Maharashtra gets India’s first wood anatomical database for mangrove tree speciesUpdated: Oct 07, 2020, 01:01 IST
Maharashtra has become the first state in India to undertake forensic timber identification of mangrove tree species for enhanced conservation of the salt-tolerant coastal trees.
The Institute of Wood Sciences and Technology (IWST), Bengaluru, has come up with a first-of-its-kind study for developing an inventory of wood anatomy of mangrove species along the Maharashtra coast. The Mangrove Foundation and state mangrove cell of the forest department sanctioned the report this week. Stem and branch wood samples from 17 species from 12 genera belonging to nine families collected from Mumbai (Daravali, Madh), Navi Mumbai (Airoli), Panvel and eight locations at Sindhudurg along the state’s coastline were studied for various anatomical and physical properties.
“Owing to lack of information on mangrove wood anatomy, identification of the cut wood or those spotted on encroached forest land poses a real challenge to the mangrove cell and other enforcement agencies. However, with this database, we will now have a strong tool and proof to verify the type of trees up to the species level,” said Virendra Tiwari, additional principal chief conservator of forests (mangrove cell).
N Mohan Karnat, former director, IWST and co-investigator of the project said, “This is exactly like the forensic analysis or DNA fingerprints for humans wherein even a small piece of wood can now be easily traced back to which species it is.”
Maharashtra is home to 20 mangrove species spread over 320 sq km across six districts with close to 50% mangrove forests under government land declared as reserved forests while remaining areas fall under private land. Though mangroves are protected under various forest laws and the Bombay high court’s 2018 order banning the destruction of the trees, isolated cases of mangrove hacking, illegal transportation of timber, and encroachment on mangrove land are regularly reported.
“Mangrove woods are illegally cut and used as fuelwood in many coastal areas,” said Neenu Somraj, deputy conservator of forest (mangrove cell) adding, “Due to limited information on wood anatomy of mangrove species, it becomes difficult to identify and differentiate them from non-mangrove species or mangrove associates in case of legal issues or during the basic investigation.”
Apart from firewood, they are used for boat building, brick-burning and to make poles for various purposes including aquaculture among other uses. Tree barks are used in tanning industries since mangrove tree barks are rich in tannin.
S Shashikala, project investigator, IWST explained that the wood structure varies for different species depending on the proportions, size and distribution of various cell elements like vessels, fibres, parenchyma and rays. “Our study not only helped to build an identification tool database but also helped to understand how the woody material could be used for value-added utilisation based on physical properties,” she said.
For example, the wood of grey mangrove (Avicennia marina) and Indian mangrove (Avicennia officinalis) were anatomically inseparable except for different ray (cellular structures) heights. “Similarly, river mangrove (Aegiceras corniculatum) can be distinguished from other species by its small vessel size and higher vessel frequency, and woods of the Rhizophoreacea family (Rhizophora, Bruguiera, Ceriops) can be distinguished from other mangrove species by the presence of scalariform perforations in vessels,” said Shashikala adding that samples collected from Sindhudurg showed higher wood density and lower shrinkage (by volume) compared to wood from Thane or Mumbai districts.
Data generated through this project is being summarised in the form of a book - Hand Book of Mangroves of Maharashtra: Morphology and Wood Anatomy – which is under publication. “Apart from identifying the cut mangrove wood, this study also provides a base for several researchers to understand the internal changes in the cell structure of mangrove wood due to changes in several environmental factors such as high salinity, lack of oxygen in sediment, diurnal tidal inundation etc.,” said Sheetal Pachpande, assistant director (projects), Mangrove Foundation and co-author of the book.
Along with wood anatomical studies, other tools like molecular, DNA and chemical marker database are also to be used in forensic discrimination of timber species. “Following Maharashtra’s approach, other coastal states need to implement this in the advent of climate change and mangroves being the first line of defence,” said Karnat.