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Climate variability rather than overstocking causes recent large scale cover changes of Tibetan pastures.

Lehnert LW, Wesche K, Trachte K, Reudenbach C, Bendix J - Sci Rep (2016)

Bottom Line: This supply function is claimed to be threatened by pasture degradation on the TP and the associated loss of water regulation functions.However, neither potential large scale degradation changes nor their drivers are known.Increasing livestock numbers as a result of land use changes exacerbated the negative trends but were not their exclusive driver.

View Article: PubMed Central - PubMed

Affiliation: Faculty of Geography, Philipps-University of Marburg, Deutschhausstr. 10, 35037 Marburg, Germany.

ABSTRACT
The Tibetan Plateau (TP) is a globally important "water tower" that provides water for nearly 40% of the world's population. This supply function is claimed to be threatened by pasture degradation on the TP and the associated loss of water regulation functions. However, neither potential large scale degradation changes nor their drivers are known. Here, we analyse trends in a high-resolution dataset of grassland cover to determine the interactions among vegetation dynamics, climate change and human impacts on the TP. The results reveal that vegetation changes have regionally different triggers: While the vegetation cover has increased since the year 2000 in the north-eastern part of the TP due to an increase in precipitation, it has declined in the central and western parts of the TP due to rising air temperature and declining precipitation. Increasing livestock numbers as a result of land use changes exacerbated the negative trends but were not their exclusive driver. Thus, we conclude that climate variability instead of overgrazing has been the primary cause for large scale vegetation cover changes on the TP since the new millennium. Since areas of positive and negative changes are almost equal in extent, pasture degradation is not generally proceeding.

No MeSH data available.


Related in: MedlinePlus

Interactions between vegetation cover and climate variables.(a) Positive trends in vegetation cover, precipitation and temperature. (b) Positive trends in temperature and negative trends in vegetation cover and precipitation. (c) Positive trends in vegetation cover and temperature and negative trends in precipitation. (d) Positive trends in precipitation and temperature and negative trends in vegetation cover. The red lines mark areas where the correlations are significant at the 0.05 confidence level (see inset in a for an explanation of the lines). The maps have been created using R statistical software40.
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f4: Interactions between vegetation cover and climate variables.(a) Positive trends in vegetation cover, precipitation and temperature. (b) Positive trends in temperature and negative trends in vegetation cover and precipitation. (c) Positive trends in vegetation cover and temperature and negative trends in precipitation. (d) Positive trends in precipitation and temperature and negative trends in vegetation cover. The red lines mark areas where the correlations are significant at the 0.05 confidence level (see inset in a for an explanation of the lines). The maps have been created using R statistical software40.

Mentions: Positive trends in the climate variables and plant cover were observed in southern Qinghai and the northern part of the TAR (Fig. 4a). Simultaneous occurrences of negative precipitation and plant cover trends were found in the far western part of the TAR and in some areas in the central TAR (Fig. 4b). Positive plant cover trends corresponded to negative precipitation trends at the northern border between Qinghai and the TAR (Fig. 4c) while the co-occurrence of the opposite trends was observed in the western part of the TAR and in the Qilian Shan (Fig. 4d).


Climate variability rather than overstocking causes recent large scale cover changes of Tibetan pastures.

Lehnert LW, Wesche K, Trachte K, Reudenbach C, Bendix J - Sci Rep (2016)

Interactions between vegetation cover and climate variables.(a) Positive trends in vegetation cover, precipitation and temperature. (b) Positive trends in temperature and negative trends in vegetation cover and precipitation. (c) Positive trends in vegetation cover and temperature and negative trends in precipitation. (d) Positive trends in precipitation and temperature and negative trends in vegetation cover. The red lines mark areas where the correlations are significant at the 0.05 confidence level (see inset in a for an explanation of the lines). The maps have been created using R statistical software40.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4829870&req=5

f4: Interactions between vegetation cover and climate variables.(a) Positive trends in vegetation cover, precipitation and temperature. (b) Positive trends in temperature and negative trends in vegetation cover and precipitation. (c) Positive trends in vegetation cover and temperature and negative trends in precipitation. (d) Positive trends in precipitation and temperature and negative trends in vegetation cover. The red lines mark areas where the correlations are significant at the 0.05 confidence level (see inset in a for an explanation of the lines). The maps have been created using R statistical software40.
Mentions: Positive trends in the climate variables and plant cover were observed in southern Qinghai and the northern part of the TAR (Fig. 4a). Simultaneous occurrences of negative precipitation and plant cover trends were found in the far western part of the TAR and in some areas in the central TAR (Fig. 4b). Positive plant cover trends corresponded to negative precipitation trends at the northern border between Qinghai and the TAR (Fig. 4c) while the co-occurrence of the opposite trends was observed in the western part of the TAR and in the Qilian Shan (Fig. 4d).

Bottom Line: This supply function is claimed to be threatened by pasture degradation on the TP and the associated loss of water regulation functions.However, neither potential large scale degradation changes nor their drivers are known.Increasing livestock numbers as a result of land use changes exacerbated the negative trends but were not their exclusive driver.

View Article: PubMed Central - PubMed

Affiliation: Faculty of Geography, Philipps-University of Marburg, Deutschhausstr. 10, 35037 Marburg, Germany.

ABSTRACT
The Tibetan Plateau (TP) is a globally important "water tower" that provides water for nearly 40% of the world's population. This supply function is claimed to be threatened by pasture degradation on the TP and the associated loss of water regulation functions. However, neither potential large scale degradation changes nor their drivers are known. Here, we analyse trends in a high-resolution dataset of grassland cover to determine the interactions among vegetation dynamics, climate change and human impacts on the TP. The results reveal that vegetation changes have regionally different triggers: While the vegetation cover has increased since the year 2000 in the north-eastern part of the TP due to an increase in precipitation, it has declined in the central and western parts of the TP due to rising air temperature and declining precipitation. Increasing livestock numbers as a result of land use changes exacerbated the negative trends but were not their exclusive driver. Thus, we conclude that climate variability instead of overgrazing has been the primary cause for large scale vegetation cover changes on the TP since the new millennium. Since areas of positive and negative changes are almost equal in extent, pasture degradation is not generally proceeding.

No MeSH data available.


Related in: MedlinePlus