Meadow fragmentation influences Posidonia oceanica density at the edge of nearby gaps

Abstract Seagrass meadows are globally threatened by anthropogenic and natural pressures that cause habitat fragmentation and ecosystem degradation. Seagrass fragmentation is manidested by the loss of vegetation in gaps within a meadow. Depending on the degree of fragmentation, the ecological services provided by theseagrass meadows may be compromised. This study aims to understand the effect meadow fragmentation hason the shoot density of the canopy (large-scale or meadow-scale effect), as well as the effect the local gap size has on the shoot density at the edge of the gap (local-scale or gap-scale effect). In other woerd, determine whether the effects on the large scale can impact the local scales of the gap. This study demonstrates that the greater the gap area is, the lower the shoot density of the vegetation surrounding the gap. Moreover, the effect of fragmentation at the meadow-scale has been proved: the higher the fragmentation degree of the meadow is, the lower the shoot density is in the surrounding vegetation near the gap. Hence, the differences in shoot density at the edges of a gap are proven to be produced by both meadow fragmentation and gap characteristics.