Greening the City of Colombo

VISION

To make the City of Colombo the greenest city in South Asia and contribute to the health and wellbeing of the community while increasing the urban green space within the city.

Executive Summary

The financial capital of Sri Lanka, the City of Colombo is the fastest growing city in Sri Lanka and as such the Colombo skyline is constantly changing with construction of many new office and residential buildings, expansion of roadways and new highways to/from the city of Colombo. 

Most expansions in urban areas take place without any proper planning that can cause damage to existing pockets of forests, landscapes and green areas in and around cities. The environmental impacts of this rapid urbanization include increased pollution, increasing heat due to expansion of roads/pavements, tall structures that block out light and wind, and the reduction of biodiversity in terms of fauna and flora. 

Urban trees can help to mitigate some of the negative impacts of unplanned and rapid urbanization, thus make cities more resilient to these changes. 

The Federation of Environmental Organizations (FEO) proposes a city wide Tree Planting Campaign in order to create an Urban Forest Strategy in both public and private lands in the greater Colombo area and this project will have a large number of stakeholders including the government, private sector and the residents of Colombo. 

We plan to kick start the program at the Borella Cemetery as it has a large land area available for planting. We plan to commence planting the first week of July 2020 with the seasonal rains. 

Benefits of “Green Areas” in Cities 

The benefits of urban green spaces span environmental, economic, cultural and political domains. These benefits are interrelated, with each cumulatively feeding into the creation of resilient and sustainable urban landscapes. Given the pressure on governments to plan for greater populations, increased urban density and climate change adaptation, there is a clear opportunity to communicate the importance and benefits of urban forests in creating resilient, sustainable cities that provide healthy and enjoyable places for people to live and work. 

Environmental Benefits: 

  • Provide shade and cool our cities: The addition of trees and other vegetation to the built environment provides the greatest benefit in mitigating the urban heat island effect. Through the process of transpiration and the provision of shade, trees help reduce day and nighttime temperatures, especially during the hotter months which also tend to be the driest. They shade streets and footpaths, and their leaves reflect more sunlight and absorb less heat than built materials, reducing the heat absorbed by the built environment. During transpiration, plants draw water from the soil and release moisture through their leaves into the air. Trees also help to reduce carbon emissions by helping to conserve energy. For example, the correct placement of trees around buildings can reduce the need for air conditioning by 30 percent thus reducing consumption of electricity. 
  • Reduce air pollution, air-borne particulates and greenhouse gas emissions: Vegetation ameliorates air pollution and reduces greenhouse gases. Through the process of photosynthesis trees remove carbon dioxide, nitrous oxides, sulphur dioxide, carbon monoxide and ozone from the atmosphere. As trees reduce temperatures, they help improve air quality through energy savings and reducing the emission of pollutants that are temperature dependent. Carbon dioxide is a greenhouse gas associated with trapping heat in the atmosphere and driving up global ambient temperatures and climate change, e­ffectiveness with which many trees sequester and store carbon is considered a key mitigation strategy for reducing levels of atmospheric carbon dioxide. Large trees are excellent filters for urban pollutants and fine particulates. They absorb pollutant gases (such as carbon monoxide, nitrogen oxides, ozone and sulpher oxides) and filter fine particulates such as dust, dirt or smoke out of the air by trapping them on leaves and bark. Studies have shown a mature tree can absorb up to 150 kg of CO2 per year.
  • Reduce storm water flows and nutrient loads: Tree canopies and root systems reduce storm water flows and nutrient loads that end up in our waterways. Tree canopies intercept and mitigate the impact of heavy rainfalls. Healthy tree roots help reduce the nitrogen, phosphorus and heavy metal content in storm water. 
  • Provide habitat and enhance levels of biodiversity: Healthy urban green spaces contribute to biodiversity and habitat provision. Urban forest pockets around the world have been shown to support a wide range of species, even endangered animals and other species of high conservation value. By planting and managing different age strata, biodiversity and wildlife habitat values can be enhanced. Trees play an important role in increasing urban biodiversity, providing plants and animals with a favorable habitat, provide food and protection. 

