Urban ecology is a relatively new field, but in the last 30 years, it has shed some light on the ways that green infrastructure, such as trees, plants, and gardens, can help to solve urban issues.
Prior to 1990, the few ecological studies conducted within cities were focused on isolated greenspaces. In the 1990s, there was a change from studying ecology within to studying the ecology within. was then seen as an ecosystem that was functioning throughout the city.
Urban ecology is a way to understand the benefits of green infrastructure and how it can improve urban sustainability and livability.
The leaves of trees and shrubs can lower the temperature in a city by up to 9 degrees Celsius. The roots of the trees allow water to penetrate the soil and infiltrate into the leaves, which reduces surface runoff. The foliage also reduces noise and traps particulate pollutants.
Plant-based solutions are important
This is evident in the United States, where cities have studied the relationship between urban planning and demographics. The lack of green space in neighborhoods with a majority of people of color has made these neighborhoods warmer and less livable than their adjacent whiter neighbors. The differences in vegetation cover are a major factor in racial and socio-economic disparities in well-being.
In most cities, the addition and maintenance of green infrastructure has become a central part of urban planning. It includes planting trees, restoring wetlands, and other forms of green Infrastructure such as Green Roofs. Edmonton is one of the cities that have implemented goat control programs.
Private gardens can be a significant part of the greenspace in a city and have a high level of functional diversity. (Karen Christensen-Dalsgaard), Author provided
The fact that most of the green space in cities is privately owned is a complicating factor. Gardening can account for between 16 and 40% of urban land and between 35 and 86 percent of total greenspace, depending on the city. The government has little control over these areas and leaves it to the individual to make the best decisions.
Gardening for the community
What you want to achieve will determine the best way to garden to provide ecosystem services and healthy habitats, but certain approaches are more effective than others.
Sealed surfaces like concrete or asphalt plague urban development. They are inhospitable for most organisms and increase surface runoff.
By removing sealed surfaces and replacing them with vegetation, you can improve biodiversity and flood mitigation. The amount of vegetation that modifies micro-climates varies depending on the plant composition and structural characteristics.
In a recent study, different types of low-height green infrastructure like lawns, meadows, and low shrubland were compared in Montreal. Infrared thermal imaging showed that surface temperatures were higher on plots with lower plant volumes. For example, lawns were warmer than flower meadows and shrubland.
