Showing items related by title, author, creator and subject.

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  Insects, Diseases, and Abiotic Disorders in Southwest Forests and Woodlands (Climate Change and Variability in Southwest Ecosystems Series)

  DeGomez, Tom; Garfin, Gregg; Natural Resources & the Environment, School of (College of Agriculture and Life Sciences, University of Arizona (Tucson, AZ), 2006-08)

  Recent events in the forests of the Southwest have prompted scientists to consider the role of climate variability in insect and disease cycles. Over 70 million pine trees along with millions of other conifers died in 2002-03. Average temperature increases of 3°C enabled the MPB at those high elevations to achieve univoltine (having one generation per year) reproduction leading to previously unheard of outbreaks in white bark pine at high elevation sites in Idaho.Aspen defoliation in Arizona and New Mexico averaged ~ 20,375 acres from 1990 to 1997. A series of events has contributed to the decline of aspen since 1997.
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  Climate Change and Wildfire Impacts in Southwest Forests and Woodlands (Climate Change and Variability in Southwest Ecosystems Series)

  Crimmins, Michael; Garfin, Gregg; Natural Resources & the Environment, School of (College of Agriculture and Life Sciences, University of Arizona (Tucson, AZ), 2006-11)

  Southwest forests are complex systems that are influenced by climate variability. Wildfires naturally occur in these forests and woodlands, but with an increasing population, land management decisions are becoming more difficult. This publication is a result of discussions from the "Workshop on Climate Variability and Ecosystem Impacts" that was sponsored by UA Cooperative Extension in February 2005. It provides a summary of the current situation, a summary of climate change science for land management, and a brief description of suggested future research in climate science as it relates to forests and woodlands.
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  Arbuscular mycorrhiza: A linkage of plant, soil and surface hydrologic processes in a southwest grassland

  Guertin, D. Phillip; Reid, C. P. Patrick; ODea, Mary Elizabeth (The University of Arizona., 2000)

  A three-year randomized field study was undertaken to evaluate the effects of prescribed burning and the intense rainfall events associated with the summer monsoon of southern Arizona, specifically examining the interchange between the plant, soil and surface hydrologic processes within a savanna. The effects of fire and rainfall treatments were evaluated by examining their specific effects on vegetation, arbuscular mycorrhizal fungi (AMF), soil structure, soil nutrient capital, surface runoff and sediment. In addition to the field study, two factorial greenhouse studies were completed in conjunction with the field study. The objectives of the greenhouse studies were: (1) to test the effects of prescribed fire and high intensity rainfall on AMF infectivity potential, and (2) to examine the effect of mycotrophy on the biomass production of native and introduced grasses grown in pasteurized and native soils. A third study examined the development of an empirical model to estimate sediment production from the field study's plots. The objectives of this third study were: (1) to develop the empirical model using two years of collected sediment, and (2) to compare model estimates with the commonly used Revised Universal Soil Loss Equation (RUSLE) model. The results of these studies indicate that a integrated mechanism exists between the plant community and biotic and physical soil processes, which when disturbed affect the hydrology of the watershed.