Treesearch

Improving the accuracy of fire behavior prediction requires better understanding of live fuel, the dominant component of tree crowns, which dictates the consumption and energy release of the crown fire flame-front. Live fuel flammability is not well represented by existing evaluation methods. High-flammability live fuel, e.g., in conifers, may maintain or increase the energy release of the advancing crown fire flame-front, while low-flammability live fuel, e.g., in boreal deciduous stands, may reduce or eventually suppress flame-front energy release. To better characterize these fuel-flame-...

Promoting sustainability of ecosystems and economic development is a dual national objective in China, as well as one of the sustainable development goals (SDGs) of the United Nations. The Three-River Headwaters Region, where a National Park initiative has been initiated in the pastoral region of the Qinghai-Tibetan Plateau, is one of the key pilot projects in China with sustainability targets for 2025 and 2035. This paper assesses the possibility of achieving established targets for the proportion of cultivated to available grassland. These targets consider both ecosystem protection and...

The worldwide decline in bee populations is threatening the delivery of pollination services, thus leading to the development of pollinator restoration strategies. In the United States, one way to protect and restore bee populations is to use seed mixes composed of pollinator-friendly native plants to revegetate federal lands following disturbance. However, we lack information about which native plant species and mixes are best for bees. We assessed the attractiveness and use by bees of 24 native plant species that are standard for revegetation projects (focal plants) on national forest...

Heat waves lasting days or weeks are among potential hazards expected to increase with climate change, but beyond heat waves, sustained temperatures may be incompatible with high urban population densities. I examined patterns of population density classes and exposure to maximum monthly temperature to identify where high urban population density classes were more at risk for prolonged heat than other density classes and if heat may have influenced high urban population densities during the recent past (1970-2000). Then, I considered exposure of population density classes to maximum...

Eastern redcedar (Juniperus virginiana L.) is increasing in density in the eastern United States and expanding in range to the west, while western Juniperus species also are increasing and expanding, creating the potential for a novel assemblage. I estimated range expansion and intersection by comparing recent USDA Forest Service Forest Inventory and Analysis surveys (mean year = 2009) to the oldest available surveys (mean year = 1981), with adjustments for sampling changes, and predicted climate envelopes during the following year ranges: 1500-1599, 1800-1849, 1850-1899, 1900-1949, and...

Over the last decade, a team of researchers and practitioners, referred to as the Wildfire Research Team (WiRē1 Team), has worked with wildfire practitioners seeking to create communities that are adapted to wildfire through an evidenced-based approach. The West Region Wildfire Council (WRWC) has been an integral partner amongst the WiRē Team throughout this time. Together, the WiRē Team has developed a systematic data collection and integration approach (the WiRē approach) that informs local wildfire risk education efforts and allows for monitoring of community adaptation over time....

Climate warming in recent decades has negatively impacted forest health in the western United States. Here, we report on potential early warning signals (EWS) for drought-related mortality derived from measurements of tree-ring growth (ring width index; RWI) and carbon isotope discrimination (Δ13C), primarily focused on ponderosa pine (Pinus ponderosa). Sampling was conducted in the southern Sierra Nevada Mountains, near the epicenter of drought severity and mortality associated with the 2012-2015 California drought and concurrent outbreak of western pine beetle (Dendroctonus brevicomis)....

Despite the ecological and socioeconomic impacts of wildfires, little attention has been paid to the spatiotemporal patterns of nighttime fire activity across the conterminous United States (CONUS). Daytime fire radiative power (FRP) detected by the Moderate Resolution Imaging Spectroradiometer (MODIS) was nearly evenly split (54% vs. 46%) between inside and outside wildfires from 2003 to 2020. In contrast, 94% of nighttime FRP was detected within wildfires, of which 95% was detected within large wildfires (> 2023 ha). Nighttime proportions (i.e., the proportion of total summed FRP...

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...

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...