Topic 8 - Forests Under Threat Flashcards
What are examples of interdependence in the tropical rainforest ecosystem?
The dense leaf layer protects the forest floor from wind and heavy rainfall
Root systems hold the soil together, this stops it being eroded.
Symbiotic relationships such as animals feeding off of plants and vice versa.
Lots of epiphytes that get water and nutrients from rainfall and get plenty of sunlight.
Deforestation reduces the amount of CO2 being absorbed from the atmosphere, adding greenhouse gases and changes the climate.
What are stratified layers?
Specific layers in the forest. It affects the amount of sunlight that can reach the different levels of vegetation. Plants are adapted to the conditions found in each layer.
Name the four stratified layers in a tropical rainforest.
Emergents - 40m
Main Canopy - 30m
Under canopy - 20m
Shrub layer - 10m
Why do some trees in the rainforest have buttress roots?
They’re big roots that support the tree and stop it from falling over.
Why do plants have “drip tips”?
They channel water to a point so it runs off - that way the weight of the water doesn’t damage the plant, and there’s no standing water for fungi and bacteria to grow in.
Name the three nutrient stores in the tropical rainforest ecosystem?
Biomass
Litter
Soil
Why are nutrients cycled quickly in the tropical rainforest?
- Trees are evergreen so dead leaves and other material fall all year round. 2. The warm, moist climate means that fungi and bacteria decompose the dead organic matter quickly. The nutrients released are soluble and are soaked by the soil. 3. Dense vegetation and rapid plant growth mean that nutrients are rapidly taken up by plants’ roots.
Why does the layered structure of tropical rainforests increase biodiversity there?
.
What are epiphytes?
Plants that grow on other plants
What is the emergents layer?
Tallest trees
Straight trunks and only have branches and leaves at the top where they can get light.
Have buttress roots to support their trunk.
What is the main canopy layer?
A line of trees with leaves only at the top, so dense it shades the rest of the forest
What is the under canopy layer?
Made of younger trees that haven’t reached their full height
Only survive in breaks in the canopy that let a little bit of light through
What is the shrub layer?
Nearest to the ground and is quite dark
Shrubs have large broad leaves to absorb as much of the available light as they can
How are plants adapted to the hot wet climate?
Thick and waxy leaves with a drip tip.
Smooth thin bark.
Climbing plants.
Plants from their leaves.
Why do trees have a smooth, thin bark?
No need to protect the trunk from cold conditions and allows water to run off easily
Why do plants climb?
Such as Lianas which use the tree trunks to climb up to the sunlight.
Why do plants drop their leaves gradually throughout the year?
So that they can go on growing all year round.
Why do plants have a thick and waxy cuticle?
To prevent insects from eating them and to repel the rain.
How are animals adapted to the physical conditions of the rainforest?
Animals can swim to cross river channels.
They have strong limbs to be able to be climbing and leaping from tree to tree.
Some animals have flaps of skin to glide or suction cups for climbing between trees.
Animals are camouflaged so they can hide from predators.
Some are nocturnal to save energy at the colder night.
Some are adapted to low light levels and have a high sense of smell and hearing so they can detect predators without seeing them.
What is the nutrient cycle of the rainforest?
What is biodiversity?
The variety of organisms living in a particular area - both plants and animals.
How much of the world’s species does the rainforest contain and of all life on earth?
Around 50% and around half of all life on earth.
How has the rainforest been able to grow a high biodiversity?
The climate doesn’t change much so many species can grow there. Layered structure provides lots of different habitats. Rainforests are stable environments and produce a lot of biomass for animals and plants to live off.
What is a food web?
Food webs show how all the food chains overlap each other creating a bigger web of chains.
What is a food chain?
Shows what is eaten by what in an ecosystem.
Why are food webs in tropical rainforests very complex?
So many different species that link to different organisms. Some animals are both primary and secondary consumers.
What are environmental impacts of deforestation?
No trees to hold the soil together, heavy rain washes it away, soil erosion. Leads to flooding and landslides. Means more CO2 in the atmosphere, which adds to the greenhouse effect. No canopy means more water reaching the soil reducing soil fertility - washes the nutrients away.
Deforestation and climate change are threats to tropical rainforests?
Deforestation is a direct threat, deliberately chopping it down. Climate change is an indirect threat, still leads to damaging the ecosystem.
What 7 reasons doe’s deforestation happen in the rainforest?
Local demand for fuel wood Mineral resources HEP (electricity) Demand for biofuels Subsistence farming Commercial farming Commercial hardwood
Why does deforestation happen due to Local demand for fuel wood?
Local people chop down trees to use as fuel for cooking or to burn to make charcoal.
Why does deforestation happen due to Mineral resources?
Minerals are often found in tropical rainforests and so explosives are sometimes needed to clear earth or deep pits are dug to reach the deposits after deforestation.
How does the nutrient cycle of the Taiga compare with the Rainforest nutrient cycle?
Trees are evergreen, so drop their needles all year round. Despite the constant leaf fall, low temperatures mean that it takes a long time for the litter to decompose and added to the soil - conditions are too harsh for many decomposers. This means the soil isn’t very fertile. Cold climate means slow plant grow - the rate of transfer of nutrients from soil to plant is low.
