Rangeland degradation on the Qinghai-Tibetan plateau: A review of the evidence of its magnitude and causes
TL;DR: The extent and magnitude of rangeland degradation on the Qinghai-Tibetan plateau (QTP) remains largely unknown because monitoring programs have been subjective and poorly documented as mentioned in this paper.
About: This article is published in Journal of Arid Environments.The article was published on 2010-01-01. It has received 855 citations till now. The article focuses on the topics: Population.
Citations
More filters
TL;DR: To reduce the uncertainties and to improve the precision of the predictions of the impacts of climate change and human activities on biogeochemical cycles, efforts should focus on conducting more field observation studies, integrating data within improved models, and developing new knowledge about coupling among carbon, nitrogen, and phosphorus bioge biochemical cycles.
Abstract: With a pace of about twice the observed rate of global warming, the temperature on the Qinghai-Tibetan Plateau (Earth's third pole') has increased by 0.2 degrees C per decade over the past 50years, which results in significant permafrost thawing and glacier retreat. Our review suggested that warming enhanced net primary production and soil respiration, decreased methane (CH4) emissions from wetlands and increased CH4 consumption of meadows, but might increase CH4 emissions from lakes. Warming-induced permafrost thawing and glaciers melting would also result in substantial emission of old carbon dioxide (CO2) and CH4. Nitrous oxide (N2O) emission was not stimulated by warming itself, but might be slightly enhanced by wetting. However, there are many uncertainties in such biogeochemical cycles under climate change. Human activities (e.g. grazing, land cover changes) further modified the biogeochemical cycles and amplified such uncertainties on the plateau. If the projected warming and wetting continues, the future biogeochemical cycles will be more complicated. So facing research in this field is an ongoing challenge of integrating field observations with process-based ecosystem models to predict the impacts of future climate change and human activities at various temporal and spatial scales. To reduce the uncertainties and to improve the precision of the predictions of the impacts of climate change and human activities on biogeochemical cycles, efforts should focus on conducting more field observation studies, integrating data within improved models, and developing new knowledge about coupling among carbon, nitrogen, and phosphorus biogeochemical cycles as well as about the role of microbes in these cycles.
615 citations
Cites background from "Rangeland degradation on the Qingha..."
..., 2012), although this has been questioned by others (Klein et al., 2007; Harris, 2010), possibly due to a different definition of grazing intensity....
[...]
...…for instance, is believed to cause severe rangeland degradation or even desertification on the QinghaiTibetan Plateau (Song et al., 2009; Wang et al., 2012), although this has been questioned by others (Klein et al., 2007; Harris, 2010), possibly due to a different definition of grazing intensity....
[...]
...Several recent articles have reviewed various aspects of the impacts of climate change on the Qinghai-Tibetan Plateau and have provided valuable information on these impacts (Cui & Graf, 2009; Harris, 2010; Yang et al., 2010a)....
[...]
TL;DR: In this article, the authors used process-based terrestrial ecosystem model to stimulate the potential climate-driven alpine grassland net primary production (NPP), and Carnegie-Ames-Stanford Approach based on remote sensing to stimulate actual grassland NPP influenced by both of climate change and anthropogenic activities over the Qinghai-Tibet plateau (QTP) from 1982 to 2011.
462 citations
TL;DR: In this paper, the spatial patterns of grassland green-up onset in relation to air temperature and precipitation before the growing season ("preseason" henceforth) in the central and eastern plateau were characterized using linear programming with correlation analysis.
341 citations
TL;DR: It is suggested that soil N availability does not determine ANPP under simulated warming and that heavy grazing rather than warming causes degradation of the alpine meadows.
Abstract: Uncertainty about the effects of warming and grazing on soil nitrogen (N) availability, species composition, and aboveground net primary production (ANPP) limits our ability to predict how global carbon sequestration will vary under future warming with grazing in alpine regions. Through a controlled asymmetrical warming (1.2/1.7 degrees C during daytime/nighttime) with a grazing experiment from 2006 to 2010 in an alpine meadow, we found that warming alone and moderate grazing did not significantly affect soil net N mineralization. Although plant species richness significantly decreased by 10% due to warming after 2008, we caution that this may be due to the transient occurrence or disappearance of some rare plant species in all treatments. Warming significantly increased graminoid cover, except in 2009, and legume cover after 2008, but reduced non-legume forb cover in the community. Grazing significantly decreased cover of graminoids and legumes before 2009 but increased forb cover in 2010. Warming significantly increased ANPP regardless of grazing, whereas grazing reduced the response of ANPP to warming. N addition did not affect ANPP in both warming and grazing treatments. Our findings suggest that soil N availability does not determine ANPP under simulated warming and that heavy grazing rather than warming causes degradation of the alpine meadows.
