Karnataka all set to go on mangrove planting spree

Karnataka’s coastal mangroves may have turned into tourist attractions and attained the status of Daiva Vanas (God’s forests). But according to a new research , mangroves not only stem tidal waves or tsunamis but also actively trap large amounts of carbon to prevent greenhouse gas from escaping into the atmosphere. This high-carbon storage suggests that mangroves may play a role in climate change management.  Taking a cue from the research, Karnataka forest department is planning to grow a series of mangroves along the coast, close to estuaries dotting Karnataka’s coastline.

The research conducted by US Forest Service’s Pacific Southwest and Northern research stations, University of Helsinki, and Centre for International Forestry Research, and posted online on Nature Geoscience on April 3, suggests that coastal mangrove forests store more carbon than any other forest on earth.

The team examined carbon content of 25 mangrove forests across the Indo-Pacific region to find that per hectare mangrove forests store up to four times more carbon than other tropical forests. The team attributes the ability to store large amounts of carbon to the mangrove’s deep organic-rich soils.

According to Daniel Donato, a  research ecologist at the Pacific Southwest Research Station in Hilo (Hawaii), mangrove-sediment carbon stores were on an average five times larger than those typically observed in temperate, boreal and tropical terrestrial forests, on a per-unit-area basis.

The team found an interesting fact: mangrove deforestation generated greenhouse gas emissions of 0.02 to 0.12 petagrams  of carbon per year – equivalent to up to 10% of carbon emissions from global deforestation, according to the research team's findings. The forest department has now taken up extensive cultivation of mangroves in the estuaries of Gurupur Nethravati, Shambhavi, Kalyanpur, Souparnika, Sharavati, and Kali rivers.

“The effort is aimed at bringing more area under mangroves. To begin with, the department has planted mangroves in 200 hectares in Nethravati and Gurupur estuaries. A group called Sneha Kunja in Honnavar and Kumta has taken up the task of planting mangroves in the Sharavati estuary,” said deputy conservator of forests of Uttara Kannada, R Gokul.

In Karnataka, only isolated areas are covered with mangroves. Over the decades, these ecosystems have lost ground due to denudation, and deforestation and re-plantation had not been taken up so far on a massive scale.

In Kundapur range, the village forest committees have planted mangroves over 300 acres, which is now called ‘Hasiru Kavacha’ (Green Armour). “We came to know about the carbon storing qualities of mangroves only recently. Since then, we’ve intensified planting of mangroves,” said Manjunath Shetty, assistant conservator of forests of Kundapur range. “If we were to dissipate the carbon contents in the air quickly, we need large expanses of mangrove forests all along the coast. Luckily, they grow pretty fast,” said Jayakar Bhandary, a botanist who guides various green groups in the coastal areas of Karnataka.

VN Nayak, director, Sub Regional Science Centre at Karwar and member of the Karnataka state environmental report committee 2011, calls it a ‘carbon sink’. “The mangroves grow in saline water. To shed salinity in their system they shed leaves rapidly and give out new leaves to make it evergreen. The leaves shed fall into the water and become organic manure. To make this process happen the trees have to ingest carbon rapidly and give out oxygen. This gives them the name carbon sink” Nayak said.