Understanding forest loss and recovery: a ...

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Understanding forest loss and recovery: a spatiotemporal analysis of land change in and around Bannerghatta National Park, India a

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Sanchayeeta Adhikari , Jane Southworth & Harini Nagendra a

Geography Department, Macalester College, Saint Paul, MN, USA

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Department of Geography, University of Florida, Gainesville, FL, USA c

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School of Development, PES Institute of Technology Campus, Azim Premji University, Bangalore 560100, India Published online: 29 May 2014.

To cite this article: Sanchayeeta Adhikari, Jane Southworth & Harini Nagendra (2014): Understanding forest loss and recovery: a spatiotemporal analysis of land change in and around Bannerghatta National Park, India, Journal of Land Use Science, DOI: 10.1080/1747423X.2014.920425 To link to this article: http://dx.doi.org/10.1080/1747423X.2014.920425

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Journal of Land Use Science, 2014 http://dx.doi.org/10.1080/1747423X.2014.920425

Understanding forest loss and recovery: a spatiotemporal analysis of land change in and around Bannerghatta National Park, India Sanchayeeta Adhikaria*, Jane Southworthb and Harini Nagendrac


a Geography Department, Macalester College, Saint Paul, MN, USA; bDepartment of Geography, University of Florida, Gainesville, FL, USA; cSchool of Development, PES Institute of Technology Campus, Azim Premji University, Bangalore 560100, India

(Received 19 September 2013; final version received 27 April 2014) Bangalore is India’s third fastest-growing city and a major information technology center of India. The city is unusual in also having a major protected area located at its periphery, which creates a significant challenge for conservation. Bannerghatta National Park and its surrounding landscape, situated south of Bangalore, have experienced significant land-use and land-cover changes over the last two decades. This analysis combines discrete and continuous approaches of satellite remote-sensingbased change detection using multitemporal Landsat and IRS LISS III imagery to analyze the rate and extent of spatiotemporal changes in and around the Bannerghatta National Park between 1973, 1992 and 2007. Most of the native forest cover loss and decrease in forest density has taken place outside the park, or at the edge of the park, and relates to increased agriculture, suburban development, grazing and illegal logging. However, forest cover inside the park has been maintained, counter to the dominant global theme of deforestation as a consequence of urbanization. Overall, despite the decrease in native forest cover the landscape has experienced a net increase in tree cover or reforestation, which can be attributed to an increase in tree plantations outside the Bannerghatta National Park. Keywords: land-use/land-cover change; remote sensing; reforestation; national park; India

1. Introduction Forest-cover decline, agricultural expansion and intensification, and an increase in built areas are taking place at increasing and alarming levels in developing countries across the globe as a result of urbanization (Lambin et al., 2001). In particular, tropical forest habitat has continued its global decline, leading to serious concerns for environmental sustainability (Southworth, Nagendra, & Cassidy, 2012). Often, these changes represent land-use transition along a trajectory of economic development that may pass through phases such as resource extraction from natural ecosystem (frontier), agricultural expansion and industrialization and urbanization (Hansen, DeFries, & Turner, 2004; Mustard, Defries, Fisher, & Moran, 2004). These transitions primarily show an intensification of land use between the phases of wildland and the urban land use. In developing countries, these wildland/natural areas/forest resources face threats, small or large scale, depending on the size and distribution of native ecosystems, patterns of demographic distribution and change, and nature of human activities (Hansen et al., 2004). *Corresponding author. Email: [email protected] © 2014 Taylor & Francis


