- In the city of Bengaluru, neighbourhood parks are an under-utilised resource for protecting local biodiversity. So far, the main goal for neighbourhood parks has been to provide a recreational zone to citizens. In a new study researchers argue that apart from recreation, biodiversity protection should also be included in parks’goals.
- Large green spaces, though great for biodiversity, are hard to set up in congested and highly populated cities like Bengaluru. On the other hand, a cluster of high-density of parks is easier to create and sustain.
- The study shows that with the right mix of vegetation, neighbourhood parks can easily provide a home to a variety of local biodiversity.
For residents of India’s IT capital, Bengaluru, a neighbourhood park (NP) is not an uncommon sight. Their role in providing the urban population a recreational space has been appreciated by both the residents and the municipal corporation. However, their contribution to supporting the urban ecosystem and sheltering urban biodiversity has been under-estimated.
In a new study, a group of urban ecologists from the Ashoka Trust for Research in Ecology and the Environment (ATREE) have challenged this view. They say parks, despite their small size, can serve as “stepping stones” that facilitate the movement of birds, butterflies, and insects between larger green areas. The study makes a case for the idea – that instead of associating nature and biodiversity with adjectives like ‘rare’,’charismatic’ and ‘away’, we should make room for and support nature in places closer to our homes.
“Large parks support a lot of biodiversity and should be established whenever and wherever there is an opportunity. However, with space constraints in the cities, chances for this are remote. Our study shows that high-density neighbourhood parks can support biodiversity reasonably well. Besides, they realise the dual role of biodiversity support and recreation,” said Soubadra Devy, one of the authors of the study and a researcher at ATREE.
The researchers conducted expansive surveys to arrive at their conclusions. Using the Bangalore Development Masterplan 2005-2015 that divides the city into three zones, the researchers chose four residential areas from the first two zones. In the last zone, which is still developing, the researchers chose only two residential areas. A total of 37 NPs distributed across 10 residential areas were sampled. “Within each of these NPs, a detailed bird, butterfly, insect and tree sampling was carried out over a two-year period,” said, Savitha Swamy, co-author of the paper.
While some species like birds and butterflies were easy to monitor, others like insects weren’t clearly visible. One of the reasons birds and butterflies are easier to monitor is because people are more fond of them. The researchers surveyed the park users to assess their fondness for a variety of biodiversity spotted in the park. The park users were asked, among snakes, snails, lizards, ants, frogs, beetles, dragonflies, birds and butterflies, which did they like most.
An overwhelming majority of the respondents said that they were most fond of birds and butterflies. Most park users were intolerant of other species and labelled them as “creepy crawlies”.
Interestingly, high fondness species like birds and butterflies can act as a proxy for the existence of other less-observed creatures. For example, “birds depend on inconspicuous creatures like grasshoppers, crickets, etc. for their food. Hence, birds revealed the presence or absence of the smaller, lesser species such as insects,” said Swamy.
To be able to support a variety of species, NPs should ideally have a diverse mix of vegetation. “The ideal mix contains trees, shrubs, and grass/lawns,” said Devy. Care should be taken to ensure NPs have plants that provide “food for larval and adult butterflies and nectarivore (nectar-loving) birds”.
Some areas should be earmarked for “open lawns”. These open areas are good for soil fauna but only if their maintenance is “devoid of chemicals”. And of course, NPs require “shrubby vegetation” and a scattering of “trees to support birds and butterflies,” explained Devy.
Another important observation made by the researchers is that the density of NPs is more important than the size of NPs. “Presence of high density of NPs within a neighbourhood could support similar biodiversity that large green spaces support”, the researchers write in their paper.
More studies are needed to define what could be the ‘ideal density’ of NPs in a neighbourhood. But, one thing is clear, “increase in density definitely supports more biodiversity,” said Devy. In highly urbanised areas, where large green zones are impossible to establish, urban developers should focus on setting up a high density of small parks.
Bengaluru was always known for its expansive gardens like Lalbagh and Cubbon park. In fact, its vast green cover earned it the moniker of ‘Garden City’ long ago. Data supports this view. Up until 1973, 68 percent of the land in Bengaluru was covered with greenery. However, rapid urbanisation in the next few decades meant the green cover was reduced to a mere 23 percent of the total area in 2012. This loss in green cover was accompanied by a loss in biodiversity as well, the study notes.
By looking at NPs with fresh eyes, Bengaluru has an opportunity to provide its urban biodiversity some room for survival. Until now, “lack of knowledge about the ecosystem functions – such as the fact that local biodiversity conservation can improve hydrological functions – among the city planners and decision-makers, has been the prime factor for the gaps in the design of NPs,” said T V Ramachandra, faculty at the Centre for Ecological Sciences (CES), Indian Institute of Science (IISc), Bengaluru.
He also recommends setting up “mini forests in a space of 1-2 hectare in each ward of the city. This would not only help in enhancing biodiversity but also help in moderating microclimate and groundwater recharge.”
The NPs and mini forests act as green links to large green spaces establishing a long continuum of greenery. As citizens, we too can plug into this continuum by making our backyards and balconies attractive for birds, bees and butterflies. Devy has the perfect recipe for Bengaluru-citizens to make their balconies biodiversity-friendly. “Growing curry leaves, lemon plants, and palms will support butterfly caterpillars. Trailing some passion flowers would attract sunbirds,” she added.
Banner image: Large parks, away from home, support a lot of biodiversity and should be established when there is an opportunity. Photo by Manupriya.