Treesearch

In the past, the dry mixed conifer forests of California’s Sierra Nevada mountains experienced frequent low to mixed severity fires. However, due to fire suppression and past management, forest structure has changed, and the new fire regimes are characterized by large, high severity fires which kill a majority of the overstory trees. These new disturbance patterns require novel approaches to regenerate the forest as they are not adapted to large, high severity fires. We forecasted growth and fire behavior of young plantations for 100 years into the future using the Forest Vegetation...

Located in North Central Utah, Emigration Canyon is a prominent and historic canyon that runs northeast from Salt Lake City into the higher elevations of the Wasatch Mountains. The Wasatch Range is characterized by steep, rocky slopes and 26-44 millimeters of annual rainfall, both of which contribute to a high threat of wildfire. The area’s landscape is diverse with oak woodland at the lower elevations up to a conifer forest type including ponderosa pine, Douglas-fir, and subalpine fir. The Utah Wildfire Risk Assessment Portal (UWRAP) rates the fire danger in Emigration Canyon as “Extreme.”...

Despite the abundance of tree diversity in the natural world, and generally high tree species richness in urban areas, urban forests continue to be dominated by a limited number of species. As socio-ecological systems, urban forests are shaped by historical and current management efforts and decision-making across a wide range of human actors. Drawing on past research, we offer a conceptual framework for describing the complex interactions among tree producers and consumers as trees are selected, grown, specified, and planted in private and public urban areas. We illustrate how multiple...

The wildland-urban interface (WUI), where housing intermingles with wildland vegetation, is the fastest-growing land use type in the United States. Given the ecological and social benefits of forest ecosystems, there is a growing need to more fully understand how such development alters the landscape context and structure of these WUI forests. In a space-for-time analysis we utilized land cover data, forest inventory plots, and housing density data over time to examine differences in forest characteristics of the northern US across three WUI change classes: (a) forest that has been in WUI...

Thousands of insect species have been introduced outside of their native ranges, and some of them strongly impact ecosystems and human societies. Because a large fraction of insects feed on or are associated with plants, nonnative plants provide habitat and resources for invading insects, thereby facilitating their establishment. Furthermore, plant imports represent one of the main pathways for accidental nonnative insect introductions. Here, we tested the hypothesis that plant invasions precede and promote insect invasions. We found that geographical variation in current nonnative insect...

Background: Wildfire is a landscape disturbance important for stream ecosystems and the recruitment of large wood (LW; LW describes wood in streams) into streams, with post-fire management also playing a role. We used a stratified random sample of 4th-order watersheds that represent a range of pre-fire stand age and fire severity from unburned to entirely burned watersheds to 1) determine whether watershed stand age (pre-fire) or fire severity affected riparian overstory survival, riparian coarse wood (CW; CW describes wood in riparian areas), LW, or in-stream physical, chemical, and...

For more than 150 years, the exotic defoliator spongy moth, Lymantria dispar L. (Lepidoptera: Erebidae, formerly known as the "gypsy moth"), has impacted forests and been a nuisance to residents in the eastern United States. Management of this non-native, invasive species dates back to the late 1800s, and more recent eradication and suppression techniques have evolved from intensive, tedious management actions to integrated pest management programs that are coordinated by state and federal agencies. Five previous management programs dating from 1923 to 1999 have laid the framework for the...

The National Slow the Spread (STS) Program represents the largest strategy to limit the impacts of the exotic spongy moth, Lymantria dispar L. (Lepidoptera: Erebidae, formerly known as the "gypsy moth"), in the United States. The STS Foundation, a non-profit organization, state and federal agencies, and university partners work collaboratively in three committees (operations, regulatory, and technical) to reduce the rate of spread of L. dispar. Since 2000, state agencies and the U.S. Department of Agriculture (USDA) Forest Service annually plan and implement trap and treatment activities,...

For 20 years, the National Slow the Spread (STS) Program has successfully slowed the rate of spread of the non-native spongy moth, Lymantria dispar L. (Lepidoptera: Erebidae, formerly known as the "gypsy moth"), to a mean rate of 2.6 km/yr, an 87 percent reduction from its historical rate of spread and surpassing the program’s goal of a 60 percent reduction. Because the program has been so successful and the location of the population front has remained in the same general area, state partners have remained fairly consistent during the course of the program. Much of the program focuses on...

The spread of spongy moth, Lymantria dispar L. (Lepidoptera: Erebidae, formerly known as the "gypsy moth"), in North America arguably represents the best-studied biological invasion in the world, due in part to extensive monitoring data from the USDA National Slow the Spread (STS) Program. In this paper, we focus on recent research on spread, with particular emphasis on findings since the publication of Tobin and Blackburn (2007). Recent advances in understanding L. dispar spread generally fall into three categories: (1) the role of mating success and Allee effects, (2) the effects of...