Sustaining Ecosystems 4.1-4.3 Geography OCR B

the concept of an ecosystem as being the interdependence of climate, soil, plants and animals

flora fauna and bacteria = biotic (living)

ecosystems are dependnet on the abiotic (non living components)

climate - the temperature and amount of rainfall determine which species can survive in the ecoystem

soil - the soil type provides the nutrient that will support different plants

water - the amount of water available determines which plants and animals can be supported.

if the biotic component changes, there will be a change in the abiotic

global distribution of polar regions and climate, flora and fauna

• North and South poles = Arctic and Antarctic

• cold climate with all year ice cover on land and sea

• in winter there can be 24 hours of darkness

• in the Arctic tundra, snow covers the land during the winter but melts in summer ot allow a short growing season for plants

• helps animals e.g. caribus to survive

• 98% of Antarctica is ice so very little vegetation grows

• in the oceans animals like seals and whales thrive in the Arctic and Antarctic

global distribution of coral reefs and climate, flora and fauna

• Found within 30’ north and south of the Equator in tropical and sub-tropical oceans.

• made up of thousands of coral polyps which live together in colonies.

• related to jellyfish they secrete calcium carbonate to make a mineral skeletop which helps build the structure of the reef.

• algea on coral produce energy through photosynthesis, giving coral its vibrant colour.

• sea grasses found in the Carribean sea provide shelter and habitat for reef animals (young of lobsters) and food for reef fish (herbivores)

global distribution of tropical rainforesst and climate, flora and fauna

• located near the eqauator e.g. Africa and Brazil.

• contain 50% of all plant and animal species

• temperatures remain high all year as the sun is high in the sky so there are no seasons.

• annual rainfall is high, over 2000.

• rains daily as the atmosphere is humid due to the moisture in the air from rainfall and vegetation.

• vegetation is mainly trees, with the tallest trees in the emergent layer and thick layers of vegetation compete for sunlight.

• the leaves are dark green and have drip tips to shed excess water to the ground

• vines grow around the trunks and connect layers of the forest, covers animals

• poison dart frog has posion and is brightly coloured to warn predators

global distribution of hot deserts and climate, flora and fauna

• located between 5’ and 30’ north and south of the Equator. usually found on the west coast of continents

• due to their location near the tropics, deserts experience 15 hours daylight in the summer and 10 hours in the winter.

• temperatures can reach 36’c with extremes of 50’c

• at night temperatures can plummet to freezing

• most plants are xerophytic, adapted to an environment with very little water

• cacti absorb large amounts of water during the rare periods of rain.

• they have thick spiky, waxy leaves to reduce the loss of water through transpiration and to prevent animals eating them

global distribution of tenoerate forests and climate, flora and fauna

• between 40’ and 60’ north and south of the equator

• no extreme temperatures - average annual temp = 10’c

• forests mostly made up of decidious or evergreen trees

• an insulating layer of cloud helps to keep the temperaure mostly above freexing.

• precipitation falls throughout the year, snow is common in mountainous areas during the winter, unlikely the fall at lower areas

• animals are adapted to changing ecosystens, including some that hibernate.

• some animals migrate to warmer places and some hibernate to escape the cold.

global distribution of Savanna/Temperate grassland and climate, flora and fauna

• between the latitudes of 5’ and 30’ north and south of the equator within central parts of continent including Mexico and the Brazillian highlands.

• ranging from the fringes of the rainforest to the beginnings of the desert ecosystem, climate can change from tropical wet to tropical dry.

• temperatures = high throughout the year

• cloud cover is limited for most of the year, allowing for daily temperatures of 25

• two seasons = a longer dry season and shorter wet seasons

• temperate grasslands = cooler

• summers = very hot reaching 38’c , winters = very cold as low as -40’C

• vegetation doesnt grow as rapidly or as tall as that of the tropical grasslands

• grasses e.g. buffalo and feather grass grow to arund 50cm in height

• providing a goo habitat for burrowing animals such as rabbits and large herbivores e.g. kangeroos.

distinctive characteristics of a tropical rainforest ecosystem - soil

• soils = latosols

• despite the vast amount of vegetation, soils in the trf are deep but not rich and lack minerals

• fertility of the soil is only sustained by the rapid replacement of nutrients from dead leaves

• the humus layer (decomposed layer) = very thin

• minerals e.g. calcium and magnesium = leached quicklu through the soil due to high amounts of rainwater

