|The presence of S. pacifica, also known as Pacific pickleweed, affected species diversity in a set of recent field experiments testing the effects of sea level rise on marsh plants. Photo by Steve Matson ©2006.|
Sea level rise is predicted to change both salinity and inundation levels—conditions that are already the two biggest stressors on plants living in Mediterranean-climate salt marshes. A recent study moved plants from higher elevations to lower ones in a southern California marsh to simulate the effects of sea level rise and test how it might affect competitive interactions and plant species diversity. This move was paired with manipulations of the dominant plant species, Salicornia pacifica, otherwise known as Pacific pickleweed, to see if plant species interactions became more competitive or facilitative.
The study found that both S. pacifica and the subordinate species were affected by inundation, but that levels of the subordinate plant species decreased with the presence of S. pacifica. Based on these results, the authors predict that increased competition and species interactions as a result of sea level rise may reduce plant diversity and exacerbate the effects of climate change on these plant communities. They conclude that restoration projects attempting to maintain a full suite of ecosystem functions should try to account for these changes by planting a high diversity of species in areas expected to see increased inundation.
Read more in the full PLoS ONE article “Early Stages of Sea-Level Rise Lead to Decreased Salt Marsh Plant Diversity through Stronger Competition in Mediterranean-Climate Marshes.”