EAGER: Combining elemental and biochemical measures of prey to improve predictions of trophic transfers of nutrients

Oklahoma State University, Stillwater OK

Investigators

Abstract

Food webs describe the flow of energy and nutrients through communities and ecosystems. Elements (e.g., carbon, nitrogen, phosphorus) are the most common currency used by ecologists for measuring food web connections and comparing them across different ecosystems. Yet, other measures of diet such as macronutrients (i.e., carbohydrate, lipid, and protein) can also be useful because they provide more information on the quality of biochemical compounds. The overall goal of this work is to develop a framework for studying food webs that combines elements and macronutrients and then to test if this better predicts the amounts and types of nutrients transferred among organisms in food webs than elements alone. This research will focus on insects and other arthropods as they are some of the most diverse and abundant members of terrestrial ecosystems and a major food source for invertebrate and vertebrate predators. Better understanding how food webs function is an important goal for management of agricultural and natural ecosystem. During the course of this work, the project will also advance secondary STEM education by providing high school students and pre-service teachers with authentic research experiences and by training teachers in ways to incorporate research into classroom lesson plans. This research will test two objectives important for better uniting elemental and macronutrient approaches to studying food webs. First, the project will test the long-held assumption that elements and macronutrients are correlated with each other in diverse arthropods, which preliminary data suggest may not be well-supported. Then, the project will test if a hybrid currency, macronutrient-partitioned elements, is a better predictor of the transfer of nutrients from prey to predator and the transfer of nutrients from arthropod carcasses to soil decomposers than elements alone. This work is intellectually risky because it represents a significant departure from two fields (i.e., ecological stoichiometry and nutritional geometry) that have traditionally measured nutrients differently (i.e., elements versus macronutrients). However, the potential rewards of this work are great as it may unite these parallel and complementary paradigms. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.