PhD project: The role of root-derived carbon for the structure and functioning of soil food webs as indicated by stable isotope and lipid analysis
Carbon translocated by roots is one of the main sources of carbon and energy for the soil food web, thereby it drives important biochemical reactions in soil including the mobilization of nutrients from organic matter resources. Although the quality and quantity of carbon input by roots varies with plant species/types, effects of plants on the carbon flux, pools and turnover in soil, and their interaction with soil organisms is not well understood. The thesis forms part of the project ‘Sustainable intensification of agriculture through agroforestry’. My PhD study will use 13CO2 pulse labelling and lipid analysis to investigate the incorporation of root-derived carbon into major soil compartments including soil arthropods, nematodes and microorganisms. Three different plant types will be investigated: arable crops, willows and grasses. In the 1st part of my thesis I will analyse the community composition of soil fauna in the rhizosphere of the three plant types, mainly focusing on soil arthropods, one of the most abundant and diverse animal group in soil. In the 2nd part I will measure the incorporation of 13C into soil arthropods after pulse labeling during a period of 28 days post labelling to analyse the flux of root-derived carbon into different compartments of the soil food web such as arthropods, nematodes, earthworms and microorganisms. In addition, the abundance of 15N will be measured to ascribe arthropod species to trophic levels. In the 3rd part of my thesis I will use lipid analysis to determine the feeding strategies of soil arthropods and ascribe them to feeding guilds such as fungivores, herbivores, bacterivores and predators. In the 4th part, results from the first three parts as well as from partners in the project will be joined to obtain a more comprehensive and broad view on the response of soil food webs to the input of root-derived carbon from arable crops, trees and grasses.
Zhipeng Li, Zufen Wei, Xiaodong Yang. 2016. Community characters and seasonal change of soil nematode in secondary succession of evergreen broad-leaved forest in Ailao Mountain. Chinese Journal of Ecology, 35(11):3023-3031.
Shengjie Liu, Zhipeng Li, Yi Sui, Douglas A. Schaefer, Peter O. Alele, Jin Chen, Xiaodong Yang. 2015. foraging strategies dominate pest suppression in organic tea plantations. BioControl: 1-9.
Guikui Chen, Zhipeng Li, Lian Chen, Mingzhong Liu, Huashou Li. 2013. Effects of simulated acid rain on the migration and transformation of hexavalent chromium in a water spinach-soil system. Journal of Agro-Environment Science, 32(3): 498-502.