Abstract

Food-chain length (FCL) is a fundamental ecosystem attribute, integrating information on both food web composition and ecosystem processes. It remains untested whether FCL also reflects the history of community assembly known to affect community composition and ecosystem functioning. Here, we performed microcosm experiments with a copepod (top predator), two ciliate species (intermediate consumers), and bacteria (producers), and modified the sequence of species introduction into the microcosm at four productivity levels to jointly test the effects of historical contingency and productivity on FCL. FCL increased when the top predator was introduced last; thus, the trophic position of the copepod reflected assembly history. A shorter FCL occurred at the highest productivity level, probably because the predator switched to feeding at the lower trophic levels because of the abundant basal resource. Thus, we present empirical evidence that FCL was determined by historical contingency, likely caused by priority effects, and by productivity.

Highlights

  • Food-chain length (FCL) is a fundamental ecosystem attribute, integrating information on both food web composition and ecosystem processes

  • Food-chain length (FCL), a measure of the number of trophic levels in a system[1,2,3,4], is a property of food web structure with connection to community composition[1,2,3] and ecosystem processes, such as energy and matter flows in ecosystems[2,5], and CO2 exchange between freshwater systems and the atmosphere[6]

  • The differences in FCLs correspond to a shift of 0.5 trophic level in these treatments, indicating that the trophic position of the top predator was substantially changed

Read more

Summary

Introduction

Food-chain length (FCL) is a fundamental ecosystem attribute, integrating information on both food web composition and ecosystem processes. It remains untested whether FCL reflects the history of community assembly known to affect community composition and ecosystem functioning. Food-chain length (FCL), a measure of the number of trophic levels in a system[1,2,3,4], is a property of food web structure with connection to community composition[1,2,3] and ecosystem processes, such as energy and matter flows in ecosystems[2,5], and CO2 exchange between freshwater systems and the atmosphere[6]. Despite the accepted role of historical contingency with regard to community composition and ecosystem functioning[24,25,26,27,28], its importance as a determinant of FCL has, to our knowledge, never been tested

Methods
Results
Conclusion
Full Text
Published version (Free)

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call