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International Journal of Environmental Sciences Devagiri et. al., Vol.1 No.2 ISSN: 2277-1948 Online version is available at: www.crdeep.org (A peer reviewed International Journal) Mapping and Characterization of Bio-rich Areas Using Satellite Remote Sensing in Southern Karnataka, India International Journal of Environmental Sciences, Vol. 1 No. 2. pp.105-117 2277-1948. 2012 ISSN 2277 – 1948 Article type Full Length Research Article Submission date 27 February 2012 Acceptance date 30 March 2012 Publication date 15 April 2012 Article URL http://www.crdeep.org/category/ijes Authors Devagiri, G. M. 1* , Santosh Hubballi 1 , Girish Pujar 2 , Murthy, M.S.R 2 ., Shivam Trivedi 2 and Bijan Debnath 2 This peer-reviewed article was published immediately upon acceptance. It can be downloaded, printed and distributed freely for any purposes from CRDEEP website. Hard copy of Journal is also available on request. For information about publishing your research in CRDEEP International Journals please visit our website www.crdeep.org © 2012. All Rights Reserved by CRDEEP CRDEEP Head Office:315/10, Kaulagarh Road, Rajendranagar, Indervihar, Dehradun, 248001, Uttrakhand, India.

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Page 1: Mapping and Characterization of Bio-rich Areas Using ... · Authors Devagiri, G. M., 1* Santosh Hubballi1 , Girish Pujar2, Murthy, M.S.R2., Shivam Trivedi2 and Bijan Debnath2 This

International Journal of Environmental Sciences Devagiri et. al., Vol.1 No.2 ISSN: 2277-1948

Online version is available at: www.crdeep.org

(A peer reviewed International Journal)

Mapping and Characterization of Bio-rich Areas Using Satellite Remote Sensing in Southern Karnataka, India

International Journal of Environmental Sciences, Vol. 1 No. 2. pp.105-117 2277-1948. 2012

ISSN 2277 – 1948

Article type Full Length Research Article

Submission date 27 February 2012

Acceptance date 30 March 2012

Publication date 15 April 2012

Article URL http://www.crdeep.org/category/ijes

Authors Devagiri, G. M. 1*, Santosh Hubballi1 , Girish Pujar2, Murthy, M.S.R2., Shivam Trivedi2 and Bijan Debnath2

This peer-reviewed article was published immediately upon acceptance. It can be downloaded,

printed and distributed freely for any purposes from CRDEEP website.

Hard copy of Journal is also available on request.

For information about publishing your research in CRDEEP International Journals please visit our website www.crdeep.org

© 2012. All Rights Reserved by CRDEEP

CRDEEP Head Office:315/10, Kaulagarh Road, Rajendranagar, Indervihar, Dehradun, 248001, Uttrakhand, India.

Page 2: Mapping and Characterization of Bio-rich Areas Using ... · Authors Devagiri, G. M., 1* Santosh Hubballi1 , Girish Pujar2, Murthy, M.S.R2., Shivam Trivedi2 and Bijan Debnath2 This

International Journal of Environmental Sciences Devagiri et. al., Vol.1 No.2 ISSN: 2277-1948

Online version is available at: www.crdeep.org

International Journal of Environmental Sciences Vol.1 No.2. 2012. Pp. 105-117 ©Copyright by CRDEEP. All Rights Reserved Full Length Research Paper

Mapping and Characterization of Bio-rich Areas Using Satellite Remote Sensing in Southern Karnataka, India Devagiri, G. M. 1*, Santosh Hubballi1 , Girish Pujar2, Murthy, M.S.R2., Shivam Trivedi2 and Bijan Debnath2

