land-cover changes and its impact on phytodiversity

Biodivers Conserv (2010) 19:3073–3087 DOI 10.1007/s10531-010-9880-3 ORIGINAL PAPER

A conceptual framework to analyse the land-use/ land-cover changes and its impact on phytodiversity: a case study of North Andaman Islands, India P. Rama Chandra Prasad • K. S. Rajan C. B. S. Dutt • P. S. Roy

•

Received: 19 August 2009 / Accepted: 21 June 2010 / Published online: 30 June 2010 Springer Science+Business Media B.V. 2010

Abstract Phytodiversity is affected both by natural and anthropogenic factors and in Island ecosystems these impacts can devastate or reduce diversity, if the native vegetation is lost. In addition to rich species richness and diversity, Island systems are the sites of high endemism and any threat to these ecosystems will consequently lead to loss and extinction of species. To understand the dynamics including feedbacks of these changes in phytodiversity of North Andaman Islands, a conceptual framework is proposed which focuses on understanding the land-use and land-cover changes and its impact with phytodiversity. In considering land-use and land-cover changes this work highlights the direct and indirect drivers of changes—socio-economic, biophysical and climatic factors. Migration of population, their socio economic needs and government policies were identified as major driving forces threatening the phytodiversity of these Islands. Apart from human beings, natural disasters like tsunami and introduced herbivorous animals like elephants also contributed to forest destruction in these Islands. The integrated analysis based on such framework will provide insights for holistic resource management including ecological conservation. Keywords Land use/land cover Deforestation Phytodiversity North Andaman Tsunami Policy

P. R. C. Prasad (&) K. S. Rajan Lab for Spatial Informatics, International Institute of Information Technology, Gachibowli, Hyderabad 500 032, India e-mail: [email protected]; [email protected] C. B. S. Dutt Atmospheric and Ocean Sciences Group, National Remote Sensing Centre, Balanagar, Hyderabad 500 625, India P. S. Roy Forestry and Ecology Division, Indian Institute of Remote Sensing, Kalidas Road, Dehradun 248001, India

123

3074

Biodivers Conserv (2010) 19:3073–3087

Abbreviations GIS Geographical information system LISS Linear imaging self scanner SPOT Syste`me Pour l’Observation de la Terre MSS Multi spectral scanner A&N Andaman and Nicobar GPS Global positioning system

Introduction Understanding the dynamics of land-use and land-cover (LULC) is one of the key concepts in global environmental change research (Meyer et al. 1996; Alcamo et al. 1998; Lambin et al. 2001; Petit and Scudder 2001). LULC changes have direct influence on the vegetation morphology (Defries et al. 2002), biodiversity, land degradation and climatic conditions of an area. A rapid increase in human population during the past three centuries has significantly expanded cropland and grass land resulting in the loss of large areas of natural ecosystems and biodiversity (Myers 1980; Keys and McConnell 2005; Bouwman et al. 2006; Pongratz et al. 2008). Changes in land use followed by consequent transformation of land cover characteristics alter the interactions between the land surface and atmosphere (Kabat et al. 2004; Davin et al. 2007) thus bringing changes in climate. A major phenomenon observed during LULC analysis is the process of deforestation. Deforestation has many ecological, social and economic consequences, one of which is the loss of biological diversity (Jha et al. 2000; Sodhi et al. 2004; Pandit et al. 2007). Large-scale deforestation could have impact on the regular climatic conditions, especially on the rainfall patterns (Meher-Homji 2001), which in turn effects the vegetation either by modifying the morphological patterns of trees or bringing transitional changes in forest types, thus altering the natural physiognomy of the forest ecosystem. A study of climate change impacts (using BIOME 3 model) on Indian forests (Jayant et al. 2006) has predicted a shift in the forest types. Within the Indian scenario several studies have been carried out to analyze the impact of LULC changes on natural resources (Jha et al. 2000; Roy and Tomar 2001; Srivastava et al. 2002; Gupta 2007; Chaudhary et al. 2008; Pranjit et al. 2008) and on the climate (Shukla et al. 1990; Jayant et al. 2006). The Indian sub-continent has a large number of Islands, some with low inhabitations are undergoing rapid changes in LULC over the last two–three decades. A detailed account of such changes is minimal. North Andaman Islands (NAI) are one such group of Islands which are also experiencing an increase in population and related LULC changes, which might result in the Islands being declared as biodiversity hot spot in near future (Krupnick and Kress 2003). Hitherto many recent studies in Andaman & Nicobar Islands (ANI) focused primarily on the assessment of the effect of 2004 tsunami (Ramachandran et al. 2005; Ramanamurthy et al. 2005; Belward et al. 2007; Curran et al. 2007; Jayakumar et al. 2008; Prasad et al. 2009a) and the anthropogenic impacts on LULC patterns of the Islands (Dharanirajan et al. 2004; Nagabhatla et al. 2006; Prasad et al. 2009a). But there is a need for an integrated assessment to understand the interactions between the various processes based on its socio-economic and biophysical characterization to help in managing these fragile Island ecosystems. Towards this end, this paper presents a conceptual framework focusing

123


3075

on the driving factors of LULC of the NAI and associated impact on the phytodiversity. This framework draws from the understanding of the interactions reported in earlier works that focused on some specific aspects of change, some of which were recorded in the last three decades (Prasad et al. 2009a). Further, the framework can assist in studying or modeling the impacts of changes on the various subsystems.

