Soil processes and ecological services in the karst critical zone of Southwest China

Lead Research Organisation: Rothamsted Research
Department Name: Sustainable Agriculture Sciences-NW

Abstract

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Planned Impact

In the long term the indirect beneficiaries of this research will be the general population of the Guizhou karst region (~35 million people). This is one of the poorest regions in China with a GDP less than 50% of the national average. The karst landscapes of the region are very susceptible to perturbation, and many parts of Guizhou province have suffered severe land degradation due to deforestation and inappropriate agricultural practices. Subsequently, this area currently has very limited potential for the development of sustainable agriculture to meet the demands of contemporary local population pressures. The region has also seen the migration of young adults to the cities, leaving the elderly and very young responsible for much of the agricultural production. Thus, the Chinese government is planning to implement appropriate land management policies to address this situation, which need to be informed by robust science that quantifies current and potential ecosystem service delivery. There is, therefore, significant potential for our research to inform improved land management strategies that will meet these demands. This will in turn lead to improved delivery of ecosystem services to the communities in this region and higher environmental quality, addressing poverty and the welfare of the population through development of sustainable land resource management and long-term sustainable economic development.

More immediate and specific users of this research include state government officials, and policy makers, land managers and land users in the Guizhou region. They will benefit from a rich evidence base on which to make land management and planning decisions. At meetings in China, we will communicate the results of our research directly to these key stakeholders including the Soil and Water Conservation Monitoring Station of Guizhou and the Puding Karst Ecosystem Observation Station. At these meetings we will engage in design and development of sustainable land use strategies and policies. We will build on the highly successful farmer-scientist participant model of extension 'Science and Technology Backyard' (STB) by developing the first such programme in Guizhou. We have already engaged with and, have the support of, each of the local stakeholders and the lead scientist of the nationwide STB programme.

The integration of the new China karst CZO within the international CZ programme will provide unprecedented feedback and expertise from the whole network, linking experience across scales, from the Guizhou citizen challenged by land degradation and poverty, to others across the world engaged in understanding and developing solutions to ecosystem service delivery and maintenance in a multitude of environments.

Schoolchildren in the Guizhou region of China and in the UK will also benefit from increased awareness of threats in both countries to the environment, their country's 'environmental footprint' and the need for sustainable land management, as well as educational links with schools in other countries.

Ultimately, human society stands to benefit from a deeper understanding of the karst CZ, and the need to preserve its very high aesthetic value which is depicted in many Chinese art forms. Karst is an outstanding cultural landscape because it has seen thousands of years of human occupation in harmony with the landscape, until very recently. Areas of karst in Guizhou province are part of the South China Karst UNESCO World Heritage Site, and the region boasts the world reference site for a mature karst landscape called 'cone karst'. For the local population of Guizhou, active maintenance of this unique landscape will deliver economic benefits through the national and international leisure and tourism industry.
 
Description At the end of the 20th century, China launched the 'Grain-for-Green' Project that recommended the abandonment of low-yielding sloping farmland (>15°) prone to soil degradation by erosion, to allow recovery through natural vegetative regeneration. This policy could affect soil nitrogen cycling. We found that the absolute abundance of nitrogen functional genes significantly varied according to the phase of vegetation recovery, and that concentrations of available inorganic phosphorus and nitrate were the best explanatory variables. The external N from fertilizer application promoted the absolute abundances of ammonia-oxidizing archaea (AOA) and ammonia-oxidizing bacteria(AOB) in sloping farmland. The relative abundances of chiA (associated with decomposition) increased with soil depth across all vegetation recovery phases. The relative abundances of chiA and nifH (associated with N fixation) accounted for the largest proportion (58-72%) of the measured NFGs, indicating that active N-acquisition increased along the vegetation recovery gradient. The ratios of (chiA + nifH)/(AOA + AOB) and the sums of (nirK + nirS) were larger in the forest soil than those of sloping farmland and abandoned sloping farmland, implying a greater capacity for N storage potential, though accompanied by increased gas N emission potential, in the karst forest ecosystems.
Exploitation Route The state government officials, policy makers, land mangers and land users in the Guizhou region should benefit from the findings on which to make land management and planning decisions.
Sectors Agriculture, Food and Drink,Environment

 
Description Using the Critical Zone as a framework to understand sustaining the ecosystem services of soil and water (CZO) A UK China Collaboration: adding value and increasing impact
Amount £157,333 (GBP)
Funding ID NE/S009094/1 
Organisation Natural Environment Research Council 
Sector Public
Country United Kingdom
Start 01/2019 
End 03/2021