Treesearch

A complex of drought, insects, and disease caused widespread mortality in the pinyon-juniper forest types of the American Southwest in recent years. Data from 14,929 plots spanning 25 years and representing over 25 million hectares were analyzed to characterize effects of drought-related mortality on the structure, composition, and distribution of pinyon and juniper species throughout their ranges. Pinus edulis experienced higher rates of mortality since 2003 than at any time between 1981 and 2002. Most Juniperus species experienced very low rates of mortality under normal conditions, and...

Benefits of a strategic national forest inventory to science and society: the USDA Forest Service Forest Inventory and Analysis program. Forest Inventory and Analysis, previously known as Forest Survey, is one of the oldest research and development programs in the USDA Forest Service. Statistically-based inventory efforts that started in Scandinavian countries in the 1920s raised interest in developing a similar program in the U.S. The U.S. Congress established the research branch of the U.S. Forest Service in 1928, shortly after Dr. Yrjö Ilvessalo, leader of the first Finnish national...

The database includes modified components of the Arizona State Museum Site Recording System (Arizona State Museum 1993) and the New Mexico NMCRIS User?s Guide (State of New Mexico 1993). When sites contain more than one recorded component, these instances were entered separately with the result that many sites have multiple entries. Information for this database originated in several sources, including the Arizona State Museum, Museum of New Mexico, USDA Forest Service, and USDI Bureau of Land Management. Approximately 5 percent of the identified components are recorded on the basis of...

This research experimentally examined seasonal effects of fire on biological soil crusts and perennial grasses in shortgrass steppe. We predicted dormant-season fire would have greater negative effects on biological soil crusts than fire during the growing season, but less of an impact on perennial grasses than fire during the growing season. Treatments were dormant- and growing-season fires and unburned reference condition plots. Response variables included biological soil crust and grass percent ground cover, and crust nitrogen fixation and chlorophyll a content. Results indicated...

The Interior West Forest Inventory and Analysis (IWFIA) program of the USDA Forest Service, Rocky Mountain Research Station, as part of its national Forest Inventory and Analysis (FIA) duties, conducted forest resource inventories of the Southwestern Region (Region 3) National Forests. This report presents highlights of the Lincoln National Forest 1997 inventory including population estimates and summaries of commonly requested variables. Any trends or disturbances (such as fire) that have occurred after 1997 will be discussed in future reports on the Lincoln National Forest.

The purpose of this chapter is to provide a general overview of the many aspects of accuracy assessment pertinent to the Landscape Fire and Resource Management Planning Tools Prototype Project (LANDFIRE Prototype Project). The LANDFIRE Prototype formed a large and complex research and development project with many broad-scale data sets and products developed throughout its various stages. The scope of the project was defined as mapping and modeling vegetation, wildland fuel, and fire regime characteristics (Rollins and others, Ch. 2). Because of the breadth of the investigation, it is...

Space and airborne sensors have been used to map area burned, assess characteristics of active fires, and characterize post-fire ecological effects. Confusion about fire intensity, fire severity, burn severity, and related terms can result in the potential misuse of the inferred information by land managers and remote sensing practitioners who require unambiguous remote sensing products for fire management. The objective of the present paper is to provide a comprehensive review of current and potential remote sensing methods used to assess fire behavior and effects and ecological responses...

We researched the environmental attributes (n = 28) associated with elk (n = 50) summer range (1 May ­30 Sep) in the central Black Hills of South Dakota, USA, during 1998-­2001. We defined high-use areas or centers of activity as landscapes underlying large concentrations of elk locations resulting from the shared fidelity of independently moving animals to specific regions on summer range. We divided the study area into 3-km grid cells to represent the distance elk travel in a 24-hour period. We computed mean elevation and slope, proportion and configuration of overstory canopy cover,...

We describe and evaluate a new analysis technique, spatial wavelet analysis (SWA), to automatically estimate the location, height, and crown diameter of individual trees within mixed conifer open canopy stands from light detection and ranging (lidar) data. Two-dimensional Mexican hat wavelets, over a range of likely tree crown diameters, were convolved with lidar canopy height models. Identification of local maxima within the resultant wavelet transformation image then allowed determination of the location, height, and crown diameters of individual trees. In this analysis, which focused...

Advective flows within soils and snowpacks caused by pressure fluctuations at the upper surface of either medium can significantly influence the exchange rate of many trace gases from the underlying substrate to the atmosphere. Given the importance of many of these trace gases in understanding biogeochemical cycling and global change, it is crucial to quantify (as much as possible) any impact these flows can have on the transport of these gases. This study (part 1 of 2) details a new model describing the influence that naturally occurring, pressure-driven, oscillatory advective flows have...