Study area NAI are a group of about 72 Islands spread over 1458 km2 and form a major portion of the Andaman district within the administrative boundaries of ANI. The immigrants mainly from the states of West Bengal, Tamil Nadu, Kerala and Andhra Pradesh inhabit these Islands. It constitutes two revenue subdivisions—Diglipur (with Narcondum, East, Curlew, Smith, Stewart and North Andaman Islands) and Mayabunder (with Aves and Interview Islands). While Diglipur covers a major portion of study area, Mayabunder revenue subdivision contributes a minor portion. This region has three protected areas viz., North Andaman, Aves and Smith Island, 67 wildlife sanctuaries and one national park- Saddle Peak (Anonymous 1983). Saddle Peak with a maximum elevation of 732 m (msl) harbors a wide variety of species richness attributed to its wet climatic and diverse topographic features (Devraj 2001; Reddy and Prasad 2008). Kalpong, the only fresh water river originates from the slopes of Saddle Peak and flows towards north, finally joining the sea near the eastern coast. The Kalpong hydroelectric power project was taken up across Kalpong River to supply power to North and Middle Andaman population and for flood moderation (Singh et al. 2000). The vegetation of these Islands consists of inland (evergreen, semi-evergreen and moist deciduous) and coastal (littoral and mangroves) forest types (Champion and Seth 1968) distributed at different topographical gradients. These forests are enriched with high phytodiversity (Prasad et al. 2007b, 2009c) and endemism (Reddy et al. 2004) observed from top canopy tree to under-growth shrub and herb species entangled with lianas and climbers.

Database development LULC mapping Advanced geospatial tools (Remote sensing and GIS) along with extensive ground surveys illustrate detailed information on the LULC, forest types and phytodiversity of NAI. The study utilized three multi-temporal satellite data viz., Landsat Multi Spectral Scanner (MSS)—29th February 1976; IRS 1D Linear Imaging Self Scanner (LISS) III—1st March 1999 and SPOT—2nd January 2005 (for details refer Prasad et al. 2009a). All the three satellites are part of the Global Earth Observation (GEO) class of satellites and their sensors have similar spectral characteristics, primarily in the visible (2 bands) and near infrared (1 band) range of the spectrum, thus making it suitable to be used interchangeably for terrestrial ecological observations or monitoring. The change analysis has been carried out on the extracted vector layers, obtained after the classification of the imagery and not compared at the imagery level. Satellite data sets were subjected to a common georeferencing system and to various image enhancement techniques for the delineation of different LULC classes. The reconnaissance survey carried out in 1999–2000 period facilitated acquaintance with the LULC of the study area thus helping in the classification

123

3076


Fig. 1 LULC map of North Andaman Islands (derived from LISS III data of 1999)

of satellite data (LISS-III-1999) to derive thematic LULC map of the NAI (see Fig. 1). This derived map was used as a base for the delineation of the LULC map of 1976 and 2005, which were then used for change analysis. MSS and LISS III data were analyzed to identify the change in forest scenario caused by anthropogenic disturbances, while LISS III and SPOT data sets were used to assess the impact of 2004 tsunami, specifically on coastal forests (details Prasad et al. 2009a). The LULC map of study area derived from LISS III satellite data show a major portion under vegetation (see Table 1). The predominant forest types are evergreen, semi-evergreen, moist deciduous, littoral and mangroves and other non forest classes that include plantations, agriculture, settlement, mud flats, barren land, water and sand (Prasad et al. 2007a). Semi-evergreen was identified as predominant vegetation type scattered across the Island, though large patches of evergreen forests can be seen in the Southern parts. This can be attributed to the climatic regime, especially the rainfall pattern prevalent in the region, which has played a major role in the distribution of forest types. Southern and

123

Biodivers Conserv (2010) 19:3073–3087 Table 1 Land use—land cover of NAI (derived from LISS III 1999)

Vegetation types/land cover

3077

Area (ha)

Total land cover (%)

Interior vegetation type Evergreen

31,010

21.3

Semi-evergreen

45,130

31

Moist deciduous

22,620

15.5

Sub-total

98,760

67.8

Coastal vegetation types Littoral

4,820

3.3

Dense mangrove

9,580

6.6

Open mangrove

12,160

8.4

Degraded mangrove Sub-total

1,980

1.4

28,540

19.6

12,400

8.5

960

0.7

Non-forest classes Agriculture/settlement Plantations Mud flats Barren land Sand Sub-total Total

