Overgrazing
Overgrazing occurs when plants are exposed to intensive
Overgrazing reduces the usefulness,
Ecological impact
Overgrazing typically increases soil erosion.[7]
With continued overutilization of land for grazing, there is an increase in degradation. This leads to poor soil conditions that only xeric and early successional species can tolerate.[8]
Turning to the aquatic environment, Ling et al. (2015)[12] have documented the phenomenon of catastrophic sea urchin overgrazing and its role in marine ecosystem regime shifts. Their study underscores the urgent need for effective management and conservation strategies to mitigate the profound ecological impacts of overgrazing, highlighting the issue's global scope. Similarly, on the Mongolian steppes, Liu et al. (2013)[13] found that approximately 60% of vegetation decline could be attributed to climate factors, with the rest significantly influenced by increased goat density due to overgrazing. This points to a complex interplay between climate change and grazing practices in ecosystem degradation.
Further expanding our understanding, Stevens et al. (2016)[14] investigated woody encroachment in South African savannahs over a 70-year period, identifying overgrazing, global changes, and the ecological effects of megafauna extinction as key factors. Their findings shed light on the multifaceted drivers behind changes in savannah ecosystems. Echoing this theme of alternative strategies to combat overgrazing, Kriegisch et al. (2019)[15] demonstrated how drift-kelp availability could reduce the foraging movement of overgrazing sea urchins, suggesting that alternative food sources may significantly influence grazing behaviors and aid in managing marine ecosystem pressures.
In a similar vein, the research by Cai et al. (2020)[16] presents a stark example of the terrestrial impact of overgrazing, showing how the fertile island effect collapses under extreme conditions in shrub-encroached grasslands. This case study emphasizes the critical need for sustainable grazing practices to protect soil health and maintain ecosystem functionality, further illustrating the wide-reaching consequences of overgrazing across diverse habitats.
Economic theory
Overgrazing is used as an example in the economic concept now known as the
Normally, rights of use of common land in England and Wales were, and still are, closely regulated, and available only to "commoners". If excessive use was made of common land, for example in overgrazing, a common would be "stinted", that is, a limit would be put on the number of animals each commoner was allowed to graze. These regulations were responsive to demographic and economic pressure; thus rather than let a common become degraded, access was restricted even further. This important part of actual historic practice was absent from the economic model of Hardin.[18] In reality the use of common land in England and Wales was a triumph of conserving a scarce resource using agreed custom and practice.
By region
Africa-Sahel region
There have been overgrazing consequences in the region Sahel region. The violent herder–farmer conflicts in Nigeria, Mali, Sudan and other countries in the Sahel region have been exacerbated by land degradation and overgrazing.[19][20] See 2010 Sahel famine.
Sub-Sahara Africa
Various countries in Sub-Sahara Africa are affected by overgrazing and resulting ecological effects. In Namibia, overgrazing is considered the main cause of woody plant encroachment at the expenses of grasses on a land area of up to 45 million hectares.
Australia
In many arid zones in Australia, overgrazing by sheep and cattle during the nineteenth century, as
Overgrazing can also occur with native species. In the Australian Capital Territory, the local government in 2013 authorised a cull of 1455 kangaroos due to overgrazing.[22] Maisie Carr (1912-1988), Ecologist and Botanist, undertook significant research and studies in overgrazing and established consequences on the surrounding land in Australia.
Caribbean
In the Caribbean region, overgrazing is a threat to vegetation areas where there is livestock farming, which is an important source of livelihood and food security for many people. a combination of small scale livestock farming with small ruminants, and mixed farming is practised. However, livestock consume vegetation faster than it can be renewed and this leads to land degradation, loss of vegetative areas, and soil erosion resulting in poor quality feed and reduced livestock yields and income. Also, these grazing lands are critical in controlling carbon dioxide and mitigating risks against severe weather such as floods and droughts. Overgrazing weakens ecological conservation.[23]
See also
References
- S2CID 55599448.
- ^ "The relationship between overgrazing and the US environment". ArcGIS StoryMaps. 13 March 2020. Retrieved 2021-03-20.
- ISBN 0896085996. Retrieved 30 March 2015.
- ^ Duval, Clay. "Bison Conservation: Saving an Ecologically and Culturally Keystone Species" (PDF). Duke University. Archived from the original (PDF) on March 8, 2012. Retrieved April 13, 2015.
- balance with, and accompanied by, prides of keystone predators.
- ^ "Holistic Land Management: Key to Global Stability" by Terry Waghorn. Forbes. 20 December 2012.
- ^ C. Michael Hogan (2009). "Overgrazing" (Archived 2010-07-11 at the Wayback Machine). Encyclopedia of Earth. Sidney Draggan, topic ed.; Cutler J. Cleveland, ed. Washington, D.C.: National Council for Science and the Environment.
- .
- ^ Côté, S. D., Rooney, T. P., Tremblay, J. P., Dussault, C., & Waller, D. M. (2004). "Ecological impacts of deer overabundance". Annu. Rev. Ecol. Evol. Syst., 35, 113-147.
- ^ Baiser, B., Lockwood, J. L., La Puma, D., & Aronson, M. F. (2008). "A perfect storm: two ecosystem engineers interact to degrade deciduous forests of New Jersey". Biological Invasions, 10(6), 785-795.
- ^ Horsley, S. B., Stout, S. L., & DeCalesta, D. S. (2003). White‐tailed deer impact on the vegetation dynamics of a northern hardwood forest. Ecological applications, 13(1), 98-118.
- PMC 4247405.
- PMID 23451249.
- PMID 27502384.
- PMID 31250188.
- ISSN 1573-5036.
- ^ Garrett Hardin (December 13, 1968), "The Tragedy of the Commons", Science, Vol. 162, No. 3859, pp. 1243-1248. Also available here and here.
- ^ Susan Jane Buck Cox (Spring 1985). "No Tragedy on the Commons". Journal of Environmental Ethics, Vol. 7.
- ^ "The Deadliest Conflict You've Never Heard of". Foreign Policy. 23 January 2019.
- ^ "The battle on the frontline of climate change in Mali". BBC News. 22 January 2019.
- ^ "Arid Recovery – Roxby Downs, South Australia". EMR Project Summaries. 15 March 2016. Retrieved 27 October 2020.
- ^ "ACT Territory and Municipal Services Directorate | Media Releases Kangaroo conservation cull to go ahead". ACT Territory and Municipal Services Directorate. Government of the Australian Capital Territory. 2013-07-10. Archived from the original on 2020-07-02. Retrieved 2021-06-12.
- ^ "Caribbean Islands - Threats | CEPF". www.cepf.net. Retrieved 2024-04-08.
Further reading
- Gonner, E. C. K (1912). Common Land and Inclosure. London: Macmillan & Co. [1]