Treesearch

The boreal biome represents approximately one third of the world’s forested area and plays an important role in global biogeochemical and energy cycles. Numerous studies in boreal Alaska have concluded that growth of black and white spruce is declining as a result of temperature-induced drought stress. The combined evidence of declining spruce growth and changes in the fire regime that favor establishment of deciduous tree species has led some investigators to suggest the region may be transitioning from dominance by spruce to dominance by deciduous forests and/or grasslands. Although...

The determination of invasion stages and the degree to which an invasive plant (non-native invasive plant, NNIP) has become established and spread in an ecosystem (\invasiveness") is essential for developing methods of mitigation and control. We mapped the invasion stages and quantified the invasiveness of four NNIPs of great concern, multiflora rose (Rosa multiflora Thunb), nonnative bush honeysuckles (including four species from the Lonicera spp family), common buckthorn (Rhamnus cathartica L.) and garlic mustard (Alliaria petiolata [M. Bieb.] Cavara & Grande) in the Upper Midwest...

Wood decay fungi are any species of fungi that utilise the structural components of wood as a source of nutrients. They comprise a very diverse group and have a worldwide distribution normally wherever trees are found. Wood decay fungi are vital to ecosystem functioning as they facilitate the decomposition of woody materials into soil. Wood decay fungi are also major contributors to damage to wood in service in both residential and industrial applications, leading to estimated $1B in losses annually. Wood decay fungi have also been exploited for use in industrial processes ranging from...

Environmental restoration projects are widely used as a means to reverse the degradation and damage done to an ecosystem by a range of different disturbances. Literature shows that engaging the public in restoration projects is important to long-term success; therefore, it is important to understand who participates in stewardship of these projects and why. Here, researchers investigate what aspects of individuals' environmental knowledge, environmental identity, demographics, views of and engagement in their community, and current civic stewardship might predict willingness to engage in...

Genetic resistance to white pine blister rust (WPBR) will play a critical role in the future trajectory of whitebark pine and the other high elevation white pines. However, as we found during the field trips at the WPEF Science Conference in September, the terminology associated with genetic disease resistance can get confusing, e.g. not all seed trees are plus trees and not all plus trees have genetic resistance.

Separating symbioses from incidental associations is a major obstacle in symbiosis research. In this survey of fungi associated with Asian bark and ambrosia beetles, we used quantitative culture and DNA barcode identification to characterize fungal communities associated with co-infesting beetle species in pines (Pinus) of China and Vietnam. To quantitatively discern likely symbioses from coincidental associations, we used multivariate analysis and multilevel pattern analysis (a type of indicator species analysis). Nearly half of the variation in fungal community composition in beetle...

Many socioeconomic constraints exist for biomass removals from federal lands in the western U.S. We examine several issues of importance, including biomass supply chains and harvesting costs, innovative new uses for bioenergy products, and the policy framework in place to provide incentives for biomass use. Western states vary greatly in the extent and utilization of forest resources, the proportion of land under federal ownership, and community and stakeholder structure and dynamics. Our research—which focused on the socioeconomic factors associated with biomass removal, production, and...

Naturally-durable wood species are offered as an alternative to chemically-treated wood for decking and siding. Restrictions on imports due to non-sustainable forest practices often limit the availability of tropical hardwoods, many of which are considered durable. The Forest Products Laboratory is evaluating native naturally-durable woods for use in covered bridge repair and rehabilitation in conjunction with the Federal Highway Administration to provide native alternatives to tropical hardwoods. Six wood species that are considered either invasive or underutilized were selected for both...

Wildland managers and law enforcement organizations devote significant resources attending to the consequences of illegal firesetting across many parts of the world. Intentional wildfires may be set for reasons of malice, as acts of protest, or as pure vandalism. Incendiary wildfires result in deaths, property, and resource damages that exceed rates found for fires of accidental or natural origin. In fact, there is a great concern with how such fires tend to occur nearer populations and values at risk. Extensive evidence suggests that arsonists were behind many of the deadly wildfires that...

Simulations of stream temperatures showed a wide range of future thermal regimes under a warming climate — from 2.9°C warmer to 7.6°C cooler than current conditions — depending primarily on shade from riparian vegetation. We used the stream temperature model, Heat Source, to analyze a 37‐km study segment of the upper Middle Fork John Day River, located in northeast Oregon, USA. We developed alternative future scenarios based on downscaled projections from climate change models and the composition and structure of native riparian forests. We examined 36 scenarios combining future changes in...