Pune City Wilderness: A case for urban biodiversity assessment
S. Nalawade1, A.
1 Lecturer, Dept. of Geography, Ferguson College, Shivaji Nagar, Pune, 411005.
2 Lecturer, Dept. of Zoology, A. Garware College, Erandawane, Pune, 411 004.
3 Secretary, RANWA, C-26/1, Ketan Heights, Kothrud, Pune, 411 029.
Love for nature resides amongst all of us, goes the Biophilia hypothesis (Wilson, 1984). This often translates into curiosity and subsequently, careful observation of the environment. Few have both the inclination and the resources to pursue such studies. Such amateur naturalists frequent cities that are centers of education and wealth. Ironically, flourishing cities made up of manmade capital survive by eroding their poor natural capital. This prompts the naturalists to lament and protest in vein the so-called development activities that only destroy the nature. Lack of information having teeth is a major reason for such shortsighted, unsustainable development. The naturalists have important perceptions about changing environment of the city but rarely record and project those to generate sharp arguments. A strong scientific argument can help, if not guarantee environmental protection. Thus naturalists do not help nature if they fail to build substantiative arguments. Naturalists from Pune, decided to make difference by overwhelmingly responding to a call by a city bred NGO, RANWA (Research and Action in Natural Wealth Administration). Incidentally, `ranwa’ means `wilderness’ in vernacular and is a term coined by the editor of this journal Dr. Prakash Gole. The enthusiastic response to RANWA’s appeal was spearheaded by the Garware College (AGC) faculty and students. This academic collaboration amongst naturalists together on an academic platform began earlier this year, strengthened and refined by about half a dozen meetings over the year, leading to this publication in the millennium year due to generous help from various quarters! In part, this study was triggered by the vision motivated by the local millennium ecosystem assessment exercise pioneered by Indian Institute of Science (IISc), coauthored by some of us (Gadgil et al, 2000).
Unlike the above assessment, we had neither financial nor human resources to investigate the non-living ecosystem components such as soil and water parameters or even air pollution. We attempted to make the best with available human resource, exposed to natural history through earlier efforts like the IISc’s college network involving the AGC (Gadgil, 1996 b). Our approach stemmed from the belief that living organisms serve as reliable ecosystem indicators (Hawkswarth, 1995). We began by standardising the methodology so that results across organismic groups become comparable and relate to levels and kinds of human impacts. Thus, a common definition of land and water habitats was arrived at through discussion and literature survey. These habitat types, specified in each organismic manuscript in this volume, are macrohabitats, ranging over the hectare scale (Gadgil, 1996 a). Information on microhabitat i.e. meter scale is also available but not analysed for this publication, which only aims to generate a preliminary, broad scale understanding. The land habitat types roughly in the decreasing orded of relative human influence include: forest (F), scrub (S), grasslands (G), plantations (P), agriculture (A), habitations (H). The first three habitat types constitute the wilderness (W) zone while the latter three types constitute the impacted (I) zone. The aquatic ecosystem classification remained at a broad level- low (W) and high (I) impact zones.
After standerdised the sampling strata, an qualitative sampling scale was designed to rank the abundance/frequency of encounter of species, as we had only a few systematic counts available and that too for a few groups. To cope up with the considerable inter-observer variation, we used the ordinal ranking popular amongst naturalists, with qualitative categories like abundant, common, occasional and rare, besides stray. Preferred habitat type of each species around Pune city is indicated in each manuscript, except the stray species. As a matter of fact, aquatic insects could be identified only up to family while ants and fungi up to genus level.