2,950

2

30

0

1,990

1.4

18,330

12.6

145,630

Prasad et al. (2007a)

western parts of the Islands receives greater rainfall in comparison to the northern side and this variation restricts most of the evergreen patches to these regions and moist deciduous to the northern side. Phytodiversity field inventory Several floristic surveys were carried out in A&N Islands and all of them either enumerated the flora, described the forest types or added new records to the existing one (Thothathri 1960, 1961, 1962, 1980; Balakrishnan and Nair 1977; Balachandra 1988; Singh et al. 1987; Dagar 1989). The only ecological study concerning the phytodiversity patterns was carried out in NAI for Saddle Peak National park (Tripathi et al. 2004). The study by Prasad et al. (2007b, 2009c) was the first to describe in detail about the floral biodiversity of these Islands. A detailed field survey (2000–2001) was carried out in the predominant forest types to collect the data on various phytosociological aspects. The filed survey consisted of 108 random plots (0.1 ha size) covering all the topographic gradients of the study area. Field data collected was subjected to analysis using various ecological indices and phytosociological methods to depict the species richness and phytodiversity. The literature review on the past floral studies in the Islands provided substantial information about the phytodiversity—status and trends. The analysis of the phytosociological data collected from field including all the life forms viz trees, shrubs, climbers and herbs showed 268 species in evergreen, 285 in semievergreen, 245 in moist deciduous, 40 in mangrove and 33 in littoral forest. The study reported 72 plant species belonging to 67 genera and 43 families of Angiosperms from

123

3078


these tropical rainforests that provide crude drugs to cure 40 ailments (Prasad et al. 2008b). Enumeration of endemism in NAI by Reddy et al. (2004) reported about 101 endemic species from various life forms. In addition, 14 new species were recorded for the first time from the survey carried out by Reddy et al. (2008). Top value durable timber is extracted from the forest of these Islands from one of the endemic species Pterocarpus dalbergioides. Significant extent of species richness was concentrated in the Saddle Peak National park. The information collected by Reddy and Prasad (2008) from various herbaria, taxonomic literature and field surveys of this park, enlisted 188 taxa belonging to 135 genera and 50 families, of which 44 are endemic contributing 23% of the total species. It is interesting to observe that an area of 36 km2 of Saddle Peak encompasses such unique species richness. The study of Tripathi et al. (2004) on community structure and species diversity of Saddle Peak also supports high species richness in the site. Phytodiversity—zone map The satellite derived vegetation map (from LISS III) was integrated with field collected phytosociological data in GIS domain to categorize different phytodiversity zones of the area. The analysis considered species richness and phytodiversity values at various altitudes (low, medium and high), aspects and in different size forest patches and classified the entire study area into high, moderate and low phytodiversity zones (see Prasad et al. 2008a). The analysis recorded most of the area under high phytodiversity zone and is depicted within semievergreen forest (Prasad et al. 2008a). An overall observation of the above analysis describes the study area as potentially species rich with high floral biodiversity and endemism. Phytodiversity and its links to LULC changes Deforestation These Islands are susceptible to various ways of encroachments, either man-made or natural, leading to deforestation and loss of forest cover, which in turn threatens the phytodiversity. The change detection in LULC patterns as observed from the satellite derived maps of 1976 and 1999 indicate about 11,670 ha of forest loss with a deforestation rate of 389 ha yr-1 (Prasad et al. 2009a). The forest loss observed can be linked to the species loss, however it is difficult to quantify this change as there are no records of earlier decades. In addition, the rapid influx of people to these areas in the last three–five decades has lead to agricultural expansion and other related land use changes including infrastructural changes, leading to further deforestation (Dey and Chakraborty 1994; Anonymous 1997). As these Islands are repository of various endemic species (Reddy et al. 2004), they are the first to get affected by the removal of forest cover, followed by rare and threatened species (Prasad et al. 2009b). Fragmentation and changes in forest type Fragmentation of large forest patches pose threat to certain sensitive species that survive only in the matrix of large patches (Prasad et al. 2009b). The process also changes the native forest species composition by favoring the growth of non-native species (Gosh 2004). Formation of canopy gaps supports the heliophytic species that grow in the

123


3079

presence of sunlight (Denslow et al. 1998) suppressing the other native species. If we assume ‘n’ as number of native species in an evergreen forest community and ‘m’ as number of non native species introduced into the system due to anthropogenic interference, then it is observed that there will be a gradual change in forest type from evergreen (n) to semi- evergreen (n & m). Further forest disturbances along with the competition between native and non-native species, increases the population of ‘m’ finally leading to a condition where n ? 0, thus modifying the forest type (Wilcox and Murphy 1985; Holdt et al. 2004). A process similar to this can be hypothesized for NAI, where semi- evergreen forest is recorded to be predominant in both area as well as species richness. Viewing the climatic conditions of these tropical rainforests, potentially evergreen forests should have been the dominant type. But the human influence and interaction at the fringes of evergreen systems, directed the invasion of species from neighbouring communities (may be from moist deciduous) modifying the evergreen to semi-evergreen. This type of transition in forest type changes not only the species composition but also impact on the endemic species of the evergreen community, leading to loss of precious phytodiversity. Although major portion of NAI were declared as wildlife sanctuaries with one National park, illegal logging activities were still observed during the field survey (Prasad et al. 2007a). All these anthropogenic activities may not only disturb the ecosystem equilibrium but also reduces the rich phytodiversity of the area. The incessant environmental degradation is not congenial for the natural regeneration of forest and the deforestation occurred so far can be considered as a permanent loss to the Island ecosystem (Rajesh and Prasad 2005).