1 University of Agricultural Science, Bangalore, College of Forestry, Ponnampet 571 216, Kodagu, Karnataka, India 2 National Remote Sensing Centre, Department of Space, Government of India, Balanagar, Hyderabad, India *Corresponding Author: Devagiri, G. M ABSTRACT Remote sensing and GIS based approach was used for characterization and mapping of floristic diversity in forests of southern districts of Karnataka, India. Present study integrates field measured phyto-sociological data with remote sensing and GIS techniques. Results reveal that dry deciduous forests (DDF) were high statured with rich floristic diversity as compared to scrub forests. Field inventories recorded tree density of 442 stems ha-1, basal area of 7.29 m2 ha-1, and species richness of 118 in DDF of this region. Importance value index (IVI) indicates the dominance of Anogeissus latifolia with gregarious Hardwickia binata mixed forest patch in Chitradurga district. As compared DDF, scrub forests recorded low tree density (119 stems ha-1), basal area (0.69 m2 ha-1) and species richness (58). Albizzia amara was the dominant tree species in scrub forests. Fragmentation and disturbance analysis based on satellite data revealed that 70 per cent of the total forest area is under medium fragmentation while 57 per cent of the forest area is highly disturbed. DDF harbor medium to high biological richness while the scrub forests are biologically less rich. In the entire region, only a small extent of forest area is floristically very rich which needs conservation attention. The present study revealed that remote sensing technique combined with field sampling provides quick and reliable mapping of bio-rich areas. Key words: Floristic diversity, remote sensing, GIS, fragmentation, disturbance, biological richness map INTRODUCTION Biological diversity is a broad term that refers to all the life forms found within forested areas and the ecological roles they perform and, floristic diversity is one of its component. Floristic diversity can be considered at different levels, including the ecosystem, landscapes, species, populations and genetic level. Forest floristic diversity is a result of evolutionary processes over thousands and even millions of years which, in themselves, are driven by ecological forces such as climate, fire, competition and disturbance. Furthermore, the diversity of forest ecosystems (in both physical and biological features) results in high levels of adaptation, a feature of forest ecosystems which is an integral component of their biological diversity. Biodiversity of communities is due to niche diversification of the co-occurring species and such diversification will lead to greater community productivity due to more effective resource exploitation. Within specific forest ecosystems, the maintenance of ecological processes is dependent upon the maintenance of their biological diversity. Global biodiversity assessment estimates the total number of animals and plant species at 13 to 14 million (Heywood & Watson, 1995). It further records that so far only 1.75 million species have been described and studied. UNEP (2000) estimated about 0.27 million species of vascular plants and 52,000 animals (vertebrates). India harbors about 9 per cent of the total species of the world. India with only 2.4 per cent of global area, exhibits 12.51 per cent of floral diversity and 6.67

per cent of faunal diversity. India has about 48,000 species of plants representing about 10 per cent of the world’s flora (Hajra & Mudgal, 1997). The state of Karnataka covers an area of over 192,000 km2, and several of its mountainous regions are covered with dense forests mainly in the Western Ghats. It has about 4758 species from 1408 genera and 178 families and accounts for about 27 per cent of the country’s floral diversity (Ganeshaiah et al. 2002). Knowledge of forest structure and floristic diversity are necessary to understand forest dynamics, plant-animal interactions and nutrient cycling. Spatial heterogeneity of the environment increases the number of different habitats, permitting a greater number of different resource use strategies, preventing competition equilibrium and exclusion and hence may result into higher diversity. In addition, disturbance is also widely believed to be one of the main factors influencing variations in species diversity (Huston, 1979). The ecology literature is virtually unanimous in postulating that species diversity is a peaked function of disturbance. The ‘‘Intermediate Disturbance Hypothesis’’ (Huston, 1979) postulates that physical disturbance prevents competitively dominant species from excluding other species from the community and that there is a trade-off between species ability to compete and their ability to tolerate disturbance. Recent studies conducted in Indian forest ecosystems have also reported the role of disturbance in regulation of biodiversity (Roy et al., 2005; Giriraj, 2003). The disturbance may arise from forest fragmentation, fires,

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International Journal of Environmental Sciences Devagiri et. al., Vol.1 No.2 ISSN: 2277-1948

Online version is available at: www.crdeep.org

grazing, trampling, wind blow etc. Due to different disturbance factors, large areas of habitat may transform into a series of smaller ones and each of which will support fewer selected species. In such a situation, forest patches can no longer sustain the production or biodiversity that it had once as a part of the larger forest. With the persistent disturbance regimes the patches become smaller, the edge to interior ratio increases, which reduces the species abundance. Field based phyto-sociological assessments combined with satellite remote sensing data can be one of the best tools to indicate the status of biodiversity. The multispectral satellite images provide definition of vegetation patches, which are related to phenological types, gregarious formations and communities occurring in a unique environmental setup. The temporal images help in monitoring all back processes of a landscape. Satellites provide nearly global coverage of the earth with spatial resolutions and repetition rates that vary from one plat form to another. Improvements in spatial resolution have enabled availability of data in varying scales. The satellite also provides mosaic of the spatial arrangement of land cover and vegetation types amenable to computer processing. Biophysical spectral modeling techniques allow to

