ecosystems
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To understand the global distribution of three ecosystems so that we can explain the variations
within the characteristics of each.
To know that, on a world scale, climate is the main factor determining the nature and extent of natural vegetation cover.- to understand the term ‘biome’.- to learn the names of the world’s main biomes.- to be able to describe the changes in vegetation cover from the equator to the polar regions.
Starter: Tropical Rainforest - Brazil
Starter: Tundra in Colorado
Starter: Desert in Merzouga, Morocco
To understand energy flows within ecosystems so that we can successfully answer and exam question.
To understand energy flows within ecosystems so that we can successfully answer and exam question.
To understand energy flows within ecosystems so that we can successfully answer and exam question.
To be able to understand the material cycling and stores in the ecosystem so that we can successfully answer an exam question.
For your notes…
To be able to understand the material cycling and stores in the ecosystem so that we can successfully answer an exam question.
To be able to understand the material cycling and stores in the ecosystem so that we can successfully answer an exam question.
For your notes…
Nitrogen Cycle
• To be able to understand that nitrogen cycles indefinitely through the Earth system and will understand the places that it is found on Earth.
• To be able to understand that nitrogen is essential for living things.
• To be able to understand that the cycle is complex and nonlinear traveling between organisms and the physical environment.
Abiotic sourceNitrogen cannot be used in this form
Nitrogen can be broken apart by lightening to make it usable. (or heat)
Abiotic sourceNitrogen cannot be used in this form
Dissolved nitrate can be returned to the atmosphere by bacteria in this process. Bacteria associated with Legume plants.
Convert atmospheric bacteria in to nitrates in the soil via ammonia.
From soils and water (N03-) Inorganic nitrate
Nitrate is commonly used by plants. Animals get nitrogen by consuming plants.
Need Nitrogen to make amino acids, proteins, DNA.
Passed on to trophic levels through feeding.
Decompose – nitrogen is converted into inorganic forms.
Carbon Cycle
Tropical Rainforest BiomeGeneral characteristics
Constant high temperaturesVery high rainfallVegetation grows quicker than any other place in the worldThis produces the greatest amount of Organic matter, referred to as net primary productivity (NPP)NPP = the amount of energy fixed in photosynthesis minus the energy lost by respiration in plants, measured in grammes per square metre (gm-2 year-1)
NPPNet primary production (g/m2/yr)
High energy 1. Rainforests (2,200)
2. Deciduous forests (1,200)
Average energy 3. Tropical grassland (900)
4. Coniferous forest (800)
5. Mediterranean (700)
6. Temperate grassland (600)
Low energy 7. Tundra (140)
8. Deserts (90)
Describing location
• Between latitudes 10°N and 10°S of the equator.
• Diurnal (during the day) temp range of 10°C.
• Evening temperatures rarely fall below 22°C
• Due to the presence of afternoon cloud temps rarely rise above 32°C
• Most afternoons have heavy showers• At night with no clouds insulating
temperature drops
Tropical Rainforest Biome
ITCZ – Inter tropical convergence zone
Near the Equator, from about 5° north and 5° south, the northeast trade winds and southeast trade winds converge in a low pressure zone known as the Inter tropical Convergence Zone or ITCZ.
Solar heating in the region forces air to rise through convection which results in a plethora of precipitation. The ITCZ is a key component of the global circulation system. In the Northern Hemisphere the trade winds move in a southwesterly direction, while in the Southern Hemisphere they move northwesterly. The point at which the trade winds converge forces the air up into the atmosphere, forming the ITCZ.
.
In the Northern Hemisphere, the wet season occurs from May to July, in the Southern Hemisphere from November to February .
There's a diurnal cycle to the precipitation in the ITCZ. Clouds form in the late morning and early afternoon hours and then by 3 to 4 p.m., the hottest time of the day, convectional thunderstorms form and precipitation begins. These storms are generally short in duration
1.Using only evidence from the diagram above, describe three characteristics of the natural vegetation in areas of tropical rainforest. [3 Marks]
2.Explain the relationship between the natural vegetation characteristics and the climate of the tropical rainforest. [4 Marks]
• The park is the largest forest reserve in South America and covers an area greater than 5.6 million acres.