Sampling intensity varied across organismic groups. For instance, birds are the most intensively studied organisms with many birdwatchers pooling their observations for decades together. In contrast, aquatic invertebrates or ants were seldom studied here earlier, resulting in poor literature. There is no illusion that this volume is a complete and accurate inventory. We believe that this first comprehensive record will trigger debate, criticism, relevant observation and publications, even elsewhere. Further, while invertebrate records are mostly only recent, records of vertebrates or trees have taken care to indicate species not recorded recently, but reported from literature. This has indeed made it a millennium assessment both symbolically and literally! The focus being diversity, no wonder that presentations in this volume have variously evolved. Thus, while Kharat and Dahanukar Thakur carefully discriminate driving forces of decline in fish diversity, Patwardhan partitions reported increase in tree diversity to observer biases and errors. While habitat typology remains the focal theme of investigation for most groups, emphasis has been added on specific localities of occurrence in case of lower or sedentary groups like ants or fungi.
The study area has radius of about 25 km from the city post office. The study area is termed as `Pune Urban Area’ measuring about 700 sq. km and consists of Pune and Pimpri-Chinchwad Muncipal Corporations besides cantonments at Pune, Khadki and Dehuroad. It also includes few semi-urban villages in the adjoining area including near the Sinhagad fort, a favourite nature study spot. The area is situated Deccan plateau in the transition zone leading to Western Ghats mountains.
Results and Discussion
Table 1 depicts the diversity levels for various organismic groups, with only ant diversity being considerably underestimated. Pune urban area appears to shelter between a third to over two third of the total taxic richness reported for vertebrate groups from the whole of Deccan plateau (Nagalu et al. 2000). In part, this high diversity relative to small expanse can be attributed to location of Pune city in the transitional zone between dryland plateau and moist mountains, connected to the city through hills. This largely explains the higher diversity of Pune urban area than the levels reported for most groups from Bangalore (Karthikeyan, 1999) and Delhi cities (Anon, 1997). Interesting biogeographic patterns include much lower fish and mammal diversity at Bangalore than Pune, the latter being much better connected to the Western Ghats through rivers and mountains. The Himalayan influence probably explains much higher diversity of birds and fish at Delhi, notwithstanding much lower levels for other groups. Some of these differences can be attributed to differing sampling intensity across cities and groups. To address this difficulty, Gadgil et al (2000) provide an interesting statistical technique to estimate total taxic richness from distinct subsamples, such as locality wise data on occurrence of ants. In any case, the comparison highlights that Indian cities also host phenomenal levels of biodiversity and few such as Mumbai or Chennai host even wildlife reserves alongside skyscrapers.
Table 2 indicates that various organismic groups differ considerably with respect to their diversity distribtuion across habitat types and human impact levels. Some groups such as butterflies, reptiles and mammals have over almost all their species recorded from wilderness zone while nearly two third of them occur in forests. In contrast, diversity of fungi, herbs and trees seems to be as much or more in impacted habitats than low impact zone. The biodiversity to be lower in impacted habitat types in case of sensitive organisms like the fishes (Kharat and Dahanukar, this volume) or birds (Ingalhallikar et al, this volume) than the less sensitive organisms such as ants (Pachpore and Ghodake, this volume). However, notwithstanding the maintenance of considerable species richness amidst the urban habitats, the unique species are even wiped out under human impact, only to be replaced by more tolerant species owing to suitable life attributes like dispersal abilities. Such species substitution explains higher species richness in habitat types such as scrub that result from moderate human impact, harbouring greater diversity than the most or least impacted habitats. While the habitat approach adapted here highlights broader picture, much remains to be projected in terms of finer impacts such as loss of squirrel or snakes populations due to conversion of old houses in the city into skyscrapers.