• top layers of soil = red due to high conc of aluminium oxide and iron oxide

• there is rapid chemical weathering (by organic and humic acids dissolved in rain water) throughout the soil profile, particularly of the orgininal rock on which the soil has formed (parent rock)

distinctive characteristics of a tropical rainforest ecosystem - water cycle

• plant roots take up water from the ground

• rain is intercepted as it falls due to the rainforest canopy

• as the rainforest heats up, the water evaporates and transfers back into the atmosphere

• clouds form to make the next days rain

• ^convectional rainfall

• the removal of trees by exploitative practises means that there is less moisture in the atmoshpere and rainfall declines, this can lead to drought.

distinctive characteristics of a tropical rainforest ecosystem - nutrient cycle

• nutrient cycling is rapid in the rainforest

• the forest floor is ho and damp which enables dead leaves to decompose quickly.

• decomposition occurs within 3-4 months in the TRF

• as organic material e.g. leaves decayes and is recycled so quickly by nutrient hungry plants and trees, few nutrients ever reach the soi

• why nany trees have their roots close to the surface of the ground, they are posied to take advantage of any nutrients available

• the greatest store of nutrients is in the biomass - the living plants and animals

interdependence of climate, water, soil, vegetation, animals and human activity on the TRF

• the warm and wet climate means that dead plant material is quickly decomposed by the fungi and bacteria on the forest floor, this makes only surface soil high in nutrients, mesning plants can grow quickly

• plants pass on their nutrients when they are eaten by animals. the dense vegetation provides lots of food therefore animal populations are high. many plant and animal species have formed symbiotic relationships (they rely on each other for survival)

• changes in the forest ecosystem such as deforestatin can have knock on effects within the whole ecosystem. deforestation increases the amount of co2 being absorbed which adds to the greenhouse effect and changes the climate.

• trees interecept and take up a lot of water, and release it back into the atmosphere, providing moisture for further rainfall. deforestation means the climate may change and the risk of drought increases affecting plants and animals that live in this ecosystem.

goods in the tropical rainforests

• the products people obtain from the forests

• foode.g. banana, cocoa, coffee can be sold and exported (good for the ecomony)

• raw materials (anything that can be sold thats tangible) e.g. rubber, wood (timber) oil.

• health - 25% of modern medicines are from rainforest ingredients e.g. vincristine helped children with cancer

services in the tropical rainforest

• the jobs forests do for them

• water acts like huge filters that purify water before people drink it

• prevents flood (trees) prevent drought (rain)

• energy, indigenous people use wood from the forest as fuel for cooking and heating

• large dams are built on rivers in rainforests in order to generate hydroelectric power 2/3 of Brazil’s energy is generated by this.

• trees absorb co2 (greenhouse gas) from the air, cooling the climate

• acts as a carbon sink, removing and storing about 15% of our carbon dioxide emissions.

human impacts in the tropical rainforest - logging

logging - felling trees for timber, indigenous people did this on a small scale for years

• with the building of roads iinto rainforests, logging is done on an industrual scale

• the timber is often exported to the USA or Europe for furniture and construction. tropical hardwood trees like mahogany are very popular

• Brazil’s space research agecy INPE recorded 5,110 square miles of deforestation in the amazon, nearly 17x NYC

• affects the forests natural resources, damages habitat, food, biodiversity for people + animals

• trees release 20 billion tonnes of moisture in day, without rain, dry forests cause drought and widlfire

• 100,000 species become extinct yearly

• reoving trees means that more sunlight reaches the floor and it dries out, no nutrients in the soil

human impacts in the tropical rainforest - mineral extraction

• for gold, copper and diamonds

• forest and soil are removed from large areas for open-cast mining.

• Chemicals used in the mining process pollute rivers

• oil and gas are also found feep below ground, drilling for them can lead to air and water pollution. building roads or pipelines leads to further destruction of rainforests

• economic benefit, lower mining cost

• in the amazon mining caused 1.2 million hectares of deforestation between 2005-2015

• brazil is the second largest ion ore producer, making up about 74% of the country’s mining sector

• 1/3 of the world’s forest may be effected by mining

human impacts in the tropical rainforest - agriculture

clearing trees in order to use land

• poor farmers clear small areas of forest to feed their families, when the soil loses fertility, they move on to clear a new patch of forest.

• in the amazon, most farming is carried out by big companies that clear vast areas of land to grow soya beans or graze cattke.