Case Study: Human Impacts/ Positive Management
• Jau National Park – Brazil
Summary• A UNESCO World Heritage site• The largest protected area in the Amazon Basin• Over 6 million hectares• One of the planet’s richest regions in terms of
biodiversity. • The site protects key threatened species,
including giant arapaima fish, the Amazonian manatee, the black caiman and two species of river dolphin.
Black Caiman
Amazonian Manatee
Pink river dolphin
Spotted Jaguar
International Designation
• 1993 Mamirauá designated a Wetland of International Importance.
• 2001: UNESCO Man & Biosphere Programme (20,859,987 ha).
Land Tenure • The Federal government owns 98.3% of Jaú National Park; • 1.7% (almost 39,000 ha is comprised of 31 legally held properties
which are to be repossessed by the state. • a further 1.5% of government land on the Unini River is settled by
175 families without ownership title which the government is seeking funds to repossess.
PeopleThere are no indigenous inhabitants in the area todayThe rural population of caboclos aredescendents of Portuguese originally attracted by rubber collecting, and the indigenous people. 112 families live along the Unini river,Most were born in the region or in the state, and still live in traditional ways, on manioc cultivation, hunting, fishing, gathering turtles and ornamental fish and the collection of timber, rubber, nuts, oils, resins and gum.
Visitors and facilities• There is no road access to the Jau National Park beyond 100 km. It is only
accessible by river, so rented boats are the usual means of access. • Visitors need prior authorisation from the Park Director at IBAMA
headquarters in Manaus. • At the entrance, there is a recently-built visitors’ center, a houseboat for
the Park guards and housing for researchers and visitors. • At present there is no registered tourist agency arranging trips to the Park,
but in 1998 there were 885 visitors.• The Rio Negro landscape of Anavilhanas attracts river excursions from
Manaus en route to Jaú which have little environmental impact and provide an income.
• 80% of the county of Novo Ayrão is natural or Indian reserves, and might come to depend on tourism to enhance local incomes.
• There are houseboats for official visitors.
Conservation Management • Jaú is one of the few conservation units in the Brazilian Amazon with a
management plan that is both complete and being implemented. • This evolved between IBAMA, the Vitória Amazônica Foundation, local
municipal governments, research institutions and members of the extraction and tourism industries following guidelines prepared by IBAMA.
• Nearly 60 expert researchers from 13 different institutions contributed. • To integrate local residents with conservation initiatives within the Park
there are periodic meetings with residents to disseminate planning decisions and to provide training for environmental education professionals and research on the economic valuation of natural resources.
Fibrarte Project• In Novo Airão, one example is the Fibrarte
Project, set up to stimulate the use of natural fibres such as aruma, Schynosiphon sp. to produce high quality handicrafts.
• Since 1993 the main body supervising research, planning and management and education in the Park has been the Vitória Amazônica Foundation.
The Management Plan has three phases:
1. Protection, minimizing impacts and integrating with neighbours
2. Research into and protection of biodiversity/ monitoring3. Specific activities:
• Regulation of the use of Park resources, such as turtles and ornamental fish, survey, research and monitoring, public use, recreation and education about the natural processes of the area, public relations, encouragement of crafts, management training for local people, political integration local and regional, administration and maintenance, and sources of sponsorship.
• A zoning plan defines four management zones: 1. Primitive: of great natural value, with minimum intervention and
maximum protection; 2. Extensive use: some human activity; 3. Intensive use: already altered by man4. Especial use: the Park services core.
Threats• Deforestation is currently the main threat - the Complex
suffers from being both very productive and relatively accessible.
• Jaú National Park is in good condition. The grass fires, blow-downs and floods which do occur being part of the natural order of the forest.
• But there are around 250 families who fish in the Unini river quite intensively.
• The Park has also been invaded from the surrounding area and is in great need of a better infrastructure. For instance, there are only two Park rangers at the entrance, making it easily invaded by outsiders who remove fish and turtles which may affect future stocks.
• However, in the surrounding region no development projects such as hydroelectric dams, gas pipelines, power lines, highways, logging or mining exist or are foreseen.
