Abstract
Soil communities are among the most species-rich communities in the world. The current debate on how the control of ecosystem diversity and functioning depends on the feedbacks between above- and belowground organisms say that soil processes can function at low levels of species richness in soil. This is due to a low degree of species specific links within the soil food web that maintain a high redundancy in functions. We claim that this “dogma” is due to the lack of suitable methods to detect and identify species specific interactions between organisms in soil food web We propose the use of techniques that will add a high resolution of the structure of soil food webs. We will: Identify the direction and specificity of links between fungi and fungal feeding invertebrates in soil food webs. Nested PCR’s of DNA extracts of soil animals and soil will identify fungal DNA sequences to species. The frequency of species encountered in amplified clones will determine the abundance of fungi and thus the feeding specialization of the soil animals. We will: Identify the structure of food webs by detecting stable 13C isotope ratios of soil organisms. Analysis with GC-IRMS of signature PLFAs of soil microorganims and of soil animals will determine their trophic levels in the food web. Press perturbation experiments with plant derived material will determine the structure and diversity of soil food webs under influence of different plant communities.
Sweden