The “green” economy is an economy aimed at preserving the well-being of society, through the efficient use of natural resources. It also ensures the return of end-use products to the production cycle. This may be called “full life-cycle environmental stewardship” or “cradle to grave stewardship.”
First of all, the “green” economy is aimed at economical consumption of those resources that are currently subject to depletion, and at the rational use of inexhaustible resources. According to experts, the development of a “green” economy will avoid the environmental crises occurring in many post-industrial countries.
Just as forests are the “lung of the planet,” urban woodland provides the “green lungs” of cities. But how exactly are the trees the lungs of the city? How do they absorb pollution and what becomes of it? The “Green City” project now underway in the Russian industrial city of Ekaterinburg provides some answers. Its industry and vehicles pollute as in every city, and that is why Ekat- erinburg needs its trees as urban lungs.
The leaves of trees are small laboratories. Under the influence of sunlight and heat, they convert the molecules of carbon dioxide into organic matter and oxygen. In turn, the organic matter is processed into the material from which the plant is built, e.g. trunk, roots, etc. Oxygen is released from the leaves into the air.
Moreover, trees clean the air by absorbing contaminants. The surface of the leaves can capture particles in the air and remove them, at least temporarily. Microscopic particles in the air can enter human lungs and lead to serious health problems or tissue irritation. It is therefore very important to reduce their concentration, and this is what trees do.
Trees can remove both gaseous pollutants (sulfur dioxide, nitrogen dioxide and carbon monoxide) and also solid dust particles. Cleansing mainly occurs with the help of so-called “stomata.” These are small openings or pores on the leaves through which water evaporates and gas is exchanged with the environment. Dust particles do not all fall to the ground, but settle on the leaves of trees. Under their canopy the air is much cleaner than over the crowns. However, not all trees can tolerate dusty and dirty conditions. Ash, linden, and spruce suffer very badly. Dust and gases can lead to blockage of stomata. Oak, poplar, and maple are more resistant to the harmful effects of the polluted atmosphere.
To be under the canopy of trees is more comfortable for people and not just because of the shade. A micro-climate exists under trees. Anyone who has walked along a shaded path has experienced it. Transpiration — the process of evaporation of water by a plant that occurs mainly through leaves — moistens the air, as does the presence on the ground of humid fallen leaves. Trees suck a lot of water out of the soil, which then evaporates through the leaves. Moreover, the wind is less under trees. All these factors together influence the temperature of the air, which is usually about 2 degrees Celsius lower under the trees than out in the sun. Many pollutants, especially those of organic origin, are released from factories more actively with increasing temperature. In short, lower temperatures, less pollution, and higher humidity are good for human health.
Nitrogen oxides (NOx) are produced by internal combustion engines. They accumulate at ground level and up five stories above the ground. The air intake for tall buildings should therefore be no lower than the fifth floor (counting the ground floor as floor one).
As the environmental situation is deteriorating, woodland’s sanitary-and-hygienic, health-improving, aesthetic, and other functions are becoming key issues. The goal of Ekaterinburg’s Green City project is to preserve and develop the city’s green endowment and to enhance the environment for the quality of life and the recreation of citizens.
In preparation for this project, the Ekaterinburg City Council mandated calling upon landscape-ecological analysis. This is relatively new science, dating from the mid-1980s. It is, according to the International Association of Landscape Ecology, “the inter-disciplinary study of spatial variation in landscapes at a variety of scales. It includes the biophysical and societal causes and consequences of landscape heterogeneity” (i.e. the diversity of plants).
The original project brief from the City Council also insisted on “systematic methodology.” This process is to be used to determine the viability of a project or procedure based on the experiential application of clearly defined and repeatable steps and an evaluation of the outcomes. The goal of a systematic approach is to identify the most efficient means to generate consistent, optimum results. For the Green City project, this means taking a scientific approach to planting: examining the social and biophysical results of plantings, and continuing or modifying methods in the light of the results.
The application of a systematic methodology implies covering many dimensions. Development and renovation, the preservation of the city’s recreational system, and improvement of the city’s environment are seen as a single green framework. All types of green space must be maintained in an optimal state, and enhanced with outdoor wooden furniture and sculpture.
The implementation of activities under this project will significantly improve the sustainability of urban woodland. These valuable areas are vulnerable to negative environmental factors, notably trampling, trash, and the pollution of soil, water, and air. Remedies include more trees, their maintenance by pruning, removal of fallen branches, and introducing a greater variety of plants. This requires a dedicated professional team, assisted by volunteers. Their work is leading to a two-fold increase in the area of green space per inhabitant, which will ultimately improve the living environment of the population of other large industrialized conurbations and their associated urban sprawl.
The green plants and woodland of Ekaterinburg are an integral part of its urban development and ecological framework. They are part of the life support system of the city. They are a most essential environmental factor responsible for ensuring the comfort and quality of the human habitat, as well as a necessary and important element of the urban landscape.
City vegetation performs various useful functions such as health and hygiene, soil- and water-protection, erosion prevention and climate regulation. It also is an important social stabilizing factor, providing daily human needs for short-term relaxation, stress and conflict relief within the urban environment, thus improving conditions of the human habitat. It contributes to the sustainable development of the city, which requires healthy people and a healthy environment to sustain immigration, business development, and productivity.