Treesearch

The Fire and Climate Synthesis (FACS) project is a collaboration of about 50 fire ecologists to compile and synthesize fire and climate data for western North America. We have compiled nearly 900 multi-century fire-scar based fire histories from the western United States, Canada, and Mexico. The resulting tree-ring based fire history is the largest and most spatially extensive in the world, consisting of annually crossdated fire records for more than 3,000 years (1248 BC -2011 AD) and representing more than 15,000 site-year fire records. State space analysis indicates that the fire history...

Ponderosa pine and dry mixed-conifer forests in the Southwest United States are experiencing, or have become increasingly susceptible to, large-scale severe wildfire, insect, and disease episodes resulting in altered plant and animal demographics, reduced productivity and biodiversity, and impaired ecosystem processes and functions. We present a management framework based on a synthesis of science on forest ecology and management, reference conditions, and lessons learned during implementations of our restoration framework. Our framework focuses on the restoration of key elements similar...

Th inning of forests has been proposed as a means to increase the carbon stores of forests. Th e justifi cation often offered is that thinning increases stand productivity, which in turn leads to higher carbon stores. While thinning of forests clearly increases the growth of residual trees and increases the amount of harvested carbon compared to an unthinned stand, there is little theoretical or empirical basis for believing that this activity increases the average carbon stores of forests. By removing trees, leaf area is temporarily decreased and carbon input to the forest via photosynthes...

Th inning of forests has been proposed as a means to increase the carbon stores of forests. Th e justifi cation often offered is that thinning increases stand productivity, which in turn leads to higher carbon stores. While thinning of forests clearly increases the growth of residual trees and increases the amount of harvested carbon compared to an unthinned stand, there is little theoretical or empirical basis for believing that this activity increases the average carbon stores of forests. By removing trees, leaf area is temporarily decreased and carbon input to the forest via photosynthes...

Th inning has been increasingly used in the Pacifi c Northwest to restore structural and biological diversity to densely-stocked young- to mid-aged forests that have been previously intensively managed for timber production. In the short term, thinning promotes development of understory vegetation, which in turn can increase habitat diversity for wildlife, particularly for songbirds. Thinning also has been identifi ed as a potential approach to accelerate the development of characteristics that are typical of older forest stands. Both the immediate and long-term response of wildlife and...

Forest thinning has been widely used in the Pacifi c Northwest as a technique to accelerate latesuccessional vegetation characteristics and promote mature forest habitats for wildlife. Th inning treatments aff ect tree and understory vegetation development. Th e eff ects of thinning on bird abundance and occurrence vary by bird species and change over time, presumably as a result of changes in understory and overstory vegetation after thinning. However, this assumption has rarely been tested. Vegetation characteristics, such as canopy cover, understory density and composition are frequently...

Epiphytic lichen communities have become a focus for ecologists concerned with forest health because lichens are particularly responsive to forest management and air quality. Furthermore, they can contribute substantially to the diversity and nitrogen fi xation of a stand, and play a valuable role in the food web of many forest-dwelling organisms. Can strategic thinning in Pseudotsuga -Tsuga forests increase biodiversity or hasten the development of late-successional features in young second-growth forests? Approximately 10 years after variable-density commercial thinning, N fixing and...

Th e Demonstration of Ecosystem Management Options (DEMO) project is a large, interdisciplinary study designed to test the biological and silvicultural eff ects of green-tree retention in Douglas-fi r (Pseudotsuga menziesii) forests. Six treatments were replicated on six blocks in Washington and Oregon, USA: no harvest, 75 percent aggregated, 40 percent (dispersed and aggregated), and 15 percent (dispersed and aggregated) green-tree retention. We studied treatment eff ects on ectomycorrhizal fungi in three of the study blocks. Ectomycorrhizae (EM) were sampled by use of soil cores. Prior...