Flashcards in Paper 3: People And The Biosphere Deck (64):
Grouping of plants and animals that interact with each other and their local environment
Large ecosystem; grouping plants and animals over a large area of the earth
Only at high latitudes, where sun rays are weak.
Trees are adapted with needle like leaves
High rainfall and seasonal variation in sun rays. Trees loss their leaves in cool winters.
Within the Arctic circle. Very weak sun and low rainfall.
Only tough short grasses survive.
Either side of the equator. Very hot and very high rainfall.
Close to the tropics (cancer and Capricorn). Where are sinks with high pressure due to circulation cells making it very hot in the day.
Living component of an ecosystem : plants and animals
Non-living components of an ecosystem. Eg. Soil, rock, water and the atmosphere
Example of how an abiotic and biotic ecosystems interact
Taiga biome has low biodiversity ->
Abiotic: long cold winters, low precipitation, frozen soil. ->
Biotic: Only specialist plants can tolerate the conditions meaning a lower population.
Shows how biotic and abiotic components interact.
Litter store, Biomass store, Soil store.
Size of arrows: size of nutrient transfer between each store.
Biosphere providing resources for people (including indigenous)
Food, Medicine, fuel, building materials.
Food from the biosphere
Fishing and meat from farming
Natural vegetation like wheat and rice
Sustainable harvesting of fruits, berries and nuts
Fuel from the biosphere
Animal dung can be dried and burnt as fuel.
Wood from trees can be combusted.
Biofuels: converting plant to fuels: eg.bioethanol from fermenting sugarcane.
The collection of the worlds ecosystems
Biosphere and demand
Becoming increasingly exploited
Eg. Overfishing causing decline in fish numbers
Biosphere and a life support system
It regulates gases in the atmosphere (carbon sink) absorbs CO2 and replaces with O2.
Regulates water cycle - plants slow the flow of water into rivers to make it clean.
Keeps soil healthy and fertile by rotting plant material
World population growth
Exponential growth demands food, energy and water.
Urbanisation and world population
2018 - 54% urban
2050 - 66% urban
Must double by 2050 to feed the worlds population.
Demand for water will rise by 55% by 2050
The middle class will grow fro, 1.8 billion to 4.9 billion by 2030
It is impossible to create enough food as rapidly as population growth so if it grows too much there will be famine reducing the population acting as a control.
Human innovation will be sparked on the demands for resources. So if there is a high demand, new techniques will be invented to maintain the supply.
Adaptations to the canopy blocking out light.
Emergents grow 40m high.
10m above the canopy.
Adaptation to preventing mould on leaves, which would block light.
Drip tips: channel out water preventing stagnant water
How plants adapt to no deep nutrients
Trees must have shallow roots but use buttress roots to give it stability.
Litter inputs and outputs
Input: precipitation, leaf fall (from biomass)
Outputs: surface run-off, decomposition (into soil)
Soil inputs and outputs
Input: rock weathering, decomposition (from litter)
Output: Leaching, uptake by plants (into biomass)
Biomass input and outputs
Input: uptake by plants (from soil)
Output: leaf fall (into litter)
Why plants must adapt to the Taiga.
short growing season
low nutrient soil
Needle-shaped leaves for Taiga
They don’t drop leaves, to maximise annual photosynthesis.
The needle reduces water loss and leaves are needle shaped and waxy
Cone-shaped trees in the Taiga
Trees have downwards facing branches to shed heavy snow.
Simple ecosystem structure:
Few plants can survive the extremes
Coniferous trees dominate with lichens and moss
Trees grow together to reduce wind damage.
The short summer attracts:
Insects attract migrating birds
How moose’s are adapted to the Taiga
Has the ability to eat pine needles.
The brown bear’s adaptations to the Taiga
Build up fat layers on summer fro hibernation of winter months.
Non-migrating species of taiga
Have thick coats or feathers which turn white in summer for camouflage
Rainforest nutrient cycle
Plants grow all year
Dead matter drops and decomposes quickly in warm and moist conditions
Fast-growing plants take up nutrients quickly
Constant precipitation leaches nutrients down deep in soil.
