pasture degradation and the impact of grazing in qinghai (tibet) · 2003. 10. 15. · the three...
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PopulationGrowth
Conversion to Agriculture
Sedentarisationof Nomads
Collectivization Non-AdaptedHerd Structure
Chinese PastureManagement
Policies
Fencing of Pastures
Overgrazing/Exploitation of Pastoral Land
IncreasingDemand for Fuel
(Wood, Dung)
PastureDegradation
IncreasingLivestockNumbers
Shortage of Pastoral Land
SupplementarySources of
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Figure 4: The development of the population in the area of investigation displays a significant increase (1949-1985, 49.900 inhabitants in 2001)
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MethodsThe three pasture types examined in the area of investigation were Achnatherum splendens-, Kobresia/Stellera- and Orinus/ Stipa-dominated societies.Vegetation transect studies were conducted in twelve fenced pasture patches (four of each society) following the Braun-Blanquetapproach.The data on the distribution of species under different levels of grazing collected in 144 vegetation surveys along transects has been analyzed with multivariate techniques. The classification was carried out using TWINSPAN (Two-Way INdicator SPecies ANalysis). For Ordination DCA (Detrended Correspondence Analysis) was applied (figure 5).Additionally, dung and soil samples were collected along the transects in order to get information on the distribution of livestock in the fenced pastures through the frequency of dung pellets and the concentrations of nitrate and phosphate.
Literature: Qinghai History Editors Committee (2000): A History of Qinghai County. Xian (in Chinese)Acknowledgements: DAAD (German Academic Exchange Service) for financial support of the fieldwork, Northwest Institute of Plateau Biology (Xining, China), Prof. Dr. Georg Miehe & Dr. Sabine Miehe for cooperationCorrespondence: [email protected], Katja Koch, Department of Geography, Philipps-Universität Marburg, Deutschhausstr. 10, 35037 Marburg, Germany
Pasture Degradation and the Impact of Grazing in Qinghai (Tibet)
A contribution to sustainable Rangeland Management
IntroductionThe Chinese Province of Qinghai is one of the largest pastoral regions in China with extensive rangeland resources. In most regions livestock production is still the most important source of income for the local population.Political changes, socio-economic transition and the adjustment of the economy to market mechanisms caused transformations in live-
Katja KochDepartment of Geography, Biogeography Working Group, University of Marburg, Germany
Northwest Institute of Plateau Biology, Chinese Academy of Sciences, Xining
stock production in many parts of Tibet over the last decades. Interviews with herders in the study area (Xinghai County, Qinghai Province, see figure 2) showed that conditions for livestock production have deteriorated together with the state of pastures over the last decade (figure 1).In the present study the occurrence of pasture degradation was examined on three common pasture types of the Tibetan Plateau on the terraces of the Yellow River .
Figure 1: The comparison between fenced and non-fenced areas shows the intensive utilization of pastures
Figure 2: The locations of Qinghai Province (China) and the area of investigation (red square)
250 km
C H I N A
I N D I ABHUTAN
X i z a n g
Q i n g h a i
X i n j i a n g
Yu n n a n
S i c h u a n
G a n s u In n e r Mo .KYRGYZSTAN
ConclusionsInterviews with herders, vegetation surveys and evaluation of population, livestock and climate data indicate that a complex interaction of factors led to a decline in pasture productivity (figure 7). The changing political interventions as well as high stocking rates and climatic changes have had an impact on the condition of pastures today.Reduced herd sizes would probably be the only possibility to initiate rangeland regeneration. As a result, the income of herders might decrease dramatically.Therefore, rangeland improvement is only possible in cooperation with political decision makers.
Number of Species
Vegetation Cover
Distance
Amount of DungAxis 1
Axi
s 2 Distance (m)
0100250500
ResultsSignificant population growth and subsequently increasing livestock numbers have had an effect on pasture productivity during the last 50 years (figures 3 and 4). The continual decline of livestock numbers since at least 1995 possibly indicates the limit of carrying capacity on pastures in the study area. It is still under discussion whether changing levels of temperature and precipitation have an impact on pasture productivity (figure 6).The study showed that severe degradation on pastures in Xinghai County occurs especially on Achnatherum splendens-dominated pastures, were stocking rates were above the carrying capacity. As the tussocks of Achnatherum are less eaten by livestock, pasture productivity is much lower than on patches dominated by Kobresia or Orinus. Because of the relative grazing resistance of Cyperaceae, Kobresia pastures are in a fairly stable condition. Orinus-dominated grazing grounds reach their carrying capacity in the investigated areas.An obvious gradient of decreasing degradation with increasing distance from the gate was identified in the more severely degraded pasture plots (figure 5).
Figure 3: The development of livestock numbers show a marked increase (Xinghai County, 1949-2001, * weighted according to FAO). Figure 5: The DCA of 4 fenced Orinus/ Stipa- dominated pastures
shows gradients mainly with distance from the gate in the numberof species, plant cover and dung amount (n=48, Eigenvalue/ Post-hoc correlation Axis 1: 0,17/0,58; Axis 2: 0,08/ 0,17)
Figure 6: The development of the annual average temperature and the annual amount of precipitation in Xinghai (1961-2001, China Meteorological Survey)
Figure 7: Factors of pasture degradation in the study area