Unit 6a Notes Flashcards
What is the world’s youngest Biome?
10,000 years ago - Covers 20% of the Earth’s surface.
Where are Tundra Biomes found?
60-75 degrees North.
Which countries are Tundra biomes found in?
Alaska, Canada, Russia, Greenland, Iceland.
What is the average temperature in the Arctic Tundra in summer?
3-12 degrees.
What is annual precipitation in the Arctic Tundra?
150-200mm - 1/3 of London’s annual rainfall.
What is a key characteristic of the soil in Tundra?
Permafrost.
What is an example of a Tundra environment?
Broughton Island - 67 degrees N.
What is the characteristic of Arctic Tundra soil?
Frozen - Gelisols. They freeze and thaw a lot, making soil heave and buckle. Low soil temperatures reduce decomposition of organic materials.
Why are Arctic Tundra regions cold and dry?
Permafrost acts as an impermeable layer under thin Tundra soil, traps moisture close to the surface. Cold - less solar radiation - higher latitude.
Why can’t Gelisols support significant amounts of vegetation?
Freezing and thawing throughout the year means physical changes in the soil. Organic matter accumulates, decomposition is very slow, and stores large amounts of carbon. Nutrients are heavily leached.
What is the profile of Gelisols?
Thick layer of dead organic matter, permafrost means permanently frozen ground.
What are the examples of Arctic Tundra plants?
Cotton Grass, Arctic Moss, Dwarf willow.
Which features does Cotton grass have, which makes it easier to survive?
Low lying, seeds scatter in the wind, narrow leaves reducing transpiration, adapted to a short growing season, dense flowerheads, reducing heat loss.
Which adaptations does Arctic Moss have, to survive?
Grows close to ground to protect it from strong winds, many small leaves to maximise photosynthesis, reproduce by growing shoots, slow growing.
Which adaptations do Dwarf willow have, to survive?
Only grow to a maximum height of 30cm, often grow horizontally instead of vertically. Short growing season, low soil nutrient levels.
How do plants growing low to the ground help them in Tundra environments?
Allows them to absorb more heat from the sun. Sun warms the soil.
How do hairs on plants help them in Tundra environments?
Insulating layer of warm air.
How many species of mammals are there in the Tundra?
48.
Why is Biodiversity low in Tundra environments?
The harsh climate and limited productivity. Biodiversity increases in summer when conditions such as sunlight increase.
Which adaptations do Caribou have which allow them to survive?
Veins and arteries that run side by side. Short ears avoid losing body heat. Split hooves spread apart to bear more weight without sinking into snow. 2 layers of fur. Short tail - avoids losing body heat. Compact body.
Which adaptations do Arctic Foxes have, allowing them to survive?
Low SA/ Volume ratio. Shorter legs, less surface area, less area for heat to escape. Thick camouflaged fur - highly insulating. Summer - thinner dark grey. Thick fur on paws. Thick fur on tail.
How are Tundra environments interdependent?
The environment is fragile, animals and people can only live in low densities. There’s a delicate balance between harsh climate, permafrost, and soils.
What are the examples of producers in a Tundra environment?
Liverwort, Grass, Caribou Moss, Lichen.
What are the examples of Primary Consumers in a Tundra environment?
Pika, Musk Ox, Caribou, Lemming, Arctic Hare.
What are the examples of Secondary Consumers in a Tundra environment?
Arctic Wolf, Brown Bear.
What is a Tertiary consumer in a Tundra environment?
Polar Bear.
Why is there rarely more than 4 trophic levels in a food web?
Energy is used up or lost at each level - energy can’t support additional organisms at each level.
What is Arctic Amplification?
The idea that climate change is more harshly felt in Arctic environments, as a result of melting permafrost.
How much have global average temperatures risen by on average, compared to Tundra regions?
Average - 1 degree. Tundra - 4 degrees.
What does the decomposition of dead organic matter lead to in Tundra environments?
Releases Carbon dioxide and methane to the atmosphere. Methane is 23x more potent that C02 as a greenhouse gas.
What is a climate tipping point?
A threshold which, if breached, can set off other feedback loops which can cause problems for the climate which may be reversible.
What is the feedback loop caused by thawing permafrost?
Means that carbon dioxide which is stored in the soil, through dead organic matter, is released, which goes into the atmosphere, which causes further warming of the earth, causing the feedback loop to repeat itself.
What are the main impacts of permafrost thawing?
Ecosystem damage, landslides, infrastructure damage, coastal erosion.
How is ecosystem damage an impact of permafrost thawing?
Local flora disappears - wildlife that feeds on it starves. Water seeps into the ground and disappears, causing drought.
How are landslides an impact of permafrost thawing?
Ice acts as cement, binding together. Thawing permafrost causes land to give way.
How is infrastructure damage an impact of permafrost thawing?
Collapse of houses, roads, pipelines. Destabilised ground.
What is another impact of permafrost thawing?
Release of viruses - releases pathogens previously trapped in frozen ground.
How many ancient viruses have been released since 2004?
Four.
What % of Alaska’s permafrost will degrade by 2100?
16%.
What is Arctic Greening?
The tundra environment being replaced by Boreal forest - 15 miles per decade.
How will Arctic Greening affect producers?
Shifts vegetation further towards shrubs and small trees, increased biomass, increased plant uptake.
How will Arctic Greening affect Primary consumers?
Traditional food sources are reduced for species such as Caribou. Reduced body condition, lower reproductive rates, decline in population.
How will Arctic Greening affect Secondary consumers?
Predators may struggle to find enough food, altering hunting patterns.
Why has the population of snow geese increased?
Due to a warming climate, providing a greater availability of food in Tundra regions. Higher reproduction success rates.
What was the population of snow geese in Tundra regions in 1980, compared to now?
2-3 Million - 1980. 15 Million - Now.
What is the impact of increased snow geese on the landscape?
Fertile grasslands are becoming salty mud flats. They graze grass too short, leaves plants exposed to mud. It’s difficult for plants to recolonise.
How are Tundra biomes considered fragile?
It’s highly affected by temperature - negative feedback loop means temperature changes are felt more widely in Tundra ecosystems.
