The Western Pamirs (Tajikistan) under environmental change - Assessing vegetation change and associated ecosystem functions and services in the Rushan Range
Final Report Abstract
In this project, we analyzed changes of vegetation and land cover in the Rushan Range (Western Pamirs). In particular, we focused on the following key questions: (1) Did land cover in the study area change in space and time? (2) Did plant functional traits and associated ecosystem functions and services change in space and time? (3) What are the predominant drivers of land cover and plant functional trait change in the study area? (4) What is the impact of land cover and plant functional trait change on the provisioning of ecosystem services, in particular on primary production, water regulation and soil conservation. The project results show that land cover in study area significantly changed throughout the last 30 years. In particular, we detected an extensive greening trend, i.e. an increase in vegetation biomass, regardless of the land cover class. This increment is consistent with rising temperatures in the study area. However, browning trends, i.e. a reduction of green biomass, could also be validated for all land cover types, albeit in smaller areas. Abrupt declines of vegetation cover could be assigned to catastrophic events of debris flows, which destroyed Tugai forests and floodplain meadows in two valleys of the study area, diminishing water regulation and soil stability. Detected gradual decreases of vegetation cover show week correlations with increasing livestock numbers, suggesting overgrazing in those areas. However, the analysis of plant functional traits (plant growth form, plant height, leaf area, leaf nitrogen, live history, spinescence) does not suggest a general overgrazing in the study area, but in some parts. The pasture quality is still very good. The harsh climatic conditions dominate the spectrum of plant functional traits over the influence grazing. The establishment of a continuous area-wide map of plant functional traits based on Landsat multispectral imagery still contains high uncertainties. Future attempts therefore should try to improve the accuracy based on hyperspectral data. Furthermore, there is a need for more detailed data on climate factors and livestock numbers and composition to improve the models on the major driving factors of vegetation and ecosystem change in the study area. Future studies should also take soil development and permafrost into account, as the conducted field studies suggest that these are important factors for vegetation and land cover change in the study area.
Publications
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(2016): Preserving a comprehensive vegetation knowledge base – An evaluation of four historical Soviet vegetation maps of the Western Pamirs (Tajikistan). PLoS ONE 11(2): e0148930
Vanselow, K.A., Samimi, C. & Breckle, S.W.
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(2018): Grasslands of Kazakhstan and Middle Asia: The Ecology, Conservation and Use of a Vast and Globally Important Area. In: Squires, V.R., Dengler, J., Feng, H. & Hua, L. (eds.): Grasslands of the world: diversity, management and conservation. CRC Press, Boca Raton, US
Bragina, T., Nowak, A., Vanselow, K.A. & Wagner, V.
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(2018): Methods of Assessing Vegetation Dynamics and Pasture Potentials in High Mountain Regions. In: Sychev, V.G. and Mueller, L. (eds.): Novel Methods and Results of Landscape Research in Europe, Central Asia and Siberia. Monograph in 5 Volumes. Vol. III Landscape Monitoring and Modelling. Russian Academy of Sciences, Moscow: pp. 209-213
Vanselow, K.A., Zandler, H. & Samimi, C.
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(2018): sPlot – a new tool for global vegetation analyses. – Journal of Vegetation Science
Bruelheide, H., Dengler, J., Jimnez-Alfaro, B., Purschke, O. ... Vanselow, K.A. ... et al.