The results confirm the widely known trends of increase in species diversity with moderate disturbance, though severe human influence tends to erode the diversity, except a few stress tolerant species, often having cosmopolitan distribution and wide habitat choice (Daniels et al, 1990). Further, rather than the total species diversity, human impact critically affects the diversity of unique species like habitat specialists as also emphasised by Daniles et al (1990). Another notable trend is lack of tight correlation across organismic groups, in response to similar human influence as reported in the literature (Kunte et al, 1999). For instance, while fish species seem to be sensitive to impact levels such as pollution, besides harvest or introduction of exotic species, aquatic invertebrates appear much less sensitive, notwithstanding the literature (Raut et al, this volume). The higher diversity recorded in some moderately or even considerably human impacted zones such as the city heart or home gardens must not mislead one to undervalue the less impacted zones like the hill forests surrounding the city. For, these continue to be the biodiversity source while most urban habitats serve merely as sinks, unable to sustain the diversity on their own. For instance, nearly a fifth of the butterfly species emerge from their food plants confined to the hill forests (Kunte, this volume) which also exclusively host over a sixth of the bird species, seldom seen elsewhere in the city campus (Ingalhallikar et al, this volume). Thus, bird or butterfly richness in the city gardens is difficult without the hill forests.
Table 3 presents the past and present landscape composition and ongoing changes, based on perceptions, besides records (Nalavade, this volume, a). Pune urban area has been expanding at an average rate of about 500m per year for the last two decades or so. Human habitations are encroaching upon the farm land, orchards of the fringe villages. The most suffered habitat type has perhaps been riverine vegetation especially babul (Acacia nilotica) tree groves along the rivers of Mula and Pawana. Grassland and scrub in the eastern outskirts has also been severely destroyed. There is heavy pressure on scrub and forest in the hill for fuel wood especially near the hutment e.g. Kelewadi slum adjoining Bhamburda forest park, Mutha canal slums near Parvati-Pachgaon. Bootleggers located in the hills are also responsible for tree cutting. Pune city hosts more than one million vehicles, over three-fourth being two-wheelers. Additional 10,000 vehicle pass through the city every day. The traffic on all the outgoing roads, particularly the high ways is heavy and continuous, even during night time. The Mumbai-Bangalore bypass constructed recently skirts the city along the western and south-western margin and virtually cut through the Parvati-Panchgaon forest park is now turned in to island. This study brings out its impacts in terms of loss of amphibian (Padhye and Mahabaleshwarkar, this volume) or mammal (Nalavade, this volume, b) populations.
Though we do not have complimentary data on non-living ecosystem parameters like air, soil and water pollution loads, their monitoring may become gradually possible, including through likely collaboration with the international ecosystem assessment (Ayensu et al, 1999), that encourages local assessments (Gadgil et al, 2000). In any case, the present millennium assessment of living components of an urban ecosystem would set the tone for their ongoing, periodic monitoring, regardless of physio-chemical studies; as already initiated by some authors in this volume (Kunte, 1997). But without eyeing for large, sponsored projects, environmental students from Pune University have voluntarily initiated chemical monitoring of various impact zones of waterbodies around Pune (Ghole, V. S., Jagdale, R., pers. comm.), furthering the earlier research (Gunale, 1987).
Our efforts were inspired by a pioneering, amateur effort to compile checklists urban fauna at Bangalore (Karthikeyan, 1999). Later, we chanced upon a more professional endeavour (Anon, 1997). However, the benchmark publication lacked the details of species habitat preference or relative abundance estimates, prompting us to provide those for future monitoring around Pune city. Most phenomenal organismic monitoring in India is perhaps the nationwide waterfowl count. While this decade old decentralised effort has inspired thousands of birdwatchers to census bird populations on that day, every year; no results appear to be churned out or popularised, despite mere compilations since long (Joost, 1987). Unfortunately, the leading national and international agencies like Bombay Natural History Society (BNHS) Asian Wetland Bureau (AWB) appear silent on this count. Interestingly, smaller groups have triggered locality specific data literacy, as evident from efforts of Prakriti Samsad, a birdwatcher’s group at Calcutta that has published their data, if not the results or signals, that would gradually emerge (Mukherjii, 1999). Similarly, Kalpavriksh, an NGO is initiating data analysis and publication from monthly bird counts across Delhi over a decade (Kothari, A., pers. comm.), besides having recently published a fieldguide to promote monitoring (Smetacek, 2000). The college/NGO network initiated by IISc along the Western Ghats (Gadgil, 1996 a, Kunte et al, 1999) has also begun emphasising importance of building local assessments and awareness, besides developing the training material (Kunte, 2000). Colleges around Nasik (Acharya, S. pers. Comm.) and Mangalore (Bhat, G. K., pers. Comm.) have already expressed interest in similar assessments and publications next year, besides parallel effort by NGOs in Nagpur city (Ladkhedkar, R. pers.comm.)
