How are herbivorous consumers limited by multiple resources simultaneously? - Development and definition of co-limitation types in a generally applicable theoretical framework

• Applicant: Dr. Erik Sperfeld
• Subject Area: Ecology and Biodiversity of Animals and Ecosystems, Organismic Interactions
• Term: from 2012 to 2015
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 228727763

Recently, a growing number of studies have shown that the growth of organisms is not limited by only one resource at any one time. Co-limitation, i.e., the simultaneous limitation of an organism¿s growth by multiple resources, is an emerging topic in ecological research. As yet, theoretical concepts for co-limitation are mainly derived for primary producers (plants/algae). Several types of co-limitation, i.e., the way how organisms are co-limited, were proposed for plants and some of which can be probably applied to consumers as well. However, consumers differ fundamentally from plants in their various resource acquisition strategies, suggesting to the need for new co-limitation types. Additionally, the proposed co-limitation types for plants are inconsistently defined among studies. Therefore, a general framework is required in which the different types of co-limitation are clearly defined. The present project aims to develop a generally applicable theoretical framework for consumer co-limitation, in which the different types of co-limitation are clearly defined and explicitly described. The project will focus on herbivorous consumers as they are especially sensitive to constraints in resource quantity and quality. I will review existing theories in nutritional ecology and conduct a comprehensive literature survey on herbivore characteristics and food categories. This knowledge is essential to develop different types of co-limitation, which will be described (i) mathematically, (ii) graphically, (iii) with help of case studies, and linked to each other in a novel theoretical framework. This framework will improve the understanding of mechanisms behind consumer co-limitation and provide a basis for the development of hypotheses which can be tested empirically. Thus, the elaboration of the proposed framework is of crucial importance in the further development of research on co-limitation.

• DFG Programme: Research Fellowships
• International Connection: New Zealand
• Host: Professor Dr. David Raubenheimer