301 citations
TL;DR: In this article, the extent and underlying causes of rangeland degradation on the Qinghai-Tibet Plateau in China through a comprehensive review of the literature are evaluated and different measures are proposed to rehabilitate rangelands that have been degraded by different mechanisms.
Abstract: With ever intensifying land use, land degradation is becoming an increasingly important issue around the world, especially in China. This paper evaluates the extent and underlying causes of rangeland degradation on the Qinghai-Tibet Plateau in China through a comprehensive review of the literature. Diverse forms and differing intensities of rangeland degradation have been reported in several regions of the Plateau. Rangeland degradation is particularly severe in South Qinghai, North Tibet and the Qaidam Basin. Anthropogenic activities, especially changing land use practices, are identified as the primary force driving rangeland degradation. Dissimilar to climate change-induced degradation, such anthropogenic degradation is a rather short-term process altering the abiotic properties of the underlying soil. On the basis of these findings, we assessed the prospects of rehabilitating degraded rangeland to productive uses. Different measures are proposed to rehabilitate rangelands that have been degraded by different mechanisms. Reduction in grazing intensity is prescribed to rehabilitate reversibly degraded rangelands. Targeted human intervention in the forms of selective planting of grasses and artificial seeding, in conjunction with ecological and biological control of the plateau rodent population, is recommended to rehabilitate ‘irreversibly’ degraded rangelands. Our studies suggest it is very difficult or even impossible to rehabilitate new assemblage of species which appear as a result of climate change. Copyright © 2011 John Wiley & Sons, Ltd.
294 citations
References
More filters
TL;DR: In this paper, the authors collected monthly surface air temperature data from almost every meteorological station on the Tibetan Plateau (TP) since their establishment, and analyzed the temperature series to show that the main portion of the TP has experienced statistically significant warming since the mid-1950s, especially in winter, but the recent warming in the central and eastern TP did not reach the level of the 1940s warm period until the late 1990s.
Abstract: Adequate knowledge of climatic change over the Tibetan Plateau (TP) with an average elevation of more than 4000 m above sea level (a.s.l.) has been insufficient for a long time owing to the lack of sufficient observational data. In the present study, monthly surface air temperature data were collected from almost every meteorological station on the TP since their establishment. There are 97 stations located above 2000 m a.s.l. on the TP; the longest records at five stations began before the 1930s, but most records date from the mid-1950s. Analyses of the temperature series show that the main portion of the TP has experienced statistically significant warming since the mid-1950s, especially in winter, but the recent warming in the central and eastern TP did not reach the level of the 1940s warm period until the late 1990s. Compared with the Northern Hemisphere and the global average, the warming of the TP occurred early. The linear rates of temperature increase over the TP during the period 1955‐1996 are about 0.16°C:decade for the annual mean and 0.32°C:decade for the winter mean, which exceed those for the Northern Hemisphere and the same latitudinal zone in the same period. Furthermore, there is also a tendency for the warming trend to increase with the elevation in the TP and its surrounding areas. This suggests that the TP is one of the most sensitive areas to respond to global climate change. Copyright © 2000 Royal Meteorological Society.
1,532 citations
"Rangeland degradation on the Qingha..." refers background in this paper
...For example, Liu and Chen (2000) estimated warming rates of 0.016 C/year for annual means but 0.032 C/year for winter means using 97 stations distributed over the entire QTP during 1955–1996....
[...]
...Sources providing statistical evidence of a general warming trend in western China over the past five decades include Hulme et al. (1994), Liu and Chen (2000), Shen and Varis (2001), Domrös and Schäfer (2003), Gemmer et al. (2003), Yu et al. (2003), Du et al. (2004), Qian and Lin (2004), and Wu…...
[...]
TL;DR: This paper articulates the understanding of how complex systems change and what determines their ability to absorb disturbances in either their ecological or their social domains and presents a list of some that could help define the next phase of resilience-related research.
Abstract: This paper is a work-in-progress account of ideas and propositions about resilience in socialecological systems. It articulates our understanding of how these complex systems change and what determines their ability to absorb disturbances in either their ecological or their social domains. We call them “propositions” because, although they are useful in helping us understand and compare different social-ecological systems, they are not sufficiently well defined to be considered formal hypotheses. These propositions were developed in two workshops, in 2003 and 2004, in which participants compared the dynamics of 15 case studies in a wide range of regions around the world. The propositions raise many questions, and we present a list of some that could help define the next phase of resilience-related research.