It is hoped that such studies would promote further scientific development such as study of plant-butterfly (Kunte, 1997) or fig-bird relationships (Utkarsh and Almeida, 1999), eventually leading to careful ecological monitoring. Such monitoring can help better understanding of the ongoing process of ecorestoration around the city, such as at Pachgaon, Bhamburda, Chandani chowk hills. Here, protection by Forest Department coupled with the vigil by nearby residents who regularly visit these areas for exercise or recreation has facilitated regeneration of natural plants and revival of native fauna. Temple trusts, educational institutions such as `Dnyanprabodhini’, NGOs such as `Nisargasevak’ have also helped this cause. The revival of natural trees or herbs amidst plantations, has triggered colonisation of these new habitats by birds, butterflies etc. Notably, even seasonal puddles, formed in these areas now harbour moults of dragonfly nymphs etc. indicating ongoing colonisation and establishment of even organisms that are highly susceptible to seasonality. Recently increasing tree cover of suitable species in some areas such as the Rajnish Park has probably similarly helped predominantly Western Ghats dweller butterflies such as the Blue Mormon, seldom seen in the city earlier (Kunte, this volume). An understanding of eco-restoration process can help its manipulation and replication in neighbouring areas and even other cities (Jordan et al., 1987). Besides, such ongoing monitoring can easily detect notable declines in certain species like the sparrows and vultures, being noticed and debated currently (Rahmani, A., pers. comm.). If such sudden population fluctuations are any signal of impending calamity, the purpose of monitoring is served much beyond academic interests. Such monitoring can even become quite popular, yet cost effective through internet publicity such as the electronic discussion group of Asian naturalists having thousands of members worldwide <nathistory-india@lists.Princeton.EDU>.
Notably, such publications based on long term observations might pre-empt the facile environmental impact assessments (EIAs) that are currently mushrooming like a fashion, such as those on the proposed dams on the river Narmada, where Puneites made significant contributions either way. While upholding the cause of dam construction, Supreme court has often expressed dissatisfaction about superficial environmental assessments. Unfortunately, environmentalists are not geared with much concrete, scientific data. Despite much hue and cry about a road cutting across the Law College hill, environmentalist have little data on likely impacts, based on seasonal or annual monitoring. That scientific data can at times lead to stringent legal action against environmental hazards is proven in case of pollution at Delhi and Agra. Unfortunately, much of the EIA activity is driven by the sponsor’s interests in promoting development at the cost of environment. Since RANWA did not seek any targeted sponsorship, this effort lacks such directed loyalty. We hope that this initiative will kick off more such efforts, both locally and elsewhere. Such proactive, decentralised monitoring, especially by the students is envisioned by the project lifescape launched by the Indian Academy of Sciences to pay tribute to Dr. Salim Ali (Gadgil, 1996 b, Kunte, 2000). If the legal activism, often seen of late takes note of such serious publications, environmental care cannot be easily wished away by the shroudy EIAs.
Reviewers, often from amongst the authors of this volume have enhanced the quality manifold. Dr. Hemant Ghate, foremost animal taxonomist and ecologist in the city needs a special mention for buttressing abilities of the group and for the finishing touch. Dr. Asad Rahmani, heading the prestigious BNHS gave an ear to these efforts and persuaded its easy, quick and compiled publication through the Ecological Society. He was more than complimented by the receptive, encouraging editor Dr. Prakash Gole. Prof. M. Gadgil and the IISc team, including WGBN members who have variously motivated and buttressed these efforts. World wide Fund for Nature- India (WWF-I), thanks to Shekhar Singh and A. R. K. Shastry, had earlier sponsored RANWA for executing part of the Biodiversity Conservation Prioritisation Project (BCPP). Our modest savings then helped us to trigger this endeavour. We remain obliged to them all, besides our friends and families that gracefully bore the brunt of our ecological obsession!