stratify vegetation types based on the canopy closure (Roy et al., 1995). Such an approach allows mapping and monitoring the forest condition and degradation process. The present study area is a part of Eastern Ghats of Karnataka and falls in arid and semi arid zone comprising of dry deciduous, scrub, thorny and grassland vegetation. In the past these areas have been ignored in terms of research. With this background, the present study was aimed at characterization of floristic diversity and mapping bio-rich areas by combining field data with remote sensing and GIS analysis. MATERIALS AND METHODS Study area The present study was carried out in five districts of southern Karnataka state viz., Bangalore rural, Chitradurga, Davangere, Mandya and Tumkur. These districts fall mostly in arid and semi arid region, with average rainfall ranging from 450 to 900 mm rainfall. This study covered mainly three vegetation types viz., dry deciduous, scrub and thorny forest and grasslands. Most part of the study area falls in Eastern Ghats and small portion under foothills of Western Ghats and is depicted in Fig. 1.

Figure 1. Map depicting the study area

Methodology In the present study, a new approach was adopted comprising the use of field based phyto-sociological as well as remote sensing data. Methodology followed for the present study can be grouped into two parts. First part involved field inventory and the second part involved applications of remote sensing

and GIS technique for characterization and mapping of floristic diversity. The detailed methodology is described below.

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International Journal of Environmental Sciences Devagiri et. al., Vol.1 No.2 ISSN: 2277-1948

Online version is available at: www.crdeep.org

Sampling design for ground inventory Stratified random sampling method was adopted for field inventory. Normalized Difference Vegetation Index (NDVI) obtained from MODIS satellite data was used for stratification. Based on the NDVI, forest in each district was divided into different stratum. On the basis of total forest area in each stratum, plots were randomly selected with the sampling intensity of 0.001 to 0.002 per cent. Exact longitude, latitude and altitude (above MSL) of each plot were recorded using GPS (Garmin-72 model). Numbers of sample plots were laid in each district as mentioned in Table 1. In dry deciduous forest, the quadrat sample plots of 0.04 ha i.e. 20 x 20 m were randomly laid. Nested sampling design (Fig. 2) was adopted at each sample point to record trees, shrubs, herbs, climbers, epiphytes and lianas. In scrub/thorny/grassland/ tree savannas, modified Whittaker plot method was adopted (Fig. 3). One main plot of 50 x 20 m was laid by looking the environmental gradient in order to position the long side (50 m) of the 1000 m2 plot parallel to the gradient. At the centre of the main plot, sub plot of 5 x 20 m was laid. Two 2 x 5 m plots were laid at the two opposite corners of the main plot. Ten plots of 0.5 x 2 m were laid, four plots were laid on the outer boundaries of the central sub plot and remaining six plots were laid in the inner boundaries of the main plot. In these sub plots, the absolute foliar coverage (%) and height (cm) by species was recorded. Application of RS and GIS Satellite data products having 1:250,000 scale for all the scenes (hardcopy) and digital data of IRS-P6 LISS-III were used for the present study. Wherever, IRS-P6 LISS-III good quality data were not available, IRS-P7, IRS-P8, IRS-P9 and IRS-P10 LISS-II data have been used. The description of the scenes used for the study is presented in Table 2. Satellite images were used to stratify different vegetation types following an integrated approach (i.e. combination of unsupervised classification, supervised classification and introduction of human knowledge from field experience) supported by biogeographic zone (Rodgers & Panwar, 1988) and altitude zone maps (Kaul & Haridasan, 1987). Wherever necessary, field knowledge was used to delineate the locale-specific types of ecological significance. Biological richness at landscape level was determined as a function of ecosystem uniqueness (EU), species diversity (H’), biodiversity value (BD), terrain complexity and disturbance index as depicted in form of flow chart Fig. 4. The advantage of this approach is that it provides detailed information on community, gregarious formations and man-made forests for further analysis. Field visits were made to collect information on cover type, locality, aspect, slope, geographical location using GPS, signs of disturbance and altitude.

