Topic 8 (Nutrient cycle in the rainforest (If deforestation takes place…
Canopy Layer - layer where abundance of food are available.
- home to tree frogs,birds,tree snakes.
Understorey layer - Layer contains young trees and large leaves to capture sunlight. Abundance of insects live here
Emergent Layer - Hardwood evergreen trees that have broken through the dense canopy layer below to reach sunlight.
Forest Floor - Dark. shade - loving ferns with large leaves live here.
- mammals + jaguar
- Buttress roots
Epiphytes - Plants live in the canopy of the tree + evolved to get nutrients from water + air than the soil .
Lianas - Climbing plants, where their stems clinging on to the trees and climb up to the canopy for sunlight while getting water + nutrients from the soil.
- Evergreen hardwood trees - Mahogany,ebony + teak trees have tall slender trunks without any branches, but have huge buttress roots to support it.
- These roots hold enormous weight of the tree.
Drip Tip leaves - rainforest have thick waxy leaves with drip tips - shed water to prevent from rotting.
- Lemurs + monkeys evolved to live in the canopy for food.
- long tails for balance.
- Strong claws to grip leaves + branches.
- Jaguars + leopards + tigers have fur to camouflage.
- dark + light fur patches to match with the shade + sunlight in the forest floor.
- Huge claws to hangup side down the branches.
- Fur help shed water when they are up + down.
- Green algae grows in fur to help camouflage from predators.
- Have loud calls to call their mate.
- Parrots + macaws powerful beaks to break open nuts
Fire - hot + dry summers.
- dry pine needles, perfect tender to start a fire.
- Hot summers generate lightning strikes
- Coniferous trees have sticky resin which burns easily.
Regenerates the forest.
- Pines + black spruce come open when burned, releasing seeds.
Too many wild life will cause:
- Forests will not regenerate , trees will not mature between fires.
- Fire tolerant species will begin to develop , reducing biodiversity.
- Trees cannot tolerate fire decline, so is the birds + insects that feed on them.
Plague of pests
Spruce bark beetle - 2.5 mn hectares of spruce have been cleared.warm winters due to global warming stopped larvae dying out.Large storms knock trees down, causing the beetles to explore new areas.
- Reduce the commercial value of forests, preventing it been sold as timber.
- Alters the ecosystem, alters the food web.
- change landscape to a more open landscape with fewer trees than a dense forest..
- Biodiversity is reduced because forests that are resistant will remain.
- Mountain pine needle - destroyed 16 mn hectares of lodge pole pine forest .
- Beetles intro a fungus that cut down the flow of water inside the tree.
White pine blister rust - blister rust prevented the trees from growing.
- Fossil fuels are burnt releasing sulphur dioxide + nitrogen dioxide into air.
- reacts with water in clouds - forming sulphuric acids nitric acids.
- Precipitation carries this
- fish + aquatic species will die. weaken trees.
- Damages needles , so less photosynthesis.
- soil becomes too acidic, damage roots
- Damage soil nutrients, less magnesium + calcium.
- Weaker roots can;t take up nutrients
- Weak trees vulnerable to disease.
- Low biodiversity,
Kilum - ljim: sustainable environmental management
- Kilum - ljim: forest an area of mountain rainforest in Cameroon, Africa
- 35 communities.
- Agroforestry - maintaining biodiversity
- Selective logging
- Extraction reserves
- get funding from Kew gardens/ UK departments/ Dutch ministry of Agriculture.
They work with local people:
- Mark out forest reserve area + made lists of forest resources
- develop rules for the sustainability of the forest.
- set up a unit to manage + monitor forest.
- educate communities about replanting trees + safe levels of hunting + logging
- 50% of the forest had been deforested between 1958 to 1988, but the forest has increased by 8%.
- sustainable farmin - crops are grown between trees +than cutting it down
- inter - cropping carried out - crops grown different heights, helps protect the soil from erosion + reduces pest numbers.
- small scale, low impact tourism
- appeals to tourist of wildlife + culture.
- tourists stay with locals.
- money from tourists goes directly to locals.
This forest face number of challenges:
- population is increasing , pressure to deforest areas.
- urban ares,roads + industry could encroach on the forest.
- money + technical support internationally could end
- climate change could degrade the forest.
Indirect threat (come from pollution,global warming or disease)to tropical rainforest
- Global warming
- Species extinct at an unprecedented rate.
Know this because:
- Plants are flowering earlier
- bird migration patterns are changing
- Arctic tundra is warming up
- vegetation zones are shifting poles every 6km every 10 years.
Drought put forests in stress by:
- Drying the leaf litter cause decomposers to die out, impact the nutrient cycle.
- causing leaves in the canopy to die, reducing the food supply + affect food webs.
- Deforestation increase more droughts , fewer trees means less evaporation + transpiration., means fewer clouds + less rain.
droughts can make forests a source of carbon dioxide tan carbon sink.
- Droughts increase forest fires. In long term tropical rainforest will become tropical grassland.
Rate of deforestation has fallen:
- In 2006 an area like france was protected by the government.
- Global recession + credit crunch since 208 reduced demand for resources.
- Government have cracked down illegal logging + clearance for cattle ranching by freezing bank accounts.
- Brazilians have now become green, 19% voted for green party candidates in 2010 election.
- most land privately owned.
- resident population is larger.
Manged by the system UNESCO biosphere reserve model
- core - no human interference, protected, scientific research + monitoring.
- Buffer - limited settlement, income from ecotourism, educated people on sustainability.
-Transition - normal economic activity, within protected area, with scientific monitoring + education.
Direct threats to Taiga
Why deforestation is high in taiga forest:
- Biome is vast
- Taiga is isolated + out of sight in northern latitudes.
