Sayhadri Conservation Series 29  
ENVIS Technical Report: 57,  August 2013
FRAGMENTATION OF UTTARA KANNADA FORESTS
Energy & Wetlands Research Group, Centre for Ecological Sciences, Indian Institute of Science, Bangalore, Karnataka, 560 012, India.
E Mail: cestvr@ces.iisc.ernet.in, Tel: 91-080-22933099, 2293 3503 extn 101, 107, 113
Summary

Landscapes are composed of interacting dynamic components with complex ecological, economic, and cultural qualities on which human and other life forms depend directly. Landscape is heterogeneous land area of interacting systems which forms an interconnected system called ecosystem. The functional aspects (interaction of spatial elements, cycling of water and nutrients, bio-geo-chemical cycles) of an ecosystem depends on its structure (size, shape, and configuration) and constituent’s spatial patterns (linear, regular, aggregated). Large, contiguous forests are divided in a manner that leaves relatively small, isolated patches of forest (known as forest fragments or forest remnants), either by natural phenomenon or by anthropogenic activities involving construction of roads, clearing for agriculture, implementation of developmental projects or human habitations. Fragmentation of forests leads to the decline of biodiversity due to the inability of individual forest fragments to support viable populations, the local extinction of species due to inbreeding pressure, and edge effects altering the conditions of the outer areas of the fragment, greatly reducing the amount of true forest interior habitat.

Uttara Kannada district has the distinction of having highest forest cover among all districts of Karnataka. Land use analysis using temporal remote sensing data reveal distressing trend of deforestation in the district, evident from the reduction of   evergreen - semi evergreen forest cover from 67.73% (1973) to 32.08% (2013). Taluk-wise analysis reveal similar trend for  evergreen - semi evergreen forest cover during 1973 to 2013; Ankola (75.66 to 55.33%), Bhatkal (61.37 to 30.38%), Honnavar (70.63 to 35.71%), Karwar (72.26 to 59.70%), Kumta (62.89 to 29.38%), Siddapur (71.42 to 23.68), Sirsi (64.89 to 16.78), Supa (93.56 to 58.55%), Yellapur (75.28 to 18.98%), Haliyal (35.45 to 2.59%), Mundgod (2063 to 1.52). Forest cover has declined from 81.75 (1973) to 60.98% (2013) in the coastal zone, 91.45 (1973) to 59.14% (2013) in the Sahyadrian interior, and 69.26 (1973) to 16.76% (2013) in plains zone. Changes in the landscape structure (through large scale land use changes) have altered functional abilities of an ecosystem evident from lowered hydrological yield, disappearing perennial streams, higher instances of human –animal conflicts, declined ecosystem goods, etc. This necessitates the restoration of native forests in the region to ensure water and food security apart from livelihood of the local people.
This highlights land use changes in the district, especially the conversion of forests to other categories. Fragmentation analysis considering the spatial extent of forests, reveal that contiguous forests (interior forests) has declined from 87.51 (1973) to 48.60% (2013). Forest fragmentation at landscape level show a decline of interior forest  72.95%  (1973) to 25.62% (2013). Land use under non-forest categories (crop land, plantations, built-up, etc.) covers 47.29% of the landscape, while areas under natural forests constitute about 542,475 Ha.  Mitigation of biodiversity loss in the district requires regeneration of forests through appropriate protection measures and also reforestation with native species of vegetation. Considering that the district has crossed the threshold of development, evident from the decline of forests,  fragmentation of forests the focus should be on reforestation and regeneration of natural vegetation, which will ensure food and water security apart from the livelihood of local people. Forest management approaches need to be innovative with holistic approaches involving local people to attain sustainable use of resources, forest regeneration and minimizing the encroachment of forests.
Keywords: Land use dynamics, forest fragmentation, interior forests, biodiversity

 

 

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