The Daintree Rainforest,Queensland Australia
(Human Impacts)
LocationThe Daintree forest lies on the North East coast of Australia in the area called Queensland, it's a part of the larger area known as the wet tropics.
It runs parallel to the other Australian wonderland the Great Barrier Reef
The wet tropics are a world heritage site, covering an area of 900,000 hectares (1/2 size of Wales)
Daintree Rainforest
Australia
SYDNEY
MELBOURNE
BRISBANE
CAIRNS
PERTH
EQUATOR
GREAT BARRIER REEF
• This is a CASSOWARY • It cannot fly.• It can ONLY be found in the
Daintree forest• It is close to wild extinction-
only 500 left.• Vital to ecosystem as scatters
seeds of over 100 species of plants
• Without this bird eating seeds and then dropping them further away seeds would not spread through large areas of forest.
• It is a protected species and since 1999 numbers have increased from 54 to 500 in wild!
Why is the Daintree so special?• 135 million years old- oldest in
world• Has plants there older than
human life on Earth!• Home to greatest no. of plant/
animal species that are rare, threatened anywhere in world!
• Of world’s 19 primitive plants 12 are found here. (Reproduce by spores)
High annual rainfall (2000m+) in intense convectional storms
Low daily temp range- rarely below 22 at night or above 32 in day
120 days with rain per year
Low annual temp range
High humidity
Vegetation• Deciduous trees, but look evergreen, as year
round growing season means trees shed leaves at different times
• 1% of sun reaches floor- shrubs etc adapt to lack of light
• About 200 species of tree in an area size of football pitch
• Soil has thick litter layer, as leaves continuously fall, but humus is thin due to rapid decomposition in humid conditions
• Nutrients are rapidly leached (drawn down into and lost in soil)
• Reddish in colour due to high concentration of iron and aluminium
• Has Australia’s largest range of ferns
• Highest no. of ENDEMIC (restricted to a particular location) mammals anywhere in Australia
• Has near ½ Australia’s bird species- 13 ENDEMIC
• ¼ of Australia’s frogs- 20+ of which are ENDEMIC
• Greater diversity of freshwater fish in Australia
• Has 65% of Australia’s butterfly and bat species
• 28 of 36 mangrove species
The IDIOT FRUIT- a primitive plant species –ENDEMIC to the region
Ulysses butterfly- symbol of the rainforest
The Strangler Fig
Vines/lianas and epiphytes
Threats: Deforestation• Began in late 1860’s
to cultivate sugar cane production continued to early 1990s
• Most clearance today, for pasture (86%), with remainder cleared for crops (10%), mining infrastructure and settlement (4%)
• Shift from central to southern Queensland away from Daintree
What are the threats to the Daintree?Tourism-
a) Worth 141.7 million Australian $ a yearb) Most come to see the scenery and the forestc) Many partake in destructive activities there- such as
fishing, 4 wheel drive tours, walking, reef diving, horse riding
d) Ferry carries 700 vehicles across river dailye) 0.5 million visitors annuallyf) Stay an average of 3.8 daysg) Increased accommodation since 1991- 20 b+bs, 1278
beds nightly, 176 camping places actually in Daintree AND 58 b+bs, 8822 beds and 770 camp itches in local area
h) 70% of tourists visit independently- 30% with registered coach companies
i) Recent improvements- road tarmac increasing visitor numbers
j) Visitors think there’s too much accommodation and enough walking tracks already in place
Growth and change in Port Douglas
a) Population 4000b) Large visitor numbers have led to decline in small local
shops replaced by a small supermarketc) Property booms- some sold land to developers others
priced from marketd) 2 new resorts just nearing completion, 2 underway and 2
more in process of planninge) Small forest areas have been divided up and sold to
developers- some have been built on and environmental concerns have been addressed others have been turned to cattle ranches
f) Red cedar became extinct in 2000 after builder removed allg) If land clearing isn’t stopped 85 rare plant species stand to
be lost
Limits to development1) Ferry capacity limits traffic,
population and visitor levels 2) No Mains electric north of
river- so people there have to generate own through RAPS, own generators or solar power
3) Local services only support small local population- no mains water or sewer disposal system
4) In 2000 planners gained permission for a McDonalds on site, but now it has been withdrawn- citing a destruction of local values and too much change as reasons
Vegetation SuccessionHeather Moorlands
Plagioclimax Community: A stable plant community that has arisen as a result of human intervention in the
natural succession of communities.