Conceptual framework LULC changes’ including deforestation has a major impact not only on the phytodiversity of the region, but also on the rate of change that can completely destroy some of the ecological balance of these regions. To understand these interactions and feedbacks a conceptual framework has been proposed in Fig. 2 highlighting the scale or level of interactions. The major subsystem level interactions are detailed in this section. Table 2 lists the major drivers of change and its severity during the period of study. Anthropogenic influence—LULC changes Anthropogenic changes observed in the Islands are mainly due to the Government policies—actively encouraging immigration to these Islands, facilitating new settlements and allowing for commercial exploitation of forests during different time periods. Immigration: Population growth The policy of government after independence to inhabit these Islands (either government sponsored/voluntary) resulted in the migration of people, mainly the refugees from Bangladesh. The policy continued till mid 1970 resulting in the drastic increase of population and by the end of 1971 the decadal growth was over 80%, which is much higher compared to all India decadal growth (Chapter VI—www.andaman.nic.in). An observation of population statistics (Anonymous 2006) of these Islands from 1901 to 2001 showed continuous increase except during 1911 and 1951 (Fig. 3). The purpose of migration is primarily economic well-being and in 1981, 58% of the total population was migrants (Dey and Chakraborty 1994). The revenue subdivision wise census (2001census) of NAI (Table 3)

123

3080


Fig. 2 Conceptual framework showing the driving factors responsible for LULC Changes in North Andaman Islands

Table 2 List showing the major drivers of change during study period along with their ranks S. no

Drivers of change

1976–1999

1999–2004

Rank

Possible action

i

Population immigration

Very high

Low

1

Restriction/check on immigration

ii

Infra-structural developments

High

Moderate

2

Activities with minimal forest disturbances

iii

Introduced animals Elephant

Moderate

Moderate

5

Setting up elephant reserves, control of the population

Deer

Low

Low

6

May need elimination or set up reserves/feeding zones

iv

Logging of forest wood

High

Low

3

Monitor/check illegal felling

v

Filed trips

Moderate

Low

7

Careful study about the species, ex-situ conservation steps

vi

Tsunami/cyclones/ climate changes

Moderate

High

4

Afforestation programs both in coastal beds and inland vegetation

123


3081

Fig. 3 Population increase in A & N Islands (1901–2001) Table 3 Tahsil-wise/Islandwise Population of Inhabited Islands (2001 Census)

Tahsil

Island

Population

Diglipur 1

Narcondum

Island

2

East

Island

17

3

North Andaman

4

Smith

Island

676

5

Curlew

Island

2

6

Stewart

Island

2

7

Aves

Island

2

8

Interview

Island

16

17 42163

Mayabunder

Total

42895

shows a population of 42,895 (Anonymous 2006) while that of Diglipur revenue subdivision indicates a decadal growth of 80% (42877) over 1991 (23734) population (Anonymous 2006). This rapid immigration of people to these Islands results in the rapid loss of virgin forest to cope up with the demand for basic needs of the expanding population. Initially people cleared the forest for settlement and domestic purposes, and in recent past started expanding the area for agriculture purpose too. The important change (1976–1999) observed in LULC analysis is the expanded settlement areas. The migrated population has contributed to a distinctively local tradition of buildings and the use of natural resources (Rajesh and Prasad 2005). The main settlements like Diglipur, Ramnagar, Kalighat, Radhanagar and Mohan Nagar which existed in 1976, expanded considerably in the course of time as observed from 1999 data to about 1230 ha indicating a peripheral increase of almost 100 km (Prasad et al. 2009a). Overall the agriculture and settlement areas increased from 6320 ha (1976) to 12400 ha (1999) with a corresponding decrease in forest area by 7490 ha (Prasad et al. 2009a). The census of 2001 identified about 80 villages in Diglipur revenue subdivision (Anonymous 2006). The census also reported a hike in density of population from 5 (persons per km2) in 1961 to 48 in 2001. The rise in population density led to higher consumption of resources per capita

