Sunday, January 25, 2009
Benefits of Trees
Most trees and shrubs in cities or communities are planted to provide beauty or shade. These are two excellent reasons for their use. Woody plants also serve many other purposes, and it often is helpful to consider these other functions when selecting a tree or shrub for the landscape. The benefits of trees can be grouped into social, communal, environmental, and economic categories.
Social Benefits
We like trees around us because they make life more pleasant. Most of us respond to the presence of trees beyond simply observing their beauty. We feel serene, peaceful, restful, and tranquil in a grove of trees. We are “at home” there. Hospital patients have been shown to recover from surgery more quickly when their hospital room offered a view of trees. The strong ties between people and trees are most evident in the resistance of community residents to removing trees to widen streets. Or we note the heroic efforts of individuals and organizations to save particularly large or historic trees in a community.
The stature, strength, and endurance of trees give them a cathedral-like quality. Because of their potential for long life, trees frequently are planted as living memorials. We often become personally attached to trees that we or those we love have planted.
The stature, strength, and endurance of trees give them a cathedral-like quality. Because of their potential for long life, trees frequently are planted as living memorials. We often become personally attached to trees that we or those we love have planted.
Communal Benefits
Even though trees may be private property, their size often makes them part of the community as well. Because trees occupy considerable space, planning is required if both you and your neighbors are to benefit. With proper selection and maintenance, trees can enhance and function on one property without infringing on the rights and privileges of neighbors.
City trees often serve several architectural and engineering functions. They provide privacy, emphasize views, or screen out objectionable views. They reduce glare and reflection. They direct pedestrian traffic. They provide background to and soften, complement, or enhance architecture.
City trees often serve several architectural and engineering functions. They provide privacy, emphasize views, or screen out objectionable views. They reduce glare and reflection. They direct pedestrian traffic. They provide background to and soften, complement, or enhance architecture.
Environmental Benefits
Trees alter the environment in which we live by moderating climate, improving air quality, conserving water, and harboring wildlife. Climate control is obtained by moderating the effects of sun, wind, and rain. Radiant energy from the sun is absorbed or deflected by leaves on deciduous trees in the summer and is only filtered by branches of deciduous trees in winter. We are cooler when we stand in the shade of trees and are not exposed to direct sunlight. In winter, we value the sun’s radiant energy. Therefore, we should plant only small or deciduous trees on the south side of homes.
Wind speed and direction can be affected by trees. The more compact the foliage on the tree or group of trees, the greater the influence of the windbreak. The downward fall of rain, sleet, and hail is initially absorbed or deflected by trees, which provides some protection for people, pets, and buildings. Trees intercept water, store some of it, and reduce storm runoff and the possibility of flooding.
Dew and frost are less common under trees because less radiant energy is released from the soil in those areas at night.
Temperature in the vicinity of trees is cooler than that away from trees. The larger the tree, the greater the cooling. By using trees in the cities, we are able to moderate the heat-island effect caused by pavement and buildings in commercial areas.
Air quality can be improved through the use of trees, shrubs, and turf. Leaves filter the air we breathe by removing dust and other particulates. Rain then washes the pollutants to the ground. Leaves absorb carbon dioxide from the air to form carbohydrates that are used in the plant’s structure and function. In this process, leaves also absorb other air pollutants—such as ozone, carbon monoxide, and sulfur dioxide—and give off oxygen.
By planting trees and shrubs, we return to a more natural, less artificial environment. Birds and other wildlife are attracted to the area. The natural cycles of plant growth, reproduction, and decomposition are again present, both above and below ground. Natural harmony is restored to the urban environment.
Wind speed and direction can be affected by trees. The more compact the foliage on the tree or group of trees, the greater the influence of the windbreak. The downward fall of rain, sleet, and hail is initially absorbed or deflected by trees, which provides some protection for people, pets, and buildings. Trees intercept water, store some of it, and reduce storm runoff and the possibility of flooding.
Dew and frost are less common under trees because less radiant energy is released from the soil in those areas at night.
Temperature in the vicinity of trees is cooler than that away from trees. The larger the tree, the greater the cooling. By using trees in the cities, we are able to moderate the heat-island effect caused by pavement and buildings in commercial areas.
Air quality can be improved through the use of trees, shrubs, and turf. Leaves filter the air we breathe by removing dust and other particulates. Rain then washes the pollutants to the ground. Leaves absorb carbon dioxide from the air to form carbohydrates that are used in the plant’s structure and function. In this process, leaves also absorb other air pollutants—such as ozone, carbon monoxide, and sulfur dioxide—and give off oxygen.
By planting trees and shrubs, we return to a more natural, less artificial environment. Birds and other wildlife are attracted to the area. The natural cycles of plant growth, reproduction, and decomposition are again present, both above and below ground. Natural harmony is restored to the urban environment.
Economic Benefits
Individual trees and shrubs have value, but the variability of species, size, condition, and function makes determining their economic value difficult. The economic benefits of trees can be both direct and indirect. Direct economic benefits are usually associated with energy costs. Air-conditioning costs are lower in a tree-shaded home. Heating costs are reduced when a home has a windbreak. Trees increase in value from the time they are planted until they mature. Trees are a wise investment of funds because landscaped homes are more valuable than nonlandscaped homes. The savings in energy costs and the increase in property value directly benefit each home owner.
The indirect economic benefits of trees are even greater. These benefits are available to the community or region. Lowered electricity bills are paid by customers when power companies are able to use less water in their cooling towers, build fewer new facilities to meet peak demands, use reduced amounts of fossil fuel in their furnaces, and use fewer measures to control air pollution. Communities also can save money if fewer facilities must be built to control storm water in the region. To the individual, these savings are small, but to the community, reductions in these expenses are often in the thousands of dollars.
