Reforestation is one of important activities to be carried out conceptually in handling environmental crisis. Once the importance of that greening is a national program conducted throughout Indonesia.
Many facts show that no development is rarely built on agricultural land and open spaces. Whereas plants in the ecosystem role as the first producer that converts solar energy into potential energy for other creatures and turn CO2 into O2 in the process of photosynthesis. Therefore, by increasing greenery in urban areas means it can reduce the CO2 or other pollutants that contribute the greenhouse effect or climate disruption. In addition to the vegetation plays a role in the lives and health of the physical environment, also plays an aesthetic as well as mental health. Considering the important role of this vegetation, especially in urban areas to address the environmental crisis it is necessary for planning and planting of vegetation greening conceptually.
From the various observations and research, there is a tendency that the implementation of greening is not conceptual, in fact so impressed origin. Selecting plant species for reasons easy to obtain, cheap and fast growing.
Urban greening
Greening in the broad sense is all the power to restore, maintain and improve land conditions in order to produce and function optimally, both as watersheds or environmental protection. There are also saying that the greening of the city is an attempt to greening the city by carrying out the management of city parks, neighborhood parks, greenways and so forth. In this case the urban greening is an activity of filling the open space in urban areas.
In the process of photosynthesis of green plants take CO2 and release O2 C6H12O6 and much-needed role of living things. Therefore, the role of green plants is necessary to solicit the release of CO2 and O2 back into the air. In addition, various metabolic processes of green plants can provide various functions to the needs of living things that can improve environmental quality.
Each year the plants on this earth compound approximately 150,000 million tons of CO2 and 25,000 million tons of hydrogen by freeing 400 000 million tons of oxygen to the atmosphere, and produce 450 000 million tons of organic substances. Every hour one ha of green leaves absorbs 8 kg of CO2 is equivalent to the CO2 that human breath like this by approximately 200 people in the same time. Each tree planted by the air cooling capacity equal to the average five air conditioning (AC), which operated 20 hours continuously every day. Each 93 m2 of trees can absorb as much as 8 decibels noise, and every one hectare of trees able to neutralize the CO2 is removed 20 vehicles. (Zoer'aini Irwan Knopf, 1996).
Once the important role of plants on this earth in handling the crisis, especially in urban environments, it is very appropriate if the existence of plants to get serious attention in the implementation of urban greening as an element of the urban forest.
Greening role and function (1) As the lungs of the city. Plants as green element, the growth of acid producing substances (O2) that is necessary for living things to respiration, (2) As a regulatory environment (micro), the vegetation will cause local environmental air into cool, comfortable and fresh, (3) environmental Creator life (ecological), (4) balancing nature (adaphis) is the establishment of places of natural life for the animals that live in the vicinity; (5) Protection (protective), the physical condition of the natural surroundings (wind, sun, gases or dust -dust); (6) beauty (aesthetics), (7) Health (Hygiene), (8) Recreation and education (educational), (9) Social and economic policy.
As found by Eckbo (1956) that the selection of plant species for afforestation in order to grow well should be considered the terms of horticulture (ecological) and physical conditions. Horticultural Terms of responses and tolerance to temperature, water requirements, needs and tolerance for sunlight, soil needs, pests and diseases, as well as other physical conditions are greening purposes, cultivation requirements, the form header, color, flavor.