123

3082


and the increased need for built environment (Rajesh and Prasad 2005). The demand for food security as well as for other basic needs also led to the forests being encroached, resulting in its deforestation. During the field survey it was observed that people encroached the forests of inaccessible Islands and developed small hamlets (e.g. Jaganthdhera— located on northern side of North Andaman). Infrastructural development The developmental policies adopted by government also contributed to certain extent towards the destruction of forest ecosystem by clearing large tracts of land for setting up industries. Despite its benefits, the construction of Kalpong hydroelectric power station cleared a portion of evergreen forest, affecting the biodiversity. The proposal of expanding the road network (South to North Andaman), widening the existing roads (http://www. and.nic.in/plan1/apwd.pdf) and construction of government buildings by the Government of A&N may also add to the deforestation. Expanded road network facilitates the anthropogenic movements into the forest and more so to exploit forest resources. Introduced animals Apart from human activities introduced herbivorous animals like elephants and deer also caused massive damage to the vegetation of these Islands. Elephants, used in the past to carry out logging operations by a Timber Company established on Interview Island (one of the major Island of NAI), were released into the forest in 1962 (Ali 2004) after the company discontinued its activities. These elephants increased their population in due course and few of them migrated (swam over) to other parts of NAI. Elephants on one hand damage vegetation by uprooting, debarking and knocking down the tree species finally creating gaps in the forest and deer on other hand feed on the seedlings effecting regeneration of species. (Sivaganesan and Kumar 1993; Ali 2004). Logging of forest wood Logging of wood and/or non-timber forest products either legally by forest department or illegally by the Islanders for construction, furniture, firewood, to support livestock population and other basic needs posed major threat to the commercial and economical tree species. Subsidies offered to the timber-based industries accelerated the logging activity. This rapid removal of the tree species beyond its optimal level may tamper with its regeneration capacity. Similar is the case that was encountered in our field survey (Prasad et al. 2008c) for Padauk (Pterocarpus dalbergoides) an endemic species of Andaman, not found even in Nicobar, for which neither seedling nor sapling was recorded indicating its poor regeneration status. This species produces high commercial value durable timber used for construction, which were exploited for over 100 years in these forests (Tamata 1991). This type of scenario may finally lead to the extinction of species. Field trips To a lesser extent, eco tourism and scientific field surveys can lead to loss of species. The movement of people into the forest either for recreation or for species collection will be a threat to the survival of species. A species collected during taxonomical surveys may be beneficial if it is densely populated, but if it belongs to either a rare or endemic category it

123


3083

may lead to the species loss and its subsequent extinction due to both reduction in number and the disturbance to the habitat. Natural factors—LULC changes The natural factors that may damage the forest resources are adverse climatic conditions and disasters like earthquakes, tsunami, cyclones etc. Being in the seismic zone these Islands are frequently prone to earth quakes and tsunami. Climate and disasters Climatic changes are mainly linked with anthropogenic activities (e.g. deforestation). One of the important and immediate effects of deforestation is the alteration of microclimates (Meher-Homji 2001). The climate simulation models predicted an increase in natural disasters, particularly increased frequency of cyclones in Bay of Bengal (Jayant et al. 2006) that can threatens the Island ecosystem. The dual action of global warming and cyclones or tsunami, probably increase the sea level resulting in flooding and inundation of low-lying areas or Islands (Prasad et al. 2009a) affecting the coastal forest. Tsunami and vegetation changes The tsunami that occurred on 24th December 2004 had great impact on the coastal ecosystem of the Islands—the mangroves and littoral forests. The change analysis using LISS III (1999) and SPOT (2005) data, indicate a loss of 3730 ha of coastal forest by tsunami and lesser by anthropogenic activities (Prasad et al. 2009a). Roy and Krishnan (2005) observed that due to tsunami the water levels in some parts of North Andaman receded by 3–4 ft, exposing the low-lying areas even during high tides. This resulted in drying of mangrove ecosystem, (ex. In villages of Deshbandhugram, Laxmipur, Milangram, and Swarajgram) wilting of several species (Rhizophora spp., Brugueiera spp.,) and colonization of opportunistic species like Acrosthicum aureum (Roy and Krishnan 2005). Mangroves also support a variety of fauna that might be endangered due to alteration in mangrove species composition and ecosystem. Management approaches Since the land use changes are influenced or affected by various factors and which in turn will impact the phytodiversity, it is important to manage the LULC for conserving the phytodiversity of the region. Management approaches should mainly focus on • Preserving or conserving the phytodiversity • How to manage LULC for minimal impact on phytodiversity • Different policies to improve phytodiversity. Towards these objectives, the primary step required to minimize the pressure on these forests is to keep a check on immigration of people to these Islands. The authors suggests a multi-prong approach that takes into account the control of immigration, reduction and elimination of forest damaging activities, increasing forest cover and providing alternative livelihood opportunities. The current policy adopted by the government has helped in reducing the decadal population growth during 1991–2001 to 26.84% compared to the