• brazil is one of the largest producers of beef and soya

• since the beginning of colonization in the 1960s around 15% of the amazon rainforest has been removed through agricultural processes

• accounts for 4% of global gdp, in some developing countries its more than 25%

• cattle ranching counts for 80% of deforestation in the amazon

• responsible for the release of 340 tonnes of carbon emissins per year 3.4% of global emissins

human impacts in the tropical rainforest - tourism

• doesnt chop trees town

• some countries have created portected areas of forest where deforestation is banned

• indigenous people can be involved in protecting the forest and continue to lead their traditional way of life

• foreign tourists like to visit rainforests and this can help the local community and economy

• out of the 6.6 million tourists in brazilonly 2% make it to the amazon

• income spent directly in the local economy helps put a monetary value of forest employment

• offers employment

• camps and lodges are being built for satisfaction of ecotourists, can destroy ecoyststems and habitats

Monteverde Cloud Forest Costa Rica - attempts to sustainably manage an area of tropical rainforest (wider)

due to feforestation reaching its peak in 1985 in Costa RIca and 32,000 hectares/year of trees being cut down

• the government started passing laws/creating protected areas of forest

• they gave land owners financial incentives in order to protect the forest by paying then to not turn it into farmingtand

• today there aare 28 national parks in COsta Rica dn 24% of the land area is protected

• agroforestry : trees and crops are being grown together, crops thrive from the tree cover and lack of soil erosion, crops get nutrients from the leaves that fall off the trees

• selective logging: trees are planted to replace the original forest, although its good that the trees are being replaced, the forest will then lack biodiversity and will struggle to grow new plants

Monteverde Cloud Forest Costa Rica - attempts to sustainably manage an area of tropical rainforest (focused)

• costa-rica welcomes millions of tourists per year

• the cloud forest spans 10,500 hectares and is one of the most popular tourist attractions in the country

• 3,000 plants, 400 species of bird, 100 species of mammals and thousands of insect species

  • rich in biodiversity

• the roads are unpaved so access is only possible by 4×4 vehicles

• tourists have specific trails and paths tourists need to stick to

• posters are displayed across the entrace telling tourists to

  • stick to guided paths

  • respect the wildlife by not touching/feeding the animals

  • limit noise by turning off phones

  • no flashphotography

Monteverde Cloud Forest Costa Rica - attempts to sustainably manage an area of tropical rainforest - pros and cons

Pros:

• 250,000 tourists/year

• important for the local economy

• harmonious relationship maintained between people and wildlife

• buildings for tourists are made to be eco-friendly

Cons:

• increasing number of tourists means accommodation needs to be built - causes loss of forest land

characteristics of the Arctic

• lies 33.5’ northof the Equator, one day a year when sun never sets and one where it never rises (solstice)

• has a vast ocean at the centre, surrounded by countries

• land masses surrounding the ocean vary from dramatic mountains to frozen plains and archipelagod

• much of the land is permafrost, ground is permanently frozen to a great depth, snow covers the land, but may thaw in arctic months

• home to 5 million people

• flora - lichen and mosses in arctic reigon

• tundra - low rowing shrubs and small flowering plants e.g. Arctic popy

• fauna - whales, seals, wolves, snow goose - all specificallly adapted to live in harsh climate

• soil - thin and poor quality, very few plnts

• underlying rock weathers slowly due to low temp

• permafrost sits below the active layer and remains frozen all year round

• buildings built of stilts to prevent damage to permafrost

characteristics of the Antarctic

33.5’ south of the Equator, very dry, less than 3cm of precipitation, making it a desert

largest ice shelves = ross and Ronne but many land based ice sheets an dglaciers

mountainous peninsla extends out form many body of continent, where many spefici bases are located (the bit toursists cisit)

mountains rise almost 5000m high

highest of all the continents

ice covered land mace = 13 million km

larger than the whole of Europe

doubles in size during wintermonths as sea ice grows out from the coast

flora - mostly lichen and some mosses, phytoplankton in ocean

faunta - no indigenous terrestrial mammals, penguins seals and whales rely on sea for their food and land provides a habitat for breeding

soil - antarctic soils can be loose, soft sandy frozen hard rocky, very little organic matter to support more than mosses or lichens

interdependence in polar environments

• the low biodiversity of cold dry climate means this interdependence is fragile and easily disrupted or damaged

• if temperatures increase e.g. due to global warming, more sea ice melts in the summer, animals such as seals and polar bears, so if it disappears these animals

• antarcica has very few plants, pytoplankton is the most important producer in the sea, rely on nutrient-rich sea currents rising o the surface from deep waters, if this doesnt happen the whole ecosystem could collapse

• the tundra in summer has greater plant cover allowing surface plants to absorb heat from the sun and preventing the permafrost below from thawing

