Two locations namely Malemane and Kanoor, were chosen for the following reasons:

1. Representative sampling sites based on preliminary results of exploratory survey.
2. Both the locations have similar conditions, i.e., both have secondary and disturbed evergreen to semi-evergreen forests.
3. Spotted Lion Tailed Macaques at Malemane.

Line transects method was adopted for sampling the flora. The species diversity indices for flora such as Shannon-Weiner, Simpson’s indices were computed for each sampling site. The indices calculated were for trees of >10 cm in circumference at a height of 130 cms from ground level. The samples in the 20 m x 20 m quadrats were again subjected to computation of diversity indices, and are listed in Table 1. Malemane with H’ = 3.25 and Kanoor H’ = 3.06 indicates higher diversity. Simpson’s index also confirms this result as it ranged from 0.95017  (Malemane) and 0.93413 (Kanoor).

Important Value Index is computed for both the locations. Malemane (Table 2) and Kanoor (Table 3) show the following results: At Malemane, IVI ranges from 1.412(the lowest) to 25.425 (the highest) and this data depicts that almost all the tree species such as Knema attenuata, Aglaia species1, Dipterocarpus indicus, Callophyllum tomemtosum, Myristica dactiloids, Syzygium gardineri, Drypeles elata, Holigarna grahmii, Aglaia species2, Litsea species1, Olea dioica, Litsea species2, Palaquium ellipticum, Hopea ponga, Garcinia morella, Myristica malabarica, Holigarna ferruginea, Garcinia cambogea, Beilschmedia fagifolia, Aglaia anamallayana, Elaeocarpus tuberculatus, Nothopegia colebrookeana, Diospyros saldanhae, Unidentified species(UI), Syzygium species1, Dimocarpus longan, Holigarna arnottiana, Cassine glauca, Elaeocarpus serratus, Actinodaphne hookeri, UI3, Syzygium species2, Mangifera indica, Aglaia species3, Macaranga peltata, Microtropis wallichiana, Syzygium species3 and Vepris bilocularis are evenly distributed. 

Table 3 lists IVI for Kanoor, which ranges from 2.830 to 37.043 and the forest is mainly dominated by a few species like Bischopia javanica, Lagerstroemia microcarpa and Olea dioica. From this, it is evident that forests of Malemane have more endemic species than that of Kanoor. Both these sites seem to be quite similar having well-established forests and spotting of LTM at Malemane confirming the need for conservation of forest habitats with rich diversity, which would conserve endangered endemic species such as the lion tailed macaque.

1. Causes and Consequences of Fragmentation

Human intervention in the ecosystem has resulted in erosion of biodiversity in the recent past in the river basin. The loss in biodiversity could be attributed to the habitat loss and fragmentation of the natural landscape. The analysis revealed extensive fragmentation in the river basin as consequences of damming the river, which include large-scale migration, population increase, encroachment of forestlands and conversion of forestlands to agricultural lands, etc. Fragmentation has resulted in the remnant areas of native vegetation to be surrounded by matrices of agricultural, horticultural and other human impacted lands. These in turn, have important influences on the biota within the remnant patches, especially along the edges of the remnant patches as well as in the surrounding matrices. The fragmentation is fuelled by anthropogenic activities, which are degrading the forest habitat of the critical watershed areas. Such human pressures have caused the fragmentation of large, unbroken tracts of forest into, smaller isolated patches. This process has lessened the value of the forest as a habitat for many of the plant and animal species native or original to the Sharavathi River basin, from where, it is feared that many will be lost forever. These consequences vary with the distance and connectivity between the neighbouring patches. The physical distances and influences modify the size, shape and the position of the individual patches and their constituents. The characteristics of the patch along with the spatial and temporal changes in the landscape were done to quantify the extent of damages. The remote sensing data in conjunction with GIS and GPS helped in landscape characterisation. Land use changes, landscape dynamics and landscape characterisation have been analysed from patch to river basin level to understand the temporal changes due to developmental activities in the river basin. Landscape analysis, showed that the indices of shape, richness and diversity provided an additional evaluation of land cover spatial distribution within the complex mountain landscape. The landscape analysis has provided an outline of the degree of propagation of the disturbance from the non-biotic source and fragmentation. It is revealed that fragmentation has caused loss of connectivity, ecotones, corridors and the meta-population structure. A spate of construction activities in the lower catchment of Sharavathi River and ongoing and threatened fragmentation from the burgeoning human population are perilous to the habitats of several animals also(Ramachandra et al., 2007).

2. Threats and Mitigation

Mitigation measures that are to be undertaken in order to overcome devastating effects of fragmentation for conservation of biodiversity in the Sharavathi river basin include the following (Ramachandra et al., 2007):

Fragmentation caused by the submersion of vast areas and also due to biotic pressures [increasing settlement, agricultural fields, quarrying, fuel wood, fodder and NTFP (Non timber forest product) collection, encroachment, roads in reserve forests, etc.]. Land uses in the catchment were monitored for changes using temporal satellite imageries (IRS 1C data) and ground surveys. A centralised planning is necessary to maintain landscape in a desirable state.

Lopping of branches for fuel wood and collection of leaves for fodder deprives animals of their food. Joint Forest Management (JFM) committees involving local people are to be formed in the catchment area and they should be associated with future management of forest in respective village territories.

Overgrazing in the region has resulted in scarcity of resources for wild animals. Village fodder farms are to be initiated and managed to meet the needs of soil and water conservation and for other ecosystem needs.

Conversion of forests into monoculture in vast areas for commercial purposes has affected the free movement of wild animals and deprived them of food and habitat.  Monoculture plantations only serve either small mammals or agricultural pests as hiding places. An action plan needs to be prepared urgently for reducing area under monoculture by introducing forest species. Moreover, conversion of plantation into natural forests is necessary for meeting other ecological requirements including enhancement of watershed value.

Fire, within limits, has an ecological role to play in the Western Ghats. But unregulated and frequent forest fires, accidental as well as intentional, have detrimental effects on the flora and fauna, and ecosystems as such. This necessitates appropriate management strategies such as creation of fire lines, restoration of evergreens, which provide greater fire immunity to the forests, adoption of a village centred fire management strategy, etc.

Theft of forest products and poaching of animals have also affected the faunal diversity. Strengthening of JFMs, creation of nature clubs in the villages, and spread of awareness can go a lopping way in controlling hunting menace. The nature club helps in the ecological and nature conservation/ awareness movements. The village based nature clubs may be associated with animal census activities and other conservation centred activities. 

Regressive and intrusive fragmentation processes occurring in the region is to be controlled by removing all encroachments surrounding the interior forests and within core areas.

Threats due to divisive type of fragmentation due to roads (which are inevitable) could be overcome by planting trees, which are likely to have wide canopy on either side of the road, and by providing ladders for animals to cross from one side of the habitat to another side (bifurcated due to a road).