Lack of ecological data hinders management of ecologically important saltmarsh ecosystems: A case study of saltmarsh plant Porterasia coarctata (Roxb.)

Saltmarsh ecosystems though ecologically important are one of the least studied ecosystems in Asia. This study reviewed the published literature from 1988 to 2021 of India to assess the current status of the data deficient saltmarsh species Porterasia coarctata (Roxb.) within its distribution limits. This saltmarsh species inhabits the lower intertidal silty-sandy habitats of India's west coast and silty-clay habitats of the east coast. In the lower intertidal zone, P. coarctata is mostly associated with Myrostachia wightiana, whereas in the upper intertidal zone the highest chance of presence was for Suaeda maritima (18%) and the lowest for Cressa cretica (1%), S. fruticosa (1%) and Scirpus littoralis (1%). The deep root system of P. coarctata helps in sediment accretion and facilitates the formation of mangrove ecosystems. From this study it was evident that most of the research on P. coarctata in India was part of survey of mangrove ecosystems. In India, significant knowledge gap exists on the reproductive ecology and population trends of this species. Most importantly, the genes responsible for salinity and submergence tolerance of P. coarctata are well documented, that can provide solutions for salt and submergence tolerant rice plants in coastal areas prone to sea level rise. The blue carbon storage potential of P. coarctata is higher than other saltmarsh plants, that can be leveraged as a nature-based solution for CO2 emission reductions. The ecosystem services of P. coarctata can also contribute towards achieving various sustainable development goals (SDG-1,2,6,13 and14). Coastal development, mangrove restoration and marine food provisioning are the most important drivers causing the decline of P. coarctata ecosystems across India. This study proposes a long-term coastal monitoring plan for essential conservation and management of existing P. coarctata beds and preventing further degradation and loss of these ecosystems. This study also showcases species-specific valuation of individual saltmarsh plants at regional scale are essential to catalogue the most efficient saltmarsh plants that can play an important role in future climate change scenarios and serve as a global model.