The City Biodiversity Index (CBI) for Siliguri provides a comprehensive assessment of the city’s biodiversity management and ecological health, structured around three key components: Native Biodiversity, Ecosystem Services, and Biodiversity Governance.
Native Biodiversity in the City: This section includes ten indicators that evaluate the presence and condition of native species and natural ecosystems within the urban area. It examines aspects such as the proportion of natural areas, connectivity measures for green spaces, and the presence of native species in built-up areas. For Siliguri, this includes detailed surveys of flora and fauna, such as vascular plants, birds, and odonates, providing a snapshot of the biodiversity that thrives within the city limits.
Ecosystem Services Provided by Biodiversity: Comprising four indicators, this segment assesses the benefits that biodiversity brings to the city and its residents. These benefits include carbon storage, climate regulation, recreational opportunities, and educational services linked to biodiversity. The evaluation of these ecosystem services helps underscore the tangible and intangible contributions of biodiversity to urban life, enhancing the wellbeing of its inhabitants and ecological resilience.
Biodiversity Governance in the City: The final nine indicators focus on the governance aspect, examining how biodiversity is integrated into urban planning and management. This includes the assessment of local policies, the allocation of budgets for biodiversity projects, public participation in biodiversity conservation, and the implementation of local biodiversity strategies and action plans. These indicators reflect the city’s commitment to biodiversity management and its capacity to enforce and support conservation initiatives effectively.
What is the CBI?
The CBI, also known as the Singapore Index on Cities’ Biodiversity, is a tool designed to help cities measure and enhance their biodiversity management and conservation efforts. Introduced by Singapore at the 9th Conference of the Parties to the Convention on Biological Diversity (CBD) in 2008, the index facilitates the self-assessment of urban biodiversity. It provides a way to gauge progress, understand impacts, and manage urban natural resources more effectively. The index consists of 23 indicators across three categories: native biodiversity in the city, ecosystem services provided by biodiversity, and governance and management of urban biodiversity.
Why does the CBI Matter?
Understanding urban biodiversity through tools like the CBI is crucial for several reasons:
- Conservation: Cities are often located in biodiversity-rich areas, making urban biodiversity management pivotal in broader conservation efforts.
- Sustainability: Biodiversity enhances ecosystem productivity where each species, no matter how small, plays an important role in ecological balance.
- Quality of Life: Urban biodiversity can improve air quality, reduce urban heat effects, and provide recreational opportunities for city residents.
Insights from the City Biodiversity Index
Ahead of the International Day for Biodiversity Conservation on May 22, here is a snapshot of one of the sections from the CBI for Siliguri, highlighting the species checklist that underscores the rich tapestry of biodiversity this vibrant city harbours.
Biodiversity in Siliguri: Highlights from the City Biodiversity Index
The CBI for Siliguri, prepared by ICLEI South Asia under the CapaCITIES project funded by the Swiss Agency for Development and Cooperation, provides an insightful look into the urban biodiversity of this city located at the foothills of the Himalayas. Here are some highlights from the species checklist and examples of biodiversity in Siliguri:
- Bird Species: The CBI for Siliguri reports the presence of a total of 243 species listed. This rich avian diversity includes several notable species but prominent ones include the Himalayan Bulbul (Pycnonotus leucogenys) — known for its melodious songs, this species is a highlight of the local biodiversity, thriving in the urban and suburban areas of Siliguri. The Asian Paradise Flycatcher (Terpsiphone paradisi) — famous for its spectacular tail feathers, the bird is a stunning sight within the city’s green spaces.
- Vascular Plants: Siliguri hosts a variety of vascular plants highlighting a total of 241 species. Among others, the Rhododendron – a genus that is emblematic of the Himalayan flora, these plants add to the region’s natural beauty and ecological value. Orchids, with their intricate and delicate blooms, represent the rich botanical heritage in and around the city.
- Freshwater Fish: The freshwater ecosystems of Siliguri supports a diversity of 71 fish species recorded in nearby rivers. The importance of aquatic biodiversity in close proximity to urban spaces with examples such as Mahseer (Tor putitora) – an important species for aquatic conservation due to its size and popularity among anglers, and Chela (Aspidoparia morar) – common in the local waterways, this species is crucial for maintaining ecological balance.
