Flashcards in Ecosystems Deck (118):
Definition of an Ecosystem?
A system in which organisms react with eachother and their environment
Definition of ecology?
The study of communities of living organisms and their relationship to their living environment
Definition of biomes?
Large areas cutting across continents yet each with their own characteristics
What are zones?
Units within biomes
What are Habitats?
More specific conditions with an adapted community
What is biomass?
The total weight of all organisms including dead plant matter
What is the aim of conservation areas?
To protect and restore natural ecosystems. By protecting species and their habitats to support the biodiversity.
What are other reasons for developing ecological conservation areas?
Improves appearance of an area- e.g. Brownfield sites
Stimulating investment to encourage multiplier effect- e.g. Tourism
Managing flood risk- e.g.- afforestation
How do we afford conservation areas?
Rely on volunteers
What is the governmental principal advisor on the natural environment?
3 examples of conservation areas?
SSSI- Natural England
National nature reserves- National trust and RSPB
Local Nature reserve
How is Sheffield blue loop funded?
By Natural England and the National lottery
How is the blue loop managed?
By a partnership of Groundwork Sheffield and the River Stewardship company
What is the aim of the blue loop?
The support and engage local communities along the waterside environment
History of Blue loop Sheffield?
The river don was used for industry but was difficult to navigate.
The opening of the Sheffield and Tinsley canal in 1819 provided the infrastructure for mass export of coal and steel.
In 1848 railway was introduced.
Decline of canal and associated industries.
Native species to blue loop?
Fish- fish ladders have been built to allow upstream movement
Otters- secluded nesting and breeding habitats provided
Butterflies- nettles along the canal provide perfect habitat
Benefits of the scheme?
Encouraged tourism and private investment
Reduced flood risk
Provides recreational activity
Where is the tropical equatorial rainforest located?
Within the tropics, between the Tropic of Capricorn and Tropic of Cancer
Lies within 5 degrees of the equator
Figures on tropical biome?
Rainforest covers less than 5% of the earths surface. It halved in 200 years. Support 50% of all living organisms
Temperature characteristic of the rainforest?
A low diurnal temperature range. Day 28 night 22
Rainfall in the rainforest?
Daily conventional storms
2M of rain each year
Violent storms occur in afternoon following intense heat
Other characteristics of the rainforest?
A year round growing season- average day 12 hours of sunlight
High humidity- rapid evapotranspiration
Number of species and trees found in the rainforest?
50 million species of animal
480 tree species per hectare
What is the stratification of the rainforest?
Emergent layer- 30-40m
Describe the soil in a rainforest?
Rapid chemical weathering of bedrock
Soils are fragile and depend on leaf fall for nutrients
The rapid decomposition of litter and work of biota results in a thin humus layer
What are the main causes of deforestation in the Amazon?
Farming- eg Cattle ranching, Cash crops plantations e.g. palm oil and soya (used to feed chickens in U.K. Fast food chains)
Mining- Amazon is the largest source of iron ore
Logging- timber production
Further causes of Amazon deforestation?
Road construction- The Trans- Amazonian Highway extends 6000km into Brazil's interior
Settlement growth- migration from poorest parts of Brazil
Environmental impacts of Amazonian deforestation?
Shifting cultivation not successfully carried out, plots lost fertility and yields decline. Knock on effect to natural cycles and species diversity.
Mononcultures demand high amounts of fertilisers and pecticides. Leaching enters water killing fish
Positive economic impacts of Amazonian deforestation?
HEP Project delivers power for mining. Minining employs over 7000 workers
Who came up with the process of nutrient cycling?
How do the nutrient cycling diagrams work?
The thicker the arrow the larger the flow.
Difference between nutrient cycle in rainforest and woodland.
Soil is larger in woodland
Higher precipitation input in rainforest therefore higher runoff
Larger litter in woodland
Weathering input higher in rainforest
Inputs into nutrient cycling?
Outputs in nutrient cycling?
Processes in nutrient cycling?
Plant nutrient uptake
Stores in nutrient cycling?
Function of reducer organisms?