Anon 1997. Fauna of Delhi. Zoological Survey of India. Calcutta.
Ayensu et al, 1999. International Ecosystem Assessment. Science. 286: 685-6.
Daniels, R.J.R., Hegde, M., And Gadgil, M., 1990. Birds of the manmade ecosystems: the plantations. Proc.Ind.Acad.Sci. (Anim. Sci.) 99: 79-89.
Gadgil, M. (1996 a) Documenting diversity: An experiment. Current Science 70: 36-44.
Gadgil, M., 1996 b. Deploying student power to monitor India’s lifescape. Current Science 71: 688-697.
Gadgil et al, 2000. Participatory Local Level Assessment of Life Support Systems. Centre for Ecological Sciences, Indian Institute of Sciences, Technical Report no. 78. See also: http://ces.iisc.ernet.in/hpg/cesmg
Gunale V. 1987. Algal communities as indicators of pollution. Jr. Env. Biol. 223-232.
Hawksworth, D. L. (ed.) 1995. Biodiversity measurement and estimation. The Royal Society and Chapman and Hall, London.
Ingalhallikar S., Purandare R., Nalavade S., Dhole S. (this volume) Bird diversity dynamics around Pune city.
Jordan, W. R., Gilpin, M. E., Aber, J. D. (Eds.) 1987. Restoration Ecology: A Synthetic Approach to Ecological Research Cambridge University Press, Cambridge.
Joost V. 1987. Asian waterfowl. International Wetland Research Bureau. Slimbridge.
Kartikayan S. 1999. The vertebrate and butterfly fauna of Bangalore: A checklist. WWF –India, Karnataka State Office. Bangalore.
Kharat S. S. and Dahanukar N. (this volume) Fresh-Water Fish Decline of Pune Urban Area
Kunte,, K. 1997. Seasonal patterns in butterfly abundance and species diversity in four tropical habitats in northern Western Ghats. Jr. Biosciences: 22(5): 593-603.
Kunte K. (2000). The butterflies of Peninsular India. University Press, Hyderabad.
Kunte, K. (this volume) Butterfly Diversity Of Pune City Along Human Impact Gradient.
Kunte, K., Joglekar, A., Utkarsh, G. And Pramod, P. 1999. Patterns of butterfly, bird and tree diversity in the Western Ghats. Current Science 77 (4): 577-586.
Lamrood P. Y. and Vaidya J. G. (this volume) Fungal Genera of the Pune City
Mukherjii, K., 1999. Mid-winter waterfowl census in southern West Bengal 1990-7. Prakriti Samsad. Calcutta.
Nagulu V., Rao V. V. and Shriniwasulu C. 2000. Wildlife Heritage of the Deccan: Deccan Heritage. University Press, Hyderabad.
Nalawade, S. B. (this volume, a) Geography of Pune urban area.
Nalawade, S. B. (this volume, b) Retreating wild mammals of Pune urban area.
Pachpor T. and Ghodke Y. (this volume) Ant Genera Distribution Across Pune City Habitats
Padhye A. D. and Mahabaleshwarkar M. (this volume) Amphibian Decline In Pune City
Raut R. N., Desai S. and Bapat R. (this volume) Survey of aquatic insects and molluscs of Pune.
Smetacek, P. 2000. Butterflies Of Delhi. Kalpavriksh, Delhi.
Utkarsh G. and Almeida M. R., 1999. Figs. Resonance 4(12): 90-100.
Wilson,E.O. 1984. Biophilia: The Human Bond With Other Species. Harvard University Press, Cambridge.
|RANWA Home Page|