Towards a more temporally explicit framework for community ecology?

Background/Question/Methods

Ecologists have long recognized that species interactions change over time, due to temporal variation in abiotic environments and in the abundance and relative life stages of interacting species. Despite - or perhaps because of - the ubiquitous role of time in structuring species interactions, other aspects of community complexity have often been emphasized ahead of temporal complexity. However, a growing emphasis on understanding how phenology, ontogeny, stage-structure and transient event-driven dynamics affect species interactions may signal the re-emergence of a “temporally explicit” perspective in community ecology. A temporally explicit view of community ecology aims to understand how species interactions change over time, and the consequences of shifts in this timing. Here, I suggest how a temporally explicit view of species interactions could build upon the ubiquitous and implicit consideration of time that is already fundamental to ecology. If we step away from common simplifying assumptions about the constancy of community structure and process, what new questions emerge? This introduction to the session will attempt to identify some common themes that are emerging from a temporally explicit perspective in ecology, illustrated with examples from recent studies in multiple systems.

Results/Conclusions

The key emerging themes of this synthesis are: 1) in systems where multiple dynamic processes operate on different timescales, it is important to consider sequential (as opposed to strictly alternative) hypotheses; 2) the study of species interactions should consider both phenology and ontogeny, especially when stage-structured interactions occur throughout life histories; 3) biotic and abiotic constraints on species interactions can define windows of opportunity in time, where quantitative shifts in the timing of key events (such as physical disturbances or resource pulses) can qualitatively alter life history outcomes; 4) a temporally explicit perspective seeks to explain the mechanisms of historical contingency in community assembly; and 5) the continued development of a temporally explicit perspective in ecology is important for understanding how real-world species interactions are coordinated in time, and the potential implications of disrupting this coordination.