FAQ: Why do cities need green zones, and Gulf needs mangroves and wetlands

    30 Jun 2021

    Western governments are so concerned about city parks conservation that they bring it into international law. This is not surprising: we’ve already written why parks save the inhabitants of cities around the world millions of dollars every year. You may check the explanation of what ecosystem services are here.

    There is Green Cities Declaration, signed on the occasion of World Environment Day, held within the framework of the United Nations Environmental Program on June 5, 2005, in San Francisco, California.

    According to it, cities undertake to create the following conditions in the city:

    ·        at a distance of 1.5 km from each house must be a park;

    ·        half of all sidewalks of the city must be under the shade of trees.

    The section “Urban Nature” of the agreement contains the following three actions:

    ·        to ensure the availability of a public park or open space for recreation at a distance of half a kilometer for each permanent city resident by early 2015;

    ·        to make an inventory of the existing level of shadow coverage in the city; and, then, set a goal based on environmental and public discussions on additional plantings to maintain a level of shade coverage of at least 50% of the total pavement area suitable for tree landscaping;

    ·        introduce legislation that protects critical residential corridors and other key habitat characteristics (such as water quality, edible plants, wildlife habitats, use of local species, etc.) from undeveloped development.

    Dirty water and air are the main causes of diseases of urban residents. So these resources should be cleaned by greenery – parks, squares, and forests.

    If the uncontrolled removal of green areas is not stopped, the environment in cities and villages can become life-threatening. After all, trees perform ecological functions. They absorb about 60% of all emissions from transport vehicles. Trees and parks reduce air temperature, increase humidity, and reduce noise levels. That is, they actually make the microclimate more favorable, softer for the life of the population.

    In the West, there are examples: even if there is a strict need to place a building or road on a certain site, where there are green areas, trees are not cut down. They are simply transplanted to another place, where they continue to grow. To do this, cities use even specially created huge machines for transplanting trees, and in no case, such trees are cut down.

    According to sources from the United States, scientists have calculated how much the green zone costs economically. That is, we can operate with environmental indicators. If something has a certain price, it is more taken into account in the decision-making process.

    The Americans estimate that if we take into account the full range of environmental services: water purification, air purification, noise reduction, carbon sequestration, biodiversity conservation, and overall landscape function, one hectare of greenery costs (saves) $560,000 a year.

    If we move our view from the relatively cold Europe and the United States to the Gulf countries, the preservation of mangroves is relevant here. These are woody plants that inhabit the intertidal zones of tropical and subtropical coasts all around the world.

    They are highly recognizable from their visible root systems which can give them the strange impression of being planted upside-down. This unique appearance is the result of adaptations developed to survive in harsh environments: e.g., high temperatures, high salinity, and intense UV exposure.

    Mangroves are able to accumulate and excrete salt in their roots and leaves in order to exist in marine environments. They are also viviparous, meaning that their seeds begin germinating before they fall from the parent tree, which increases the chance of successful rooting in tidal environments.

    The dominant species in the Arabian Gulf region is the gray mangrove (Avicennia marina).

    Dr. Guillermo Friis, a postdoctoral associate in the marine biology lab from New York University Abu Dhabi, said the ecological conditions in which mangroves thrive are particularly extreme in the region, both in terms of salinity and temperature variability. Let’s quote his explanation for the National News:

    “Mangroves are the only evergreen forest in the Gulf and their unique ability to survive in this habitat makes them what we know as an “ecosystem engineer”, providing shelter and foraging to many marine and terrestrial species,” he said. “In addition, different biological, chemical and physical processes connect mangroves to adjacent ecosystems including coral reefs or seagrass meadows.”

    That is why when we talk about Europe, we always mention the conservation of virgin forests and the last steppes. And when we talk about the Gulf countries – we emphasize the conservation of wetlands (e.g., in Iraq) and mangrove forests. Let’s talk about mangroves more broadly in the next articles.

    You may read our explanation of what the forest ecosystem is here.  

    Why some forests on the map are not actually forests? Take a look here.

    Leave a Reply

    Your email address will not be published.