• the permafrost provides water and diluted nutrients for plants and any damage to the permafrost will cause it to melt, leading to flooding and stopping plant growth

• it also releases trapped greenhouse gases (methane) - leading to increased global warming and changed to the climate of cold environemnts, threatening plants and animals as a cycle

cold environemnts can have very low biodiversity (particularly Antarctica)

meaning that when the population of one species changes it can affect the population of dependent species e.g. changes in the number of Arctic hares affect the number of Arctic foxes. global warming is causing some species to move towards the poles, where it is cooler to cope

those species that have already adapred e.g. polar bear have nowhere else to go and are at risk of exctinction

value of polar environments

• approx 70% of the world’s freshwater supply is locked in ice - the Arctic reigon holds roughly 10% with the Antarctic holding 60% of the world’s freshwater supply

Human impacts on the Arctic -

scientific research

• RSS David Attenborough will add to pollution within the Arctic waters

• research stations and ships produce chemical and sewage pollution, they have also dumped rubbish

indigenous people

• only take what they need so dont upset the balance of the ecosystem

• many now live in towns and cities e.g Canada, these urban areas impact the environment through waste disposal, air and noise pollution from vehicles, and heat from buildings which melts permafrost

whaling

• bowhead whale lives all year round and hunted to almost excitction

• still hunted by Iceland and Norway

• humpback whales remain the main species still hunted in waters

fishing

• the Arctic waters provide 70% of the world’s white fish catch

• reduced fish populaitons have knock-on effects onother species n the food chain

mineral extraction

• russia has exploited a large portion of the tundra to extract minerals

• the extraction process of metals produces pollution, damaging local ecosystems

energy

• heat from terminal buildings, worker’s homes has led to permafrost melt and buildings subsding

• oil spills are difficult to clean up and can harm habitats

• pipelines are used to transport oil and gas but have melted the permafrost below

tourism

• increases shippung and air travel, leading to water and air pollution

• increased ris of boats grounding, causing oil spills

• trampling damages fragile vegetation and erodes the landscape, leaving paths

• as decomposition rates are so slow in the cold temps, litter and waste disposal damages habitats and threatens wildlife.

small scale example of sustainable management- touism

svalbard = archipelago in northern europe, permanent population of 2700

lowest temp = -20 in winter and highest = 7 in summer

• extreme tourism has grown popular in recent years, with poeple visiting for unique wildlife (e.g. polar bears), glacier walks, veiws of northern lights and extreme activities on oveer. in 2011 70,000 people visited Longyearbyen, 30,000 were cruise passangers, tourism provides jobs for 300 people

• more tourism requires more building and infreastructure providing challenges for the cold environment.

• over 60% of Svalbard is protected, e.g. strict limits on the use of off road vehicles

• tour operaters and visitors have to get permission to visit the nature reserves

• different zones have different levels of protection

• tourism areas = fewer regulations

• Ny Alesund is a town run by a company called Kings Bay AS. most northernly settlement in the world

• populaiton = mostly scientific researchers

• the company and researchers have taken actions to limit the impact of tourism

• cruise ships are required to tell passengers about the rules visitors have to follow

• visitors have to stick to the 1.5 km paths around the settlement and htere are loads of boards with environmentla info for touriss

• ships can only remain anchored for 2-3 hours to reduce pollution e.g. disel fumes entering the local environment

global example of sustainable management - Antarctic Treaty

Antarctica is a global common - a part of the Earth not owned or managed by any single country, their shared resources belong to everyone and they require a cooperative approach to management by global institutions

• legally binding agreement that governs antarctica and the surrounding southern ocean

• originally signed in 1959 by 12 nation sand now 56 countries are signatories

• ensures that all nations have the right to freely inspect any activities taking place in the region

• prohibits new territorial claims

• promotes freedom and cooperation for scientific investigation

• can only be used for peaceful puposes, no military use

• visitors have to wear disinfected over-boots when on the continent

• restrictions on eating, drinkin gand toileting whilst ashore

• only 100 visitors are allowed to land at any one time

• cruise ships with over 500 passengers cannot stop

strenghts and weaknesses of the Antarctic Treaty

strengths

• the Antarctic Treaty is widely recognised as one of the most successful international agreements

• it has lasted over 60 years with no major problems

• it promotes peaceful cooperation and has helped to prevent military conflicts and tensions

• it promotes scientific research and environmental protection

weaknesses

• if countries disagree about an issue, one country can stop a resolution going forward

• there are no legal penalities for violating agreements

• sometimes it takes a long time for decisions to be made because o fthe consensus based decision-making process