Acid rain is rain or any other form of precipitation that is unusually acidic. It has harmful effects on plants, aquatic animals, and infrastructure. Acid rain is mostly caused by human emissions of sulfur and nitrogen compounds which react in the atmosphere to produce acids. In recent years, many governments have introduced laws to reduce these emissions.

Soil biology and chemistry can be seriously damaged by acid rain. Some microbes are unable to tolerate changes to low pHs and are killed. The enzymes of these microbes are denatured (changed in shape so they no longer function) by the acid. The hydronium ions of acid rain also mobilize toxins, e.g. aluminium, and leach away essential nutrients and minerals.

Soil chemistry can be dramatically changed when base cations, such as calcium and magnesium, are leached by acid rain thereby affecting sensitive species, such as sugar maple (Acer saccharum).

Adverse effects may be indirectly related to acid rain, like the acid's effects on soil or high concentration of gaseous precursors to acid rain. High altitude forests are especially vulnerable as they are often surrounded by clouds and fog which are more acidic than rain.

Other plants can also be damaged by acid rain but the effect on food crops is minimized by the application of lime and fertilizers to replace lost nutrients. In cultivated areas, limestone may also be added to increase the ability of the soil to keep the pH stable, but this tactic is largely unusable in the case of wilderness lands. When calcium is leached from the needles of red spruce, these trees become less cold tolerant and exhibit winter injury and even death.

The Spider Plant, Chlorophytum comosum, is a species of Chlorophytum native to South Africa.

Spider plants have long narrow leaves that are 20–40 cm (8–15 in) long and 5–20 mm (0.2–0.8 in) broad, which grow from a central rosette. At the spot where a leaf would normally develop a node, these plants will produce adventitious roots down into the soil, and new above ground shoots. It also produces branched stolons with small white flowers and baby plantlets.

It is a popular houseplant. The most widely grown is the variegated cultivar 'Variegatum', with one or two broad yellowish-white bands running along the length of each leaf, but natural, entirely green plants are also grown. The Spider Plant is an especially popular plant with beginners, as it is easy to grow and propagate and is very tolerant of neglect, being able to thrive in a wide range of conditions.

Spider plants have also been shown to reduce indoor air pollution.

Spider Plants can be propagated by splitting its main rosette, or more easily by removing plantlets from the stolons and potting them separately or putting them in a glass of water. They will root readily in water but establish faster in soil while still attached to the parent plant. Pinning the plantlet to the soil with a bent paper clip can be helpful. Make sure the soil is damp and well draining. The plantlet can then be removed from the parent plant in 7-10 days.

Source: Wikipedia (All text is available under the terms of the GNU Free Documentation License)

For More Information:
Acid Rain: K-12 Experiments & Background Information