Myristica swamps — tree-covered wetlands within the evergreen forests of the Western Ghats that once formed a large hydrological network all along the Western Ghats — now exist as small, isolated pockets, said a new study.
Authors Priya Ranganathan, G. Ravikanth and N.A. Aravind from the Ashoka Trust for Research in Ecology and the Environment (ATREE), stated that the Myristica swamps are one of the most threatened ecosystems in India due to increased human pressure. According to the researchers, even with their little-known biota, the swamps harbour several rare-relic floristic and faunal taxa comprising many endemic and threatened species, with most plant species highly restricted in their distribution. These swamps are one of the most unique and primeval ecosystems of the Western Ghats, they said.
The paper, ‘A review of research and conservation of Myristica swamps, a threatened freshwater swamp of the Western Ghats, India’, was published in Wetland Ecology and Management in August.
It said critical inland swamp habitats of India are the Myristica swamps, the Elaeocarpus swamps and the Hadlus, all of which are forested wetland ecosystems that are invariably freshwater in character.
Myristica swamps have the characteristic traits of a dense evergreen closed forest, presence of abundant knee roots protruding from waterlogged soil, soils with high humus content, and are moist or inundated throughout the year.
The ancient swamp forests are endemic to the Western Ghats and a smaller distribution exists in the Andaman and Nicobar Islands. There are 60-odd swamps reported from Kerala and there may be many smaller ones, which are either not mapped or reported. An attempt has been made to map the swamps in Karnataka and a few studies have focused on swamps in Goa and Sindhudurga, the northernmost limit of swamps in Maharashtra, the paper said.
“Recently, fossil remnants dating back to the late Pleistocene age (2,580,000 to 11,700 years ago) of the Myristicaeae family have been recovered from the Konkan Coast in the Ratnagiri district of Maharashtra. These remnants suggest that the Konkan region in the northern Western Ghats had a longer rainfall period from both the northeast and southwest monsoons and would have been home to abundant evergreen rainforests of the likes of Myristica swamps,” it adds.
“In recent years, many Myristica swamps in the central and southern Western Ghats are threatened by the growing agricultural demand and are often converted to paddy fields, or arecanut and teak plantations. This is especially true of those swamps existing outside protected forest tracts in the Western Ghats landscape. While wetlands have been given prioritisation in the past, swamps in India have been relatively ignored by scientists and policymakers,” the researchers said.
They also highlight how the RAMSAR convention, held in 1971 in Iran to discuss the conservation of globally important wetlands, does not include any swamps on its list of internationally protected wetlands, though India added 10 new RAMSAR sites to its list of protected wetlands in 2020, taking the country’s total number of sites to 41.
Myristica swamps, like the floral plateaus of the northern Western Ghats and the Shola grassland mosaics, face a higher threat of destruction than other evergreen forest types. Though freshwater swamps fall under the umbrella category of “ecologically sensitive areas,” and Myristica swamps classified as “unique evergreen regions,” many do not fall within India’s Protected Area network, although some swamps in Kerala and Karnataka are within protected forest landscapes, it stated.
The Biodiversity Act of 2002 by the Government of India declares important biodiversity areas, including Myristica swamps, as Biodiversity Heritage Sites. “However, site-based initiatives are yet to be taken by the state forest department and State Biodiversity Board of Karnataka, where most of these swamps exist today,” said the authors, adding that many swamps are in reserve forests or sacred groves/community conservation landscapes, which do not grant them protection from land use conversion, and are also highly fragmented and isolated.
As of February 2021, 58 scientific studies have been conducted on the floristic components and vegetation of Myristica swamp forests and according to them, there are at least 79 tree species, 26 shrubs, 27 climbers, and 44 herb species recorded.
Mr. Aravind, Convenor and Senior Fellow (Associate Professor), Suri Sehgal Center for Biodiversity and Conservation, ATREE, and one of the authors of the study, said, “Any loss of the swamps will also lead to the extinction of associated species.”
The researchers have called for the creation of a clear policy for swamp conservation, a large-scale project to map and carry out further research on Myristica swamps across the Western Ghats and comprehensive documentation of the remaining swamps, their genetic diversity and local threats.