Benefits of Trees
Trees provide numerous aesthetic and economic benefits but also incur some costs. You need to be aware that an investment is required for your trees to provide the benefits that you desire. The biggest cost of trees and shrubs occurs when they are purchased and planted. Initial care almost always includes some watering. Leaf, branch, and whole tree removal and disposal can be expensive.
To function well in the landscape, trees require maintenance. Much can be done by the informed home owner. Corrective pruning and mulching gives trees a good start. Shade trees, however, quickly grow to a size that may require the services of a professional arborist. Arborists have the knowledge and equipment needed to prune, spray, fertilize, and otherwise maintain a large tree. Your garden center owner, university extension agent, community forester, or consulting arborist can answer questions about tree maintenance, suggest treatments, or recommend qualified arborists.
To function well in the landscape, trees require maintenance. Much can be done by the informed home owner. Corrective pruning and mulching gives trees a good start. Shade trees, however, quickly grow to a size that may require the services of a professional arborist. Arborists have the knowledge and equipment needed to prune, spray, fertilize, and otherwise maintain a large tree. Your garden center owner, university extension agent, community forester, or consulting arborist can answer questions about tree maintenance, suggest treatments, or recommend qualified arborists.
Monday, January 19, 2009
PLASTIC BAGS ARE SACKING OUR ENVIRONMENT
They are ugly, bad for the environment and potential animal killers, but we love them all the same. Each year billions of plastic bags are used by shoppers to carry home goods. But their utility and popularity could prove to be their downfall.
Many of us can still remember a visit to the supermarket where a young store attendant would pack the groceries into a large brown paper bag. That all changed when plastic bags began appearing in the shops in the 1970s.At first, they were considered a gift from God: they were sturdy, cheap to produce and more convenient for carrying items. Today, almost 30 years on, hundreds of billions are produced each year worldwide. Many end up hanging from trees, clogging drains and are accidentally consumed by land and sea animals. In the European Union alone, 5-10 million tonnes of plastic waste ends up in landfills or is incinerated. Several nations around the world, including Australia, Bangladesh, South Africa, Taiwan and Ireland, have taken the radical step of taxing plastic bags to discourage their use, according to a National Geographic report.In March 2002, Ireland introduced a 15 cent tax on each plastic bag sold. This resulted in a 95% cut in their use. An official at the Friends of the Irish Environment in County Cork has hailed the tax as an “extraordinary success” in reducing plastic bag consumption in the country. The majority of Irish shoppers now carry around reusable bags, he confirms.Kicking the plastic habitSimilar approaches are being considered in parts of England and by US authorities, the report continues. But concerns have been raised about large job losses in the plastic bag industry, as well as potential deterioration of the environment if the alternative becomes paper bag use. According to the American Plastics Council, producing paper bags is actually more expensive, uses more energy and landfill space and potentially causes more environmental pollution than plastic bags.To successfully implement a system of levies on plastic bags, it would need to be backed up with a campaign to encourage sensible use of alternatives, such as reusable shopping bags. Those stores and consumers continuing to use plastic bags could be persuaded to recycle or reuse them instead of simply dumping them. “The [plastics] industry works with its US retail customers to encourage recycling of plastic bags, which are in high demand from companies… for use in [for example] building materials,” a spokesperson from the Council is quoted as saying.The European Union’s Sixth Framework Programme for research has set aside over €2.1 billion to tackle the challenges associated with ‘Sustainable development, global change and ecosystems’. Past EU-funded research projects have looked into the areas of bioplastics, biorecycling and ecological impacts of non-biodegradable materials, to name a few.
Many of us can still remember a visit to the supermarket where a young store attendant would pack the groceries into a large brown paper bag. That all changed when plastic bags began appearing in the shops in the 1970s.At first, they were considered a gift from God: they were sturdy, cheap to produce and more convenient for carrying items. Today, almost 30 years on, hundreds of billions are produced each year worldwide. Many end up hanging from trees, clogging drains and are accidentally consumed by land and sea animals. In the European Union alone, 5-10 million tonnes of plastic waste ends up in landfills or is incinerated. Several nations around the world, including Australia, Bangladesh, South Africa, Taiwan and Ireland, have taken the radical step of taxing plastic bags to discourage their use, according to a National Geographic report.In March 2002, Ireland introduced a 15 cent tax on each plastic bag sold. This resulted in a 95% cut in their use. An official at the Friends of the Irish Environment in County Cork has hailed the tax as an “extraordinary success” in reducing plastic bag consumption in the country. The majority of Irish shoppers now carry around reusable bags, he confirms.Kicking the plastic habitSimilar approaches are being considered in parts of England and by US authorities, the report continues. But concerns have been raised about large job losses in the plastic bag industry, as well as potential deterioration of the environment if the alternative becomes paper bag use. According to the American Plastics Council, producing paper bags is actually more expensive, uses more energy and landfill space and potentially causes more environmental pollution than plastic bags.To successfully implement a system of levies on plastic bags, it would need to be backed up with a campaign to encourage sensible use of alternatives, such as reusable shopping bags. Those stores and consumers continuing to use plastic bags could be persuaded to recycle or reuse them instead of simply dumping them. “The [plastics] industry works with its US retail customers to encourage recycling of plastic bags, which are in high demand from companies… for use in [for example] building materials,” a spokesperson from the Council is quoted as saying.The European Union’s Sixth Framework Programme for research has set aside over €2.1 billion to tackle the challenges associated with ‘Sustainable development, global change and ecosystems’. Past EU-funded research projects have looked into the areas of bioplastics, biorecycling and ecological impacts of non-biodegradable materials, to name a few.
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