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ECOSYSTEMS CASE STUDIES
Transcript of ECOSYSTEMS CASE STUDIES
GEOGRAPHY REVISION An ecosystem is a living community of plants and animals, and elements of the natural world such as soils and the climate. Producer: An organism that creates energy from the sun.
Consumer: Something that eats something else, can be classified into primary, secondary etc.
Food Chain: Simple diagram with arrows to show energy transfer.
Food Web: More complex food chain. TROPICAL RAINFORESTS Distribution: *Located close to the equator - Amazon Basin, Brazil; Zaire Basin, Africa; Indonesia and Malaysia. CLIMATE:
*Av. temp.: 26'C
*Lots of sunlight.
*2400mm rain a year REMEMBER: *STATE GENERAL PATTERN
*QUOTE HIGHEST AND LOWEST
*IDENTIFY ANY ANOMALIES The emergents grow up to 50m in order to reach sunlight. Trees in the canopy are about 30m tall. The trees in the under canopy have no leaves n the trunk due to low light levels. The shrub layer is less than 10m tall. There is also a herb layer, which is extremely close to the ground. There is little undergrowth as only 2% of sunlight reaches the forest floor. MORE PLANT ADAPTATIONS.............. Spikes detect prey as they feed off the nectar. Slippery sides trap prey as they fall to a watery grave. They have closing mechanisms to trap prey. Carniverous Plants A climbing vine with thick woody stems. Can be up to 1000m long. Use other trees for support as they grow quickly to reach sunlight. Animals provide more nutrients than the soil. Tall with extremely long roots. The seed begins as an epiphyte. As the roots grow they suffocate the host tree eliminating all competition. They grow high up on trees. They can reach sunlight better. Lianas Vines Strangler Figs Epiphytes Roots that grow out of the ground (up to 15ft). Enables more nutrients to be absorbed from the shallow topsoils and provides support for the tallest trees. Buttress Roots Long, narrow downward curling tips. Solution to drainage problems and it means that leaves don't break with the weight of the water and they stop the accumulation of debris so photosynthesis is effective. Drip Tip Leaves Saprophytes Fungi plants which act as rainforest decomposers. The spores land on dead organisms, and then the plants begin to decompose it so nutrients are released into the soil. SOILS!! Nutrients from leaf litter rapidly recycled. Soil is red due to iron and aluminium oxides. Acidic soils with the minerals washed down by leaching. 10m The amount of rainfall is greater than the amount of evapotranspiration. Hydrogen in rainwater makes the soil acidic and the oxygen reatcs with nitrogen to make oxides which are soluble so they sink to the parent rock. This is why the rainforest has a rapid nutrient cycle. CAUSES OF DEFORESTATION MALAYSIA: *GOVERNMENT POLICIES:
- Poor people set up farms on cheap land.
- From 1956 - 1980s, 15,000ha felled. *FOOD:
- Large areas for cattle ranches. The beef is sent to MEDCs. (TRANSNATIONAL COMPANIES)
- Rapid LEDC growth so more food for more people. *PLANTATION FARMING:
- Growing coffee, sugar and rubber.
- 10% tax breaks for plantation farmers to increase cash crops.
- Extinction of Orangutans in Borneo. *LOGGING:
- Malaysia is world's largest exporter of timber and illegal logging in Borneo is common.
- Only mahogany and rosewood are needed so many other trees are killed unnecessarily.
- Second largest cause of deforestation.
- MEDCs import timber, giving LEDCs income. REMEMBER: MANY
PLANTATIONS CONSEQUENCES OF DEFORESTATION IN MALAYSIA *WORLD CLIMATE CHANGE:
- Burning rainforests released carbon dioxide.
- 1/2 the world's oxygen supply comes from the Amazon rainforest. (Photosynthesis) *DECREASE IN HARDWOODS:
- 3 billion m3 harvested annually.
- Companies don't replant them as it is expensive.
- Only 1 in 20 trees is valuable so many die for no reason. *SOIL EROSION:
- When trees are removed the soil is exposed for the first time in millions of years.
- This results in desertification as the nutrient cycle fails.