- Amphibians and Reptiles: The presence of 37 amphibian and reptile species in the city reflects the need for conservation practices for the herpetofaunal community. The Himalayan Newt (Tylototriton verrucosus), a rare amphibian, is of significant conservation interest while the Common Indian Toad (Duttaphrynus melanostictus), a widespread species, is another example of species that play a key role in controlling insect populations in urban areas.
- Odinates: A total of 69 species of Odonates (dragonflies and damselflies) were observed within the vicinity of the University of North Bengal, just a few kilometers from Siliguri. This diverse group includes species such as the Agriocnemis kalinga (Kalinga Wisp), a recently discovered species notable for its rarity and specific habitat preferences, and the Rhyothemis variegata (Common Picture Wing), known for its strikingly patterned wings and widespread occurrence across varied aquatic habitats. This rich diversity of Odonates highlights the ecological richness and the varied aquatic ecosystems around Siliguri.
- Invasive Species: The CBI recorded 49 invasive plant species. Among these, notable examples include Lantana camara, a highly adaptive species known for its aggressive growth and impact on native plant communities, and Parthenium hysterophorus (Parthenium weed), which is notorious for its allergenic properties and its ability to outcompete local flora. These species pose challenges to local ecosystems by displacing native species, altering habitats, and affecting the fauna that depend on indigenous plants for survival. Managing these invasive species is crucial for preserving the ecological balance and maintaining the health of natural habitats in and around Siliguri .
Quotes
“Siliguri’s City Biodiversity Index serves as a vital tool for understanding and managing its natural resources. Among various sections of the CBI, the species checklist is one that not only underscores the richness of the city’s biodiversity but also highlights the challenges in conserving these natural assets amidst rapid urbanisation. By continuing to monitor and implement strategic biodiversity management practices, Siliguri can protect its natural heritage while promoting sustainable development,” said Emani Kumar, Executive Director, ICLEI South Asia.
“This detailed and structured exploration of Siliguri’s biodiversity through the lens of the CBI highlights the important interplay between urban development and biodiversity conservation. For cities like Siliguri, recognising and integrating biodiversity into urban planning is not just beneficial; it is essential for sustainable future growth,” said Dr. Monalisa Sen, Senior Programme Coordinator (Biodiversity), ICLEI South Asia.
Climate Regulation and Carbon Storage
The assessment of Siliguri’s capabilities in climate regulation and carbon storage primarily focuses on the city’s tree canopy coverage. Covering nearly 15% of the total terrestrial area, the tree canopy is instrumental in providing shade, reducing the urban heat island effect, and sequestering carbon dioxide. This green canopy not only supports the city’s climate goals but also enhances the quality of air and life for its residents. The strategic management and expansion of these green spaces are critical for sustaining and boosting Siliguri’s environmental health and resilience against climate change.
Natural Areas Coverage: Natural areas in Siliguri constitute 16% of the city’s total area, indicating an integration of natural ecosystems within the urban landscape while tree patches contribute to nearly 20% of the natural asset area. This coverage not only supports diverse wildlife but also enhances the ecological services provided to the city.
Recreational Green Spaces: The city provides ample recreational spaces that contribute to the community’s well-being and environmental education.
Permeable Surfaces: Accounting for 52.22% of the city’s terrestrial area, these surfaces are crucial for effective water management and climate regulation. By allowing rainwater to percolate into the ground, they reduce water runoff, help maintain moisture levels, and moderate urban temperatures, contributing to climate regulation.
City’s Land Use
The CBI report for Siliguri delineates the composition of the city’s land use with a focus on its ecological assets and urban landscape.The natural asset area within the city constitutes 16% of the total area, incorporating rivers, ponds, river banks, riverine vegetation, open green spaces, and sparse vegetation. Tree patches, crucial for urban wildlife, constitute approximately 19.96% of the total natural asset area. Open green spaces, essential for recreation and urban ecology, account for about 4.16% of this area. Playgrounds and parking grounds, which facilitate community interaction and physical activities, make up around 13.03%. The river systems, vital for maintaining biodiversity and ecological balance, stretch over a significant 46.79% of the natural assets. Although small ponds cover just 0.11%, they are critical for the local aquatic life. Riverbank and riverine vegetation, important for stabilising riverbanks and supporting diverse life forms, comprise about 9.18%. Sparse vegetation, providing essential green cover and habitat for various urban fauna, occupies 15.49%. These areas together constitute a mosaic of habitats that support the biodiversity within the Siliguir’s urban expanse.
