Treesearch

Trying to monitor changes in the size of a bear population and frustrated with the small sample size due to budget constraints? Have you considered that many species provide easy-to-obtain samples by rubbing on all sorts of things and leaving hair throughout their range? Surveys conducted annually in Glacier NP, USA, 1983-1997 to investigate the use of passive bear sign deposition to monitor bear population trend revealed the high prevalence and wide geographic extent of bear rubbing and resulting hair deposition (K. Kendall, unpublished data). Further, bears like to use trails and roads,...

A warming climate and extended growing season may confer competitive advantages to temperate conifers that can photosynthesize across seasons. Whether this potential translates into increased growth is unclear, as is whether pollution could constrain growth. We examined two temperate conifers—eastern white pine (Pinus strobus L.) and eastern hemlock (Tsuga canadensis (L.) Carrière)—and analyzed associations between growth (476 trees in 23 plots) and numerous factors, including climate and pollutant deposition variables. Both species exhibited increasing growth over time and eastern white...

Although Dutch elm disease (DED) is the primary threat to American elm (Ulmus americana L.), we hypothesized that shoot freezing injury may also limit tree productivity and survival in the north. We assessed shoot cold tolerance and field winter injury of American elm bred for DED tolerance planted in Lemington, Vermont. We tested for differences in cold tolerance associated with date, maternal DED tolerance sources, paternal sources from plant hardiness zones 5a, 6a, and 6b (determined using data from 1996 to 2005), and the interactions of these. Cold tolerance was greatest in the winter,...

The Forest Sector Outlook Study 2020-2040 for the UNECE region provides information that supports decision making by showing the possible medium and long term consequences of specific policy choices and structural changes using scenario analyses whenever possible. The study is the first to cover the entire region and provides results for the main UNECE sub regions of Europe, North America and the Russian Federation. The study provides insight on six priority questions which were identified through a transparent and participatory process: (i) How would different demand changes affect the...

Dispersal is a key process that impacts population dynamics and structures biotic communities. Dispersal limitation influences the assembly of plant and microbial communities, including mycorrhizal fungi and their plant hosts. Mycorrhizal fungi play key ecological roles in forests by feeding nutrients to plants in exchange for sugars, so the dispersal of mycorrhizal fungi spores actively shapes plant communities. Although many fungi rely on wind for spore dispersal, some fungi have lost the ability to shoot their spores into the air and instead produce enclosed belowground fruiting bodies...

Wildfire management in the US relies on a complex nationwide network of shared resources that are allocated based on regional need. While this network bolsters firefighting capacity, it may also provide pathways for transmission of infectious diseases between fire sites. In this manuscript, we review a first attempt at building an epidemiological model adapted to the interconnected fire system, with the aims of supporting prevention and mitigation efforts along with understanding potential impacts to workforce capacity. Specifically, we developed an agent-based model of COVID-19 built on...

The wildfire management community has made great strides incorporating new decision support tools into how it plans for and responds to wildfire incidents. Despite improvements in risk assessment and management at the incident scale, increasing fire activity and critical resource shortages reveal a system under strain in need of strategies that more efficiently allocate scarce resources across incidents while promoting the well-being of the firefighting workforce upon which the system relies. A scaled-up infusion of data-driven analysis and decision-making could enhance the performance of...

Forest management guidelines are designed to protect water quality from unintended effects of land use changes such as timber harvest, mining, or forest road construction. Although streams that periodically cease to flow (nonperennial) drain the majority of forested areas, these streams are not consistently included in forest management guidelines. This paper reviews management guidelines for nonperennial (intermittent and ephemeral) streams draining temperate forests in the continental U.S., evaluates potential impacts of land use activities on ecosystem services provided by these...

This chapter is a review and synthesis of research conducted at Glacier Lakes Ecosystem Experiments Site (GLEES) on stream nutrients and biological responses. It is intended to inform national and regional water quality regulatory agencies, such as the U.S. Environmental Protection Agency and Wyoming Department of Environmental Quality (WDEQ), about existing results of relevant scientific studies that are available at GLEES, and to identify future field and synthetic research of potential use to regulatory agencies that might be conducted at GLEES.

Genetic diversity is essential because it provides a basis for adaptation and resilience to environmental stress and change. The fundamental importance of genetic variation is recognized by its inclusion in the Montréal Process sustainability criteria and indicators for temperate and boreal forests. The indicator that focuses on forest species at risk of losing genetic variation, however, has been difficult to address in a systematic fashion. We combined two broad-scale datasets to inform this indicator for the United States: (1) tree species occurrence data from the national Forest...