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Urbanization has given rise to major impacts on land change in many developing countries, and India is no exception. In 2010, 377 million people lived in Indian cities, with India accounting for 11% of world’s urban population – by 2031, projections indicate that this proportion will rise to 15%, with 600 million people living in Indian cities. Urbanization presents one of the greatest threats to India’s natural areas, and in particular its forest cover, because of its rich biodiversity and historically declining amount. The forest cover in India is around 675,000 km2 and constitutes approximately 20% of the country’s total land area (FSI, 2000). To protect the country’s forest cover, India has taken the approach of creating protected areas (PAs) in the form of national parks and wildlife sanctuaries. This approach of conserving forest resources, also popularly known as fortress conservation (Blaike & Muldavin, 2004), restricts resource extraction and human occupation in the PAs (Nagendra, Paul, Pareeth, & Dutt, 2009). In India, the formal declaration of PAs began after independence, in 1947, but exclusionary approaches to forest conservation have a longer history, dating from colonial period. The Forest Act of 1878 excluded local communities from forest management in practice, even though people’s participation was permitted on paper (Bandopadhaya, Soumya, & Shah, 2005; Guha, 1996). After independence, state control over forest resources and exclusion of local communities from traditional forest resource use were further strengthened through the Forest Policy of 1952 (Guha, 1983; Saxena, 1999). Commercial exploitation of forest resources for industries however continued until the 1980s to accommodate the expanding economic growth in India, with a focus on timber exploitation through large-scale monoculture of native and exotic species such as Tectona grandis (teak), Pinus tropicalis (tropical pines) and various species of Eucalyptus (Guha, 1983). The National Forest Policy (1988) prohibited the commercial and industrial exploitation of forests, and the subsequent Tree Felling Act and Supreme Court Orders of 1996 banned tree felling and fuelwood extraction within PAs (Arora, 1994; Nagendra et al., 2009; Saxena, 1999). PAs in India have thus shifted from a productive forest management for commercial purpose to a more protective management system focused on conservation (Arora, 1994; Guha, 1983). Globally, as well as in India, parks have been widely deployed for conservation, yet their social effects in terms of excluding local communities from forest resource use and management have been debated (Karanth, Kramer, Qian, & Christensen, 2008; Nagendra et al., 2009). India has had a strong focus on conservation through PAs, resulting in an increase in PAs from six national parks and 59 wildlife sanctuaries in 1970 to 89 national parks in India and 497 sanctuaries by the end of the twentieth century (Khare et al., 2000; MOEF, 2002). PAs occupy at least 5% of the country’s land and are located mostly in areas occupied by human populations. According to a survey carried out in the mid1980s, over 65% of the PAs in India were characterized by human settlements and resource use (Kothari, Pandey, Singh, & Variava, 1989). Urbanization further accelerates this trend of human resource extraction on forest areas. In addition to the threats to the PAs from the human settlements inside their borders, the high proportion of unprotected forest areas outside PAs also suffers from high deforestation rates (DeFries, Karanth, & Pareeth, 2010). Understanding change in the broader landscape surrounding PAs is very important in developing countries such as India as these areas have considerable forest cover, experience dynamic change in demography, land use and land cover, and are characterized by biological and sociopolitical risks not usually found elsewhere (Loucks, Ricketts, Naidoo, Lamoreux, & Hoekstra, 2008; Nagendra, 2008). Changes in land use and land cover, coupled with biological and sociopolitical transformations in the surrounding landscape, may affect the PA through changes in its effective size, changes in


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ecological flows into and out of the reserve, loss of crucial habitat outside of the reserve and increased exposure to edge effects and human pressures such as fires, invasive species and hunting (Brashares, Arcese, & Sam, 2001; Brooks et al., 2002; Hansen & DeFries, 2007; Hansen & Rotella, 2001; Laurance et al., 2002; Woodroffe & Ginsberg, 1998). Land change studies have been undertaken using a multitude of methods. This is due to the hybrid nature of the land change arena (Meyer & Turner, 1992). One widely used methodological framework for landscape-level studies builds on satellite remote sensing (Kozak, Estreguil, & Troll, 2007; Msoffe et al., 2011; Theis, Meyer, Nauss, & Bendix, 2012; Walsh & Crews-Meyer, 2002), which provides an efficient approach for observing and monitoring land-cover changes occurring in park landscapes at multiple spatial and temporal scales (Hartter & Southworth, 2009). Satellite remote-sensing methods of analysis in land-cover change studies generally use a discrete classification system of a landscape into homogeneous divisions, with discrete boundaries (Pearson, 2002; Southworth, Munroe, & Nagendra, 2004). Although discrete land-cover classes have been used extensively in land change studies for across class change analysis, much of the variability within a class are lost and changes within a class cannot be observed using this method (DeFries, Hansen, & Townshend, 2000). Continuous data sets, for example, vegetation indices, can provide a different perspective in addition to discrete land-cover classes (Southworth et al., 2004), yet their utilization in the land change community has been relatively low compared with the widespread use of categorical approaches to image change analysis (Jensen, 2007). The objective of this landscape-level study is to determine the land-use and land-cover changes in and around Bannerghatta National Park, Bangalore, India, from 1973 to 2007 by measuring and mapping the spatial and temporal land-use and land-cover dynamics in the region. Specific research questions are: (1) Did the park maintain its forest cover due to its PA status as opposed to the forest cover outside the park? (2) How does the pattern of forest-cover change inside the park compare to pattern of forest-cover change outside the park? (3) What additional perspectives on land change can be provided by examination of a continuous vegetation index? We expect that the forest cover inside the park would have been maintained due to protection and the forest cover outside the park would have declined because of no protection and due to its close proximity to the rapidly developing urban area of Bangalore, given the large number of potential driving forces, including population pressure, agricultural expansion, urban expansion, infrastructural development and other socioeconomic activities that have increased across this region since the rapid accelerated growth and expansion of Bangalore that has taken place in recent decades.

