T135 Karst Critical Zone Evolution: The Rapid Responses of Carbonate Systems to Changes in Climate, Sea Level, Groundwater Pumping, and Land Cover/Land-Use

Monday, 26 September 2016
1:30 PM - 5:30 PM
Room 504

SOIL PROCESSES AND ECOLOGICAL SERVICES IN THE KARST CRITICAL ZONE OF SW CHINA

Paper number: T135-2
Program: Technical Sessions
Time: 1:35 PM – 1:50 PM

Authors

Abstract

Covering extensive parts of Southwest China, karst is a key landscape that is exceptional because rapid land use change has caused severe ecosystem degradation within only the last 50 years. This environmental degradation comprises rocky desertification, and is comparable to that caused by the better known extreme rates of erosion of the sandy loess soils in North China. Therefore, establishment of a critical zone observatory (CZO) in the karst landscape of SW China along a dynamic perturbation gradient in varying states of transition between states of rocky desertification to natural forest would fill a significant gap in the current database and research effort. Furthermore, there is a socioeconomic imperative to establish a CZO in the karst landscapes of SW China. The population of 36 million are amongst the poorest in China, with regional GDP less than 50% of the national average, and sustainable solutions to land management, potentially including abandonment and economic compensation, will be integral to lifting the population out of poverty.

The CZO was established in June 2016. We investigate the integrated geophysical-geochemical-ecological and social responses of the CZO to past perturbations, along a gradient from undisturbed natural vegetation through human perturbed landscapes at 3 levels of use – sloping farmland, recovery phase 1 (recently abandoned, within 5 years) and recovery phase 2 (secondary forest, abandoned > 5 years). We integrate measurements of: (1) plant, soil, mycorrhizal fungi and free-living soil microbes; (2) rates of rock weathering, elemental release and soil formation processes; (3) rates of erosion and soil redistribution; and, (4) pools and fluxes of soil organic C (SOC), nitrogen (N) and phosphorus (P) within the karst ecosystem. Through explicit consideration of plant-microbe-soil and plant-microbe-rock interactions, we will identify the biological controls on nutrient availability, soil formation and loss in the CZO. This talk encompasses the early stages of the project and presents some preliminary results.

Geological Society of America Abstracts with Programs. Vol. 48, No. 7

doi: 10.1130/abs/2016AM-279592

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