Landscape ecological indicators (i.e. fragmentation, patchiness, porosity, interspersion and juxtaposition) were calculated using BIOCAP geospatial software (NRSC, Hyderabad). Wherein, a user grid cell of n x n, where n = 500 m was moved with the spatial data layer and a given criterion of deriving the number of patches within the grid cell. The iteration was repeated by moving the grid cell through the entire spatial layer. The output layer that contains the normalized data of the patches per cell was scaled between 0 and 10. Vegetation type map was used as the input layer to derive fragmentation, patchiness, porosity, interspersion and juxtaposition for calculating the disturbance index. Field derived information was assigned to vegetation type map to derive EU, H’ and BD maps. At landscape level, disturbance is related to patch structure and spatial arrangement that determines the fate of patches and their size and duration. Disturbance is one of the main factors influencing the variation in species diversity. Baseline details on roads and settlements were used to create a 2.5 km buffer (i.e. influence zone around the source of disturbance). Variable buffering with respect to radial distance from the point of disturbance was performed by imposing the condition that greater the distance lesser the weight. Disturbance index (DI) was computed by adopting linear combination of defined parameters on the basis of probable weights using the model (DI = fx{Fragmentation, patchiness, interspersion, porosity, biotic disturbance, buffer, juxtaposition}). Ecological importance with respect to species uniqueness in terms of plant endemism was considered for establishing ecosystem uniqueness using field data. Each species was evaluated for its occurrence in the Eastern Himalayas and accordingly, proportional weights were assigned to them. The weights of the number of species present in different vegetation types were added to derive relational weights, which provided input to estimate the biological richness index. Species diversity, i.e. Shannon’s index was calculated as the number of species in a sample or habitat per unit area. This index is based on the total number of species and total number of individuals in the sample or habitat. Higher the value higher species richness. Economically important plants are the species which have social and economic value. Importance value was derived based on primary uses like forage, medicinal applications, human food, fuel wood, timber, charcoal, etc. A scale of 0–10 points for each use was assigned based on the available literature as well as field information collected from local people to calculate the biodiversity value. Terrain complexity was derived using elevation information through digital elevation model. Biological richness (BR) values were scaled to five qualitative grades and was assessed using the model (BR = fx{Ecosystem uniqueness, species diversity, biodiversity value, terrain complexity and disturbance index}).

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International Journal of Environmental Sciences Devagiri et. al., Vol.1 No.2 ISSN: 2277-1948

Online version is available at: www.crdeep.org

Table 1: Details of the sample plots laid in different districts of southern Karnataka

Sl. No.

Name of district

Total Geographic

Area (sq.km.)

Forest area

(sq.km.)

Forest area

(% of Dist. Geo. Area)

Number of sample points

Number of sample points

(scrub/grassland)

1 Bangalore Rural 5815 836 12.71 27

58

2 Chitradurga 8440 434 6.60 10

3 Davangere 5924 772 11.74 18

4 Mandya 4961 516 7.85 22

5 Tumkur 10597 698 10.62 31

Sub-total 108

TOTAL 161

Table 2. Description of the remote sensing data used in the present study State Satellite Sensor Path Row Date 1 Date 2

Karnataka IRS P6 LISS III 97 60 20-Oct-05 6-Apr-06

Karnataka IRS P6 LISS III 97 61 21-Oct-05 6-Apr-06

Karnataka IRS P6 LISS III 97 62 22-Oct-05 6-Apr-06

Karnataka IRS P6 LISS III 97 63 19-Nov-05 6-Apr-06

Karnataka IRS P6 LISS III 98 60 20-Oct-06 11-Apr-06

Karnataka IRS P6 LISS III 98 61 20-Oct-05 11-Apr-06

Karnataka IRS P6 LISS III 98 62 31-Dec-06 11-Apr-06

Karnataka IRS P6 LISS III 98 63 7-Dec-06 11-Apr-06

Karnataka IRS P6 LISS III 98 64 7-Dec-06 29-Jan-06

Karnataka IRS P6 LISS III 99 60 20-Oct-05 27-Feb-06

Karnataka IRS P6 LISS III 99 61 6-Oct-05 27-Feb-06

Karnataka IRS P6 LISS III 99 62 6-Oct-05 27-Feb-06

Karnataka IRS P6 LISS III 99 63 6-Oct-05 27-Feb-06

Karnataka IRS P7 LISS III 99 64 17-Dec-05 27-Feb-06

Karnataka IRS P8 LISS III 99 65 17-Dec-05 27-Feb-06

Karnataka IRS P9 LISS III 100 64 28-Nov-05 13-Feb-05

Karnataka IRS P10 LISS III 100 65 28-Nov-05 13-Feb-05

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International Journal of Environmental Sciences Devagiri et. al., Vol.1 No.2 ISSN: 2277-1948

