Final Report Summary - TROPHDIVERSE (Trophic diversity, resource compartmentation, and the stability of ecosystems)
Project objectives
This project aimed to:
i) employ a molecular method (DNA gut content analysis) to characterise soil food webs at a level of resolution that was previously unattainable;
ii) to use this new understanding of soil food webs to test hypotheses related to the relative importance of resource compartmentation and consumer trait diversity in the stabilisation of energy flows through soil ecosystems.
Project outcomes
The project had several successful outcomes. During the work it was determined that additional challenges needed to be addressed prior to the successful application of DNA gut content analysis in resource-consumer interactions in soil. We developed a protocol that effectively removes contaminant DNA from the surface of soil invertebrates. In one application, this approach has been validated by detecting site-specific interactions between mites and fungi in Antarctica (this research is ongoing). We also addressed issues related to the matching of environmental DNA sequences to microbial species, developing an approach that better accounted for species niches and uncertainty in classification. The approach also revealed that current approaches for estimating microbial diversity may substantially underestimate species richness.
The stability of food webs are strongly linked to the strength of consumer-resource interactions; we demonstrated that these interaction strengths are linked to both the diversity of resources that are present, as well as the identity of those resources. Linked to this, interactions in resource communities were clearly shown to be structured by competition driven by nutrient availability, as opposed to simply being structured by the availability of these resources. These outcomes have consequences for wildlife management, suggesting that practices cannot rely solely on the outcomes of niche distribution models, but also require knowledge regarding how the biota co-occurring within an environment interact with each other.
The project facilitated the training of highly qualified personnel, including one diploma student, two Bachelor students, and several students in an undergraduate ecology laboratory. The fellow participated in several other research projects within AG Rillig, including those lead by PhD students and resulting in an additional eight publications. The fellow also disseminated outcomes widely at conferences and was invited to seminars in several countries (Germany, Poland, Sweden, Canada, and Australia).
This project aimed to:
i) employ a molecular method (DNA gut content analysis) to characterise soil food webs at a level of resolution that was previously unattainable;
ii) to use this new understanding of soil food webs to test hypotheses related to the relative importance of resource compartmentation and consumer trait diversity in the stabilisation of energy flows through soil ecosystems.
Project outcomes
The project had several successful outcomes. During the work it was determined that additional challenges needed to be addressed prior to the successful application of DNA gut content analysis in resource-consumer interactions in soil. We developed a protocol that effectively removes contaminant DNA from the surface of soil invertebrates. In one application, this approach has been validated by detecting site-specific interactions between mites and fungi in Antarctica (this research is ongoing). We also addressed issues related to the matching of environmental DNA sequences to microbial species, developing an approach that better accounted for species niches and uncertainty in classification. The approach also revealed that current approaches for estimating microbial diversity may substantially underestimate species richness.
The stability of food webs are strongly linked to the strength of consumer-resource interactions; we demonstrated that these interaction strengths are linked to both the diversity of resources that are present, as well as the identity of those resources. Linked to this, interactions in resource communities were clearly shown to be structured by competition driven by nutrient availability, as opposed to simply being structured by the availability of these resources. These outcomes have consequences for wildlife management, suggesting that practices cannot rely solely on the outcomes of niche distribution models, but also require knowledge regarding how the biota co-occurring within an environment interact with each other.
The project facilitated the training of highly qualified personnel, including one diploma student, two Bachelor students, and several students in an undergraduate ecology laboratory. The fellow participated in several other research projects within AG Rillig, including those lead by PhD students and resulting in an additional eight publications. The fellow also disseminated outcomes widely at conferences and was invited to seminars in several countries (Germany, Poland, Sweden, Canada, and Australia).