Covering extensive parts of China,Karst landscapes are exceptional because rapid and intensive land use change has caused severe ecosystem degradation within only the last 50 years.The 20th century intensification in food production through agriculture has led to a rapid deterioration of soil quality,evidenced in reduced crop production and rapid loss of soil.In many areas,a tipping point appears to have been passed as basement rock is exposed and ‘rocky desertification’ dominates.Through the establishment of the “Soil processes and ecological services in the karst critical zone of SW China (SPECTRA) Critical Zone Observatory (CZO) we will endevaour to understand the fundmental processes involved in soil production and erosion,and investigate the integrated geophysical-geochemical-ecological responses of the CZ to perturbations.The CZ spans a gradient from undisturbed natural vegetation through human perturbed landscapes.We seek to understand the importance of heterogeneity in surface and below-ground morphology and flow pathways in determining the spatial distribution of key stocks (soil,C,vegetation,etc.) and their control on ecosystem service delivery.We will assess the extent to which the highly heterogeneous critical zone resources can be restored to enable sustainable delivery of ecosystem services.This paper presents the CZO design and initial assessment of soil and soil organic carbon stocks and evidence for their stability based on caesium-137 (137Cs) data.
Timothy Quine Dali Guo Sophie M.Green Chenglong Tu Iain Hartley Xinyu Zhang Jennifer Dungait Xuefa Wen Zhaoliang Song Hongyan Liu Heather Buss Timothy Barrows Richard Evershed Penny Johnes Jeroen Meersmans
Geography,College of Life and Environmental Sciences,University of Exeter,Rennes Drive,Exeter,EX4 4R Institute of Geographic Sciences and Natural Resources Research,Chinese Academy of Sciences,Beijing, Key Lab of Environmental Geochemistry,Institute of Geochemistry,Chinese Academy of Sciences,550002,G Rothamsted Research-North Wyke,Okehampton,Devon,EX20 2SB,UK Institute of the Surface-Earth System Science Research,Tianjin University,Tianjin 300072,China College of Urban and Environmental Sciences,Peking University,Beijing,100871,China University of Bristol,Bristol,BS8 1RJ,UK Cranfield University,Cranfield,Bedfordshire,MK43 0AL