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Figure 2. Sample plot design used for field inventory in dry deciduous forest

Figure 3. Modified Whittaker plot for scrub forest used for present study

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International Journal of Environmental Sciences Devagiri et. al., Vol.1 No.2 ISSN: 2277-1948

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Figure 4. Flow diagram depicting methodology for assessment of disturbance index and biological richness

RESULT AND DISCUSSION Community structure Density of trees (with >10 cm) ranged between 391 to 543 stems ha-1 and 40 to 146 stems ha-1 in dry deciduous and scrub forest, respectively (Table 3). These values compare with tree density 230 to 620 stems ha-1 reported by Pitchairamu et al. (2008) for dry deciduous forests of Eastern Ghats, Tamil Nadu, while the density was lower (17 to 362 stems ha-1) than that reported by Devagiri et al. (2012) for DDF of Mysore and Hassan districts of Karnataka. In scrub forest, tree density is far lower than that of deciduous forests and also when compared with the other studies reported (169 stems ha-1) by Reddy et al. (2008) for Mudhumalai Wildlife Sanctuary. On the other hand the density values for scrub forest in the present study were comparatively higher than those reported (0.88 to 5 tree/ha) for Rampara forest in Gujarat by Panchal and Pandey (2004). Poor growth of trees with wide range of tree density in the study area is probably due to the variation in soil moisture availability, low nutrient status in addition to the anthropogenic pressure prevailing in the respective areas.

Basal area is an important criterion for evaluating the timber production and above ground biomass accumulation in forest

ecosystem (Agarwal, 1992). The estimated basal area ranged from 4.62 to 10.72 m2 ha-1 and 0.54 to 0.88 m2 ha-1 in dry deciduous forest and scrub forest, repectively (Table 3). Basal area recorded in the current study in dry deciduous forest was lower than that reported by Mohandas and Davidar (2009), Ayyappan and Parthasarathy (1999), Ganesh et al. (1996) and Krishnamurthy et al. (2010) while it compares with the values reported by Devagiri et al. (2012) for DDF. Basal area recorded for scrub forest in present study was lower than that reported earlier by Reddy et al. (2008) for Mudumalai Wildlife Sanctuary (6.12 m2 ha-1) and was higher than that reported by Panchal and Pandey (2004) for Rampara forest in Gujrath (0.01 to 0.33 m2 ha-1). Floristic Diversity Species richness is the simplest way to describe community and regional diversity (Magurran, 1988) and this variable forms the basis of many ecological models of community structure (McArthur & Wilson, 1967; Connel, 1978). The trends of high species diversity coupled with low species density have been documented in tropical forest inventories. The results presented in Table 3 revealed that the species richness values in different district ranged from 42 to 62 and

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International Journal of Environmental Sciences Devagiri et. al., Vol.1 No.2 ISSN: 2277-1948

Online version is available at: www.crdeep.org

19 to 34 for dry deciduous and scrub forest, respectively. These values lie within the reported range of species richness values for tropical forests. Chittibabu and Parthasarathy (2000) reported 26-56 species in Kolli hills and Kadavul and Parthasarathy, (1999a) reported 42-47 species in Kalrayan hills (42-47). Species diversity is one of the fundamental characters of an ecosystem which encompasses species richness and evenness. The simple measure of species diversity is Shannon’s diversity index. In the present investigation, the values of Shannon’s diversity index ranged between 2.68 to 3.47 and 2.35 to 2.96 in dry deciduous and scrub forest, respectively and these values are well within the reported ranges for tropical forests. High Shannon’s diversity value (>3) coupled with low species richness indicates that species are evenly distributed in DDF. Furthermore, higher index value indicates the presence of more number of species sharing the resources more or less equally. Lower diversity index could be due to dominance of few species. High species diversity is an indication of maturity in the ecosystem (Marglef, 1963; Odum, 1969) and low species richness is the result of incorporation of same species through competition. Parthasarathy (2001), reported that the species diversity of a given forest area, besides climate and geographic location, would also depend on site representativeness, plot dimension, various site attributes, and the extent of human interaction in the past and present. Population structure The results on IVI of growing stock (Table 4) indicated that Anogeissus latifolia was dominant species in DDF while, Albizia amara in scrub forest. In a diverse community the species are adapted to narrowly drawn niches and are extraordinarily successful within those niches. Extreme perturbations are in the order of greater magnitude in scale and may change the gross environment of an area so substantially that conditions are no longer within the range of tolerance of the organisms that formerly occupied the area. Species wise analysis shows that Anogeissus latifolia was found to be one of the ecologically dominant species contributing high IVI in dry deciduous and scrub types. This indicates a wide range of growth and adaptability of Anogeissus latifolia throughout the region.