Taiga nutrient cycle
Plants can only grow for 3-5 months
Litter accumulates because of decomposition only happens in summer.
Soils are thin, acidic and low in nutrients
Plants grow very slowly due to short growing season and poor nutrient supply.
Causes of TRF deforestation:
Subsistence and Commercial.
Causes of TRF deforestation
Agriculture, wood for fuel or hardwood logging, mining, biofuels, HEP
Climate change threats
1.Warming Global Temperature could cause Northward Shift of the System which brings constant wet conditions.
2.TRF become drier and hotter.
3.TRF plants an animals can’t tolerate to a sudden temperature spike.
4.TRF plants can’t tolerate long draughts resulting in death and stressed animals which are more susceptible to diseases.
5. Drier TRF increases risk of Fires which the ecosystem isn’t adapted for.
Direct threats to the Taiga
Softwood logging. This is a direct threat to the Taiga because of softwood, pulp and paper production.
Indirect threats to the Taiga
Tar sand mining for fossil fuels.
HEP dams require flooded forested valleys
They’re indirect as they’re side effects.
Acid precipitation from industry.
Acid precipitation damages Taiga trees resistance to pests and diseases.
Biodiversity risk in the Taiga
Siberia tiger have heavy fur coat and high levels of fat making them heat intolerant
Warmer winters allows ‘disease’ and ‘pests’ to spread into the Taiga which the biodiversity isn’t adapted to.
‘Forest Fires’ are more common which species aren’t adapted for.
Protection of TRF schemes
CITES and REDD
Convention on International Trade in Endangered Species (wild fauna and flora)
CITES protects 35000 different species. Countries who agree must stop exports of endangered species.
Reducing Emissions from Deforestation and forest Degradation.
Supports schemes to reduce rate of deforestation.
UN monitors the schemes by remote sensing and schemes.
Advantages of CITES
Have large influence: 181 countries
Disadvantages of CITES
It is difficult to check all countries are enforcing the rules
Eg. South Africa had over 1000 rhinos killed by poachers.
Advantages of REDD
Backed by the UN giving large amounts of money for support.
REDD scheme in Brazil is backed by a US $1B fund
Disadvantages of REDD
Unclear what they interpret as ‘forest’. Some palm tree plantations received REDD funding despite damaging the rainforet.
Keeping something going at the same rate.
Things to consider:
Keep going without using up natural resources
Doesn’t require lots of money to keep going.
Meets the needs of people now and in the future
Sustainable biosphere management
Ecosystems can recover quickly from any use
Prevents damage to ecosystem
Helps local people benefit from ecosystem and understand why the management benefits them
Economic tensions over sustainability of TRF
Communities want to make as much money possible so will use natural resources in the biosphere to do so. Providing tension as it could destroy in long term.
Social tensions and sustainability of TRF
To be socially sustainable: must not benefit from one group at the expense of another or future generations.
Consulting must be done on an equal basis.
If all groups benefit the environment might be at risk.
Environmental tensions and sustainability of TRF
Not harming any natural resource so can’t it can’t regenerate (renewable) in the long term. This makes conflict with making money and living standards for all.
Why protect the Taiga
Taiga is fragile and will takes long to recover
Plants grow slowly because of short growing season and low nutrients. Pollution remains in the ecosystem for decades.
Low biodiversity means a disease could impact the whole ecosystem
Taiga animals are specialised so cant adapt to climate change well.
National Parks and Protected Wilderness
Prevent exploitation of natural resources
1. Conservation- restoring habitat protects the biodiversity
2. Scientific research- finds out more about ecosystems, its threats and protection.
3. Education-informs visitors about Taiga and why it should be protected.
After trees are cut down, more are replanted with native Taiga species. Forestry plots are managed to conserve key species.
Problems with Parks and Reserves
1. Migration- Taiga species often migrate long distances, unless the park is very large they can’t be entirely protected.
2. Money- Exploiting the Tar Sands for fossil fuels could lift a whole country out of poverty, governments have pressure to develop them.
3. Pollution-Taiga is damaged through atmospheric pollution. However if parks are far from cities few tourists will help them and money fuels conservation.