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24 Cards in this Set
- Front
- Back
- 3rd side (hint)
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Pioneer Species |
First organisms to colonise an area |
1st |
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What do they contain? |
Adaptions - helps colonise an area where abiotic conditions are harsh |
Adaptions, Abiotic |
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What do they do to the area when they colonise it? |
Change the environment so that it favours the next group of species |
Changes, favours |
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What happens when a new species is introduced? |
Out-competes pioneer / old species, achieves dominance and oust it. continues until climax community is reached |
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During succession what happens to height and mass of vegetation? |
Increases |
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What happens to the index of diversity? |
Increases |
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As index of diversity increases what happens to habitats and food supplies. what does this effect? |
Provides more habitats and food supplies for more species of carnivores |
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What happens to the abiotic conditions as succession proceeds? |
Become more favourable |
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What happens to biotic conditions as succession proceeds? |
More important - competition and predation |
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What can happen at climax community? |
One species achieved dominance and leads to drop in diversity |
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Whats an example of a species that has achieved dominance? |
Large oak trees reduce light available to smaller plants below them so decreases number of plant and animak species |
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Being able to easily disperse and produce seeds is an advantage to pioneer Species Why? |
Chance of finding areas of bare soil is low so chances are Increased Chance of survival is low so chances are Increased |
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Suggest an advantage of a high rate of photosynthesis |
Rapid growth Able to reproduce quickly More energy to produce more seeds |
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The communities A to D are composed of different species. Explain how the change in species composition occurs in a succession |
Species present changes the abiotic environment (habitat) This allows other species to colonise New species are better competitors and out compete old species, ousting them out |
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Which community A to D is the most stable? Explain what makes this the most stable community |
D More species present, more complex food webs, change in on species doesn't effect the other species as have multiple food sourcesn |
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Suggest why a transect will be more appropriate than a random quadrat |
Gradient of environmental factor that produces a series of changes over a long distance
This ensures every community is sampled which quadrat sampling can't ensure |
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Succession occurs in a natural ecosystem. Describe and explain how succession occurs (6marks) |
Colonise of pioneer Species Changes the abiotic environment by adding nutrients into soil Conditions are now more favourable for another species to colonise This species Out-competes pioneer Species Changes in biodiversity Stability increases as less hostile environment This continues until climax community is reached |
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The increase in the index of diversity is one indication that a biological succession is taking place in the area. Describe those features of a succession that would bring about an increase in the index of diversity |
Initial environment hostile so few organisms are adapted Those which are adapted (pioneer species) change the environment by adding nutrients to the soil when they die and decompose More organisms can now survive and colonise area which allows more habitats and niches
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What happens at each stage of Succession? |
Certain species can be recognised which changes the environment so that it becomes more suitable for other species |
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What does change in the abiotic environment cause? |
Less hostile environment, more stability and changes diversity |
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Describe how changes in the environment lead to increased biodiversity during succession |
Primary colonisers ( pioneer species) photosynthesis and fix nitrogen They then directory and nutrients are transferred to the soil Further colonisers can survive in this soil Environment is less hostile More habitats and food is available This allows other species to survive Which increased biodiversity |
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What are the 5 common features of Succession? |
Nonliving environment becomes less hostile Greater number and variety of habitats Increased biodiversity More complex food webs Increased biomass |
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Define succession |
Process by which an ecosystem changes over time |
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Name 5 adaptions pioneer species tend to have |
Tolerance to extreme conditions Able to fix nitrogen in the air so soil has few nutrients Photosynthesis light as food isn't available Easily disperse seeds across big distances Rapid germination of seeds |
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