123

3084


decadal growth of 48.7% during 1981–91(Anonymous 2002). Further efforts at reducing the in-migration to near zero will put a stop to forest clearing in these islands. In a recent order by Supreme Court of India (Anonymous 2002) all sawmill and wood based industries have been banned with effect from April 2002 (except government industries) to prevent timber-felling operations in these Islands. But there needs to be better monitoring mechanism in place to prevent illegal logging operations. To protect pristine forest of these Islands forest department has declared these areas as conservation zones. Better forest management practices to be employed to provide a conducive environment for regrowth and control of invasive species. Afforestation programme should concentrate more towards the introduction of the native species to regain the original forest structure. Other alternative sources of employment such as tourism, fisheries and IT sector may provide opportunities to the local population for engaging in activities other than those directly dependent on forest and natural resources. This will in due course of time help in conserving the forested regions. As these Islands harbor rich forest reserves along with non-polluted beaches, they can best utilized under the policy of ecotourism. Conclusions NAI, similar to other ecosystems that encompass high species richness and endemicity, needs to be conserved. The inland forest types like evergreen, semi-evergreen and moist deciduous primarily suffer with the activities of human whereas the coastal elements of mangroves and littoral experience threat both by human and natural disasters. The analysis of phytodiversity and impacts on it indicates that change in land cover through land use is a significant factor. The LULC changes in these Islands can be attributed to population increase, policies supporting commercial activities, infrastructural development and natural disasters. The conceptual framework developed is based on the various studies on specific issues and highlight the interconnectedness of these various factors that change LULC and hence impact on phytodiversity. The rate of change in the past has altered some patches of the ecosystem in a way that can make it vulnerable to forest state or type changes. The framework suggests that directed effort on one or the other factor might not have the intended impact on conservation. Hence there is a need for holistic or integrated approach that can influence the multiple factors driving changes for improved forest management. The framework discussed in this paper has been developed in the context of the ecological conditions prevailing in NAI. Similar approach or a modified framework can be applicable to other ecologically sensitive regions. Acknowledgements Authors extend their thanks to Department of Science and Technology and Department of Space for funding the project ‘‘Biodiversity characterization of Andaman and Nicobar Islands at landscape level using Remote Sensing and GIS’’, which is the basis for the study presented. Acknowledge colleagues of Forestry and Ecology division of National Remote Sensing Center, ISRO, Hyderabad and personnel of Andaman Forest Department for their help during the study. Also thankful to the Global Land cover facility (MSS data), Centre for Remote Imaging, Sensing and Processing (CRISP) of the National University of Singapore, Geoinformation PhD Programme of the Tor Vergata University, Rome, Italy (SPOT data), for making availability of pre and post tsunami satellite data of the study area.

References Alcamo J, Leemans R, Kreileman E (1998) Global Change scenarios of the 21st century. Results from the IMAGE 2.1 model. Elsevier, Amsterdam, 296 pp

123


3085

Ali R (2004) The effect of introduced herbivores on vegetation in the Andaman Islands. Curr Sci 86(8):1103–1112 Anonymous (1983) 100 years of forest trees in Andaman; 1883–1993. Forest Department, Andaman and Nicobar Islands Anonymous (1997) Prioritization of Biodiversity rich sites of conservation significance in the Andaman and Nicobar Islands. http://ces.iisc.ernet.in/PBR/PBR%20of%20Nicobar%20Islands.pdf. Accessed 12 July 2009 Anonymous (2002) Speech of the Hon’ble Lt. Governor, Andaman & Nicobar Islands for the 50th meeting of the National Development Council on 21 Dec. http://www.planningcommission.nic.in/plans/planrel/ pl50ndc/adman.pdf. Accessed 18 Sept 2008 Anonymous (2006) Statistical hand book on Andaman District & Nicobar District 2005–2006. Directorate of Economics and Statistics Andaman and Nicobar Administration, Port Blair. http://www.and.nic.in. Accessed 18 Sept 2008 Balachandra L (1988) A comprehensive account of mangrove vegetation in Andaman and Nicobar Islands. Indian Forester 114:741–751 Balakrishnan NP, Nair NG (1977) New records of plants from Andaman and Nicobar Islands. Indian Forester 103:638–640 Belward AS, Stibig H-J, Eva H, Rembold F, Bucha T, Hartley A, Beuchle R, Al-Khudhairy D, Michielon M, Mollicone D (2007) Mapping severe damage to land cover following the 2004 Indian Ocean tsunami using Moderate Spatial Resolution Satellite Imagery. Int J Remote Sens 28(13–14):2977–2994 Bouwman AF, Kram T, Klein Goldewijk K (2006) Integrated modelling of global environmental change. An overview of IMAGE 2.4. MNP Report 500110002. Netherlands Environmental Assessment Agency (MNP), Bilthoven. http://www.mnp.nl/en/publications/2006/Integratedmodellingofglobalenviron mentalchange.AnoverviewofIMAGE2.4.html. Accessed 12 Dec 2008 Champion HG, Seth SK (1968) A revised survey of the forest types of India. Govt. of India Press, Delhi Chaudhary BS, Saroha GP, Yadav Manoj (2008) Human induced land use/land cover changes in Northern Part of Gurgaon district, Haryana, India: natural resources census concept. J Hum Ecol 23(3):243–252 Chowdhury RR (2006) Driving forces of tropical deforestation: the role of remote sensing and spatial models. Singap J Trop Geogr 27(1):82–101 Curran PJ, Dash J, Llewellyn GM (2007) Indian Ocean Tsunami: the use of Meris (Mtci) data to infer salt stress in coastal vegetation. Int J Remote Sens 28:729–735 Dagar JC (1989) Endemic plant species of Bay Islands. J Andaman Sci Assoc 5:161–168 Davin EL, de Noblet-Ducoudre´ N, Friedlingstein P (2007) Impact of land cover change on surface climate: Relevance of the radiative forcing concept. Geophys Res Lett 34:L13702. doi:10.1029/2007GL029678 DeFries R, Bounoua L, Collatz GJ (2002) Human modification of the landscape and surface climate in the next fifty years. Glob Chang Biol 8:438–458 Denslow JS, Ellison AM, Sanford RE (1998) Tree fall gap size effects on above-and below-ground processes in a tropical wet forest. J Ecol 86:597–609 Devraj P (2001) Forests of Andaman Islands. International Book Publishers, Dehradun, xiv, 404 pp Dey C, Chakraborty D (1994) Migration in the Andaman and Nicobar Islands during 1901–1981: trend and pattern. Demogr India 23(1–2):167–182 Dharanirajan K, Ramachandran S, Saranathan E, Kasinatha Pandian P, Gurugnanam B, Anitha S, Srinivasan D, Divien Marie Irene Preeti, Rajakumari S, Arul Raj M (2004) Man-made impacts on sandy beaches in South Andaman Island—a case study using remote sensing and GIS. Indian J Geomorphol 9(1): 25–32 Gosh P (2004) Forest fragmentation: a threat to global bio diversity. ENVIS Bull Himalayan Ecol 12(2): 20–29 Gupta HK (2007) Deforestation and forest cover changes in the Himachal Himalaya, India. Int J Ecol Environ Sci 33(2–3):207–218 Holdt MB, Daniel LC, James DH (2004) Forest fragmentation due to land parcelization and subdivision: a remote sensing and GIS analysis. ASPRS annual conference proceedings, May 2004; Denver, Colorado, pp 1–8 Jayakumar S, Naik KA, Ramanamurthy MV, Ilangovan D, Gowthaman R, Jena BK (2008) Post-tsunami changes in the littoral environment along the southeast coast of India. J Environ Manag 89(1):35–44 Jayant S, Shukla PR, Ravindranath NH (2006) Climate change, sustainable development and India: Global and national concerns. Curr Sci 90(3):314–325 Jha CS, Dutt CBS, Bawa KS (2000) Deforestation and land use changes in Western Ghats, India. Curr Sci 79:231–238

