Local disturbances drive the decrease of the area covered by Posidonia oceanica in the Mediterranean. Mechanical impacts during the development of coastal infrastructures alter sea floor and the recolonization of benthic community will depend on the recovery of pre-disturbance environmental conditions and on the intrinsic characteristics of the local community that was disturbed. We transplanted 468 rhizome fragments and 450 seedlings of P. oceanica in a meadow disturbed by the trenching and deployment of a power line to evaluate the suitability of the disturbed sea floor for rehabilitating P. oceanica meadows. We quantify and compare the survivorship and vegetative development of the transplanted/planted (i.e. fragments/seedlings) material in the two types of the unconsolidated substrata left after infrastructure deployment works finished: sand and burlap bags filled with coarse gravel. The latter was used as a corrective measure for topographic restoration. Three experimental plots with sixteen transplanted fragments or twenty-five seedlings were placed at each substratum type at three different depths (i.e. 15, 20 and 25 m). Our results show that the transplanting of P. oceanica rhizome fragments in the disturbed substrata had low survival rates (0–31%) after 40–48 months. The survivorship of seedlings was lower than that of fragments. Our results highlight the importance of substratum for P. oceanica recovery after mechanical impact; disturbed, non-consolidated substrata will preclude P. oceanica rehabilitation through planting. Preservation of meadow substratum (i.e. dead matte) is a critical element that coastal infrastructure projects should consider to enable future recovery of P. oceanica meadows.

局部扰动导致Posidonia Oceanica在地中海的覆盖面积减少。沿海基础设施开发过程中的机械影响改变了海底，底栖群落的重新定植将取决于扰乱前环境条件的恢复以及受到扰乱的当地社区的内在特征。我们将 468 个根茎碎片和 450 株P. Oceanica幼苗移植到因挖沟和部署电力线而受到干扰的草甸中，以评估受干扰的海底对恢复P. Oceanica的适宜性草地。我们量化并比较了在基础设施部署工作完成后留下的两种松散基质中移植/种植（即碎片/幼苗）材料的存活率和营养发育情况：沙子和填充粗砾石的粗麻布袋。后者被用作地形恢复的矫正措施。在三个不同深度（即 15、20 和 25 m）的每种基质类型上放置三个试验地块，其中有 16 个移植碎片或 25 个幼苗。我们的结果表明，在受干扰的基质中移植P. Oceanica根茎碎片在 40-48 个月后存活率较低（0-31%）。幼苗的成活率低于碎片的成活率。我们的结果强调了底物对于P.机械冲击后的大洋洲恢复；受干扰的、未固结的基质将阻止P. oceanica通过种植恢复。草甸底层（即死者的保存亚光）是沿海基础设施项目，应考虑使未来复苏的一个关键因素P.大洋洲的草地。