Seagrasses constitute a key coastal habitat world-wide, but are exposed to multiple perturbations. Understanding elements affecting seagrass resistance to disturbances is critical for conservation.
This study addressed whether the resistance (change in shoot abundances) and performance (change in leaf morphology and growth) of the seagrass Cymodocea nodosa to a local stressor, light reduction, varied across three regions (SE Iberia, the Balearic Sea, and the Canaries).
The obtained results show the existence of inter-regional variation in the resistance and performance of C. nodosa. Under moderate and high shading, shoot abundance was abruptly decreased in the Canaries with concurrent, but less accentuated, changes in leaf morphology and no changes in growth. While in the other two regions, moderate and high shading had a negligible effect on shoot abundance, leaf morphology, and growth.
On the other hand, it is stated that shading had no overall effect over the total abundance and assemblage structure of epifauna.
From a conservation perspective, it is concluded that larger regional susceptibility to perturbations, in particular, should encourage protection at regional scales to guarantee the persistence of highly vulnerable species. And the authors highlight that if resistance differs among biogeographical scenarios (as the paper shows), universal conservation rules for seagrasses are challenging.
Tuya et al. (2018) Biogeographical scenarios modulate seagrass resistance to small-scale perturbations. Journal of Ecology doi: 10.1111/1365-2745.13114.