Moorlands - plant succession
• On frost shattered rock a pioneer community, often algae and lichen start to form
• Plants spread, form a crust and absorb water and minerals
• As plants die, small amounts of organic matter build up
• Grasses and mosses take advantageof the new niches created bypioneering plants
• A plant sequence of plant communities inhabiting a site is a plant succession or a sere
• There are several stages on a site as it changes over time - from the pioneer stage then the building stage and finally a mature climatic climax
• Climatic climax - vegetation is relatively stable
• Self sustaining - inputs of energy and nutrients balanced by outputs of energy and nutrients
Moorlands - plant succession
• Arresting factors e.g. burning prevents a climatic climax being reached
• Plant community e.g. moorland is prevented from developing further through man’s actions and is described as a plagioclimax
Moorlands - plant succession
Moorlands - plant succession
• Conservation and regeneration measures e.g. deer fencing, deer culling and tree planting have been put in place to help encourage forest ecosystems
Moorlands - plant succession
• An attempt is being made to increase the small area (c3% of land surface in Scotland) covered with natural climax vegetation
Heather management - grazing
• Prevents natural regeneration of trees• Damage by deer and sheep, if unrestricted,
prevents young saplings growing into trees
• Heather provides good nutrition for sheep, red deer, cattle and red grouse
Heather Burning (muirburn)
• Periodic burning of heather helps creates young nutritious growth for grazing animals, particularly red grouse
• The older taller heather creates an environment suitable for nesting and cover for birds
• Careful burning creates a heather ecosystem with a mix of different ages of heather
• 4 growth stages of heather are: pioneer
,building,
mature and degenerative
As a result of grazing and burning, heather remains a plagioclimax community preventing the climax stage of Scots pine and birch woodland from establishingRed grouse originally occupied the woodland but have now adapted to the open moorland ecosystem, they depend on green heather shoots, buds and seeds for most of their dietThey also eat other plants e.g. bell heather, sheep’s fescue, blaeberry (and midges!)
Moorlands - plant succession
Since around 1950 the extent of heather and number of grouse have declined due to:
- reclamation of low lying land- reforestation by commercial forestry- overgrazing by sheep and deer- poor muirburn- soil erosion- increased grouse diseases- increased protection of birds of prey- increased incidence of heather beetle
Moorlands - plant succession
Glossary
Equilibrium:
A unit which links living organisms with each other and their physical environment (rock, soil, air and water)
Climax Stage: Taller and more complex plants can grow
Plants from earlier stages die out because of competition for light and water
Ecosystem:
When a vegetation community is relatively stable and self sustaining
Burning to manage the structure of heather as a habitat for grouse
Muirburn:
Niches: Status of an organism within its environment and community
Pioneer stage: The first species to colonise a new environment
Plagioclimax: A stable plant community that has arisen as a result of human intervention in the natural succession of communities
Glossary
Plant succession/ sere:
Sequence of plant communities inhabiting the same site through time
Reclamation: Modification of land to a “usable” condition
Reforestation: Re-establishment of a forest environment
Glossary
Case Study: UK – Temperate Deciduous woodland Biome
Sand Dunes (Psammosere) The Theory
Definition of Urban niche Within an ecosystem all living
organisms occupy a niche. Their niche is the place where they live
(their habitat) and how they interact with other species (their
role in the ecosystem).The woodlouse's habitat is under logs and stones and, particularly at night when it's cool and damp, under leaf litter
The woodlouse's role in the ecosystem is (a) feeding on dead plant material, breaking it down into small pieces helping to speed up decomposition by fungi and bacteria and (b) providing a food source for a range of other species, e.g. toads, shrews, hedgehogs and other invertebrates
Human use means urban ecosystems are subject to more change and at a faster pace than any other ecosystems. Changes in: DrainageMicro-climatesComposition of surface materialIntroduction of new species (accidentally + deliberately) Removal of established species= ecosystem unlikely to reach stability