- in the 1970s, large areas of TRF were converted into palm oil so now soil fertility has to be maintained with fertilisers.
- Gullying is caused by continuous surface runoff. *DECREASE IN BIODIVERSITY:
- Extinction of thousands and species.
- Some have medicinal properties which can cure cancer and AIDS.
- Of the 203 mammals found in Malaysia 78% live only in forests.
- Malaysian forest support 5,500 species of flowering plants, 2,600 species of trees and 1000 species of butterfly - all are decreasing rapidly. *EFFECTS ON AMERINDIANS:
- Sharp decrease in tribes over last 40 years.
- The Bakun Dam in Sarawek led to the forced removal of 9,000 indigenous Kenyah people from the area.
- Less than 2,000 tribes are left in the Amazon Basin. REMEMBER: SO
HARDWOODS SUSTAINABLE MANAGEMENT OF TRFs IN MALAYSIA AND ECUADOR *NATIONAL FOREST POLICY:
- National Forest Act passed in 1977.
- It encourages:
~ Use of alternate timber sources.
~ Public awareness of forests.
~ Research into forests.
~ Involvement of local communities in forest projects *PERMANENT FOREST ESTATES AND NPs:
- PFE means certain areas are protected.
- 10% of the land has special conservation status ensuring the survival of the rainforest. *FOREST STEWARDSHIP COUNCIL:
- International organisation promoting sustainable forestry.
- FSC educates manufacturers and consumers about wood from sustainable sources.
- It aims to reduce demands for hardwoods * ECOTOURISM - ECUADOR:
- Delos Ecolodge:
~ 20 minute trek to lodges - no pollution.
~ Only 16 tourists in hotel at once - no path erosion or scared animals.
~Local guides - local knowledge, no pollution, employment of local people.
~Local building materials, e.g. bamboo and palm - Less pollution.
~ Local food - Grown using traditional methods, low food miles, employment of local people. INTERNATIONAL SOLUTIONS: *CONSERVATION SWAPS AND DEBT RELIEF:
~ Giving countries a monetary value in return for the protection of their rainforests. *CARBON SINKS:
~ 2008 Sierra Leone's border with Liberia became a NP.
~ The 75,000ha park is supported by NGOs such as RSPB as well as the European Commision and French government. *NORTH EAST INDIA: ELEPHANTS!!!!!!!!!!!!
- Elephants drag teak through forest - no pollution, no fuel costs, no roads built so no trees cut down unnecessarily.
- Selective logging and replanting TEMPERATE DECIDUOUS FOREST POND ECOSYSTEM:
* ALGAE, WATER LILY - PRODUCER
*POND SNAIL,DUCK - PRIMARY CONSUMER
*GREAT DIVING BEETLE, DUCK, HERON, PERCH, FROG - SECONDARY CONSUMER
* RAT TAILED MAGGOTS - DECOMPOSERS DISTRIBUTION:
North and south of the tropics, e.g. Europe, New Zealand, Eastern Canada and USA, Japan and Eastern China. CLIMATE:
Clear evidence of seasons
Winter: 3-8'C Annual rainfall 550-1500mm Trees drop their leaves in autumn to save water, which is hard to come by in the cold soils. Their leaves have lots of stomata, which they can potentially lose 830l of water through. They lose their leaves early in dry summers. Bluebells flower in early spring to avoid lack of sunlight due to the leafy canopy. Oak trees have thick bark to withstand the cold winter months. STRUCTURE:
*CANOPY - 20 - 30m
*SUB-CANOPY - Young trees nd tall shrubs.
*HERB LAYER - Non woody plants, e.g. brambels, bluebells and ivy.
*GROUND LAYER - Mosses close to soil. 30cm Dark brown as lots of organic matter provides nutrients. Leaching of nutrients is slow so good agricultural soils. Worms mix up the layers. EPPING FOREST USES: PAST USES:
Rich hunt deer.
Peasants grazed animals.
Collecting firewood and building materials.
Pollarding - allows tree to be cut but doesn't kill it as new shoots regrow. MANAGEMENT: *POLLARDING
*Protected by law since 1878
*SSSI - 1600ha
*Specific car parks and disabled access stops soil erosion.
