Extended Job Description

(Information for Applicants of Post 2407)

Background: Renewable resource provisioning, especially agricultural production, requires stable ecosystem functions provided by sufficient water and nutrients but also various facets of biodiversity. However, neither is biodiversity considered in renewable resource models [6,7] nor is it applied in high-level global scale assessments, for instance, on food provisioning and biodiversity. This feedback between efforts spent to obtain resources (such as applying fertilizers, pesticides, labour, technology etc.) and the decline of biodiversity-based ecosystem functions—the so-called biodiversity-production mutualism [1]—acknowledges this essential feedback. It can be described as a non-linear, non-monotonic, and likely hump-shaped version of the law of diminishing marginal returns [8] and is the critical gap in understanding resource production systems [1]. Second, a portfolio effect [9] suggests that a larger number of different resources supports the long-term stability of resource production, denoted as resource-use diversity (RUD). However, multiple resources are rarely considered in renewable resource models. Third, numerous resources are also prone to be exchanged or traded between resource users, communities, societies, countries or regions. Trade favours local specialization and provides availability to numerous different resources accessible across the globe [10]. Trade can lead to a stabilization of production and can also result in a homogenization of resources, i.e., a decline in resource diversity [11] but trade is also is a driver of declining biodiversity [12]. This different consequence makes the exchange of resources through trade a double-edged sword: It is the starting point for an entirely new quality of resource-use problems.    

Your Task: This project is supposed to conduct a synthesis of theories and follows a theoretical, conceptual modelling approach to implement renewable resource-use models that consider feedback through the biodiversity-production mutualism [1]. By solving the resulting optimum resource-use problems, hypotheses on the existence of different harvesting strategies are tested that are supposed to define new generic solutions of sustainable biodiversity-friendly resource use. The position will develop the conceptual models and based its work on available data-sets from global to the case study, either in collaboration with scientists at UFZ and/or based on meta-analytic approaches. Given the experiences of the candidate, one or more of the following research questions should be tackled and answered

  • Is there a medium level of optimum efforts that maintain a sufficient level of biodiversity and ecosystem function while at the same time optimizing yields?
  • Is stability improved when producing fewer resources in large amounts (low evenness) or a larger number with lesser amounts (high evenness)?
  • How will these results change if different traits of biodiversity production mutualism feedback are incorporated?

Further Reading / Cited References

  1. Seppelt, R. et al. (2020) Deciphering the biodiversity-production mutualism in the global food security debate. Trends Ecol. Evol. DOI: 10.1016/j.tree.2020.06.012
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  6. Clark, C.W. (2010) Mathematical bioeconomics: the mathematics of conservation, 3rd ed.Wiley. ISBN: 978-0-470-37299-9
  7. Gordon, H.S. (1954) The Economic Theory of a Common-Property Resource: The Fishery. J. Polit. Econ. 62, 124–142
  8. Lloyd, P.J. (1969) Elementary Geometric/Arithmetic Series and Early Production Theory. J. Polit. Econ. 77, 21–34
  9. Loreau, M. and de Mazancourt, C. (2013) Biodiversity and ecosystem stability: a synthesis of underlying mechanisms. Ecol. Lett. 16, 106–115
  10. Nyström, M. et al. (2019) Anatomy and resilience of the global production ecosystem. Nature 575, 98–108
  11. Khoury, C.K. et al. (2014) Increasing homogeneity in global food supplies and the implications for food security. Proc. Natl. Acad. Sci. 111, 4001–4006
  12. Lenzen, M. et al. (2012) International trade drives biodiversity threats in developing nations. Nature 486, 109–112