Types of plants which initially colonise a site are influenced by: Slope – horizontal/gentle slopes debris accumulates to create soil Moisture availability – horizontal/slopes rainwater accumulates, steep slopes faster runoff Aspect – south facing slopes = warmer + drier Porosity (ability to hold water) – surfaces that hold water are colonised more quickly Surface roughness – allowing plants to get a hold, glass + metal are too smooth for most plants Pollution levels – depend on previous use of the site. Substances that are toxic to plants e.g. lead may contaminate the land
Keywords (match the correct definitions to each key term)
Conservation
Ecology
Sustainable Development
Substrate
The surface on which a soil forms. This is usually rock, but can also be a deposit such as river sediments, glacial till or boulder sediment. Preservation of the natural environment The study of the relationship between living things and their environment
The management of resources in such a way that the ability of the system to replace itself is greater than the level of exploitation
Case Study: The Colonisation of Wastelands
E.g. The colonisation of most wastelands is a lithosphere type succession
Lithosphere - (a sere originating on rock) is a plant succession that begins life on a newly exposed rock surface
Many wastelands are often temporary becoming redeveloped after a couple of years but if they are allowed to develop the following is likely to occur:
E.g. Larchfield Mill, Leeds, abandoned textile mill Victoria and Hunslet Mills in Leeds
Then……………………
……………..and now
Hunslet Mills
Victoria Mills
Invasive Species• As we have traversed the world
species have been moved both knowingly and unknowingly
• They can pose a threat to the native ecosystem
• Along with that many species become invasive along with other problems
Alien Species share several features• Enhanced survival rates• Lack native predator• Not as susceptible to disease
This means that they are often very difficult to control
Case Study: Cane Toads
VIDEO: Cane Toads: An Unnatural History
• Why Is This Important?• The reason behind the introduction of cane toads to Australia was well
intended but the results were unimagined. This is a good example of the fallibility of scientists and what can happen when an exotic species invades an ecosystem.
Ecological Case Study/Urban Conservation - Avon Gorge
To understand ecosystems along route ways so that we can successfully answer an exam question.
Route ways through and between urban areas have their own special ecosystems that are affected by many processes and flows that are different from other parts of the urban or semi-urban areas through which they pass. Among these processes and flows are:
• Construction techniques that make the surface quite different from elsewhere.
• Drainage systems that are quite different from most other areas which help create a varied patchwork of niche ecosystems.
• Maintenance that involves some management of the ecosystem and some total neglect.
• A constant linear movement of traffic along the route ways, often carrying and dispersing seeds, etc.
• An absence of people from the verges and embankments, reducing one kind of human interference.
• The addition of large amounts of salt (and other substances) to reduce the risk of ice in winter.
• Pollution from traffic fumes and litter.
What is a fragile environment?• A fragile environment or ecosystem is one
that lacks resilience to a change in conditions, cause by human activity, foreign species or natural events such as a flood or drought. According to the UN, they include arid and semi-arid areas, mountainous areas, polar locations, freshwater and intertidal wetlands, rainforests and coral reefs. Many are regional in scale, others are small scale.
KeywordsBiodiversity – the variation in life forms in a
given ecosystem/biome/planet. Diversity exists at 3 levels – genetic, species, ecosystem.
Sustainability – meeting the needs of the present without compromising the ability of future generations to meet their own needs.
Conservation - the preservation and careful management of the environment and of natural resources
Exploitation – the act of using something, usually unfairly
Ecosystem issues on a global scaleThe relationships between human activity, biodiversity and sustainability. The management of fragile environments (conservation versus exploitation): two contrasting case studies of recent (within the last 30 years) management schemes in fragile environments should be undertaken.
Your task: Produce a case study on the Serengeti National Park/Jaú National Park
• Where is it? What is it?• Explain why it is a fragile environment. • What is being done to conserve the area?• How is the fragile environment being exploited?• Are the attempts at conservation successful? Evaluate
how sustainable it is.
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