Reciprocal facilitation between annual plants and burrowing crabs: implications for the restoration of degraded salt marshes

​​​​​​Increasing evidence shows that facilitative interactions between species play an essential role in coastal wetland ecosystems. However, there is a lack of understanding of how such interactions can be used for restoration purposes in salt marsh ecosystems. We, therefore, studied the mechanisms of reciprocal facilitative interactions between native annual plants, Suaeda salsa, and burrowing crabs, Helice tientsinensis, in a middle-elevation salt marsh (with generally high plant density and moderate tides) in the Yellow River Delta of China.

We investigated the relationship between the densities of the plants and crab burrows in different seasons. Then, we tested whether and how salt marsh plants and crabs indeed facilitate each other in a series of field and laboratory experiments. Finally, we applied the results by creating a field-scale artificial approach for microtopographic modification to restore a degraded salt marsh.

We found that the density of plant seedlings in...