Ecological Services
Vegetation can deliver a range of important ecological
services and later in this guide we highlight examples of
how this can be achieved:
- Carbon sink – Trees have a significant capacity to absorb carbon dioxide. 1 hectare of woodland can absorb emissions equivalent to 100 family cars.
- Pollution control – Vegetation has a significant capacity to attenuate noise and filter air pollution from motor vehicles. Street trees can remove sulphur dioxide and reduce particulates by up to 75%. Noise attenuation can be as much as 30 dB per 100 metres. Wetland ecosystems are also effective in filtering polluted run-off and sewage.
- Air conditioning – In urban areas the heat island effect can increase temperatures relative to open countryside by up to 5 degrees celcius. Vegetation provides natural air conditioning. A single large tree can be equivalent to five room air conditioners and will supply enough oxygen for ten people.
- Microclimate control – Vegetation can improve local microclimate conditions by providing shade in summer. It can also reduce wind effects created by streets and wind loads on buildings, potentially reducing heating requirements by up to 25%.
- Flood prevention – Vegetation can reduce excessive run-off and increase rainfall capture. This reduces the risk of flooding in low lying areas and can also recharge soil moisture and groundwater.
There is a strong case for biodiversity to be designed into
new developments to offset climate change effects, thereby improving their liveability.
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