The perusal of the result from Fig. 5 and Fig. 6 reveals that more number of individuals have been distributed in lower girth classes (10 to 20 cm, 20 to 30 cm and 30 to 40 cm) both in dry deciduous and scrub forest. Similar trend was reported by Reddy et al. (2008) in tropical forests of Mudumalai wildlife sanctuary, where he recorded higher number of individuals in lower girth class. The absence or very few

individuals of higher girth class could be probably attributed to high anthropogenic pressure and unfavorable climatic and edaphic factors prevailing in these areas. This is consistent with many other dry deciduous forests which are characterized by the presence of lower diameter class individuals (Devagiri et al. 2012). Mapping of fragmentation, disturbance and bio-rich areas Remote sensing data in combination with phyto-sociological data was used to prepare biological richness map. Biologically rich areas are those habitats where landscape ecological conditions are favorable for natural speciation and evolutionary process. Fragmentation analysis presented in Fig. 7 revealed that 70 per cent of the total forest area in the region is under medium fragmentation category and the rest is under high (17%) and low (13%) fragmentation category. As regards disturbance level, about 57 per cent of the forested landscape is highly disturbed and the remaining area is under low to medium levels of disturbances (Fig. 8). Results on biological richness of the region is depicted in Fig. 9 which revealed that 43 percent of the total forest area is under medium rechness followed by low and high biological richness. Relatively very small proportion of the forest area is under very high biological richness category (0.79%). These results support the hypothesis that though tropical forests are rich in biodiversity, they are also under different levels of fragmentation and disturbances. Relatively high biological richness was observed in low disturbance and less fragmented areas since these parameters directly affect the biodiversity (Fig. 10). Alteration in land use pattern has resulted in fragmentation of habitats, ecosystems and landscapes in most parts of the world. Habitat fragmentation and disturbance is a leading cause of biodiversity loss (Singh, 2002). Many studies have similarly reported that smaller patches support less species richness and diversity. Raghubanshi and Anshuman (2009) analyzed landscape matrices using satellite images and GIS tools and reported that fragments of smaller size had lesser number of plant communities compared to larger fragments. Generally, some species are specialized to the microclimate of the forest, and such species are affected by the fragmentation, since no suitable habitat is available for them as time proceeds and hence there is a sever threat for such species. In some forest patches, fragmentation is low but the disturbance has adversely affected the biological richness. Anthropogenic pressures constantly decrease the resource availability and as a result it adversely affect the biodiversity (Brokaw, 1985). MacArthur and Wilson (1967) have postulated that continued human induced ecosystem perturbations might lead to the decrease in average population size of forest species and over a period of time they face danger of accelerated rate of extinction.

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International Journal of Environmental Sciences Devagiri et. al., Vol.1 No.2 ISSN: 2277-1948

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Table 3. Community structure and floristic composition

Vegetation type Density (No. of

stems/ha)

Basal area (m

2/ha) Species richness

Shannon- Weiner’s index

Pielou’s equitability

index Dry deciduous forest

442 07.29 118 3.57 0.75

Scrub forest 119 0.69 58 3.03 0.74

Table 4. Dominant tree species in dry deciduous and scrub forests based on IVI

Species Dry deciduous forest Scrub forest

Acacia catechu 24.64 (2) 46.47 (2) Albizia amara 17.53 (4) 53.63 (1) Anogeissus latifolia 36.95 (1) 24.10 (3) Azadirachta indica --- 7.13 (10) Buchanania lanzan --- 7.62 (9) Chloroxylon swietenia 11.81 (5) --- Dalbergia paniculata 6.36 (10) 8.79 (7) Diospyros melanoxylon --- 13.86 (5) Hardwickia binata 22.85 (3) 14.98 (4) Stereospermum chelonoides 9.23 (7) 7.31 (8) Terminalia alata 9.39 (6) --- Terminalia bellerica 5.84 (9) --- Terminalia paniculata 7.55 (8) --- Wrightia tinctoria ----- 10.91 (6)

