Causes of Plant Extinction in Urban Communities and Cities
written by: ciel s cantoria•edited by: Laurie Patsalides•updated: 5/27/2011
What are the causes of plant extinction in urban communities and cities? In order to find out, researchers compared the extinction rates for plants in rural and urban communities. Results show that Volatile Organic Compounds and poor water quality have driven plants to extinction in the cities.
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The Poor Quality of Air and Water in Urban Communities and Cities
In determining the causes of plant extinction in urban settings, the focus of our attention will once again be drawn to polluted air, poor water quality, contaminated soil and intense global radiation.
Currently, studies about plants are mostly the causes of their extinction and how humans can help them survive in polluted air, thrive in degraded soil and exist with acidified water. Researchers are concerned about the rates of plant extinction in urban environment, because the basic essentials by which plants could grow and stay alive, have deteriorated.
The following sections furnish information about each basic element and how they contribute to the causes of plant extinction.
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The Volatile Organic Compound Emissions in Urban and City Air
Think about the quality of air that plants breathe in. Plants need carbon dioxide and the current atmospheric air is said to be full of it. However, the air that plants and human take in also contain volatile organic compound (VOC) emissions and they combine with nitrogen oxide, of which 80% comprises atmospheric air.
Add the intense heat of solar radiation and the interaction between these three elements produce what scientist call as ground level ozone layer or O3. Ozone gas is good because it absorbs the harmful UV radiations of the sun and if it stays as the lower layer of the Earth’s stratosphere. However, studies have shown that it is capable of becoming bad if it's in the Earth’s troposphere, or near the ground and forms its own layer of O3. Bad ozone is urban smog and is found below 6 miles from where the good ozone begins.
Large concentrations of bad ozone are found in urban areas, especially in towns or cities where motorized vehicles are in multitudes and where the use of VOC products is most prevalent. VOC can be found in almost anything and almost everywhere, even in ordinary households. VOCs are found in the smallest bottle of nail polish, to detergents, fabric cleaners, paints, thinners, kerosene, fuel containers, automotive cleaners and paint strippers. Name it and almost every product contains volatile organic compound
Medical communities have shown that inhaled O3 or smog is capable of scarring lung linings. It has been pinpointed as the major cause of lung ailments like asthma, emphysema, bronchitis, etc. It is the largest contributing factor in reducing plant growth and has been proven to cause about $500 million in crop production losses each year.
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How Urban and City Dwellings Provide Plants with Water:
In urban areas where groundwater cannot be tapped, the supply of water is limited even to a point of being scarce. Factors such as population growth and the cost of water contribute largely to the availability or unavailability of water. Unlike in rural areas where water can be drawn from wells, springs or river, city water passes through pipes. The supply is also limited since there is a schedule to follow and water is available only every other day or at least three times a week.
Those who are into gardening or some form of vegetation make use of rainwater. Rather than provide the solution, sustaining the vegetation with rainwater can prove to be even more damaging to plant growth.
The sulphur dioxide and nitrogen oxide that rises in the atmosphere will interact with the rain or snow fall, thus increasing the levels of salinity and acidity in the quality of water.Rainwater particularly in urban areas has increased acidity levels compared to that in the rural areas.
The precipitation of air contains pollutants coming from motorized vehicles and industries that make use of fossil fuel. The larger demand for heat and electrical generation common to city life further aggravates air pollution. Even ambient air or that which comes from outside the city carry polluted air, albeit coming from other contaminated sources. .
The poor quality of water is also influenced by human waste water disposal, where groundwater reservoir in the city's outskirts are contaminated with mismanaged wastes coming from irresponsible business establishments including hospitals, medical and dental clinics, factories and industrial sites.
Water-run offs passing through city streets littered with wastes that leach or of heavy metals that interact with acid water and oil puddles. Run-offs pass through canals and are eventually carried to the mainstreams especially when flooding occurs.
These are the factors that degrade the quality of water in city and urban environment.
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The Quality of Plant Nutrients in Urban Vegetations
Plants get their nutrients from the soil, but soil can be found degraded in urban towns and cities. Air and water pollution precipitates and goes back to the ground as rain water or snow. The acidic rainwater seeps into the ground and will leave pollution residues as part of the soil’s nutrients.
Hotels, restaurants, malls, clinics, salons, spas and other businesses are required to maintain waste water treatment facilities. That way, waste water can be released without the dangers of contaminating water resources. However, some of the treated waste water will also form part of water that seeps to the ground used for vegetation in outlying areas.
Treated waste water contains minerals which the soil will absorb. Like humans, plants are also affected by excesses or having more than what is normally required. Phosphorus, as an example is needed by plant life but there are urban areas where excessive phosphorus content came to affect the quality of the soil..
As a result, the over supply of phosphorus in vegetations has caused rapid breakdown of oxygen that plants produce. Plant growth becomes affected as the supply of oxygen ceases, impairing their food production processes; hence, they slowly wither and die. As this conditions occur, the rate of extinction among plants in urban and city areas, hastens. .
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In an urban setting, it is not so much as the ability of the sun’s ultra violet rays to penetrate the Earth’s atmosphere that is harmful. It is more of the presence of Volatile Organic Compound emissions and the resulting ground level ozone that cause damages to both human and plant life. In fact, urban smog tends to block sunlight, which limits the amount received for photosynthesis.
Plants need air, water, nutrients and sunlight to grow, but like humans, plants also demand quality in order to live healthy and not just to thrive and survive.
Plants are driven to extinction in urban communities or cities because of too little water sustenance or because of water that contains too many harmful substances.
The rates of extinction in urban communities and cities increase because the quality of soil has been altered. An over-abundant supply of mineral creates an adverse effect in a plant’s food production cycle.
Actually, if we sum up all these factors, the main cause of plant extinction in any environment are the humans that interfere with the Earth's natural conditions.