Treesearch

In recent history, there has not been a more ecologically important event than the introduction of cheatgrass (Bromus tectorum) and red brome (Bromus rubens) into the Intermountain West. These grasses are very similar in ecology and history and are separated mostly by function of elevation. Both species are from the Mediterranean region, and both arrived in the Western United States about the same time (1880). Cheatgrass and red brome have greatly affected fire frequency and intensity, which has been detrimental to native shrubs and other perennials in these systems. Red brome may have had...

(Please note, this is an abstract only) After a century of fire suppression, livestock grazing, and even-aged timber harvest practices, forest managers in the Southwest face an enormous challenge. Millions of acres of ponderosa pine forest are extremely susceptible to uncharacteristic, high intensity wildfires, the consequences of which were amply demonstrated by recent mega-fires in Arizona and New Mexico. Current condition of ponderosa pine forests are also atypically homogeneous in structure and composition, which results in reduced habitat biodiversity for wildlife. In response, land...

(Please note, this is an abstract only) Forest restoration treatments are currently being conducted throughout the state of Arizona. Restoration treatments open the existing forest structure and may improve foraging habitat for mule deer (Odocoileus hemionus) but may reduce the suitability of day bed sites or decrease fawn recruitment due to removal of sufficient hiding cover. To evaluate mule deer habitat selection patterns across a restoration-treated ponderosa pine (Pinus ponderosa) landscape, we outfitted 15 female mule deer with GPS store-on-board collars in 2003. Our main objectives...

Several exotic annual grass species are invading the Intermountain West. After disturbances including wildfire, these grasses can form dense stands with fine fuels that then shorten fire intervals. Thus invasive annual grasses and wildfire form a positive feedback mechanism that threatens native ecosystems. Chief among these within Nevada are Bromus tectorum (cheatgrass), Bromus rubens (red brome), and Schismus barbatus (Mediterranean grass). These grasses have an early phenology for both green-up and senescence that can be detected from the difference in greenness between two well-timed...

(Please note, this is an extended abstract only) Extensive tree mortality occurred in ponderosa pine forests and pinon-juniper woodlands of Arizona from 2001-2004. This mortality has been attributed to a combination of an extensive drought, overstocked stands of pine, and increased bark beetle populations. A complex of Ips and Dendroctonus species worked in concert to kill ponderosa pine. Pinon pine was attacked primarily by pinyon ips and to a lesser extent twig beetles. Initial tree mortality was associated with poor site quality (i.e., shallow soils, cinder hills, south-facing aspects,...

(Please note, this is an abstract only) In 1905, the Bureau of Forestry became the U.S. Forest Service and was given responsibility for protecting newly designated forest reserves. A critical part of its charge was the prevention and control of fires. In 1908 Congress set up a unique system, like an open checkbook, that assured payment for fire suppression as needed. Since that time the fire suppression checkbook has never run out of blank checks and federal land management agencies continue to spend orders of magnitude more money on suppression than on pre-fire fuel control. We argue that...

(Please note, this is an abstract only) Most people agree that ponderosa pine and dry mixed conifer stands need to be thinned and burned to move the stands to within a normal range of variability. Unfortunately, people are in disagreement beyond that point. To some, restoration and fuels reduction means restoring stands to more open, pre-European (pre-1880) conditions. To others, fuels reduction should involve the removal of only the smallest trees (less than 6-9") within the treated stands. The Forest Vegetation Simulator (FVS) stand model, along with the Fire and Fuels Extension (FFE) of...

(Please note, this is an abstract only) Selective logging, fire suppression, forest succession, and climatic changes have resulted in high fire hazards over large areas of the western United States. Federal and state hazardous fuel reduction programs have increased accordingly to reduce the risk, extent and severity of these events, particularly in the wildland urban interface. In this study, we examined the effect of mechanical fuel reduction treatments on the activity of conifer-infesting bark beetles in ponderosa pine, (Pinus ponderosa Dougl ex. Laws.), stands. Treatments were applied...

Restoration of the Mt. Logan ponderosa pine ecosystem has been on-going since 1995. This effort included tree thinning to a density based on what the tree density was in 1870. The desired plant community objectives from the Mt. Trumbull Resource Conservation Area Plan had a forest objective as 50% trees to be in old-growth - i.e., a diameter class of 20-31.9+ inch diameter at breast height (dbh). The other 50% of the trees were to be spread amongst the diameter classes ranging from openings to 19.9 inch dbh trees. The two Lava Units, on Mt. Logan, were logged, thinned, burned in 1996; one...

(Please note, this is an abstract only) Widespread mortality in several forest types is associated with several years of drought in the Southwest. Implementation of USDA Forest Service Forest Inventory and Analysis (FIA) annual inventory in several states coincided with the onset of elevated mortality rates. Analysis of data collected 2000-2004 reveals the status and trends of mortality in pinyon-juniper and ponderosa pine forests across the Southwest. A complex of drought, insects, and disease is responsible for mortality rates approaching 100 percent in some areas, while other areas have...