* Values within parenthesis indicate the species ranking

Figure 5. Girth class distribution in dry deciduous forest

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International Journal of Environmental Sciences Devagiri et. al., Vol.1 No.2 ISSN: 2277-1948

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Figure 6. Girth class distribution in scrub forest

Figure 7. Extent of forest fragmentation in the region

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International Journal of Environmental Sciences Devagiri et. al., Vol.1 No.2 ISSN: 2277-1948

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Figure 8. Extent of forest area under different levels of disturbances

Figure 9. Extent of forest area under different levels of biological richness

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International Journal of Environmental Sciences Devagiri et. al., Vol.1 No.2 ISSN: 2277-1948

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Figure 10. Vegetation map (a), Fragmentation map (b), Disturbance index map (c) and Biological richness map (d) of the entire

region

CONCLUSION Satellite remote sensing has high potential to classify vegetation with substantial accuracy for biodiversity characterization and mapping. The fragmentation and disturbance regimes assessed across the landscape will allow focusing on the ecosystems, which are under stresses. Field survey indicates some forest areas with very high diversity, indicating that the region is an important habitat for a species for bio-prospecting. Biological Richness indices (BR) indicated some areas which should be treated on top priority in decision making and at management level for conservation of biodiversity. There is a need to bring the areas of very high biological richness under protected area network. Scrub forest in the entire study area does not fall in very high biological richness class but sustainable management in this area is more important and there is need to see scrub forest as an ecosystem than that as degraded forests. ACKNOWLEDGEMENTS Authors thank National Remote Sensing Centre, Hyderabad for funding this project under DOS-DBT-GOI project on

biodiversity characterization. Our thanks are also due to the Head and faculty of Forestry and Ecology Division, NRSC, Hyderabad for data analysis and developing maps using RS and GIS software’s. Thanks are also due to the Dean (Forestry), College of Forestry, Ponnampet, Kodagu for encouraging the collaboration with NRSC, Hyderabad. Authors are also grateful to the PCCF, Aranya Bhavan, Karnataka State Forest Department, Bangalore for permission and support during field work in forest areas. REFERENCES Agarwal, S. K. (1992) Fundamentals of Ecology. Ashish

Publishing House, New Delhi: 216p.

Ayyappan, N. and Parthasarathy, N. (1999) Biodiversity inventory of trees in a large scale permanent plots of tropical evergreen forest at Varagaliar, Anamalais, Western Ghats, India. Biodiversity and Conservation, 8: 1533-1554.

115

Page 13: Mapping and Characterization of Bio-rich Areas Using ... · Authors Devagiri, G. M., 1* Santosh Hubballi1 , Girish Pujar2, Murthy, M.S.R2., Shivam Trivedi2 and Bijan Debnath2 This

International Journal of Environmental Sciences Devagiri et. al., Vol.1 No.2 ISSN: 2277-1948

Online version is available at: www.crdeep.org

Brokaw, N. V. (1985) Gap phase regeneration in a tropical forest. Ecology, 66: 682-687.

Chittibabu, C. V. and Parthasarathy, N. (2000) Attenuated tree species diversity in human-impacted tropical evergreen forest sites at Kolli hills, Eastern Ghats, India. Biodiversity and Conservation, 9: 1493–1519.

Connel, J. H. (1978) Diversity in tropical rain forests and coral reefs. Science, 199: 1302-1303.

Devagiri, G. M., Money, S., Sarnamsingh, S., Dadhawal, V. K., Prasanth Patil, Anilkumar Khaple, Devakumar, A.S. and Santosh Hubballi. (2012) Assessment of above ground biomass and carbon pool in different vegetation types of south western part of Karnataka, India using spectral modelling. Tropical Ecology, (in press)

Ganesh, T. R., Ganesan, M., Soubadra, D., Davidar, P. and Bawa, K. S. (1996) Assessment of plant biodiversity at a mid-elevation evergreen forest of Kalakad Mundanthuari Tiger reserve, Western Ghats, India. Current Science, 71: 379-392.

Ganeshaiah, K. N., Sagar, K. and Umashaanker, R. (2002) Floral resources of Karnataka: A geographic perspective. Current Science, 83(7): 810-813.

Giriraj, A., Murthy, M. S. R., Britto, S. G., Rajashekhar, G. and Dutt. C. B. S. (2003) Diagnostic analysis of conservation zones using remote sensing and GIS techniques in wet evergreen forest of Western Ghats-An ecological hot spot, Tamilnadu, India. Biodiversity and conservation: 596-635.