2. Materials and methods 2.1. Study region The Bannerghatta National Park is a tropical mixed dry deciduous forest in southern India and is situated only 22 km south of Bangalore city in Karnataka state (Figure 1a). Established in 1971, the Bannerghatta National Park represents an area of 109.25 km2, which includes 12 reserve forests in the Anekal Range of the Bangalore Forest Division. The average rainfall is around 700 mm annually, with temperatures in the range of 15–38° C throughout the year. The principal inhabitants of the national park are elephants, which migrate from Kollegal and nearby Tamil Nadu territory to the Bannerghatta National Park, for the major part of the year. Some of the other inhabitants of the park include wild pigs,

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Figure 1. Study region of the Bannerghatta National Park in Bangalore, India. (a) Shows the location of Bannerghatta National Park and the buffer of 5 km around the Bannerghatta National Park; and (b) shows major roads, villages inside the park and the Talli reserve forest on the southeast region of the Bannerghatta National Park.


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panthers, bears, sambar, spotted deer and the black buck. Some of the dominant vegetation species in the park include Terminalia tomentosa (tamarind), Azadirachta indica (neem), Terminalia arjuna (Arjuna), Santalum album (sandalwood), Tamarindus indica (tamarind), Bambusa vulgaris (Bamboo), Eucalyptus cinerea (Eucalyptus), Bauhinia purpurea (Butterfly tree) and Peltophorum pterocarpum (Golden flame) (Radha Devi, 2003). The Bannerghatta National Park is well connected with Bangalore city in the north, east and west through several roadways. Areas in proximity to the Bannerghatta Road have recently experienced rapid establishment of multinational information technologyrelated companies resulting in rapid land development in the area (Audirac, 2003). Two other important roads in the region are the Kanakpura Road and the Hosur Road to the west and east of the Bannerghatta National Park, respectively (Figure 1b). The ‘Electronic City’, one of India’s largest electronic industrial parks with information technologyrelated companies like Wipro, Infosys, Hewlett-Packard and Siemens, has been established further south on the Hosur Road, resulting in land development in the surrounding areas (Audirac, 2003). In the southeastern and southern part of the park lies Talli reserve forest and Bilikal reserve forest, respectively, administratively within the neighboring state of Tamil Nadu. There are seven villages inside the park, which also form three large enclosures with human settlement (Figure 1b). A fourth enclosure is present in the southern part of the park, which forms the farming estate of Ukkara. The Bannerghatta National Park is also surrounded by many villages on the western, eastern and southern part where people’s livelihoods range from livestock rearing, agriculture, silkworm rearing, construction work, working in stone quarries and carpentry. The interacting feedbacks between the population dynamics, the park and the land-use and land-cover changes are important for understanding changing landscape in the region. 2.2. Data sources and preprocessing Landsat and Indian Remote Sensing Satellite Linear Imaging Self-Scanning (IRS LISS) III satellite imagery was acquired for analysis. Although near anniversary image acquisition dates are more appropriate for land change studies of this nature, we used two cloud-free, dry season date images, 27 February 1973, 14 January 1992, and one wet season 10 May 2007 image. Even though May is a wet season in the study area, the image was acquired on 10 May, which is a pre-monsoon/onset of monsoon time period and thus should be considerably dry. The 1973 image is Landsat MSS (path 154, row 51), the 1992 image is Landsat TM (path 144, row 51) and the 2007 image is LISS III (path 100, row 64). Topographic maps at 1:50,000 scale were collected from Survey of India and were converted to a raster system using the 30 × 30 m pixel size associated with Landsat TM imagery. The topographic maps were used for the base rectification of the 1992 image, which was projected to the UTM WGS84 coordinate system. The other images were geometrically corrected using image-to-image registration method using the base image of 1992. Resampling was performed using a nearest-neighbor algorithm. The transformation had a root mean square (RMS) error of less than 0.5 pixels (