The simulations confirmed the experimental observations as to what the impact of the heating mode is on ignition. The convection-only and combined convection and radiation modes resulted in ignition and flaming whereas the radiation-only mode did not....