123

3086


Kabat P, Claussen M, Dirmeyer PA, Gash JHC, de Guenni LB, Meybeck M, Vorosmarty CIJ, Hutjes RWA, Lu¨tkemeier S (2004) Vegetation, water, humans and the Climate. A new perspective on an interactive system. Springer Verlag, Heidelberg, Germany, p 566 Keys E, McConnell WJ (2005) Global change and the intensification of agriculture in the tropics. Glob Environ Chang 15:320–327 Krupnick GA, Kress WJ (2003) Hotspots and ecoregions: a test of conservation priorities using taxonomic data. Biodivers Conserv 12:2237–2253 Lambin EF, Turner BL II, Geist H, Agbola S, Angelsen A, Bruce JW, Coomes O, Dirzo R, Fischer G, Folke C et al (2001) Our emerging understanding of the causes of land-use and land cover change. Glob Environ Chang 11:261–269 Meher-Homji VM (2001) Bioclimatology and plant geography of Peninsular India. Jodhpur Scientific Publishers, India Meyer WB, Billie LT II (1996) Land-use/land-cover change: challenges for geographers. GeoJournal 39(3):237–240 Myers M (1980) Conversion of tropical moist forests. National Academy of Sciences, Washington, DC Nagabhatla N, Roy PS, Jagdale R (2006) Evaluating the change (1968–2001) in landscape pattern and analyzing disturbance in Baratang Forest Division (Andaman Islands), South East Asia, GIS Development. http://www.gisdevelopment.net/application/nrm/overview/over003_1.html. Accessed 20 Aug 2008 Pandit MK, Sodhi N, Pin Koh L, Bhaskar A, Brook B (2007) Unreported yet massive deforestation driving loss of endemic biodiversity in Indian Himalaya. Biodivers Conserv 16:153–163 Pongratz J, Reick C, Raddatz T, Claussen M (2008) A reconstruction of global agricultural areas and land cover for the last millennium. Glob Biogeochem Cycles 22:GB3018. doi:10.1029/2007GB003153 Pranjit KS, Bibhuti PL, Sonali G, Abhijit R, Jyoti PD, Naba KN, Santanu D, Namita B (2008) Land-use and land-cover change and future implication analysis in Manas National Park, India using multi-temporal satellite data. Curr Sci 95(2):223–227 Prasad RCP, Reddy CS, Rajasekhar G, Dutt CBS (2007a) Mapping and analyzing vegetation types of North Andaman Islands, India. GIS Dev 3(1). http://www.gisdevelopment.net/application/nrm/overview/ over004_1.htm. Accessed 9 Aug 2008 Prasad RCP, Reddy CS, Dutt CBS (2007b) Phytodiversity assessment of tropical rainforest of North Andaman Islands, India. Res J For 1(1):27–39 Prasad RCP, Reddy CS, Dutt CBS (2008a) Phytodiversity Zonation in North Andaman Islands, India using remote sensing, GIS and phytosociological data. Res J Environ Sci 2(1):1–12 Prasad RCP, Reddy CS, Raza SH, Dutt CBS (2008b) Folklore medicinal plants of North Andaman, India. Fitoterpia 79:458–464 Prasad RCP, Reddy CS, Raza SH, Dutt CBS (2008c) Population structure, age gradations and regeneration status of Pterocarpus dalbergioides Roxb, an endemic species of Andaman Islands, India. Pac J Sci Technol 9(2):667–673. http://www.akamaiuniversity.us/PJST9_2_667.pdf. Accessed 9 Feb 2009 Prasad RCP, Reddy CS, Rajan KS, Raza SH, Dutt CBS (2009a) Assessment of tsunami and anthropogenic impacts on the forest of the North Andaman Islands, India. Int J Remote Sens 30(5):1235–1249 Prasad RCP, Sringeswara AN, Reddy CS, Nidhi N, Rajan KS, Giriraj A, Murthy MSR, Raza SH, Dutt CBS (2009b) Assessment of forest fragmentation and species diversity in North Andaman Islands (India)—a geospatial approach. Int J Ecol Dev 13:35–48 Prasad RCP, Sringeswara AN, Reddy CS, Vijayakumari P, Varalakshmi RK, Raza SH, Dutt CBS (2009c) Vegetation structure and ecological characteristics of North Andaman Forest, India. Biol Lett 46(2):51–67. doi:10.2478/v10120-009-0006-0 Rajesh P, Prasad BVR (2005) Built environment in the Andaman and Nicobar Islands: a tradition on the brink of disappearance. Anthropologist 7(3):205–207 Ramachandran S, Anitha S, Balamurugan V, Dharanirajan K, Ezhil VK, Marie Irene PD, Senthil VA, Sujjahad HI, Udayaraj A (2005) Ecological impact of tsunami on Nicobar Islands (Camorta, Katchal, Nancowry and Trinkat). Curr Sci 89(1):195–200 Ramanamurthy MV, Sundaramoorthy S, Pari Y, Ranga Rao V, Mishra P, Bhat M, Usha Tune, Venkatesan R, Subramanian BR (2005) Inundation of seawater in Andaman and Nicobar Islands and parts of Tamil Nadu coast, during 2004 Sumatra tsunami. Curr Sci 88:1736–1740 Reddy CS, Prasad RCP (2008) Tree flora of Saddle Peak National Park, Andaman, India. J Plant Sci 3(1): 1–17 Reddy CS, Prasad RCP, Murthy MSR, Dutt CBS (2004) Census of endemic flowering plants of Andaman and Nicobar Islands. J Econ Taxon Bot 28(3):712–728 Reddy CS, Prasad RCP, Dutt CBS (2008) Additions to the flora of Andaman and Nicobar Islands, India. J Bombay Nat Hist Soc 104(3):379–382

