Treesearch

The twolined chestnut borer, Agrilus bilineatus (Weber), is a native North American buprestid beetle that normally infests oak (Quercus) trees stressed by drought or defoliation. However, during the 1980s and early 1990s, A. bilineatus preferentially infested English oak (Quercus robur L.) trees that initially appeared healthy at two experimental plantings in southern Michigan as well as on the Michigan State University (MSU) campus in East Lansing, Michigan. At both experimental plantings the English oaks were intermixed with native white oaks (Quercus alba L.) and had a border of native...

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...

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...

The U.S. Department of Agriculture, Forest Service National Best Management Practices (BMP) Program assists in meeting agency Clean Water Act objectives with nationally consistent monitoring. National BMP program monitoring protocols are used to evaluate BMP implementation (including planning) and effectiveness for most types of land-disturbing activities that occur on national forests and grasslands. This report summarizes data from the first two full monitoring periods—federal fiscal years 2015–2016 and 2017–2018—for aquatic ecosystems, chemical uses, facilities and nonrecreation special...

The emerald ash borer [Agrilus planipennis Fairmaire (Coleoptera:Buprestidae)] was first discovered in the United States in 2002 near Detroit, Michigan, and has spread quickly throughout the eastern United States and Canada, with isolated populations as far west as Oregon and British Columbia. Because ash trees in North America lack natural resistance to the beetle, emerald ash borer populations grew very quickly and have killed more than 100 million native ash trees. Since 2003, researchers with the U.S. Department of Agriculture, Forest Service, Northern Research Station have studied...

National forest inventory (NFI) programs provide vital information on forest parameters' status, trend, and change. Most NFI designs and estimation methods are tailored to estimate status over large areas but are not well suited to estimate trend and change, especially over small spatial areas and/or over short time periods (e.g. annual estimates). Fine-scale space-time indexed estimates are critical to a variety of environmental, ecological, and economic monitoring efforts. In the United States, for example, NFI data are used to estimate forest carbon status, trend, and change to support...

Forest canopy complexity (i.e., the three-dimensional structure of the canopy) is often associated with increased species diversity as well as high primary productivity across natural forests. However, canopy complexity, tree diversity, and productivity are often confounded in natural forests, and the mechanisms of these relationships remain unclear. Here, we used two large tree diversity experiments in North America to assess three hypotheses: (1) increasing tree diversity leads to increased canopy complexity, (2) canopy complexity is positively related to tree productivity, and (3) the...