Department of Environmental Science & Natural Resources 

South China Agricultural University, Guangzhou
In association with the LEC-SCAU-GIG Joint Institute of the Environment

2-year Post-doctoral Research Position

Soil Ecology – Carbon sequestration in Chinese grassland soils

Supervisors:   Prof Nick Ostle (Lancaster Environment Centre, Lancaster, UK)

Profs Yongtao Li and Chunling Luo (South China Agricultural University, Guangzhou, China)

Prof Gan Zhang (Guangdong Institute of Geochemistry, Chinese Academy of Sciences)

Background: Grasslands cover 40% of the earth’s land surface, with the largest areas being found in Asia, Sub-Saharan Africa and South America. These grasslands support human livelihoods with food, fuel and fibre, and play a vital role in climate and water regulation, and influence global biogeochemical cycles. Furthermore, across the world, grasslands are of crucial importance for social cohesion, supporting traditional farming communities, cultures and wider populations. Nonetheless, estimates suggest that over 50% of the earth’s grasslands are degraded, due largely to over-grazing and inappropriate management, with climate change accentuating the problem. This has far-reaching socio-economic consequences, affecting poverty, and creating major environmental problems at local, regional and global scales, such as reduced carbon and water quality, and accelerated soil erosion. Given this, it is all the more surprising that understanding of the causes of grassland degradation remains limited, resulting in a staggering paucity of science-based policies for their restoration. To make matters worse, knowledge of the factors that make grasslands resilient to climate change, or other perturbations such as fire and flood, is severely constrained. There is now an urgent need to improve scientific understanding to underpin policy, decisions and management practice that ensure the sustainability of global grasslands.

In China, grasslands occupy more that 30% of the land surface with growing evidence of damage and degradation due to over-exploitation and climate change. In some regions the degradation of grasslands has led to ecosystem collapse, soil erosion and even desertification (e.g. Qinghai plateau and Inner Mongolia). This has effectively removed large areas of valuable land from the food production system with critical consequences for dependent communities. One key to the sustainability and function of grasslands is soil organic carbon. The capacity of any grassland ecosystem to capture and sequester carbon below ground is an important natural ecosystem service that contributes to the mitigation of fossil fuel derived greenhouse gas emissions. In this way, grasslands ‘mop up’ atmospheric CO₂ through photosynthesis and input organic matter into the ground as decaying matter or live root exudates. These inputs feed a voracious heterotrophic community that together regulate soil carbon sequestration and total ecosystem carbon stocks.

Science Uncertainty: Changes in land use and management coupled with ongoing climate warming and shifts in hydrological regimes are now strongly influencing this key grassland function. Evidence from other ecosystems indicate that interactions between management and climate factors can be important. Specifically, the effects of changes in grazing intensity and climate on the form and quantity of soil carbon stocks remain limited particularly across Asia constraining understanding on the regulators of soil carbon sequestration across the region and, consequently, the provision of innovations for soil security and grassland restoration.

Research questions: In this research project, we will be asking:

1. How have intensive management and climate change affected Chinese grassland soil carbon stocks?

2. How resilient are Chinese grassland soil carbon stocks to future perturbation including climate change?

3. How do the management and climate induced change in soil carbon stocks influence CH₄ and N₂O emissions?

The science: Research will involve joining with UK and Chinese scientists at Lancaster University and the South China Agricultural University (SCAU) to design sampling surveys, collect samples, prepare materials for analyses, analyse data and lead publications for peer reviewed journals. Advantage will be taken of existing grassland soil archives in China and newly sampled materials from across Chinese grassland ecosystems and climatic gradients. A combination of novel techniques will be used, including soil organic matter analyses (fractionation and chemistry), biotic assays (plant and microbial biomarkers, enzymology and greenhouse gas emissions), isotopic measurements ⁽¹³C and ¹⁴C) as well as standard soil physico-chemical metrics (macro- and micro- aggregates). The role will complement projects with sample regimes across Inner Mongolia and the Tibetan-Qinghai plateau linking with UK GCRF PDRAs on projects held by Prof Ostle and Profs Li and Zhang.

Join an exciting research environment. You will join the large and vibrant Environmental Isotope and Soil Function Group at South China Agricultural University, while also being affiliated with the Soil, Plant and Land Systems Research Group at the Lancaster Environment Centre (LEC) and the CAS Guangzhou Institute of Geochemistry (GIG). The PDRA researcher and project will be jointly supervised by Prof Nick Ostle (LEC), Profs Li and Luo (SCAU) and Prof Zhang (GIG). Research infrastructure and resources will be available for this project at the newly appointed ‘Joint Institute for the Environment’ (JIE) located in SCAU in Guangzhou, China – at which you will be primarily based – and within the Lancaster Environment Centre, UK. We envisage time split between the Chinese and UK organisations, though successful candidates will have to spend a minimum of 12 months in China before 1^st April 2019.

Be part of the EU SEW-REAP research community. This post is one of three within the framework of the European Union’s SEW-REAP (Addressing food Security, Environmental stress and Water by promoting multidisciplinary Research EU And China Partnerships in science and business) project which aims to provide solutions to the Agri-Food-Water-Environment Nexus within China, which will base 3 postdoctoral positions at SCAU. Additionally, SEW-REAP has already based 9 PhD-level researchers within China (most of whom are based at the JIE).

Who should apply:  You should have a PhD in Biological, Environmental or Ecological Sciences with experience of soil research, an interest in organic matter chemistry and strong statistical skills. You must have proven capacity for creative, high-quality research, evidenced by your publication record. Ability to lead and co-ordinate independent research and a work autonomously.

