Treesearch

Fractal dimensions derived from log-log variograms are useful for characterizing spatial structure and scaling behavior in snow depth distributions. This study examines the temporal consistency of snow depth scaling features at two sites using snow depth distributions derived from lidar datasets collected in 2003 and 2005. The temporal snow accumulation patterns in these two years were substantially different, but both years represent nearly average 1 April accumulation depths for these sites, with consistent statistical distributions. Two distinct fractal regions are observed in each...

High-severity wildfires can increase runoff and erosion rates by one or more orders of magnitude, and these increases can threaten life and property as well as severely degrading water quality and aquatic ecosystems. Each year millions of dollars are spent on emergency postfire rehabilitation treatments to minimize flood runoff and soil erosion. Few data have been available to systematically evaluate the effectiveness of these treatments over time, much less understand why the different treatments might vary in their effectiveness. There also is an urgent need to develop and test models...

A principal task of evaluating large wildfires is to assess fire's effect on the soil in order to predict the potential watershed response. Two types of soil water repellency tests, the water drop penetration time (WDPT) test and the mini-disk infiltrometer (MDI) test, were performed after the Hayman Fire in Colorado, in the summer of 2002 to assess the infiltration potential of the soil. Remotely sensed hyperspectral imagery was also collected to map post-wildfire ground cover and soil condition. Detailed ground cover measurements were collected to validate the remotely sensed imagery and...

Wild salmon in California, Oregon, Washington, Idaho, and southern British Columbia are in serious trouble. South of the Canadian/United States border, most runs are less than 10 percent of their pre-1850 levels and over two dozen are listed as threatened or endangered under the U.S. Endangered Species Act. Similarly, several runs in British Columbia are listed under the Canadian Species at Risk Act. Worse, from California to British Columbia, many runs have disappeared, and more will follow unless there is a reversal of the long-term downward trajectory (Lackey 2003).

I investigated the relative importance of floristics and physiognomy in determining community organization of autumn-migrating landbirds in a riparian corridor in New Mexico invaded by Tamarisk (Tamarix ramosissima). All six avian measures were associated with floristics, physiognomy, or both. However, usefulness in predicting migrant parameters differed between floristics and physiognomy, and depended on the vegetation measures used (direct measures vs. plant community-structure indices) and the scale investigated (micro- vs. macrohabitat). Using direct vegetation measures, migrant...

I observed that whitebark pine (Pinus albicaulis Engelm. [Pinaceae]) germinants treated with biological controls, one commercially available (Trichoderma harzianum strain T-22), and the other being studied for potential efficacy (Fusarium oxysporum isolate Q12), experienced less seedling mortality caused by root disease than did a non-treated control. Seedlings treated with the biological controls and nonsymptomatic seedlings in the control treatment had similar morphology. The simple use of biological controls may be useful to nursery managers looking to reduce incidence of root disease...

Growing trees and shrubs in nurseries is rewarding. You may wish to grow trees and shrubs for many reasons: 1) reforestation; 2) land stabilization; 3) fire wood (energy); 4) improving water quality; 5) urban landscapes; 6) providing shade; 7) producing fruits or nuts. If you enjoy growing plants, you are more likely to produce better trees and shrubs (Figure 1.1). In this book, we intend to provide basic biology and simple, effective techniques to grow trees and shrubs. Although we will discuss growing new trees and shrubs from seeds, cuttings, and grafts, we will refer to them all simply...

Growing trees and shrubs in nurseries is rewarding. You may wish to grow trees and shrubs for many reasons: 1) reforestation; 2) land stabilization; 3) fire wood (energy); 4) improving water quality; 5) urban landscapes; 6) providing shade; 7) producing fruits or nuts. If you enjoy growing plants, you are more likely to produce better trees and shrubs (Figure 1.1). In this book, we intend to provide basic biology and simple, effective techniques to grow trees and shrubs. Although we will discuss growing new trees and shrubs from seeds, cuttings, and grafts, we will refer to them all simply...

Between 1998 and 2002, six sites were established immediately after large wildfires in the western United States to determine the effectiveness of contour-felled log erosion barriers in mitigating post-wildfire runoff and erosion. In each pair of matched, burned, and small watersheds (1-13 ha), one was treated with contour-felled log erosion barriers and one was left untreated as a control. For 4 to 6 post-fire years, runoff and sediment yields were measured and correlated with rain properties. High-intensity rainfall produced most of the measured runoff and sediment yields except in the...

Selenium (Se) is a potential soil contaminant in many parts of the world where it can pose a health risk to livestock and wildlife. Phosphate ore mining in Southeast Idaho has resulted in numerous waste rock dumps revegetated with forages to stabilize the dumps and support grazing. Alfalfa (Medicago sativa L.), smooth brome (Bromus inermis Leyss.), and western wheat grass [Pascopyrum smithii (Rydb.) A. Love] are the dominant forage species on these lands. To demonstrate the feasibility of using sulfur (S) as a soil amendment to restrict plant Se uptake, 3 kg pots containing 50:50 w/w soil...