That flora plays a decisive role in the functioning of sandy coasts is established by research world-wide, as the key component that guarantees stability of the beach – dune ecosystem is vegetation. For this reason, prevailing coastal protocols in India have classified pioneer frontal dune fields as ecologically sensitive areas. These strips are out of bounds for any human activity. But our littoral laws notwithstanding, the dune flora is under constant anthropogenic pressure due to tourism footfalls in particular, resulting in rapid elimination of sand dunes and its associated vegetation. Therefore, it would be incumbent in the draft CZMP 2019 at least, to ensure that a robust policy is enacted in favour of vegetal species that sustain fragile sandy shores. Sadly, this aspect has not come about.
Under the coastal laws, CRZ I comprises ecologically sensitive areas, such as sand dunes, mud flats, mangrove marshes, coral reefs and areas rich in genetic diversity. However, this instrument neither proposes strategies for restoration of landforms nor does it guarantee the conservation of dune vegetation.CRZ 2011 casually mentions that if mangroves are destroyed, five times the number need to be restored. In CRZ 2019, Annexure I/1.9 states: (e) afforestation, if any, on the sand dunes shall be done only with native flora; (f) the States shall prepare management plans for the demarcated sand dunes. Thus, CRZ 1991, 2011 and 2019 do not have adequate provisions that guarantee the health of coastal flora and fauna. And neither does the draft CZMP 2019 of Goa propose any packages related to greening of coasts. Hence, considering that coastal vegetation is depleting drastically, there is pressing need for aggressive plantation programmes.
The coastal sand dunes of Goa are colonised by a wide variety of vegetal species ranging from grasses, shrubs to tall trees. Some of the major varieties are briefly summarised:(a) Dune grass is often found in patches, on frontal dunes that merge into the beach; (b) Ipomoea creepers with bright purple flowers are most abundant all along the coast; at places, a thick carpet covers large areas of pioneer dunes; this species does not need any special care; (c) Spinifex, the spiny variety of dune vegetation, can also be observed at many sites; (d) Spiny shrubs, about 1-2 m in height, can be noted mostly on hind dunes; (e) Casuarina trees are the most prominent along certain stretches as in Keri, Betalbatim, Varca and Galgibaga coasts; rising to a height of 30 to 40 m, these species form luxuriant coastal forests; (f) Coconut groves are also found all along the coast; the most imposing patches can be found along Velsao-Cansaulim-Majorda sectors; (g) Inland native trees are also occasionally seen.
Our post-tsunami observations and measurements in Tamil Nadu revealed that areas with coastal tree vegetation were markedly less damaged than areas without. The villages on the open coast were completely destroyed, whereas hamlets behind the forests suffered the least. Similarly, villages located within casuarina plantations experienced only partial damage, as these plantations were intact, except for rows of 5 to 10 trees nearest to the shore. As such, mangroves and casuarina plantations attenuated tsunami-induced waves and protected shorelines against damage, as tree vegetation shielded coastlines by reducing wave amplitude and energy. Therefore, having realised that coastal plantations were indeed beneficial as bio shields, massive plantation programmes were initiated, both at the government level as well as by local communities. Vast sandy stretches were covered by plantation programmes. Thousands of casuarina trees were planted on the bare dunes impacted by the tsunami.
We propose that functional green belts should ideally comprise a gradation of species from the edge of the dune line towards the hinterland: a pioneer zone of shallow rooted herbs such as grass, ‘ipomoea’ and ‘spinifex’; a midshore zone of medium rooted shrubs, bushes and dune plants; and a backshore zone of deep rooted hydric species of taller trees as casuarinas, coconut, and eventually fruit bearing trees on higher land. Green shelter belts can be created by strip planting of shorelines, a concept based on social forestry, eco-development and participatory planning.
Such buffer zones serve several purposes: (a) Creepers control erosion and stabilize the dune; (b) Green belts significantly alleviate wind energy thus protecting the hinterland from oceanic forces; (c) A greenbelt of trees effectively reduces the force of devastating storm surges and waves; (d) Trees are beneficial for biodiversity and can induce habitats for wild life; (e) People inhabiting hazard prone coasts would benefit from green belts in terms of security, access to food, materials for shelter; and even income; (f) Strips behind the green belts serve as areas of peace and tranquillity. As such, strips have to be reserved for adequate afforestation; sea side land can be converted into recreation parks, forests, gardens or agriculture farms.
In brief, the ecosystem services provided by coastal vegetation have rarely been considered by the polity that governs littoral states and managers who deal with coastal issues. Prevailing coastal regulations do not safeguard the welfare of coastal woodlands. Field surveys and measurements confirm the role of coastal forests as efficient energy dissipaters during the Dec 2004 tsunami event. Coastal hamlets shielded by dense forests remained unharmed. Scientific designing of an effective woody shelter belt along sandy coasts is imperative. The CZMP ought to have considered such afforestation for the sake of biodiversity of coastal flora.
(Dr Antonio Mascarenhas is a former Scientist, NIO, Goa)
