Coniferous forest- Industrial Development

• Coniferous forests exist in many parts of Northern Europe, especially Scandinavian countries such as Sweden and Norway.
• Industrial development in Europe has led to acid rain becoming an increasing problem for this biome
• Acid rain is rainwater that has a Ph of less than 5.6 It occurs when fossil fuels are burned in power stations and vehicles.
• Burning fossil fuels releases sulphur dioxide and nitrogen oxide intothe atmosphere. These combine with rainwater to form sulphuric acid and nitric acid. These then fall to the ground as acid rain.
• The maximum amount of acid rain that a biome can receive without damage to the soils and vegetation is called its Critical load
• It is estimated that in Europe 20 % of forests have acid deposition greater than their critical load.
• Many of these forests are in Scandinavia. These countries are not heavily industrialised, however prevailing winds in Europe blow emissions from heavily industrialised countries such as Britain and Germany to Scandinavian countries
• It can take up to 10 days for sulfur particles to settle back down and reach the earth. In this time, they can travel thousands of miles and affect countries far from their source.
• Acid rain damages trees in a number of ways. 1. Acid rain damages the surface of the leaves reducing its ability to photosynthesise (produce its own food). As a result the overall health of the tree suffers and it is left open to attack from insects, fungi and frost.
• 2. Seeds from acid-damaged trees have lower germination rates reducing forest growth. In Sweden, it is estimated that the loss of growth amounts to 495 million euro each year. This is a serious loss to an economy where forests are considered “green gold”
• 3. Acid rain depletes the soil of essential nutrients such as calcium and phosphorus. This damages the trees’ health. Soils in Norway are 10 times more acidic today than they were 10 years ago.
• 4. Acid rain also increases the concentration of aluminium in the soil. This damages the root hairs of a tree, preventing them from absorbing essential nutrients from the soil. This results in the trees starving since they cannot make or absorb the food they need.
• It is estimated that acid rain has damaged over half of Germany’s trees.
• In order to neutralise the acid in the soil, it is lined.
• In Southern Sweden it takes about 3 tonnes per hectare of lime to protect a field from acid rain for about 20 years. This is expensive, 7,500 lakes in Sweden also have to be limed on a regular basis