Return remaining nutrients back to the soil for plant growth
How much energy is lost at each trophic level?
How are energy losses illustrated?
What is urban wasteland?
Abandoned land that has been left for nature to take its course
Examples of urban wasteland?
Brownfield sites- former factories, route ways and railways
First step in wasteland succession?
Pioneer species colonise bare surfaces, death of these adds humus and moisture to the layer
Second step in wasteland succession?
Seed plants grow in sheltered cracks with moisture available
Final step of wasteland succession?
Tall herbs outcompete smaller species where nutrients are.
Taller grass and bushes thrive in deeper soils
Positive non-native species?
Tomato and corn
Figure on Japanese knotweed?
Has doubles its coverage in the last 20 years. Mostly present along Londons waterways
How can Japanese knotweed be killed?
Strong herbicides and burning roots
What is the soil profile of the tropical equatorial rainforest?
Iron and aluminium build up gives the soil a dark red colour
Clays produced further down
Some redeposited silica gives a yellowish colour
Weathered bed rock and parent material
Why is leaching high in the tropical rainforest?
Statistic on Japan and need for logging?
Japan is solely responsible for using 11 million cubic metres of equatorial hardwood each year
Example of mining in the Amazon?
Carajus in Amazonia is home to the largest source of iron ore
What are other reasons for deforestation?
Road construction- Trans Amazonian highway
Statistics about Brazil's people?
Over 25 million landless people
Background to deforestation?
1950's- beginning of mechanised logging and development of integrated transport and infrastructure has caused the deforestation rates to soar
Environmental impacts of deforestation?
Approx 20,000 tropical equatorial rainforest species become extinct each year.
Increased flooding- change in rainfall patterns
What roles do tropical equatorial rainforests play in the carbon cyle?
A tropical equatorial tree is a carbon sink for 22.5kg of carbon dioxide each year.
Burning the rainforest accounts for 20% of the global atmospheric carbon dioxide each year
Economics impact of deforestation?
Workers exploited by corrupt government or TNC powerhouses. The economic benefit rarely trickles down.
The world bank has supported plans to expand timber production in Congo and Indonesia
Social impacts of deforestation?
The Quichua Indians of Tina, in Ecuador. Native people who inhabit rainforest. Deforestation destroys their social cohesion, language, culture and tradition.
Government corruption in Brazil?
Brazilian government offers rainforest land to those better off financially- sidelining smaller settlers
By offering subsidies to large commercial operations.
What export is Brazil a world leader in?
TNC's frequently from USA have made Brazil a world leader in beef and soya exports
Social tensions in the Amazon?
Miners try to illegally steal land from native Indians.
The traditional Yanomami and Yekuana tribes oppose mining.
New settlers bring diseases- Panara Indians have all but been wiped out
What is an example of an agribusiness?
A large US transnational food, agricultural, financial and industrial agribusiness
Background figures on Cargill?
Employs 138,000 people in 67 countries
In 2009 recorded net profit of over $3.3 billion.
We will develop ways of reducing environmental impacts and help conserve natural resources
We will invest in communities where we work
How is Cargill environmentally unsustainable?
Arrived in Brazil in 1965
Between 2002 and 2004 annual deforestation rates have jumped from 15,000 to 28,000 hectares where Cargill operates
Area where Cargill operates?
What is the predominant use for soya?
97% for animal feed
Fact in Brazil and U.K.?
78% of UK soya beans are from Brazil
Example of unsustainable tourism?
In 1992- The Bwindi Impenetrable Forest was upgraded to a national park. The indigenous Batwa Pygmies were removed.
When are non-native species bad?
When they compete with native plants, have no predators
Niches along routways?
Restricted access- railways
Halophytes from salt spreading
Examples of adapted plant communities?
What is vegetation succession?
How plant communities evolve and develop over time
What is each stage in succession called?
What occurs if succession occurs without being disturbed?
Vegetation is in equilibrium with the environment
Definition of Climatic climax?
The final stage of natural succession where vegetation is in equilibrium with the climatic and environmental conditions.
What are the 2 types of succession?
Primary and secondary
Describe primary succession?
