Recovery of a Halodule wrightii donor meadow

Few restoration studies have quantified the recovery of the donor meadow. We evaluated the recovery of a monospecific donor meadow of Halodule wrightii, the second most commonly used transplanting species, and assessed the possible effect of 24 plots of 1 m(2) placed in an approximately 3,400 m(2) large monospecific meadow with a mean cover of 45%, foliar shoot density of 1,280 shoots/m(2), and 16 cm canopy height. Extraction densities were 9, 25, 64, and 121 small-sized extraction cores (4.5 cm diameter, 20 cm depth), with control and procedural control without extractions (N = 4 per treatment). After 6 months, even the plots with the highest extraction densities recovered, as indicated by the shoot number in the extraction areas and seagrass cover in the plots approaching the levels in the controls. The recovery occurred under the environmental conditions: light availability (22,000 +/- 51 lx), relatively stable sediments (0.8-1.16 cm) with a fine sandy composition (mean grain diameter, D50: 0.5 +/- 0.22 mm), and low organic matter (0.22 +/- 0.012%). The recolonization rate was 1-3 shoots per month in the 4.5 cm diameter extraction areas, independent of the extraction level. Thus, approximately 20% of the H. wrightii meadow (corresponding with 121 cores/m(2)) could be extracted in our study area. This high extraction intensity can be attributed to the adequate selection of donor species, meadow, and size of the planting unit.