Treesearch

Small-scale variation in wildfire behavior may cause large differences in belowground bacterial and fungal communities with consequences for belowground microbial diversity, community assembly, and function. Here we combine pre-fire, active-fire, and post-wildfire measurements in a mixed-conifer forest to identify how fine-scale wildfire behavior, unburned refugia, and aboveground forest structure are associated with belowground bacterial and fungal communities nine years after wildfire. We used fine-scale mapping of small (0.9–172.6 m2) refugia to sample soil-associated burned and...

The population of the United States is aging as the Baby Boom generation grows older. In 2020, 23 percent of the U.S. population had reached age 60. The share of the population at older ages is forecast to increase to 26 percent in 2030 and 29 percent in 2050. Wildfire risks are also increasing, and older populations are especially vulnerable. This report found that most (87 percent) of the recent population growth in places with moderate-to-high wildfire risk has been among people over the age of 60. Already, the proportion of older people living in places with more wildfire risk is...

1. Disturbance regimes, like low-intensity fire, canopy gaps and ungulate browsing, play a critical role in determining ecological composition and structure in temperate forests around the world. 2. Each disturbance (or lack thereof) can lead to unique plant communities, but we do not understand how combined disturbances change plant diversity and the resulting soil seed bank. Changes in the soil seed bank, which depend on the plants that survive post-disturbance, can then influence future biodiversity and succession. 3. We used a long-term experiment in West Virginia, USA, that factorially...

Forest patches in urban landscapes make outsized contributions to biodiversity, ecosystem function, and human health and well-being. However, urbanization can alter environmental conditions that underpin forest health. Most studies of forest health in urban landscapes have focused on few forest patches across a single metropolitan region, and synthesis is needed to understand broader patterns. We assessed variation among measures of forest health across land cover gradients and ecoregions by determining (1) whether the degree of urban, agricultural, and forested land surrounding a forest...

Large-diameter trees provide vital ecological functions in forested ecosystems. Old, large-diameter trees may also be vulnerable to climate-driven mortality events, but past work on large tree populations has been geographically limited. Here, we characterize the population of large-diameter trees from two size categories, 50 to 100 cm diameter at breast height (DBH) (medium) and >100 cm DBH (big), within the United States using Forest Inventory and Analysis data. Although populations of big trees are concentrated along the west coast, populations of medium trees are more evenly distributed...

Audible sound is known to originate from wildland fires. We show audible sound is accompanied by infrasound emissions, originating from the active combustion zone in a prescribed fire. We collected data from one of multiple prescribed burns conducted at Eglin Airforce Base, Florida in March of 2023. Single-unit infrasonic sensors and a six-element array were deployed outside the burn unit to capture acoustic signals. The array was configured as a hexagon with aperture of ~10 m. Dual-band radiometers were deployed inside the unit to track the fire’s evolution. A broadband signal is observed...

In the US, environmental governance has devolved from a government-led process to one that empowers participation by environmental non-governmental organizations, such as land trusts (LTs). While public participation in US public land-use planning has been largely institutionalized, LTs and their use of conservation land acquisitions (both fee-simple and conservation easements (CEs)) do not have similar public input requirements. Some scholars have questioned whether CEs are in the public interest or represent more narrow interests. To explore how LTs interact with public planning processes...

Cryptogenic species are those that are not yet “demonstrably native or introduced” in a given area, such as crayfish in western Montana, USA. Delving into evidence from diverse fields can help clarify the status of cryptogenic species. Primary historical sources and indigenous knowledge have informed various ecological questions but are seldom used to clarify the status of cryptogenic species, especially aquatic taxa. We summarize types of evidence used to illuminate species status and offer a case study applying historical sources to cryptogenic crayfish in Montana. We searched for...

A long-term study of forest management, like the one established in the 1950s by the U.S. Department of Agriculture, Forest Service at the Penobscot Experimental Forest in Maine, provides a unique opportunity for landowners to learn about different approaches to management and their outcomes. After more than 70 years of research at the Penobscot Experimental Forest, it has become apparent that the management approaches applied have changed the species composition, tree quality, wildlife habitat, carbon storage, productivity, and financial value of the forest. The side-by-side comparisons...

Wildfire activity in the western U.S. has highlighted the importance of effective management to address this growing threat. The Lookout Mountain Thinning and Fuels Reduction Study (LMS) is an operational-scale, long-term study of the effects of forest restoration and fuel reduction treatments in ponderosa pine (Pinus ponderosa Dougl. ex Laws.) and mixed-conifer forests in central Oregon, U.S. The broad objectives of the LMS are to examine the effectiveness and longevity of treatments on wildfire risk and to assess the collateral effects. Treatments include four levels of overstory...