Treesearch

Awildfire at Blacks Mountain Experimental Forest provided the opportunity to observe fire severity at the point of transition between treated and untreated stands. At several locations in the forest, the wildfire burned from a dense stand of largely pole-size trees, into an area that had been recently treated with combinations of thinning and prescribed fire. These treatment areas are part of a large-scale experiment designed to evaluate stand structure, grazing and prescribed fire in an interior ponderosa pine (Pinus ponderosa P.&C. Lawson) forest. Tree survival and damage were sampled on...

Although the majority of fires in the western United States historically occurred during the late summer or early fall when fuels were dry and plants were dormant or nearly so, early-season prescribed burns are often ignited when fuels are still moist and plants are actively growing. The purpose of this study was to determine if burn season influences postfire vegetation recovery. Replicated early-season burn, late-season burn, and unburned control units were established in a mixed conifer forest, and understory vegetation was evaluated before and after treatment. Vegetation generally...

Bats frequently use basal hollows in trees to gain access to interior roost sites but it has been challenging to verify which species do so because it is difficult to capture bats or identify bats using acoustic methods at these locations. We employed noninvasive genetic sampling of guano to identify the species of bats that use basal hollows in redwood (Sequoia sempervirens) trees in coastal northern California. Guano was collected using screen traps suspended within the hollows of trees in the northern and central range of the redwood, in Del Norte and Mendocino County, California,...

This paper summarizes the occurrence and identification of California's first Lesser Frigatebird (Fregata ariel), a subadult female photographed on 15 July 2007 at Lanphere Dunes near Arcata, Humboldt Country. This record is the fourth of this species for North America and the first in the eastern Pacific Ocean of the Western Hemisphere.

We censused landbird populations on a small island during a year of intense trapping of the Common Myna Acridotheres tristis. We successfully removed mynas on Moturoa Island, Bay of Islands, with populations on the island decreasing in most areas, while holding steady on other, nearby islands where no trapping was conducted. The populations of many other bird species increased coincidently with the removal of mynas. This was most notable in the Tui Prosthemadera novaeseelandiae, Grey Warbler Gerygone igata, and Blackbird Turdus merula. Of 60 species-route comparisons, we found that 23...

Limber pine (Pinus flexilis James) stands along the eastern escarpment of the Sierra Nevada, California, experienced significant mortality from 1985 to 1995 during a period of sustained low precipitation and high temperature. The stands differ from old-growth limber pine forests in being dense, young, more even-aged, and located in warmer, drier microclimates. Tree growth showed high interannual variability. Relative to live trees, dead trees over their lifetimes had higher series sensitivity, grew more variably, and had lower growth. Although droughts recurred during the 20th century,...

We offer a conceptual framework for managing forested ecosystems under an assumption that future environments will be different from present but that we cannot be certain about the specifics of change. We encourage flexible approaches that promote reversible and incremental steps, and that favor ongoing learning and capacity to modify direction as situations change. We suggest that no single solution fits all future challenges, especially in the context of changing climates, and that the best strategy is to mix different approaches for different situations. Resources managers will be...

Crimson fountaingrass (Pennisetum setaceum) is a nonnative invasive grass that has occupied a significant portion of the western side of the island of Hawai`i. As a result, several fires in excess of 4,049 ha have occurred in the area over the past 20 y. We are studying the effectiveness of cattle grazing, aerial application of glyphosate herbicide, and prescribed burning to reduce the fuel loading of fountaingrass in this dry, tropical setting. Grazing and prescribed burning were applied as whole-plot treatments to plots ranging in area from 2.4 to 6.5 ha; glyphosate herbicide was...

Soil nourishes and sustains the forest, yet it’s also one of the least understood ecosystem components. In a landmark experiment involving the Forest Services of both the United States and Canada, scientist Robert F.Powers leads the world’s largest effort at understanding how to best manage this resource to improve the health and productivity of the forest.

Catastrophic wildfires burn every year in the forests of the Western United States. In the past, low-intensity wildfires were common and played an important ecological role that benefited these forests. But fire suppression policies over the last century have interrupted natural fire regimes. As a result, forests that were once characterized by an open structure and large trees are now densely packed with underbrush and smaller trees. As a further consequence, fires today tend to be uncharacteristically intense and destructive. Fire management treatments that reduce fuels through thinning...