Treesearch

A negative-ion proton transfer chemical ionization mass spectrometric technique (NI-PT-CIMS), using acetate as the reagent ion, was applied to the measurement of volatile inorganic acids of atmospheric interest: hydrochloric (HCl), nitrous (HONO), nitric 5 (HNO3), and isocyanic (HNCO) acids. Gas phase calibrations through the sampling inlet showed the method to be intrinsically sensitive (6-16 cts/pptv), but prone to inlet effects for HNO3 and HCl. The ion chemistry was found to be insensitive to water vapor concentrations, in agreement with previous studies of carboxylic acids. The inlet...

The Interagency native Plant Materials Development Program outlined in the 2002 Report to Congress (USDI and USDA 2002), USDI Bureau of Land Management programs and policies, and the Great Basin Restoration Initiative encourage the use of native species for rangeland rehabilitation and restoration where feasible. This project was initiated to foster the development of native plant materials for use in the Great Bas in and to provide information that will be useful to managers when making decisions about selecting appropriate plant materials for seedings. A second major objective is to...

Fire was a natural occurrence in many ecosystems of the Southwest Borderlands before Euro-American settlement. However, natural fire frequencies and the burning characteristics of the fires have been altered since the early 1900s, largely because of past livestock grazing practices, which removed significant portions of the fire-carrying herbaceous vegetation, and past fire suppression policies of land management agencies (Edminster et al. 2000, Fule and Covington 1995). These practices and policies have resulted in overcrowding of tree overstories on many sites, with the trees more...

Agaves are among the more conspicuous plants in the drylands of the Southwestern Borderlands region in almost any landscape whether natural or manipulated. All agaves have succulent or semi-succulent leaves that form rosettes from a few inches to several feet across, but there are many variations to this basic pattern (Turner et al. 1995, Phillips and Comus 2000). Various species of agave are sources of food, fences, rope, medicine, and liquor. Surprisingly, however, little information is available on the effects of disturbances such as the occurence of fire on the status of agave in the...

The 462,600 acre Rodeo-Chediski Wildfire of 2002 was the largest known in Arizona's history and the ninth largest wildfire in the United States (National Interagency Fire Center 2009) in terms of the 462,600 acres impacted by the burn. It damaged or destroyed ecosystem resources, disrupted hydrologic functioning, and altered loadings of flammable fuels in much of the ponderosa pine (Pinus ponderosa) forests exposed to the bum. An opportunity to study the impacts of this wildfire on ecosystem resources, hydrologic functioning, and flammable fuels presented itself on the Stermer Ridge...

Water is a vital natural resource and its paucity in the Southwest makes it of particular importance. There is a long history in the Southwest of research on increasing water yields from forests starting in 1911 at Wagon Wheel Gap Experimental Watershed in central averaged 22.01 inches while summer precipitation Colorado. Watershed studies in the Salt River Basin began in 1925 with the Summit Plots upstream from Roosevelt Dam. The Summit Plots were established to study the effects of vegetation change and mechanical stabilization on stormflows and sediment yields after it was discovered...

Riparian areas are special vegetation zones that are frequently used as buffer strips to mitigate sediment movement from upland forest and agricultural management areas (Neary et al. 2010). These areas are often called streamside management zones. Understanding any concept and accompanying literature is ultimately based on knowledge of the descriptive terminology used. Therefore it is appropriate to discuss the terms used in the literature to describe since there is a lack of uniformity in how these near-stream landscape units are named. The most commonly used terms mentioned by Neary et...

Over the past several years, fire managers have increased their use of mastication treatments, the on-site disposal of shrubs and small-diameter trees through chipping and shredding. Mastication is a relatively untested management practice that alters the chemical and physical conditions of the forest floor and may influence vegetation regrowth and fuel development for years or decades. Eighteen sites were established across four ecosystems of the southern Rocky Mountains and the Colorado Plateau: lodgepole pine (Pinus contorta), mixed conifer (Pinus ponderosa, Pseudotsuga menziesii, Pinus...

Current space-based lidar systems for Earth remote sensing have a number of inherent limitations that impact their use for broader science applications. These include no cross-track coverage, fixed spatial sampling that forces pointing control to be performed by the spacecraft, cloud loss over many types of scenes, and, in general, lifetimes set in part by the number of laser shots fired. The Electronically Steerable Flash Lidar (ESFL) is a new concept developed to help in overcoming these limitations. It combines a new “Flash” focal plane technology that allows both imaging and waveform...

This field guide supplemental describes the data items to record for Fire Effects and Recovery Study (FERS) plots; it is a supplement to the 2010 Field Instructions for the Annual Inventory of California, Oregon, and Washington (i.e., "2010 PFSL manual"). These plots are pre-selected; data items are required as specified when FIRE PLOT = Y. Additional information is collected on these plots, along with any other required measurements for the plot (e.g., P2 and P3 data). P2 measurements are always done when FIRE PLOT = Y, whether the fire plot is on panel that year or not; P3 measurements...