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Publications

Below is a list of WERC's peer-reviewed publications. If you are searching for a specific publication and cannot find it in this list, please contact werc_web@usgs.gov

Filter Total Items: 3617

The use of multi-temporal Landsat Normalized Difference Vegetation Index (NDVI) data for mapping fuels in Yosemite National Park, USA

The objective of this study was to test the applicability of using Normalized Difference Vegetation Index (NDVI) values derived from a temporal sequence of six Landsat Thematic Mapper (TM) scenes to map fuel models for Yosemite National Park, USA. An unsupervised classification algorithm was used to define 30 unique spectral-temporal classes of NDVI values. A combination of graphical, statistical
Authors
Jan W. Van Wagtendonk, Ralph R. Root

Status of amphibians at the Zoige Wetlands, Sichuan Province, China

No abstract available.
Authors
Gary M. Fellers, Yuezhao Wang, Liu Shaoyin

Growth rate predicts mortality of Abies concolor in both burned and unburned stands

Tree mortality is often the result of both long-term and short-term stress. Growth rate, an indicator of long-term stress, is often used to estimate probability of death in unburned stands. In contrast, probability of death in burned stands is modeled as a function of short-term disturbance severity. We sought to narrow this conceptual gap by determining (i) whether growth rate, in addition to cro
Authors
Phillip J. van Mantgem, Nathan L. Stephenson, Linda S. Mutch, Veronica G. Johnson, Annie M. Esperanza, David J. Parsons

Introduced species and their missing parasites

Damage caused by introduced species results from the high population densities and large body sizes that they attain in their new location. Escape from the effects of natural enemies is a frequent explanation given for the success of introduced species. Because some parasites can reduce host density and decrease body size, an invader that leaves parasites behind and encounters few new parasites ca
Authors
Mark E. Torchin, Kevin D. Lafferty, Andrew P. Dobson, Valerie J. McKenzie, Armand M. Kuris

Effects of desert wildfires on desert tortoise (Gopherus agassizii) and other small vertebrates

We report the results of standardized surveys to determine the effects of wildfires on desert tortoises (Gopherus agassizii) and their habitats in the northeastern Mojave Desert and northeastern Sonoran Desert. Portions of 6 burned areas (118 to 1,750 ha) were examined for signs of mortality of vertebrates. Direct effects of fire in desert habitats included animal mortality and loss of vegetation
Authors
T. C. Esque, C. R. Schwalbe, L.A. DeFalco, R.B. Duncan, T.J. Hughes

Rare male aggression directed toward females in a female-dominated society: Baiting behavior in the spotted hyena

Spotted hyenas (Crocuta crocuta) are gregarious carnivores. The females are socially dominant to males, and adult males rarely direct aggression toward adult females. This study analyzed all cases in which adult immigrant males behaved aggressively toward adult females in a large population of free-living hyenas in Kenya, observed for 11 years. Our goals were to describe the conditions under which
Authors
Micaela Szykman, Anne L. Engh, Russell C. Van Horn, Erin E. Boydston, Kim T. Scribner, Kay E. Holekamp

How should environmental stress affect the population dynamics of disease?

We modelled how stress affects the population dynamics of infectious disease. We were specifically concerned with stress that increased susceptibility of uninfected hosts when exposed to infection. If such stresses also reduced resources, fecundity and/or survivorship, there was a reduction in the host carrying capacity. This lowered the contact between infected and uninfected hosts, thereby decre
Authors
Kevin D. Lafferty, Robert D. Holt

Marine reserve design for conservation and fisheries management: a case study from the California Channel Islands

Five races of cottontail rabbits belonging to three species occur in Virginia. One of them, the Mearns cottontail (Sylvilagus floridanus mearnsi), is reported here for the first time. It occurs in six southwestern counties of the state, while the eastern cottontail (S. f. mallurus) occurs in the remainder of the state with the exception of Smith and Fishermans islands off the eastern coast of Cap
Authors
S.J. Airame, E. Dugan, K. D. Lafferty, H.M. Leslie, D.A. McArdle, R.R. Warner