نتایج جستجو برای: livestock ecosystem

تعداد نتایج: 104389  

2007
Barbara Allen-Diaz Randall D. Jackson

Livestock grazing effects on herbaceous vegetation diversity and ecosystem function are summarized from peer-reviewed literature. Ecosystem responses are linked to grazing management via residual dry matter (RDM), which is alternatively called litter or mulch. Residual dry matter is the dead herbaceous aboveground biomass remaining on a site at the time of autumn germination in annual grassland...

2015
ARIANNE J. CEASE JAMES J. ELSER ELI P. FENICHEL JOLEEN C. HADRICH JON F. HARRISON

Coupled human and natural systems (CHANS) are systems of feedback linking people and ecosystems. A feature of CHANS is that this ecological feedback connects people across time and space. Failing to account for these dynamic links results in intertemporal and spatial externalities, reaping benefits in the present but imposing costs on future and distant people, such as occurs with overgrazing. ...

1999
R. J. COULTER

The occurrence of disease is a direct manifestation of the failure of a production brn to provide adequate compensation for increased physiological demands on the ,iock in that system. The long term control of disease requires an holistic approach to the “ecopathology” he biosystem. The development of this approach typically follows an evolutionary cess including a number of phases that are con...

Journal: :Proceedings of the National Academy of Sciences of the United States of America 1997
J H Brown T J Valone C G Curtin

Natural ecosystems contain many individuals and species interacting with each other and with their abiotic environment. Such systems can be expected to exhibit complex dynamics in which small perturbations can be amplified to cause large changes. Here, we document the reorganization of an arid ecosystem that has occurred since the late 1970s. The density of woody shrubs increased 3-fold. Severa...

2015
Hermel Homburger Andreas Lüscher Michael Scherer-Lorenzen Manuel K. Schneider

BACKGROUND In order to understand the impact of grazing livestock on pasture ecosystems, it is essential to quantify pasture use intensity at a fine spatial scale and the factors influencing its distribution. The observation and analysis of animal activity is greatly facilitated by remote tracking technology and new statistical frameworks allowing for rapid inference on spatially correlated dat...

Journal: :Ecological applications : a publication of the Ecological Society of America 2014
Wiebke Hanke Jürgen Böhner Niels Dreber Norbert Jürgens Ute Schmiedel Dirk Wesuls Jürgen Dengler

A general understanding of grazing effects on plant diversity in drylands is still missing, despite an extensive theoretical background. Cross-biome syntheses are hindered by the fact that the outcomes of disturbance studies are strongly affected by the choice of diversity measures, and the spatial and temporal scales of measurements. The aim of this study is to overcome these weaknesses by app...

Journal: :Journal of environmental management 2015
David D Briske Mengli Zhao Guodong Han Changbai Xiu David R Kemp Walter Willms Kris Havstad Le Kang Zhongwu Wang Jianguo Wu Xingguo Han Yongfei Bai

Semi-nomadic pastoralism was replaced by sedentary pastoralism in Inner Mongolia during the 1960's in response to changes in land use policy and increasing human population. Large increases in numbers of livestock and pastoralist households (11- and 9-fold, respectively) during the past 60 yrs have variously degraded the majority of grasslands in Inner Mongolia (78 M ha) and jeopardize the live...

2003
O. E. SALA XINSHI ZHANG

Grasslands are the potential natural ecosystem type on approximately 25% (33x lo6 km2) of the land surface of the earth (Shantz 1954). Current estimates of the global extent of grasslands range from 16% (Whittaker and Likens 1973, 1975) to 30% (Ajtay et al. 1979). The difference between the estimates of the potential extent of grasslands and the current extent provides an indication of the degr...

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