2018 ESA Annual Meeting (August 5 -- 10)

PS 54-81 - Post-disturbance recovery patterns vary with latitude in subtidal marine communities

Friday, August 10, 2018
ESA Exhibit Hall, New Orleans Ernest N. Morial Convention Center
Mariana Bonfim, Biology, Temple University, Philadelphia, PA and Amy L. Freestone, Department of Biology, Temple University, Philadelphia, PA
Background/Question/Methods

Disturbance operates as a structuring process, often increasing niche opportunities for new species. During recovery, diversity and other productivity-enhancing mechanisms can increase recovery rates and affect compositional trajectories. These mechanisms, however, can vary across biogeographic gradients, such as latitude, suggesting that post-disturbance recovery may also hinge on geographic location. Using sessile marine invertebrate communities, we tested whether tropical communities would recover more quickly than at higher latitudes. We further predicted disturbance in the tropics would initiate a shift in community composition in manipulated communities. Experiments were conducted in four regions from the tropics to high-temperate zone (8º - 55º N). Communities were disturbed iteratively using randomized biomass removals (20 and 60 percent cover), in early and late succession (3- and 12-months, respectively). Unmanipulated panels were used as controls

Results/Conclusions

Lower latitude communities recovered faster relative to higher latitudes in term of biomass recovery and space occupation. While similarity indices revealed no consistent compositional differences among disturbance treatments after initial community assembly, different compositional outcomes emerged in developed communities depending on disturbance intensity in the tropics. Our results suggest that tropical communities can undergo more rapid recovery after disturbance, but recovery may result in different compositional endpoints. Examination of growth and colonization dynamics will likely deepen understanding of mechanisms driving this pattern. Latitudinal variation in recovery dynamics has important implications for our understanding of community stability across biogeographic gradients.