COMMUNITY ASSEMBLY OF DEEP-SEA CHEMOSYNTHETIC COMMUNITIES
2016 - Currently
“It is this contingency that makes it difficult, indeed virtually impossible, to find patterns that are universally true in ecology. This, plus an almost suicidal tendency for many ecologists to celebrate complexity and detail at the expense of bold, first-order phenomena. Of course the details matter. But we should concentrate on trying to see where the woods are, and why, before worrying about the individual tree.” John H. Lawton, 1999.
Community assembly is the process by which species composition and patterns of communities are determined (Mittlebach and Schemske 2015). Historically, community ecology focused on species and their relationships with environmental factors (Lawton 1999; McGill et al. 2006). Yet, biodiversity is a multifaceted complex concept that also embraces, for instance, species performances, i.e., the functioning of species or the functional diversity (Diaz and Cabido 2001). The analysis of functional diversity is an alternative to produce more ecological meaningful statements and to better understand the processes and mechanisms underlying species distributions (McGill et al. 2006). In other words, instead of focusing on evolutionary differences (species) functional diversity focus on the different ecological performances of taxa. On the top of that, functional diversity also reflects the ecological processes that control the fluxes of energy, nutrients and organic matter through an environment, i.e., the functioning of ecosystems (Cardinale et al. 2012). Understanding how communities are assembled and thus the dynamics of biodiversity in space and time is of paramount importance to address current global treats to ecosystems such as global change and industrial impacts.
The assembly of communities result from multiple interacting process acting as “sieves” that “filter” at different spatiotemporal scales (Mittlebach and Schemske 2015). Over large temporal scales, speciation and extinction determine regional species pools. Dispersal and environment select for certain species’ traits, and inter- and intraspecific biotic interactions further determine the composition and abundances of species at local scales (HilleRisLambers et al. 2012, Weiher et al. 2011; Kraft et al. 2015). Productivity and environmental stress are major drivers of the assembly of communities (Chase and Leibold 2002; Chase 2010; Weiher et al. 2011). Locally, species richness is often positively correlated with primary productivity (Mittelbach et al. 2001; Chase 2010), and high environmental stress “filters” for suitable species traits, therefore limiting colonization and reducing species and functional diversity (Weiher et al. 2011; Mouillot et al. 2013).
Mainly due to the financial and accessibility constrains related with the deep sea science, deep-sea ecology has largely remained descriptive focusing on the species-environment relationships. Contrary to terrestrial and shallow water ecology the performance of experiments and thus the formal test of ecological hypotheses have been the exception in the deep ocean (McClain and Schlacher et al. 2016). Deep-sea chemosynthetic communities are of special interest to study and test community assembly hypotheses.
