The network of multi-functional green spaces and features that make up our green infrastructure (from parks, playing fields and woodlands, to gardens, street trees and sustainable drainage systems) can provide important environmental and quality of life benefits.[1]
Urbanisation, intensive agriculture and climate change are some of the main causes of the ongoing rates of biodiversity loss, and it is increasingly recognised that the climate and biodiversity crises are interconnected; the American entomologist, Prof. Douglas Tallamy, suggests four things that every landscape needs to do from an ecological perspective:
- Manage the watershed in which it lies
- Support pollinators
- Support a viable food web
- Sequester carbon.[2]
Tallamy focuses on the idea of keystone plants that, just like other keystone species, are the ones that have a particularly important role in the local ecosystem. One example of a keystone plant is the oak tree, and others include the native plants that support the highest numbers of pollinators or caterpillars, which in turn sustain the wider food web.[3]
Many public and private urban green spaces won’t have space for an oak, but a wide variety of other plants fulfil similar functions depending on the space and conditions – a case of ‘right plant, right place’ – an approach to gardening that was championed from the 1960s by Beth Chatto in order to identify which plants will survive, thrive and provide other important benefits. Variety is key, but equally important in new developments is good design, maintenance and stewardship. The RHS’s Plants for Purpose work intends to support such efforts through the identification of plant cultivars that are best suited for specific aims such as pollination, pollution capture, water management, thermoregulation, and carbon capture.
Not all communities have supported the growing interest in functional, wildlife and pollinator-friendly planting in recent years, and in this respect, Tallamy considers the retention of some areas of mown grass to be a “cue for care”; a practical option as well as a visual signal that you understand the prevailing norms, and that your green space is being actively maintained. For similar reasons, others have put up signage when creating areas of wildflower meadow, which might be useful for individuals, local authorities, and other stewards who face local resistance to change.
Managing water, supporting pollinators and a viable food web, and sequestering carbon are not actions that are limited to large-scale landscapes; these are all things that individual gardeners, community groups and official stewards can undertake to cumulatively enhance a diverse network of urban gardens and other green spaces.
This idea is promoted in the US through Tallamy’s Homegrown National Park, and in the UK through the work of conservation and wildlife charities, and projects such as the Weald to Waves gardens & greenspace initiative in Sussex, where village greens, playgrounds, verges and footpaths, allotments, churchyards, woodland and many other spaces could make up part of a larger nature recovery corridor. This initiative sits alongside work with farmers and landowners in the same area to support an ecological corridor running from the High Weald to the Sussex coast (Fig. 1) that aims to connect landscapes to ‘boost biodiversity, capture carbon, enhance food production and enrich our rural economy’.[4]
Stepping stones of habitat allow movement across fragmented landscapes, and the more connected and complementary these are, the greater the potential for effective, multi-scale outcomes. Focusing on a mosaic of habitat zones within an urban environment and its rural hinterland has been identified as one of the most effective ways of achieving this.[5]
The use of these different types of green corridors is an example of a nature-based solution that – when well-informed, designed and governed – can provide context-specific contributions to the mitigation and adaptation of climate change.
This type of forward-thinking spatial planning was feared to have become extinct in the UK, yet examples do exist: Sylvia Crowe’s contribution to the masterplan of Harlow (one of the post-war New Towns) resulted in the retention of the existing site topography, with houses built in neighbourhoods of high ground between valleys of ‘green wedges’ that linked to the surrounding countryside.[6]
A better-known example from Germany is Stuttgart’s ‘green fingers’, which act as ventilation corridors to draw cool air down from the surrounding mountains into the city (Fig 2), and are informed by climate maps that shape the city’s planning to address overheating and poor air quality.[7]
At the site level, a more recent example is the Kidbrooke Village development on the old Ferrier estate in London, where a green corridor links nature reserves to the north with Sutcliffe Park in the south, expands wetland and reduces flooding risk through sustainable urban drainage systems. This is one of a number of sites where housing developers have worked with wildlife trusts to create a place with multi-functional green spaces that provide environmental benefits, improve quality of life, and make use of many of the types of native wild plants promoted by Tallamy and others who are working at the forefront of ecologically focused landscapes.
[1] TCPA (no date) What is Green Infrastructure? https://www.tcpa.org.uk/what-is-green-infrastructure/
[2] NYT (2025) The Four Ecologically Crucial Things You Should Do in Your Garden: https://www.nytimes.com/2025/04/09/realestate/ecological-gardening.html
[3] Ibid
[4] Weald to Waves (no date) Creating a corridor for nature: https://www.wealdtowaves.co.uk/
[5] Goddard, Mark A et al. (2010) Scaling up from gardens: biodiversity conservation in urban environments, 25 (2), 90-98: https://www.sciencedirect.com/science/article/pii/S0169534709002468#bib67
[6] Bradbury, M. (2025) How the postwar New Towns can help us in building resilience to flooding: https://www.theplanner.co.uk/2025/06/03/how-postwar-new-towns-can-help-us-building-resilience-flooding
[7] Haas, M. (2022) Ventilation Corridors’ Funnel Cool Mountain Air Into Steamy Stuttgart: https://reasonstobecheerful.world/stuttgart-ventilation-corridors-green-cool-air/