Hajra, P. K. and Mudgal, V. (1997) Plant diversity; Plant diversity conservation, India. (eds) Botanical Survey of India, Ministry of Environment & Forests (Calcutta): 179 p.

Heywood, V. H. and Watson, R. T. (1995) Global Biodiversity Assessment. New York: Cambridge University Press, pp. 174-185

Huston, M. A. (1979) A general hypothesis of species diversity. American Naturalist, 113: 81-101.

Kadavul, K. and Parathasarathy, N. (1999a) Structure and composition of woody species in tropical semi-evergreen forest of Kalrayan hills, Eastern Ghats, India. Tropical Ecology. 40: 77-90.

Kaul, R. N. and Haridasan, K. (1987) Forest types of Arunachal Pradesh –A preliminary study. J. Econ. Taxon. Bot., 9: 379–389.

Krishnamurthy, Y. L., Prakasha, H. M., Nanda1, A., Krishnappa, M., Dattaraja, H. S. and Suresh, H. S. (2010) Vegetation structure and floristic composition of a tropical dry deciduous forest in Bhadra Wildlife Sanctuary, Karnataka, India. Tropical Ecology, 51(2): 235-246.

MacArthur, R. H. and Wilson, E. O. (1967) The Theory of Island Biogeography, Princeton University Press, Princeton, NJ: 224 p.

Magurran, A. E. (1998) Ecological Diversity and its Measurement. Princeton University Press, Princeton, USA.

Marglef, R. (1963) On certain unifying principle in ecology. American Naturalist, 97: 357-374.

Mohandass, D. and Davidar, P. (2009) Floristic structure and diversity of a tropical montane evergreen forest (shola) of the Nilgiri Mountains, southern India. Tropical Ecology, 50(2): 219-229.

Odum, E. P. (1960) The strategy of ecosystem development. Science, 164: 262-270.

Panchal, N. S. and Pandey, A. N. (2004) Analysis of vegetation of Rampara forest in Saurashtra region of Gujarat state of India. Tropical Ecology, 45(2): 223-231.

Parthasarathy, N. (2001) Changes in forest composition and structure in three sites of tropical evergreen forest around Sengaltheri, Western Ghats. Salim Ali School of Ecology and Environmental Sciences, Pondichery University, India, Current Science, 80(3): 389-393.

Pitchairamu, C., Muthuchelian, K. and Siva, N. (2008) Floristic Inventoryand Quantitative Vegetation Analysis of Tropical Dry Deciduous Forest in Piranmalai Forest, Eastern Ghats, Tamil Nadu, India. Ethnobotanical Leaflets, 12:204-216.

Raghubanshi, A. S. and Anshuman, T. (2009) Effect of disturbance, habitat fragmentation and alien invasive plants on floral diversity in dry tropical forests of Vindhyan highland: a review. Tropical Ecology, 50(1): 57-69.

116

Page 14: Mapping and Characterization of Bio-rich Areas Using ... · Authors Devagiri, G. M., 1* Santosh Hubballi1 , Girish Pujar2, Murthy, M.S.R2., Shivam Trivedi2 and Bijan Debnath2 This

International Journal of Environmental Sciences Devagiri et. al., Vol.1 No.2 ISSN: 2277-1948

Online version is available at: www.crdeep.org

Reddy, C. S., Ugle, P., MurthY, M. S. R. and Sudhakar. S., 2008, Quantitative Structure and Composition of Tropical Forests of Mudumalai Wildlife Sanctuary, Western Ghats, India. Taiwania, 53(2): 150-156.

Rodgers, W. A. and Panwar, H. S. (1988) Biogeographical Classifications of India, Wildlife Institute of India, Dehradun.

Roy, P. S., Tomar, S. and Jegannathan, C., (1995) Biodiversity characterization at landscape level using satellite remote sensing. NNRMS Bulletin B- 31: 19-21.

Roy, P. S., Padalia, H., Chauhan, N., Porwal, M. C., Gupta, S., Biswas, S. and Jagdale, R. (2005) Validation of geospatial model for biodiversity characterisation at landscape level – a study in Andaman and Nicobar island, India. Ecological modelling, 185 (2-4): 349-369.

Singh, J. S. (2002) The biodiversity crisis: a multifaceted review. Current Science, 82:638-647.

UNEP (2000) Global Biodiversity: Earth living resource in the 21st century,Cambridge, world conservation press.

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