Myristica Swamps — Living Museums of the Western Ghats

Freshwater tree-covered wetlands are India’s biodiversity hotspot.

Myristica swamps need more protection. (Source: Flickr)

The article was originally published on WeNaturalists, as a part of the curated section by the editorial team. For similar stories, head to our Explore section.

From the Amazon and its tributaries to Papua New Guinea, from Sweden’s valleys to Odzala National Park, Congo — freshwater swamps occur in different parts of the globe. India has its fair share in the Brahmaputra Valley, the Siwalik and Doon Valley. A very special kind of freshwater tree-covered wetlands called the Myristica swamps are however endemic to India’s biodiversity hotspot — the Western Ghats.

Myristica Swamps can be considered as living museums — as they are a proof of the ‘vast hydrological network along the Western Ghats’ since its inception, and exclusively serve as the habitat for the primitive plant family Myristicaceae.

Myristica Swamps — A Biodiversity Hotspot

Myristica Swamps are located in the evergreen forests of three localities in India — Uttara Kannada (Karnataka), Sindhudugra district (Maharashtra) and southern Kerala. Apart from being endemic to the Western Ghats, these swamps are found in Venezuela, Papua New Guinea and Amazon basin only.

Special Adaptations

These primeval and unique ecosystems have adapted to the water-logged conditions well. What characteristics have helped them in the process?

• Two kinds of Roots: Stilt Roots and Knee Roots help in water inundation.

1. Stilt Roots

• Aerial adventitious roots emerge from the main trunk.
• Provides additional support to the swamp trees in soft soil.

2. Knee Roots

• Horizontally growing spongy roots.
• Facilitates gas exchange.
• Provides underground roots with air.
• Have aerated tissues that grow well in anaerobic conditions and help in the transportation of ions to the xylem.

Apart from the special roots, the other physiological adaptations of the swamps include:

Lenticels

Aerial loops that thicken with age and have enlarged air pores.

• Facilitates the exchange of gases between the swamp plant’s internal tissues and the external environment.
• Helps cope with deficiency of oxygen in the soil through anaerobic respiration.
• Acts as entry points for oxygen into the roots.

Rhizomes

Thick spongy stems that are buried in the soil.

• They’re more tolerant to floods than roots.
• Seed Germination
• Seeds of swamp plants remain in the water for a long period.
• Regeneration occurs exclusively during the drought period.

These characteristics make it feasible for the Myristica Swamps to flourish in the Western Ghats region. It has also been observed that though they occur in small, isolated pockets — they have been home to many types of flora and fauna.

Enhancing the Ecosystem

Did you know that these magical swamps from the Western ghats play a critical role in the recycling of nutrients and microbial relationships? The plant-animal interactions get better through this process.

Due to the presence of various micro habitats in these Myristica swamps — the region also acts as a favourable breeding and survival ground for different molluscs, annelids, fish, arthropods, reptiles, birds, mammals and amphibians.

Furthermore, the water bodies in the swamps, the slope and the altitude of the swamps play a central role in the survival of most flora species.

Flora

As per surveys, 130 plant species were discovered in these swamps — out of which, 63 were endemic to the Ghats. The major tree species (total of 82 tree species) that predominated the swamps were Holigarna grahami, Gymnocranthera canarica, Semecarpus travancorica, Hopea wightiana, Lophopetalum wightianum,, Sysygium laetum, Myristica fatua, Mastixia arborea, etc. In addition, there were 94 species of shrubs and herbs, coupled with 49 lianas. The critically endangered swampy tree species Semecarpus kathalekanensis is also a part of the flora diversity.

Fauna

Taking the fauna diversity of 630 species into account, 1 species of Nemathelminthes, 3 species of Platyhelminthes- (Bipalium-2, tapeworm-1), 10 species of molluscs, 281 species of insects, 27 species of mammals, 129 aves species, 56 species of amphibians, 55 species of reptiles, 6 species of Myriapoda, 54 species of arachnids, 1 unidentified species of crustaceans, 4 species Annelida (Oligochaeta-2 and Hirudinea-2), and 14 species of Pisces are present. The Kottigehar Dancing Frog (Micrixalus kottigeharensis) is the major highlight of these Myristica swamps.

Apart from serving as a habitat to this vast biodiversity (out of which some figure in the IUCN Red List), there are other functions of these Myristica Swamps.

Importance of the Myristica Swamps

Proof of Evolution

• These swamps trace back to the origin of Gondwanaland.
• They are called “living fossils” as they did not get extinct due to archaic and primitive features.
• Home to the angiosperms.

Watershed Value

• Help stabilize the water table.
• Act as a natural flood control device.
• Help replenish underground water reservoirs.

Biological Importance

• Shelter unique varieties of flora and fauna which are endemic to the Western Ghats.
• These flora and fauna can be investigated for studying biochemistry and genetics.
• These swamps are home to the wild relatives of cultivated plants like — Cinnamomum spp., Zingiber spp., M. fatua, Piper nigrum, Piper hookeri, Garcinia spp., etc.
• They provide food to the various fauna.

Enhancing Economy

• Swamps favour growth of many medicinal and economically important plants — Myristica malabarica, Ochlandra scriptoria (used for basket and weaving), Apama siliquosa, Saraca indica, etc.
• Members of the Myristicaceae are used as cosmetics and antioxidants and coupled with the bio-control of fungi and Trypanosoma.

Curating Conservation

It has been observed that there are several threats to Myristica swamps, mostly affected by human encroachment.

From rice cultivation to tree-felling for timber extraction, oil and teak plantations. In addition, the diversion of streams has caused 17 out of the 51 swamps in Uttara Kannada to go extinct. Furthermore, climate change has been a contributor to the mortality rate of these swamps. Lack of germination of the seeds has led to poor harvest and in turn, led to poor regeneration of the swamps.

Amidst this climate crisis, the decision to make the Myristica Swamps a “sanctuary” has come as a harbinger of hope. Moreover, researchers believe that teaching the youth about the importance of these Myristica swamps will aid in their conservation.

Most importantly, saving these swamps will help us discover the “secret lives of the flora and fauna inhabiting these enigmatic, archaic ecosystems” that have survived amidst the varied effects of climate change, over the years.