Rangeland Health


Book Description

Rangelands comprise between 40 and 50 percent of all U.S. land and serve the nation both as productive areas for wildlife, recreational use, and livestock grazing and as watersheds. The health and management of rangelands have been matters for scientific inquiry and public debate since the 1880s, when reports of widespread range degradation and livestock losses led to the first attempts to inventory and classify rangelands. Scientists are now questioning the utility of current methods of rangeland classification and inventory, as well as the data available to determine whether rangelands are being degraded. These experts, who are using the same methods and data, have come to different conclusions. This book examines the scientific basis of methods used by federal agencies to inventory, classify, and monitor rangelands; it assesses the success of these methods; and it recommends improvements. The book's findings and recommendations are of interest to the public; scientists; ranchers; and local, state, and federal policymakers.




Equids--zebras, Asses, and Horses


Book Description

The new Equid Action Plan provides current knowledge on the biology, ecology and conservation status of wild zebras, asses, and horses. It specifies what information is lacking, and prioritizes needed conservation actions. The Action Plan also provides chapters on equid taxonomy, genetics, reproductive biology, and population dynamics. These chapters highlight unsolved issues of taxonomy and genetics. They also provide information and insight into the special demographic and genetic challenges of managing small populations. The chapter on disease provides a review of documented equine disease and epidemiology and focuses on priorities for equid conservation health. The final chapter deals with the importance of developing an assessment methodology that explicitly considers the role of equids in ecosystems and the ecological processes that are necessary for ecosystem viability. The approach of combining ecological field studies and ecosystem modeling should prove useful for the scientific management and conservation of wild equids worldwide. These chapters provide research and conservation practitioners with new information and paradigms.




The Conservation Biology of Tortoises


Book Description







Resource Selection by Animals


Book Description

We have written this book as a guide to the design and analysis of field studies of resource selection, concentrating primarily on statistical aspects of the comparison of the use and availability of resources of different types. Our intended audience is field ecologists in general and, in particular, wildlife and fisheries biologists who are attempting to measure the extent to which real animal populations are selective in their choice of food and habitat. As such, we have made no attempt to address those aspects of theoretical ecology that are concerned with how animals might choose their resources if they acted in an optimal manner. The book is based on the concept of a resource selection function (RSF), where this is a function of characteristics measured on resourceunits such that its value for a unit is proportional to the probability of that unit being used. We argue that this concept leads to a unified theory for the analysis and interpretation of data on resource selection and can replace many ad hoc statistical methods that have been used in the past.




Yellowstone Grizzly Bears


Book Description




Lexical Matters


Book Description

This volume contains new research on the lexicon and its relation to other aspects of linguistics. These essays put forth empirical arguments to claim that specific theoretical assumptions concerning the lexicon play a crucial role in resolving problems pertaining to other components of grammar. Topics include: syntactic/semantic interface in the areas of aspect, argument structure, and thematic roles; lexicon-based accounts of quirky case, anaphora, and control; the boundary between the lexicon and syntax in the domains of sentence comprehension and nominal compounding; and the possibility of extending the concept of blocking beyond the traditional lexicon. Ivan Sag is a professor of linguistics at Stanford University. Anna Szabolcsi is an associate professor of linglustics at UCLA.




Management Policies


Book Description