Effects of Acid Rain on Plants
Investigating Long Term Acidic Pollution’s Damage to Vegetation
Jan 30, 2009
Acid rain is prevalent in this United States (US) and Canada. Acid rain is caused by burning fossil fuels such as coal and gasoline, and from natural sources like volcano eruptions and decaying vegetation. These primary sources of acid rain release sulfur dioxide or nitrogen oxide into the air when burned or released naturally. This results in the earth’s atmosphere containing large amounts of sulfuric and nitric acid.
When rain, snow, hail, sleet, or fog reaches the ground in an atmosphere polluted with sulfuric and nitric acid, plants are damaged. The damage caused by acid rain is not limited to plants, animals die and stone buildings are damaged. Acid rain is even suspected of causing health issues in humans.
Plants are damaged because nutrients are washed away and toxic metals enter the plants. Many lakes and ponds in the northeastern US and eastern Canada have few or no fish due to effects of large concentrations of acid in the water, a result of acid rain removing nutrients that fish need to survive. Acid rain affects the northeastern US and eastern Canada the most because of prevailing winds, which move from west to east.
Investigation of Acid Rain Effects on Plants
In this scientific inquiry investigation, students will observe the direct effects of acid rain on plant growth. Non-acidic water is used to water control plants, while acidic water is used to water experimental plants.
Materials (per group):
- One large container for storing vinegar/water mixture
- Four large beakers or four jars with ML markings on the outside
- White vinegar
- Distilled water
- pH test strips 3.0-5.0 range and 6.0-8.0 range
- Baking soda
- Stirring stick
- Teaspoon
- Two cuttings of a philodendron plant (one leaf and small amount of stem)
- Two cuttings a begonia or coleus plant (one leaf and small amount of stem)
Procedures:
- Pour one teaspoon of vinegar into 2 cups of distilled water, stir well, and the check the pH. The pH should be about 4.0 (typical acid rain pH). If the mixture is lower than 4.0 (too acidic) then add a small amount of baking soda (base) and measure the pH again. If above 4.0 then add a drop or two of vinegar and test the pH again. Keep repeating until the vinegar/water mixture has a pH of 4.0.
- Measure the pH of the distilled water, if lower than 7.0 add some baking soda and if above 7.0 add a few of drops of vinegar until the pH of 7.0 is obtained. Keep repeating the process as necessary to ensure the distilled water has a pH of 7.0.
- Label the four beakers: water philodendron, acid philodendron, water begonia (or coleus), and acid begonia (or coleus).
- Fill the beakers labeled water philodendron and water begonia half full of distilled water.
- Fill the beakers labeled acid philodendron and acid begonia half full of vinegar/water mixture.
- Place one philodendron cutting in each philodendron labeled beaker, covering the stem and part of leaf.
- Place one begonia cutting in each begonia labeled beaker, covering the stem and part of leaf.
- Record your observations use writing in science as a guide, along with a taking a picture with a digital camera.
- Place all four beakers where they will get some sun.
- Every two days check the placement of the plant cuttings and add distilled water or vinegar/water mixture as necessary.
- After one week record your data and observations, along with taking pictures.
- At the end of week two record your data, observations, and take pictures.
- Prepare a presentation using Power Point, iWorks, or similar program to present your group's data, findings, and conclusions.
Student Questions:
- Which plant grew the most and the least?
- What do you will think will happen to plants and trees if acid rain continues?
Use 20 Questions to Ask Students in Science Projects as a guide for additional questions.
Long Term Effects of Acid Rain
Acid rain continues to be a problem in the northeastern US and eastern Canada, even with all the pollution controls installed on fossil fuel consuming industries. The long term effect of acid rain is that large areas of forests will die in these regions of the US and Canada. Acid rain will not directly kill the trees; however, the trees will become weak and then susceptible to diseases that kill trees. Acid rain is a problem that can be solved; it just takes a strong reaction and determination of the people to force action.
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