Community and Social Benefits 

  • Reducing sun exposure: The prevalence of skin cancer and other illnesses due to sun exposure have shown that protection from sunlight’s UV rays is vital. Shade alone can reduce overall exposure to UV radiation by up to 75%. Trees provide the best form of natural shade, with broad canopied trees being the most effective. 
  • Improving mental wellbeing: Access to, and views of, green spaces and trees have positive effect on people’s wellbeing. Research shows that living in close proximity of urban green spaces and having access to them, can improve physical and mental health, for example by decreasing high blood pressure and stress. This, in turn, contributes to the well-being of urban communities. 
  • Encouraging outdoor activity: Well-vegetated parks, gardens and streets encourage the use of open spaces, with health benefits such as reduced obesity and improved general physical and mental wellbeing. 
  • Reconnecting children with nature: By enticing children into ‘make believe worlds’ of computer games, electronic technology is contributing to inactivity and childhood obesity, leading to physical diseases like diabetes, coronary heart disease as well as psychological issues such as depression. Studies have shown that green spaces provide therapy to children, allow creativity of mind, encourage exploration and adventure, promote physical activity, build resilience and enhance experiential learning 
  • Reducing heat related illnesses: The shade provided by trees on hot summer days helps to reduce localized temperatures by up to 3 degrees Celsius. Evidence suggests that people in buildings with little or no surrounding vegetation are at higher risk of heat related morbidity 

Program Goals and Objectives 

To achieve this vision of a healthy and livable city, we need to create better urban environments for everyone. 

The five main goals are of this city wide tree planting project are: 

1. Increase canopy cover – provide shade, thereby reducing the temperature in certain parts of the city 

2. Increase urban ecology and biodiversity – increase tree diversity and provide a habitat for small mammals, birds and insects 

3. Improving vegetation health – as replacements for aging trees in the city 

4. Mitigate the urban heat island effect by bringing our inner-city temperatures down 

5. Reduction in Air Pollution 

The FEO proposes to initiate several long term City tree planting projects utilizing private and public lands within greater Colombo. Mostly indigenous species will be planted, however, selected exotics will also be selected based on specific requirements. 

We plan to start the program at the Borella and Jawatte cemeteries. The goal is to plant trees along the perimeter of the cemetery (where possible) with deep root trees so that they roots don’t disturb the surface. 

New Parking space at the Borella cemetery along Kitulwatte Road
Borella cemetery Cremation area

We also hope to interspace these trees with flowering plants and shrubs to encourage butterflies, bees and birds. The new parking space near the Borella crematoriums will also be planted with deep root shading trees interspaced with flowering plants. We have also identified areas to plant shrubs and flowering plants in-between graveyards and along walkways etc.

The following services will be provided by FEO

  1. Technical expertise in selecting the best plant species and sourcing such plants
  2. Planting including obtaining compost
  3. Providing a protective cage if required for the plant
  4. Overseeing the watering and maintenance the plants until they are established

Plants will be selected based on the following categories

  • Trees that provide shade – for roadsides and other areas
  • Trees that attract birds, butterflies and other beneficial pollinator species
  • Flowering and fruit trees
  • Specific indigenous trees to increase biodiversity

Methods/Implementation

The approval to plant at the Borella and Jawatte cemeteries is in the process of being acquired through the office of the Chief Medical Officer of the Colombo Municipal Council. Plant species and sizes will be decided based on the specific requirements at each of these sites.  Attention will be given to plant a diverse range of species of plants to for birds and butterflies in addition to providing shade. 

FEO would source suitable plants/saplings, provide the compost etc as required, carry out the planting and secure the plants (if necessary) with a protective cage around the plant if required. 

FEO will also oversee the watering and maintenance of the plants which will be carried out by the gardening staff at the cemetery.   

Estimated Costs PER PLANT for the First Year

The total cost of planting 1500 plants (500 plants for the butterfly gardens and 1000 plants inside the boundaries and along walkways etc), inclusive of maintenance and watering for the first year is estimated at Rs. 2,500,000/-.

How YOU can support

Like most non-profit organizations we would not be able to do our project without the generous support of sponsors. Corporate tree planting projects is a great way to reduce the carbon foot print and give back to the community while being socially responsible. 

We also welcome volunteers, especially young children, to share your time with us to help plant trees. 

We would be posting the tree planting project on our Facebook/Instagram pages so that you can see how and when you can get involved. Through your generous support, the community at large will recognize you or your company as being a green partner with FEO.

Sources:

https://www.melbourne.vic.gov.au/SiteCollectionDocuments/urban-forest-strategy.pdf

http://www.fao.org/zhc/detail-events/en/c/454543/

https://www.natureworkseverywhere.org/resources/sustainable-urban-design-toolkit/9/

https://data.worldbank.org/indicator/SP.URB.TOTL.in.zs

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