Responses of Plant Communities to Grazing in the Southwestern United States :

Responses of Plant Communities to Grazing in the Southwestern United States :
Author: Daniel G. Milchunas
Publisher:
Total Pages: 134
Release: 2006
Genre: Grazing
ISBN:

Grazing by wild and domestic mammals can have small to large effects on plant communities, depending on characteristics of the particular community and of the type and intensity of grazing. The broad objective of this report was to extensively review literature on the effects of grazing on 25 plant communities of the southwestern U.S. in terms of plant species composition, aboveground primary productivity, and root and soil attributes. Livestock grazing management and grazing systems are assessed, as are effects of small and large native mammals and feral species, when data are available. Emphasis is placed on the evolutionary history of grazing and productivity of the particular communities as determinants of response. After reviewing available studies for each community type, we compare changes in species composition with grazing among community types. Comparisons are also made between southwestern communities with a relatively short history of grazing and communities of the adjacent Great Plains with a long evolutionary history of grazing. Evidence for grazing as a factor in shifts from grasslands to shrublands is considered. An appendix outlines a new community classification system, which is followed in describing grazing impacts in prior sections.

Assessment of Native Species and Ungulate Grazing in the Southwest

Assessment of Native Species and Ungulate Grazing in the Southwest
Author: United States Department of Agriculture
Publisher: CreateSpace
Total Pages: 80
Release: 2015-06-26
Genre:
ISBN: 9781511476140

Range managers in the Southwestern States are increasingly being required to develop management strategies that take into consideration the conservation of wildlife populations. However, information on many aspects of the fundamental biology and impacts of grazing on individual species is still lacking in the scientific and government literature. This report documents a project designed to assemble this information for terrestrial wildlife in Arizona and New Mexico that have the potential to be negatively impacted by grazing or range management practices.

The Effects of Large Herbivores on Small Mammal Communities

The Effects of Large Herbivores on Small Mammal Communities
Author: Elliott Wentworth Reed Parsons
Publisher:
Total Pages: 125
Release: 2011
Genre: Electronic dissertations
ISBN:

Large herbivores are major drivers of community structure and function in many terrestrial systems. Through their direct effects on plants, large herbivores can influence the structure and complexity of habitats, the population abundance of animals that rely on those habitats, and the rates of ecosystem processes within those systems. These manifold impacts on systems are potentially magnifying, as removal of top predators and changes in land use have triggered large increases in large herbivore populations. Although increasing evidence suggests that large herbivores can critically shape the structure and function of the ecosystems they inhabit, few studies have detailed the direct and indirect effects of large herbivores on vegetation, animal populations, and ecosystem processes in the same system. Typically these varied impacts are studied in isolation and it is often unclear what the magnitude or sources of spatio-temporal variation in these effects might be. I used a large-scale replicated elk-exclusion experiment to determine the effects of elk on small mammal communities, plants, and ecosystem processes. I found that five years of elk exclusion led to noticeable changes in small mammal communities; some small mammals increased in the exclosure while others declined on controls. These changes were likely due to increasing habitat quality inside the fences and declining habitat quality outside. Elk browsing also decreased the recruitment of two dominant deciduous species and the quantity of litter of both of these species deposited on the forest floor during the peak in litterfall. Elk similarly reduced the cover of nitrogen fixing forb species, and the decomposition rates of both aspen and maple litter were more rapid inside the fences after 2 years of decomposition. These results indicate that elk are influencing the quantity and quality of litter inputs into this system as well as the decomposition environment. Finally, I found that mixtures of deciduous and evergreen litter influenced decomposition dynamics, the net mineralization of nitrogen, and plant growth. These results suggest that shifts in litter quantity and quality from browsing ungulates could have important indirect effects on plant growth. Overall, this work indicates that elk can have effects on multiple components of the community and ecosystem in only a short five year time period.

Invasive Species in Forests and Rangelands of the United States

Invasive Species in Forests and Rangelands of the United States
Author: Therese M. Poland
Publisher: Springer Nature
Total Pages: 455
Release: 2021-02-01
Genre: Science
ISBN: 3030453677

This open access book describes the serious threat of invasive species to native ecosystems. Invasive species have caused and will continue to cause enormous ecological and economic damage with ever increasing world trade. This multi-disciplinary book, written by over 100 national experts, presents the latest research on a wide range of natural science and social science fields that explore the ecology, impacts, and practical tools for management of invasive species. It covers species of all taxonomic groups from insects and pathogens, to plants, vertebrates, and aquatic organisms that impact a diversity of habitats in forests, rangelands and grasslands of the United States. It is well-illustrated, provides summaries of the most important invasive species and issues impacting all regions of the country, and includes a comprehensive primary reference list for each topic. This scientific synthesis provides the cultural, economic, scientific and social context for addressing environmental challenges posed by invasive species and will be a valuable resource for scholars, policy makers, natural resource managers and practitioners.

Rangeland Systems

Rangeland Systems
Author: David D. Briske
Publisher: Springer
Total Pages: 664
Release: 2017-04-12
Genre: Technology & Engineering
ISBN: 3319467093

This book is open access under a CC BY-NC 2.5 license. This book provides an unprecedented synthesis of the current status of scientific and management knowledge regarding global rangelands and the major challenges that confront them. It has been organized around three major themes. The first summarizes the conceptual advances that have occurred in the rangeland profession. The second addresses the implications of these conceptual advances to management and policy. The third assesses several major challenges confronting global rangelands in the 21st century. This book will compliment applied range management textbooks by describing the conceptual foundation on which the rangeland profession is based. It has been written to be accessible to a broad audience, including ecosystem managers, educators, students and policy makers. The content is founded on the collective experience, knowledge and commitment of 80 authors who have worked in rangelands throughout the world. Their collective contributions indicate that a more comprehensive framework is necessary to address the complex challenges confronting global rangelands. Rangelands represent adaptive social-ecological systems, in which societal values, organizations and capacities are of equal importance to, and interact with, those of ecological processes. A more comprehensive framework for rangeland systems may enable management agencies, and educational, research and policy making organizations to more effectively assess complex problems and develop appropriate solutions.