TY - CHAP

T1 - Resilience or vulnerability? Vegetation patterns of a Central Tibetan pastoral ecotone

AU - Miehe, Georg

AU - Miehe, Sabine

AU - Bach, Kerstin

AU - Wesche, Karsten

AU - Seeber, Elke

AU - Behrendes, Lena

AU - Kaiser, Knut

AU - Reudenbach, Christoph

AU - Nölling, Jasmin

AU - Hanspach, J.

AU - Herrmann, Mark

AU - Yaoming, Ma

AU - Mosbrugger, Volker

PY - 2013

Y1 - 2013

N2 - The question of the resilience or vulnerability of Tibetan highland pastures is notonly of regional importance but also of global relevance for the Earth's energy budgetand atmospheric circulation. A climate and grazing driven environmental change of theTibetan highland albedo could induce feedback effects within an ecotone ofapproximately 200 km between Cyperaceae-dominated grazing-lawns and alpine steppesstretching over 2000 km between the Qilian Shan (38°N) and the Himalaya (28°N).Understanding the vegetation structure of this region would enable accurate modelingapproaches for global change scenarios. We analyzed the Central Tibetan pasture vegetation in the wider Nam Co area usingphytosociological vegetation surveys and remote sensing techniques (ASTER, SRTM).The survey described in this chapter recorded a total of 105 vegetation relevés, with atotal of 233 species. The species-based approach using DCA and phytosociologicalclassification distinguishes six plant communities including juniper woodlands andjuniper open dwarf shrublands, alpine steppe communities, Kobresia pygmaeacommunities and transitional mosaics with fragments of Kobresia turf and alpine steppe.The most common community was the transitional mosaic of Kobresia pygmaea matsand alpine steppe. Except for the phanerophytic communities and the grazing lawns ofKobresia pygmaea, plant communities are characterized by low overall plant cover withtwo thirds of species showing values lower than 1%. An analysis of plant functional typesshows that most species are adapted to intense grazing regimes. The prevalence of dwarfgrowth forms, rhizomes and repellent characteristics shows that the pastures are grazingresilient. By contrast, the fragmented turf cover is vulnerable and endangered by intensegrazing, digging by small mammals, turf removal and periglacial weathering.

AB - The question of the resilience or vulnerability of Tibetan highland pastures is notonly of regional importance but also of global relevance for the Earth's energy budgetand atmospheric circulation. A climate and grazing driven environmental change of theTibetan highland albedo could induce feedback effects within an ecotone ofapproximately 200 km between Cyperaceae-dominated grazing-lawns and alpine steppesstretching over 2000 km between the Qilian Shan (38°N) and the Himalaya (28°N).Understanding the vegetation structure of this region would enable accurate modelingapproaches for global change scenarios. We analyzed the Central Tibetan pasture vegetation in the wider Nam Co area usingphytosociological vegetation surveys and remote sensing techniques (ASTER, SRTM).The survey described in this chapter recorded a total of 105 vegetation relevés, with atotal of 233 species. The species-based approach using DCA and phytosociologicalclassification distinguishes six plant communities including juniper woodlands andjuniper open dwarf shrublands, alpine steppe communities, Kobresia pygmaeacommunities and transitional mosaics with fragments of Kobresia turf and alpine steppe.The most common community was the transitional mosaic of Kobresia pygmaea matsand alpine steppe. Except for the phanerophytic communities and the grazing lawns ofKobresia pygmaea, plant communities are characterized by low overall plant cover withtwo thirds of species showing values lower than 1%. An analysis of plant functional typesshows that most species are adapted to intense grazing regimes. The prevalence of dwarfgrowth forms, rhizomes and repellent characteristics shows that the pastures are grazingresilient. By contrast, the fragmented turf cover is vulnerable and endangered by intensegrazing, digging by small mammals, turf removal and periglacial weathering.

KW - Ecosystems Research

KW - Alpine steppe

KW - Grazing

KW - Kobresia pygmaea

KW - Plant functional types

KW - Qinghai-Tibet plateau

KW - Remote sensing

UR - http://www.scopus.com/inward/record.url?scp=84892036471&partnerID=8YFLogxK

M3 - Chapter

AN - SCOPUS:84892036471

SN - 978-162-808-298-2

SP - 111

EP - 151

BT - Steppe Ecosystems

A2 - Morales Prieto, Manuel B.

A2 - Traba Diaz, Juan

PB - Nova Science Publishers, Inc.

CY - Hauppage, New York

ER -