The purposeful use of any silvicultural method, including mechanical methods, managed wildfire, prescribed fire, or a combination of approaches, to intentionally alter the fuel complex in such a way as to modify fire behavior and thereby minimize the potential negative impacts of future wildfires on ecosystem goods and services, cultural resources, and human communities.
Naturally occurring genetic diversity is the material upon which much of the biodiversity we attribute to forested ecosystems is based. The structuring of genetic diversity within natural populations of forest trees results from the interplay of numerous evolutionary forces, such as genetic drift, migration, and natural selection.
The health and regeneration of sugar pine (Pinus lambertiana), a major species in the mountain forests of California (USA), has been substantially affected by an exotic pathogen, Cronartium ribicola, which causes white pine blister rust. Seedlings from trees with major gene resistance (MGR) are being used to increase field survival in plantations.
Forest residues, including unmerchantable and small-diameter trees, tops, and limbs, produced during thinning and timber harvest operations can be used to produce renewable bioenergy and bioproducts. The more efficient utilization of forest residues could also help offset the high costs of forest restoration activities, fire hazard treatments, post-harvest activities and forest management in general.
Massive tree mortality has occurred rapidly in frequent-fire-adapted forests of the Sierra Nevada, California. This mortality is a product of acute drought compounded by the long-established removal of a key ecosystem process: frequent, low- to moderate-intensity fire. The recent tree mortality has many implications for the future of these forests and the ecological goods and services they provide to society.
To see a frequent-fire forest burn for the first time is to experience a remarkable teat of nature. Most people are accustomed to the slow change of forests with the seasons, not the instantaneous conversion of green and brown plant mass to smoke and char. Yet to visit such a forest a week after it bums is to see bright green shoots emerging, highlighted against a background of charcoal.
Wilderness management can be tricky. The conservationist Aldo Leopold, who is considered by many to be the father of wildlife ecology and the U.S. wilderness system, was probably thinking about this when he said, “All conservation of wildness is self-defeating, for to cherish we must Wilderness managers in North Cascades National Park opted for chemical treatments to remove invasive fish species.
The Lick Creek Demonstration/Research Forest is one of those places in the West that many foresters may not be familiar with by name but by photographs. Posters depicting forest change over the years circulated widely from the 1980s to 2000s, following Forest Service General Technical Reports from Gruell et al. (1982) and Smith and Arno (1999).
The boundary between woodlands and shrublands delineates the distribution of the tree biome in many regions across the globe. Woodlands and shrublands interface at multiple spatial scales, and many ecological processes operate at different spatial scales to determine the position of the woodland-shrubland boundary.
Climate change is already resulting in changes in cold desert ecosystems, lending urgency to the need to understand climate change effects and develop effective adaptation strategies. In this review, we synthesize information on changes in climate and hydrologic processes during the past century for the Great Basin and Columbia Plateau and discuss future projections for the 21st century.