Forests are a very essential part of life on Earth. They always fulfil the demands of human beings by providing shadow, shelter, refreshment including clean air and water. In the present world of growing global population the demand of forest products is on the increase; so the forests are at big risks of degradation.
To raise awareness of the importance of all types of forests, United Nations International Day of Forests is celebrated on March 21. The theme of the day this year is “Ecosystem Management”.
Cities across the world, due to the rapid growth of their populations and large-scale developmental investments, are vulnerable to the impacts of climate change. A major challenge for the cities is to maintain environmental sustainability. Sustainable forest management significantly contributes to mitigation of the harmful effects on the environment. In general, the term mitigation refers to all activities aimed at reducing greenhouse gas emissions and removal of CO2 from the atmosphere. Actions needed in the forest sector include expanding forests through afforestation, reducing deforestation and reversing the loss of forest cover, providing an enabling environment for investments and market access to sustainable forest-based products.
Forests cover 30 per cent of the Earth’s land surface providing a critical ecosystem. Forests help alleviate land degradation and desertification. Deforestation and desertification adversely affect agricultural productivity, health of humans and livestock and economic activities such as ecotourism. According to a UNEP report, 13 million hectares of the world’s forests are converted into other land uses every year. India has lost 367 sqkm of forest cover in the past two years as per the Forest Survey of India (FSI).
Forests have been a source of food, water, fibre and livelihoods. They are also central to combating climate change. Climate change is the greatest global threat as it can cause great damage to water and land resources, ecosystem, food security and health. Forest loss enhances the loss of the inhabitant animal species. Deforestation leads to the global warming. Desertification and the associated loss of vegetation cause biodiversity loss and contributes to climate change.
What is needed is an environmentally appropriate, socially beneficial, and economically viable management of forests for present and future generations. This contributes to food security, poverty alleviation, economic development and sustainable land use in the wider context of sustainable development. Forests and climate change are inherently linked. As greenhouse gases build up in the atmosphere, they trap heat. The increased heat leads to changes in climate patterns. Managing forests to help them retain and increase their carbon storage potential can maximise their ability to mitigate climate change.
A sustainable urban forest management is important to sustain the numerous values associated with urban trees. These values are threatened by the advent of climate change. The urban forest can be defined as the trees of the city. Urban forests differ from hinterland forests in several ways. Firstly, urban forests have a diverse structure. Urban trees can be found in stands, in a park, arranged in lines along streets or as single trees and be close to infrastructure or people. They can be remnants of native forests or be deliberately grown. The interactions between climate change and urban forests include three main elements –urban forest contributions, urban forest vulnerability and the impacts of climate change on urban forests.
Urban trees help regulate the urban microclimate, augmenting or minimising climatic change. This occurs either by reducing albedo and providing shade and cover or by regulating the hydrological regime of cities that affects the urban microclimate. Heat from the earth is trapped in the atmosphere due to high levels of carbon dioxide and other heat-trapping gases that prohibit it from releasing the heat into space. This creates a phenomenon known as the “greenhouse effect.” Therefore, trees help remove CO2 from the atmosphere during photosynthesis and return oxygen back into the atmosphere as a by-product. Trees act as carbon sinks, alleviating the greenhouse effect. Trees also reduce the greenhouse effect by shading houses and office buildings. This reduces the need for air-conditioning by up to 30 per cent which in turn reduces the amount of fossil fuels burnt to produce electricity.
In the warmer months of the year, urban areas realise lower air temperatures when trees are strategically planted along streets and near buildings. Trees also help with energy costs in the winter by blocking cold winds thereby reducing the strain on heating units. These energy savings can reduce the demand for power production by utility plants, which also reduce the amount of air pollutants produced by the power plants.
City “climate action plans” often incorporate urban forestry into climate change mitigation and adaption strategies, recognising that healthy trees and forests can strengthen a community’s ability to withstand climate-related threats. An active urban forest management for climate change strengthens community resilience to climate change impacts.
Urban forests should be included in the city planning process and incorporated successfully into modern, high-density towns and cities.
(Dr Mayarani Praharaj works in the Department of Architecture, College of Engineering and Technology, Bhubaneswar)