The global change is expected to cause stressful environmental conditions for many species, and there is concern that many of them will not be able to keep pace with the direct and indirect impacts of these changes. Species-specific responses to multiple climate drivers are causing modifications in the timing, direction, and magnitude of movements and life events among biota and regions and may have adverse impacts on the distribution and viability of biological communities, species and populations. Ultimately, the reshuffling of communities and declines of populations have the potential to impact ecosystem structure, function, and productivity, threatening the many goods and services that humans depend on. Biodiversity and ecosystem services are intrinsically linked, and biodiversity is often considered an ecosystem service in itself.
Establishing general patterns of biodiversity response under rapid environmental changes, and identifying generalities on an important paradigm such as the dichotomy between rare and common species, are central issues in ecology and conservation biology. The wider geographic distribution of common species is linked to their capacity to survive in a greater array of environmental conditions, guaranteeing their persistence in a wider range of environments. Conversely, the infrequent occurrence of rare species can be often explained by their narrower tolerance windows and lower level of phenotypic plasticity. Consequently, rare species are expected to be more sensitive to even small shifts from their optimal range of environmental conditions, and thus more at the risk of decline or local and global extinction under future global changes. Given the increasing evidence of rare species’ importance in supporting unique ecosystem functions, their higher sensitivity represent a threat for the integrity of ecosystems, and the services they provide.
The acquisition of a mechanistic understanding of common and rare species' responses to multiple global change drivers may serve as a tool to improve predictions on species’ distributional shifts or loss under future global change scenarios. The rapid rates of increase of seawater temperatures and decrease in pH, known as ocean warming and ocean acidification, respectively, can lead to the impairment of the physiological performance of organisms, with detrimental effects on individual fecundity, growth and survival. In order to not overestimate or underestimate the impacts of the global changes, we need to investigate all the mechanisms and processes that may prevent species loss, such as trans-generational plasticity (the capacity of one generation to influence the way the next generations interact with their environment), and rapid adaptation.
The EvolMarin project – ‘Rapid evolution and geographic ranges: predicting marine species persistence and distribution in a changing ocean’ – aimed at investigating the relationship between species tolerance, plasticity and patterns of geographic distribution, seeking to more reliably predict species persistence in a changing ocean. This was achieved by comparing the capacities for trans-generational plasticity and rapid adaptation in common and rare marine benthic species from coastal habitats, assessing their level of vulnerability to ocean warming and acidification scenarios, in isolation and combined, after a multigenerational exposure.
The EvolMarin project provides among the few empirical evidence on the higher vulnerability of rare species under scenarios of ocean warming, offering a mechanistic understanding of the patterns underlying commonness and rarity in marine ectotherms from coastal habitats. Given the increasing evidence of rare species’ importance in supporting unique ecosystem functions, their higher sensitivity to ocean warming represent a threat for the integrity of ecosystems, and the services they provide.