*Allowing trees to die naturally, so STAG BEETLES can live.
*Controlled mountain biking so less soil erosion.
* Since 1981, 1,000 trees have been RE-POLLARDED.
*Managed grazing to maintain biodiversity, e.g. wild flowers.
*Preserving herd of fallow deer, so naturally grazing.
*Maintaining ponds maintaining diversity. REMEMBER Epping
Timber HOT DESERTS DISTRIBUTION:
30' North and South of the equator. Sahara, North Africa; Central Australian Desert; Gobi Desert, Asia. CLIMATE:
Precipitation: Less than 250mm
Evening: -18'C Saguaro Cactus Takes 130 years to mature to a height of 15m. Can absorb 1000l of water after heavy rain. 8000l of water can be stored in its consatinaed body. Thick waxy skin prevents water loss and reflects the sun's heat. Arms grow afer 75 years. XEROPHYTES: Roots 10m long to access water. Spikes instead of leaves reduce moisture loss and stop animals from eating it. Prickly Pear Cactus Takes 10 years to grow 3m. Yellow flowers. Fleshy stem to store water. Cacti seeds lie dormant until heavy rainfall. Rubbery to stop evaporation. Aloe Vera and Other Succulents EPHEMERALS: After heavy rainfall, the dormant seeds germinate, reproduce and die in a matter of weeks. CREOSOTE BUSH: Waxy leaves avoid water loss. Shallow widespread roots means all surface water is absorbed. Horrible smell deters predators. They can survive for thousands of years. LEDC DESERT: THAR,
Southern Pakistan and NW India HUMAN USES: *Hunting and gathering buy local tribes- only takeing what they need.
*Subsistence farming - only grow what they need and sell extra for a small profit.
*Irrigation - Indira Gandhi canal is 650km and built in 1958 and irrigates commercial farmland where cotton, wheat and crops can be grown. ISSUES: *Population pressure - rapidly growing LEDCs.
*Soil erosion - over cultivation and overgrazing. No plants so topsoil is blown away.
*Fuel - Shortage of trees so manure is used. Manure would have been used as fertilizer.
*Water Management - Salt walter used to irrigate land but the water evaporates leaving salty soil. Salinisation occurs. SUSTAINABLE MANAGEMENT: THE DESERT DEVELOPMENT PROGRAMME - 1977 in Rahajasthan
*Ber tree has been developed. Biger fruits that survive without little water. These can be sold for profit.
*Stabilising sand dunes by planting trees to stop them moving.
*Preserved irrgation and roads by building fencing to stop sand from blowing onto them.
*THAR DESERT NATIONAL PARK to protect 3000km2 of rare plants and wildlife. MEDC DESERT: SONORAN DESERT, ARIZONA HUMAN USES: *COMMERCIAL FARMING:
- Irrigation enables Marana to grow crops e.g. cotton, pecans and durum wheat for export. * IRRIGATION:
- In 1920 a new irrigation system was built underground, so no evaporation. Farmers and drinking. *MINERAL EXTRACTION:
- Lead, zinc and coal are economically important. * RETIREMENT MIGRATION:
- Warm climate, peaceful, golf, open spaces attract many OAPs to live in new complexes. *TOURISM:
- GOLF!!!!!!!!! In 2007 Marana began hosting PGA championships. ISSUES: *INCREASE IN MIGRATION:
- Developing area is becoming more and more populated so more housing is built which threatens habitats, e.g. PYGMY OWLS *TOURISM:
- Pressure is put on water supplies to provide drinking water, swimming pools and golf courses. MANAGEMENT: SONORAN DESERT CONSERVATION PLAN:
*Started in 1998 to preserve cultural and natural resources whilst accommodating rising population and economic expansion.
- Protects native plants.
- Protection areas for sites of ecological significance.
- Restrict building on hillsides.
- Design sustainable homes e.g. low flush, energy efficient etc. 10m
to water table Salt deposits. Very little organic matter due to lack of vegetation. Deep Ground water store (WATER TALE) Water drawn to surface due to high evaporation rate.