Energy availability has long been recognized as a predictor of community structure, and changes in marine productivity under climate change necessitate a deeper understanding of this relationship. Wood falls – derived from natural or anthropogenic inputs of wood into the oceans – constitute an important deep-sea habitat, harboring endemic and unique communities ultimately entirely dependent on the wood for chemical energy. In this study we take advantage of the unique features of an experimental wood fall deployment to examine assembly rules for deep-sea wood falls quantifying how connectivity and niche dynamics alter the relationship between community structure and energy availability. The study design combines advantages of both experimental (tractability, control of key environmental parameters) and observational (natural colonization by taxonomically diverse communities) studies.
Results/Conclusions
We show that alpha diversity increases with increasing energy availability over 32 wood-fall communities. This pattern weakens as connectivity increases among wood falls. Increases of species richness appear to be related to energetic niche dynamics where high metabolic demand species are lost from communities where energy availability is low. Increases in species richness are also concordant with packing into modal size class that may represent an energetic optimum.