Abstract

Foundation species such as corals, trees, and bivalves enhance ecosystem function and biodiversity by creating habitat for associated organisms, ameliorating stress, and modifying energy flow. However, theory generally ignores their ecological functions after death. Here we review the traits and functions of dead foundation species relative to their living counterparts, and the processes that control their persistence. We also conduct a meta-analysis to quantify where the effect of dead foundation species on community functions is unique or redundant to their living counterparts. We focus on marine ecosystems due to the greater diversity of foundation species they support and the increasing prevalence of mass-mortality events in these systems. Our study reveals how foundation species continue to provide important functions after death and exhibit new functions that are distinct from when they are alive. We develop a framework using broad, trait-based functional differences among types of dead foundation species to predict whether they will promote stability by enhancing ecosystem resilience or promote shifts to alternate states. Our synthesis establishes how an understanding of the ecological importance of dead foundation species can assist in predicting system trajectories, enhance restoration and conservation efforts, and contribute to ecological theory on habitat heterogeneity and ecosystem function.