123


3087

Roy SD, Krishnan P (2005) Mangrove stands of Andamans vis-a`-vis tsunami. Curr Sci 89(11):1800–1804 Roy PS, Tomar S (2001) Landscape cover dynamics pattern in Meghalaya. Int J Remote Sens 22:3813–3825 Shukla J, Nobre C, Sellers P (1990) Amazon deforestation and climate change. Science 247:1322–1325 Singh R, Mahabir Dixit, Dhawan AK (2000) Characterization of foundation rock of Kalpong Hydro Electric Project in North Andaman. http://www.csmrs.nic.in/kalpongigc2000.PDF. Accessed 9 Dec 2008 Singh VP, Garge A, Pathak SM, Mall LP (1987) Pattern and processes in mangrove forests of the Andaman Islands. Vegetatio 71(3):185–189 Sivaganesan N, Kumar A (1993) Status of feral elephants in Andaman. In: Daniel JC, Datye HS (eds) In a week with elephants: proceedings of the international seminar on the conservation of Asian elephant. Oxford University Press, Oxford Sodhi NS, Koh LP, Brook BW, Ng PKL (2004) Southeast Asian biodiversity: the impending disaster. Trends Ecol Evol 19:654–660 Srivastava S, Singh TP, Singh H, Kushwaha SPS, Roy PS (2002) Assessment of large scale deforestation in Sonitpur district of Assam. Curr Sci 82:1480–1484 Tamata BR (1991) Andaman and Nicobar Islands. National Book Trust, New Delhi Thothathri K (1960) Studies on the flora of the Andaman Islands. Bull Bot Surv India 2:357–373 Thothathri K (1961) New records of plants from Andaman and Nicobar Islands. J Bombay Nat Hist Soc 58:310–317 Thothathri K (1962) Contribution to the flora of the Andaman and Nicobar Islands. Bull Bot SurvIndia 4:281–296 Thothathri K (1980) Plant resources and their utilization in the Andaman and Nicobar. J Econ Taxon Bot 1:111–114 Tripathi KP, Tripathi S, Selven T, Kumar K, Singh KK, Shanta Mehrotra, Pushpangadan P (2004) Community structure and species diversity of Saddle Peak forests in Andaman Island. Trop Ecol 45(2): 241–250 Wilcox BA, Murphy DD (1985) Conservation strategy: the effects of fragmentation extinction. Am Nat 125:879–887

123