1,268 citations
"Rangeland degradation on the Qingha..." refers background in this paper
...Although implementation may encounter obstacles (Levine, 1995; Clarke, 1995; Nyima, 2003; Yan et al., 2000; Yeh, 2003), its high costs in monetary, social, and cultural terms may disqualify it from constituting a sustainable social-economic system (sensu Walker et al., 2006)....
[...]
Abstract: [1] In this paper we summarize recent research in geocryological studies carried out on the Qinghai-Tibet Plateau that show responses of permafrost to climate change and their environmental implications. Long-term temperature measurements indicate that the lower altitudinal limit of permafrost has moved up by 25 m in the north during the last 30 years and between 50 and 80 m in the south over the last 20 years. Furthermore, the thickness of the active layer has increased by 0.15 to 0.50 m and ground temperature at a depth of 6 m has risen by about 0.1° to 0.3°C between 1996 and 2001. Recent studies show that freeze-thaw cycles in the ground intensify the heat exchange between the atmosphere and the ground surface. The greater the moisture content in the soil, the greater is the influence of freeze-thaw cycling on heat exchange. The water and heat exchange between the atmosphere and the ground surface due to soil freezing and thawing has a significant influence on the climate in eastern Asia. A negative correlation exists between soil moisture and heat balance on the plateau and the amount of summer precipitation in most regions of China. A simple frozen soil parameterization scheme was developed to simulate the interaction between permafrost and climate change. This model, combined with the NCAR Community Climate Model 3.6, is suitable for the simulation of permafrost changes on the plateau. In addition, permafrost degradation is one of the main causes responsible for a dropping groundwater table at the source areas of the Yangtze River and Yellow River, which in turn results in lowering lake water levels, drying swamps and shrinking grasslands.
703 citations
"Rangeland degradation on the Qingha..." refers background in this paper
...There is general agreement that the QTP is particularly sensitive to global climate change (Cheng and Wu, 2007; Wang et al., 2007)....
[...]
...Thus expansion of the depth or extent of the active layer could lead to erosion and loss of productivity, and has been implicated as a factor in retreating lakes and wetlands (Wang et al., 2006a; Cheng and Wu, 2007; Zhang, 2007)....
[...]
TL;DR: In this article, the authors investigated the independent and combined effects of experimental warming and grazing on plant species diversity on the north-eastern Tibetan Plateau, a region highly vulnerable to ongoing climate and land use changes.
Abstract: We investigated the independent and combined effects of experimental warming and grazing on plant species diversity on the north-eastern Tibetan Plateau, a region highly vulnerable to ongoing climate and land use changes. Experimental warming caused a 26–36% decrease in species richness, a response that was generally dampened by experimental grazing. Higher species losses occurred at the drier sites where N was less available. Moreover, we observed an indirect effect of climate change on species richness as mediated by plant–plant interactions. Heat stress and warming-induced litter accumulation are potential explanations for the species responses to experimental warming. This is the first reported experimental evidence that climate warming could cause dramatic declines in plant species diversity in high elevation ecosystems over short time frames and supports model predictions of species losses with anthropogenic climate change.
472 citations
"Rangeland degradation on the Qingha..." refers background in this paper
...In contrast, Klein et al. (2004) demonstrated that losses in vegetation species richness would likely accompany warming, although losses were reduced in the presence of simulated grazing (i.e., clipping)....
[...]
TL;DR: In this paper, the authors studied the effect of glacial retreat on the hydrological processes in the Tibetan Plateau and surrounding regions, and found that the retreat is relatively small in the interior of the Tibetan plateau and increases to the margins of the plateau with the greatest retreat around the edges.
Abstract: Glacial retreat on the Tibetan Plateau and surrounding regions is characteristic since the 1960s and has intensified in the past 10 yr. The magnitude of glacial retreat is relatively small in the interior of the Tibetan Plateau and increases to the margins of the plateau, with the greatest retreat around the edges. Glacial retreat in this region is impacting the hydrological processes in the Tibetan Plateau and surrounding regions. The glacial retreat has caused an increase of more than 5.5% in river runoff from the plateau. In some areas, such as the Tarim River basin, the increase in river runoff is greater. Glacial retreat has also caused rising lake levels in the areas with large coverage of glaciers, such as the Nam Co Lake and Selin Co Lake areas. Rising lake levels are devastating grasslands and villages near the lakes.
388 citations
"Rangeland degradation on the Qingha..." refers background in this paper
...As with the warming trend, there is little dispute that glaciers on the QTP are in general decline as a result of recent climate change (Rikiishi and Nakasato, 2006; Baker and Moseley, 2007; Pu et al., 2007; Yao et al., 2007; Li et al., 2008b; Xin et al., 2008; Yang et al., 2008)....
[...]