Due to the nature of funding (postdoctoral salary in China which is supplemented by a contribution from the EU SEW-REAP project), only UK / European citizens are eligible to apply. A willingness to embrace new research challenges while living in China for at least 1 of the 2 years is essential.

Funding: The PDRA will be an employee of the South China Agricultural University (SCAU). A 2-year post-doctoral research assistant (PDRA) salary (equivalent to €17,805 per annum at today’s rates) will be paid by SCAU and supplemented with RMB 1500 (€190) per month for accommodation costs in China. Income from SCAU will be taxed and paid in China. 12 months living and travel expenses are also available from the SEW-REAP programme, at a rate of €1680 free of tax per calendar month spent in China. Together, the combined funding for this post is approximately €27,885 p.a. averaged across the two years.

Deadline for applications:  [31^st October 2017]

Provisional Interview Date (by Skype if necessary): [6^th November 2017]

Start Date: 1 January 2018

For further information or informal discussion about the position, please contact Prof Nick Ostle (n.ostle@lancaster.ac.uk)

Application process: Due to the limited time between the closing date and the interview date, it is essential that you ensure references are submitted by the closing date or as soon as possible.

Further reading

• Jiang, L., Song, M., Yang, L., Zhang, D., Sun, Y., Shen, Z., Luo C., Zhang, G. (2016). Exploring the Influence of Environmental Factors on Bacterial Communities within the Rhizosphere of the Cu-tolerant plant, Elsholtzia splendens. Scientific reports, 6, 36302.

• Zong, Z., Wang, X., Tian, C., Chen, Y., Fang, Y., Zhang, F., … & Zhang, G. (2017). First assessment of NOx sources at a regional background site in North China using isotopic analysis linked with modeling. Environmental Science & Technology.

• Li, Y. T., Rouland, C., Benedetti, M., Li, F. B., Pando, A., Lavelle, P., & Dai, J. (2009). Microbial biomass, enzyme and mineralization activity in relation to soil organic C, N and P turnover influenced by acid metal stress. Soil Biology and Biochemistry, 41(5), 969-977.

• Lin, Z., Zhen, Z., Wu, Z., Yang, J., Zhong, L., Hu, H., … & Zhang, D. (2016). The impact on the soil microbial community and enzyme activity of two earthworm species during the bioremediation of pentachlorophenol-contaminated soils. Journal of Hazardous mMaterials, 301, 35-45.

• Li, X., Lin, Z., Luo, C., Bai, J., Sun, Y., & Li, Y. (2015). Enhanced microbial degradation of pentachlorophenol from soil in the presence of earthworms: Evidence of functional bacteria using DNA-stable isotope probing. Soil Biology and Biochemistry, 81, 168-177.

• Zhang, Y., Kaiser, K., Li, L., Zhang, D., Ran, Y., & Benner, R. (2014). Sources, distributions, and early diagenesis of sedimentary organic matter in the Pearl River region of the South China Sea. Marine Chemistry, 158, 39-48.

• Xu, H. J., Wang, X. H., Li, H., Yao, H. Y., Su, J. Q., & Zhu, Y. G. (2014). Biochar impacts soil microbial community composition and nitrogen cycling in an acidic soil planted with rape. Environmental science & technology, 48(16), 9391-9399.

• Zhang, Y., Wang, L., Li, W., Xu, H., Shi, Y., Sun, Y., … & Li, Y. (2017). Earthworms and phosphate-solubilizing bacteria enhance carbon accumulation in manure-amended soils. Journal of Soils and Sediments, 17(1), 220-228.

• Broadbent, A.A.D., Orwin, K.H., Peltzer, D.A., Dickie, I., Mason, N.W.H., Ostle, N.J., Stevens, C.J. (2017). Invasive N-fixer impacts on litter decomposition driven by changes to soil properties not litter quality. Ecosystems. p. 1-13. 13 p.

• McCormack, C.G., Ostle, N.J. (2016) Key impacts of climate engineering on biodiversity and ecosystems, with priorities for future research. Journal of Integrative Environmental Sciences. 13, 2-4, p. 103-128.

• Baxendale, C.L., Ostle, N.J., Wood, C.M., Oakley, S., Ward, S.E. (2016) Can digital image classification be used as a standardised method for surveying peatland vegetation cover? Ecological Indicators. 68, p. 150-156.

• Armstrong, A.B., Ostle, N.J., Whitaker, J. (2016) Solar park microclimate and vegetation management effects on grassland carbon cycling. Environmental Research Letters. 11, 7, 11 p.

• McKenzie, S.W., Johnson, S.N., Jones, T.H., Ostle, N.J., Hails, R.S., Vanbergen, A.J. (2016) Root herbivores drive changes to plant primary chemistry, but root loss is mitigated under elevated atmospheric CO₂. Frontiers in Plant Science. 7.

• Hill, R., Saetnan, E.R., Scullion, J., Gwynn-Jones, D., Ostle, N.J. (2016) Temporal and spatial influences incur reconfiguration of Arctic heathland soil bacterial community structure. Environmental Microbiology 18, 6, p. 1942-1953.

• Walker, T., Garnett, M.H., Ward, S.E., Oakley, S., Bardgett, R., Ostle, N.J. (2016) Vascular plants promote ancient peatland carbon loss with climate warming. Global Change Biology. 22, 5, p. 1880-1889.