Acid Rain Experiment.
Investigating the effects of acid rain in the growth of cress seedlings IntroductionAcid rain is rain or any other form of precipitation, which is unusually acidic. It has harmful effects on plants, animals and buildings. Acid rain is mostly caused by human emissions of sulphur and nitrogen compounds which react in the atmosphere to produce acids.
Acid rain can slow the growth of vulnerable forests and cause leaves and needles to turn brown and fall off. In addition, it depletes minerals from the soil and then it stunts the growth of the plant. Some of the most dramatic effects on forests have been observed in Europe. In 1983, a survey in West Germany showed that 34 % of the country's total forest is damaged by air pollution. This included about one half of the famous Black Forest. Switzerland has recorded damage to 14 % of its forest trees.
In this experiment, I will find out what consequences acid rain has on the germination and subsequent growth of cress seedlings. I will use cress seedlings, which germinate quickly and can grow a few centimetres in a matter of days and sodium metabisulphite, which reacts slowly with water to produce sulphur dioxide gas. The seedlings will have to be in an enclosed system so the sulphur dioxide does not escape. The experiment is a simulation trying to model a powerstation producing sulphuric acid, falling on the seedlings as acid.
Research QuestionHow do different concentrations of acid rain affect the growth rate of cress seedlings?HypothesisI predict that the stronger the concentration of the acid the fewer seeds will germinate and the less they will grow because acid rain has very harmful effects on plants, damaging the leaves, removing water from the waxy cuticle and limiting the nutrients available.
VariablesIndependent variable (to manipulate, alter) Concentrations of sodium metabisulphite, pHDependant variable (measurements) Change in the height of the stem of the cress seedlingsControlled variable (to keep
Acid rain can slow the growth of vulnerable forests and cause leaves and needles to turn brown and fall off. In addition, it depletes minerals from the soil and then it stunts the growth of the plant. Some of the most dramatic effects on forests have been observed in Europe. In 1983, a survey in West Germany showed that 34 % of the country's total forest is damaged by air pollution. This included about one half of the famous Black Forest. Switzerland has recorded damage to 14 % of its forest trees.
In this experiment, I will find out what consequences acid rain has on the germination and subsequent growth of cress seedlings. I will use cress seedlings, which germinate quickly and can grow a few centimetres in a matter of days and sodium metabisulphite, which reacts slowly with water to produce sulphur dioxide gas. The seedlings will have to be in an enclosed system so the sulphur dioxide does not escape. The experiment is a simulation trying to model a powerstation producing sulphuric acid, falling on the seedlings as acid.
Research QuestionHow do different concentrations of acid rain affect the growth rate of cress seedlings?HypothesisI predict that the stronger the concentration of the acid the fewer seeds will germinate and the less they will grow because acid rain has very harmful effects on plants, damaging the leaves, removing water from the waxy cuticle and limiting the nutrients available.
VariablesIndependent variable (to manipulate, alter) Concentrations of sodium metabisulphite, pHDependant variable (measurements) Change in the height of the stem of the cress seedlingsControlled variable (to keep