Seagrass resilience: where and how to collect donor plants for ecological restoration of eelgrass Zostera marina
As seagrasses are not available with commercial nursery stock, the removal of a large amount of plant material may damage donor populations. We evaluated the recovery of eelgrass Zostera marina following the removal of entire plant patches (0.01-0.49 m2) at edge and interior of eelgrass bed through a field experiment. We investigated the shoot density, morphology and growth of recovery plants following excavation. We found that the removal of entire small patches with excavation area ≤ 0.25 m2 at interior of eelgrass bed was the most suitable strategy for harvesting donor plants of Z. marina. Small patch excavation (≤ 0.25 m2) could promote asexual reproduction of recovery plants and their shoot density and morphology would equal or exceed those of natural plants ¡ 7 months after harvesting. These results indicate that Z. marina plants have a strong resilience capacity from physical disturbance through rhizome elongation to the harvested area.