Bio-Corridors: Linking Habitats For Productive And Ecological Connectivity

by Shaurya Singh

The variety of all living creatures in our world, our biodiversity, has been alarmingly dwindling in recent years, largely as a result of human activity. According to WWF’s 2020 Living Planet Report, the number of mammals, birds, fish, reptiles, and amphibians has decreased globally by an average of 68% since 1970. Habitat damage due to unsustainable logging or agriculture accounts for a large portion of the loss. Direct exploitation such as hunting, excessive grazing, and overfishing, Changes in land use (such as deforestation, intense monoculture, and urbanization), and Pollution, Although it hasn’t been the primary cause of biodiversity loss thus far, invasive alien species and climate change are predicted to fill that position in the next decades.

In these pressing times, we should advocate for urban development that preserves biodiversity since it boosts ecosystem productivity while preserving the food chain in order to safeguard individual species, maintain habitat, and build a stable ecosystem, otherwise, the disruption in the food chain could affect the entire ecosystem affecting both the environment and humans leading to a shortage of resources and putting endemic species in danger. 
Addressing these concerns the project ‘Bio-Corridors: Linking Habitats For Productive And Ecological Connectivity’ aims to re-design the existing street networks to connect disparate ecological and productive ensembles into continuous bio-diverse corridors.
Gandhinagar has approximately 40% under green cover. The study attempts to club these lands under different ensembles such as Forest, Park, Planned, Agricultural, and Wilderness. Mapping these revealed they are fragmented and sparsely distributed. The project thus redesigns street networks to connect disparate ecological and productive ensembles into continuous biodiverse corridor systems. 
The tertiary streets are proposed to become six continuous bio-corridors connecting peripheral ecological ensembles to the city center while Introducing various bio-retention strategies on streets. This is achieved by continuous medians and bioswales/rain gardens. The Primary streets are for people to engage with biodiversity, The city ring road becomes a green buffer for pollution control, and green thickets on adjacent lots are identified for conservation. 
These strategies at the city scale will build a continuous habitat,  introduce a larger range of survival, provide food for fauna, enable water percolation, and reduce the urban heat island effect while contributing towards ecosystem services and climate change.
The layers of landscape evident from Gandhinagar are an integral strategy for the green filament. All species of this layered landscape will heavily contribute to hosting and sustaining various forms of life on streets and in the proposed bio-diverse pockets.
Following the planting strategy from the previous slide, several bio-retention strategies have been introduced for primary streets, R.O.W of 100 mt, 85 mt, and 65 mt. Bio-swales, green medians, and rain gardens act as permeable surfaces for water percolation while a continuous sidewalk and bicycle-lane network hosts the pedestrians and cyclists. 
The dimensions of swales will vary as per the street width from 3 mt long to 15 mt long spans while the width varies from 1 mt to 5 mt. All swales will have planting in layers, however, strategies are different depending on the context of the street such as:
Inner streets are the densest with wild and healthy species.
The Primary streets are lightly planted with opportunities for people to grow and engage with biodiversity,
And the city ring road is largely to contain a green buffer and have dense foliage varieties for pollution control.
The inner streets of all sectors are re-designed to become six continuous bio-corridors in the SE- NW direction, connecting the larger ecological ensembles in the periphery of the city. One part of this is demonstrated for Sector 4 where streets of 20mt, 13mt, and 10mt are redesigned to connect and host biodiversity. This is done through a continuous green network introduced on streets primarily with medians and bioswales. Besides the green cover, all streets have a proposed footpath and Identified green thickets on adjacent lots for conservation
All these strategies at different scales contribute to building a continuous habitat, introducing a larger range of survival, providing more food for fauna, enabling water percolation, reduce the urban heat island effect while also contributing towards ecosystem services and climate change.
The above drawing addresses the landscape character developed for the dense tertiary filament that brings and hosts biodiversity from the ecological ensembles from the city periphery. Stormwater management, bio-retention elements, incentives for residents to include green buffers, porous concrete roads, strategic placement for under-street services, and materiality of elements are the major proposals that together contribute towards a bio-diverse corridor.
This tertiary street network strongly discourages the movement of vehicular traffic, which they are only permitted during emergencies. The street however supports pedestrians and bicyclists, this will reduce the hustle making the tertiary streets to be more dense and calm for fauna to move and navigate their way into the city fabric. A continuous sidewalk runs while also opening up access to all public lands. The thicket marked on the adjacent plots will fall under preserved green cover.
The bio-corridors will provide a habitat for biodiversity but it also supports and accelerates endless ecosystem services for humans while also providing other social, cultural, environmental, and economic perks of being associated with streets and neighborhoods that have preserved and conserved the rich landscape of native flora and fauna. Some of these benefits are shown in a conceptual storyboard above.
Cultivating a dense landscape is not an overnight process, therefore the above policies and phasing strategies shall contribute towards a smooth run in achieving a bio-diverse corridor. Different conditions such as re-wilding the tree plantation areas, cultivating vacant plots, and re-development of streets as green corridors are addressed and a suitable phasing plan is proposed for each.  
Seasonal Changes on Street of R.O.W 10 mt: Autumn
The biodiversity that thrives in swales and other bio-retention methods will undergo seasonal changes that will be evident with a drastic change in street characters and fauna behavior including the relationship of humans with the ever-changing landscape. 
Seasonal Changes on Street of R.O.W 10 mt: Monsoon
With a change of season, biodiversity will thrive and take over streets, giving nesting and breeding habitats to a plethora of fauna while also providing opportunities for humans to engage with the landscape. The monsoon might also invite various migratory species beneficial for ecosystem services while maintaining and supporting a healthy food chain.  
Analyzing the above native species for a brief study revolving around the species’ maintenance, blooming season, water requirements, sunlight requirements, flowering color, foliage size, and other characteristics.
Envisioning the future once the bio-corridors are introduced…