- Few cute cuddly species under threat.
Softwood used for:
- construction of timber : roof beams + window and door frames.
- Board for chipboard + fiberboard for flooring + furniture.
How paper is made
- paper made by turning softwood into pulp
- crushed + ground using chemicals to produce a sludge that is made into paper.
- Found between 50 - 70 latitude , northern hemisphere.
- Russia + Canada - huge ares covered by boreal forests
- Trees are coniferous(evergreen) + deciduous + have adapted to cold climate their shape allows the snow to fall , than weighing on branches.Their pine needles, prevent damage from snow + wind.
- Have a subarctic climate - short, wet summers of three months ,when temp rise to 20c.
- Long cold dry winters freezing as low as -20c.
- Low precipitation - below 20mm for five months + only 350 - 750mm per year.
Adapting to extreme climate in Taiga
- Low biodiversity
- Low prouctivity
- Growing season is 4-5 months, less food in the winter.
- Many mammals have thick fur, (grizzly bears), to help retain body heat + provide water proofing.
- Animals hibernate due to lack of food in the winter.
- 200 species migrate due to lack of food.
- Cone shape, many coniferous trees help shed winter snow.
- Needle like leaves protected by waxy coating prevents damage from frost and limits water loss in dry periods.
- Seeds protected by woody cones.
- Coniferous trees are tall + narrow to form canopy layer.
- Flexible branches to shed the winter snow.
- Thick layer of pine needles , are acidic prevents other plants from growing.
- Sharp pine needles help borrow inside for winter.
- fern, mosses, and lichens grow on the forest floor because it is dark.
- Trees roots are shallow + wide to support the tree.
- Summer - soil is waterlogged.
1-2 meters below ground soil is froze, so roots can't penetrate.
- NPP used to measure the number of species growth/ biomass.
Nutrient cycle in the Taiga
- biggest store is litter because pine decay slowly , so release nutrients slowly.
- low precipitation + chemical weathering is limited in cold temperatures.
- Biomass store is slow trees grow slowly.
Direct threats (deliberate cutting down of trees for timber, to make roads/to convert forest to farmland.) to tropical rainforest
- Poverty - Low income countries cut down trees for farmland to make a living.
- Debt - Countries cut down forests , export timber or grow cash crops to pay off debts.
- Economic Growth - developing countries sacrifice forests to build roads, expand cites + build HEP.
- Demand - forest destroyed to feed the growing population.
- Mineral exploration - Poorer families clear out large areas of forests to dig mines to sell it off for TNC's .
Biofuels - forests cleared for palm oil plantations.
Biodiversity is high in rainforests because:
- Climate is perfect all year round for growth + reproduction.
- Thousands of different species have evolved because rainforest is ancient + have a stable climate.
- Multiple layers in the rainforest have evolved to adapt to these different specialised habitats.
Threat of Tar sands(mixture of fossil fuels + sediment that van be mined + heated to separate the oil.)
James Bay HEP, Canada - cost over 20 billion dollars.
- hold 1.7 trillion barrels of oil.
produces toxic waste collected in tailings ponds.
- mining uses 2-4 tonnes of water for every tonne of oil produced.
- mercury was released as the flooded forest decayed in the reservoirs , polluting rivers.
- Nutrients added to the ecosystem by weathering + precipitation.
- Also removed by runoff + leaching
- Taken up the biomass to grow
- They return back as litter decays.
- No dry season, at least 60mm of rainfall each month, some get three metres of rainfall each month.
-Temperature is high all year round 26 - 32c , no summer or winter.
Strip mining - open pit, open cats / surface mining involves digging larger holes in the ground to extract ores + minerals that are close to surface.
Economic sustainability - reducing poverty by increasing income from alternative livelihood. .g ecotourism + sustainable farming.
Web of life
- Food web - how species rely on each other for resources.
- primary producer - trees,flowers
- Primary consumers - sloths, ants
- secondary consumers - birds, frogs
- tertiary consumers - snakes, jaguars
- Detrivores - fungi,bacteria
Why taiga pressured to develop:
- Oil, gas + mineral extraction +HEP.
- timber fro paper + construction.
In wilderness areas:
- motorized transport is not allowed.
- recreation is allowed , but people cannot leave behind activity.
- logging, mining + road building is banned.
Wood Buffalo national park in canada.
- created to protect mountain bison from hunting
- mix of taiga + wetland.
- lies in north of Athabasca tar sands mining area.
- access from north, limited winter, south = visitor facilities
- central + western areas are inaccessible are reserved for wildlife.
- tar sad pollute the Athabasca river , reduce flow when water taken for mining.
RAMSAR wetland + world heritage sites:
- they agree to conserve them , by protecting species through the provided funding
- but protecting them from global warming, pollution + hunting + mining is difficult.
- clear cutting - increase soil erosion, take decades to regenerate.
- destroy mosses, lichen + other plants on forest floor.
- landslide + river bank erosion increase.
- Selective logging carried out in large scale, destroy valuable trees.
Sustainable forest management in finland
- 8% of forest protected+ much of this cannot be logged.
- even though forest logged commercially , habitats like wetlands are strictly prohibited.
- logged areas are replaced for biodiversity.
- 95% of commercial forests are sustainably managed.
- forest is growing because planted than logged.
- local government
- brings jobs, income + remote areas.
- resources exported,boosting GDP
- Exploitation affect tiny fraction of vast biome
- .Exploitation renewable e.g. HEP + replanted forests.
Conserve taiga biodiversity
- indigenous people
- taige last untouched biome
- forests are carbon sinks for global warming
- culturally important
- exploitation causes pollution, degradation + deforestation.