Threats to the Taiga (Edexcel GCSE Geography: B (1GB0))

• Deforestation is the felling and clearance of trees
• Some of the highest levels of deforestation are in the taiga biome
  • Between 2000-2013 the loss of trees in taiga was one and half times the rate of deforestation in the Amazon over the same period
  • Most of this deforestation occurred in Canada and Russia
• The main causes of deforestation include:

Causes of deforestation in the taiga

• The exploration and deforestation of the taiga can also lead to:
• • Air pollution from transport and road building/mining
  • Water pollution from mining
• These impact on biodiversity of the biome as plant and animal populations are reduced

Acid rain

• Forms when sulphur dioxide and nitrogen dioxide react with the water in the atmosphere
• The reaction increases the acidity of the water to pH lower than 5.7
• The sulphur dioxide and nitrogen oxide are released when fossil fuels are burnt

Impacts

• Damages the tree's needles, making them less able to photosynthesis
• Plant nutrients in the soil such as calcium are depleted
• Trees are weakened and become more vulnerable to pests and disease
• Loss of trees impacts on biodiversity as insects and other animals lose food sources and habitats

Acid rain formation

Global warming and climate change

• Increased temperatures 
• Warmer and drier conditions
• Species from high latitudes may have nowhere to move to when conditions are no longer suitable for them
• New species may be introduced due to changing temperature and precipitation

Impacts

• Increased pests and diseases
• Risk of wildfire spread increased 
• Extinction of animals unable to adapt or move to other areas
• New species may out compete native species

Wildfires

• Wildfires are a natural feature of the taiga and allow regeneration. They occur due to:
  • Pine needles and dry leaves cover the forest floor and can easily catch fire
  • Resin in coniferous trees burns easily
  • Summers can be hot, summer storms mean lightning which can spark fires
• Studies show an increase in wildfires due to:
  • Warmer summers and less precipitation
  • Drier conditions mean the litter and trees catch fire more easily

Impacts

• Dominance of species which can withstand fire increase - this reduces biodiversity
• Reduced variety of tree species reduces habitats and food sources
• More frequent fires means the ecosystem has no time to regenerate

Pests and diseases

• Warmer temperatures mean more pests survive the winter
• Pests such as silkworm have spread into the taiga biome leading to the death of many trees
• Spruce bark beetle is increasing in the taiga biome with 1.1 million acres currently affected in Alaska
• Western gall rust and armillaria root disease are affecting areas of taiga trees

Impact

• Reduced variety of tree species reduces habitats and food sources
• Fewer trees leads to more open spaces 
• Biodiversity is reduced