On surfaces which haven't had previous vegetation growing their. E.g.- bare rock after a volcanic eruption
Describe secondary succession?
On surfaces which have been colonised by vegetation previously, but have since been changed or destroyed.
How do the pioneer species induce growth of the next sere?
Hardier plants die and decompose by bacteria
Weathering breaks down rock and adds to humus
What does each seral stage have?
Increase in height of plants and no. Of species
Hydrosere step 1.
Spores of algae and mosses blow onto water surface creating a pioneer community of floating vegetation
Hydrosere step 2.
Floating and submerged water weeds (lillies) can then develop
Hydrosere step 3
These weeds trap sediment at the waters edge to allow marsh plants such as reeds and rushes to establish
Hydrosere step 4
Continuing sedimentation of silt and plant debris slowly builds which will eventually rise above water
What is a Carr?
A low lying area of land emerging from a fresh water pond or lake
Hydrosere step 5
This will produce a Carr of small shrubs and trees such as willow and alder
Hydrosere step 6
Finally the climatic climax of oak and ash trees can emerge. Dominating the whole site once the pond silts up entirely
Features of the temperate deciduous woodland biome?
Dominant oak trees- ave 20m
Leaves have large crowns
Thick leaf litter
Brown earth soil
Stratification in deciduous woodland?
Oak, ash and chestnut trees
Rowan, holly and hazel- shrub layer
Brambles, bracken and flowering plants e.g.- bluebells - field layer
Mosses and lichens- ground layer
Describe brown earth soil?
Deep, well drained, fertile, and support and large amount of fauna
Example of deciduous woodland?
Hayley wood in Cambridgeshire
Why is brown earth soil ideal for growth?
Decomposes break down leaf litter to rich, dark brown humus
Earthworms and rodents mix the layers to aerate the soil- prevent leaching and water logging
What is a plagioclimax
When succession is disturbed by human intervention, preventing climatic climax
Where are the heather moorlands?
History of Heather Moorlands?
Three thousand years ago was the climatic climax.
Woodland cleared for farming and soils deteriorated.
The efficient nutrient cycle was distorted and ground was exposed to heavy rainfall.
What happened after woodland was cleared?
Soils were left eroded and leached of its nutrients.
Resulting in thin, less fertile, peaty podsols
What was the result of podsolization?
Hardy plants colonised upland areas- grass, bracken and heather (mixed moorland vegetation)
A valuable, evergreen forage plant. Major food douse for hill sheep. Staple diet of red grouse.
What are the 4 heather phases?
Building phase - most productive
How and why is the heather burnt?
In a 10-15 year rotation in areas of 1 hectare at a time.
Controlled burning is to keep heather in its building phase
What would happen if the burning stopped?
Secondary succession l
Scrub and birch followed by climax community
How much sunlight gets to the forest floor in the rainforest?
As little as 1%
Adaptations of plants on the forest floor?
Large flat leaves
Adaptation of Mimoca Pudisa
Folds its leaves inwards or droops when leaves surface is contacted
How are the canopy leaves adapted?
Approx 80% have Drip tip leaves- sheds water quickly
Example of symbiotic relationship?
Epiphylls growing in puddles on leaves surface, steeling sunlight
Example of sustainable tourism?
Loss of 80% orang-Utan habitat in 20 years.
Sepilok Rehabilitation centre- 1964
Background to oil spill?
2010 Deepwater Horizon Oil rig disaster in the Gulf of Mexico
Worlds largest accidental oil spill
Environmental consequences of oil spill?
48km plume of oil
Impact on food webs
Marshland ecosystems covered in black poisonous sludge
80% of jobs in fishing and tourism threatened
Oil clean up?
Pom-poms- collected oil around rocky areas
Containment booms- trapped oil by sticking to booms
Natural processes- weathering and tidal action
3/4 of spill removed
Which species did the oil threaten?
Marshlands and coastal grassland
Turtle species- 500 dead
Blue fin tuna
The Antarctic Treaty?
Twelve nations signed
Figure on tourism to Antarctica?
Tripled in last 20 years
Which cities are at threat from rising sea levels?
New York and Venice