Describe the location and climate of the Taiga biome?
- 50-70 degrees N of equator
- South of tundra, north of temperate woodland
- subarctic climate with long cold, winters and short-mild summer
- low avg precipitation <500mm/yr
- significant seasonal differences - short growing season for plants - cold & dark for much of year
State some plant adaptations in the taiga
- needle shaped leaves with small surface area and a waxy coating to prevent water loss/transpiration/save energy
- shallow roots linked w frozen soil conditions
- evergreen/coniferous trees due to short growing seasons (too little time for shedding and regrowth)
- dark green leaves to absorb more sunlight
- small amount of sap in leaves so they don’t freeze easily
- trees grow close together to gain protection from the wind
- cone shaped trees/sloping branches cause snow to slide off without breaking them
State some animal adaptations for the taiga
- thick fur coats for insulation, smaller ears & shorter tales to avoid frostbite
- hibernation - bears build up lots of fat in the summer and go into a den for winter, entering a sleep like state
- camouflaged so can hide from predators in snow & better insulation as white fibres provide warmth
Describe the nutrient cycle in the Taiga
- low levels of biodiversity
- migration away during winter means less biodiversity during winter
- smallest biomass as cold climate means plants grow slowly and slow transfer of nutrients
- litter store largest as pine needles decompose very slowly in cold temps
- small soil stores - acidic pine needles so small plants and less decomposition
What are direct threats from human activity for taiga?
Removal of trees for
Direct threats:
Logging for softwood
Pulp and paper production
Indirect threats:
Exploitation of minerals, fossil fuels - chopped down trees
HEP potential - flooding areas of land
No pine trees means no nutrients
What are three ecological threats to the taiga?
Acid rain
Forest fires
Pest and disease
How is acid rain formed?
- fossil fuels burnt in industry & power plants create SO2 and NO
- these react with water, create acids and fall as acid rain
- damage to plants, soils, lakes and ponds by higher acid content
How does acid rain affect the taiga?
- acidic soils release more aluminium compounds which damage roots & there’s lack calcium/magnesium which are important nutrients
- acid kills insects & eggs so fewer insects means migrating birds don’t have anything to eat
- acid kills soil microbes and roots, stopping nutrients getting into the roots
How do forest fires come about in the taiga?
- caused by lightning strikes, camp fires or gas flares
- hot dry summers & acidic pine needles, acidic litter, sticky resin all easily burn
- high temps and reduced rainfall means more frequent fires
How do forest fires affect the taiga?
- destroy huge numbers of trees
- may change distribution of species as some species are better at recolonising burnt areas
- breaks forest into smaller sections making it hard for migratory animals that need lots of space to find enough food
How do pest and disease come about in taiga?
- fungus and mould species damage needles, trunks and roots reducing their value
- insects eat pine cones, needles and young shoots
- invasive species spread from neighbouring biomes and climates become less extreme
How do pest and disease affect the taiga?
- cause damage to organisms
- many are specific to one species and often single tree species are in an area so easy for pests/diseases to spread and multiply causing damage
What are some conservation methods in taiga?
Conservation method help protect areas or control how they’re used
Creating a wilderness area
Creating a national park
Sustainable forestry
How does creating a wilderness area act as a conservation method? Give pros and cons
An area undisturbed by human activity, managed with the aim of protecting the landscape
Strengths:
- high protection as most human activity banned
- covers large area so large scale processes like migration can take place
- trees prevent frozen soil from thawing which stops methane escaping
Weaknesses:
- hard to police large, remote areas
- pressure from companies and tourists to build roads allowing greater access
- econ pressure from logging, mining and energy companies who want to use resources
How does creating a national park act as a conservation method? Give pros and cons
An area that is mostly in its national state, managed to protect biodiversity and promote recreation
Pros:
- often covers large areas
- unsustainable human activity illegal
- good access for tourism
Cons:
- prevents indigenous culture using land
- tourism may be required to pay for conservation but access roads and pollution from them can harm the ecosystem
How does creating sustainable forestry act as a conservation method? Give pros and cons
Ways of harvesting timber from forest without long term damage
Pros:
- companies may be required to regenerate area after logging
- selective logging means some trees remain - some economic exploitation
- limits can be placed allowing forest to regenerate
- can provide migration corridors for wildlife
Cons:
- some countries struggle to enforce restrictions
- lack of clear management or information about ecosystem
- slow growing trees in taiga
- different groups may not agree with rules
What are the conflicting views on managing the Taiga?
Protection:
Global carbon sinks absorb co2
Taiga trees protect frozen soil from thawing preventing methane escaping, CC
Culturally important for indigenous
Exploitation:
Demand for resource increasing - wood, fuel, minerals
Forest industries provide jobs
Generates lots of wealth
