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27 Cards in this Set
- Front
- Back
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Increasing NPP Light intensity |
Light intensity affects photosynthesis. Plants are planted early to provide longer growing season to harvest more light Some plants are grown under light banks. |
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Increasing NPP Lack of water |
Irrigating crops Drought resistant strains have been bred. |
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Increasing NPP Temperature |
Also has an affect on chemical reactions in a plant. Greenhouses provide warmer temperatures for growing plants increase NPP Planting field crops early provide longer growing season helps to avoid the impact of temperature on final yield |
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Increasing NPP Nutrients |
Nutrients affects photosynthesis. For example, a lack of nutrients can slow down the rate of photosynthesis. Crop rotation Nitrogen fixing crops Crops have been bred to be responsive to high levels of fertiliser. |
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Increasing NPP Pesticides |
Spraying pesticides helps remove pest which remove biomass and stored energy from the food chain thus lowering the yield. Plants can be bred to be pest resistant Can be genetically modified with a bacterial gene which gives plant resisitance. |
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Increasing NPP Fungal diseases |
Reduce NPP, causes root to rot therefore reduces water absorption. Damages xylem vessels (water transport) and phloem (translocation of sugars.) Spray fungicides Crops bred to be resistant to fungal infections. |
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Increasing NPP Herbicides |
Kill weeds which compete with the plant for light, water and nutrients |
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Manipulating energy transfer from producer to consumer |
1. Harvesting animals just before adulthood so less energy is wasted in growth. 2. Treated with steroids to make them grow faster. Increases proportion of energy allocated to growth. 3. Selective breeding used to produce breeds with faster growth rates increased production (eggs or milk) 4. Animals treated with antibiotics to avoid unnecessary loss if energy to pathogens and parasites 5. Prevent animals from moving so energy is not wasted, supply if food and constant temperature. ANIMAL WELFARE ISSUES |
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Succession process |
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Why are sand dunes used to show succession? |
They display all the stages of succession in the same place at the same time. Sand just about the high water mark is the start of the process of succession. Sand much further away hosts it's climax community. |
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Definition for Succession Primary succession Secondary succession |
Succession- directional change in a community of organisms over time Primary succession- development of a community from bare ground Secondary succession - reintroduction of plants/animals into animals read that have been previously colonised but have been damaged/disturbed in some way. |
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Pioneer Species |
First to colonise on bare rock Moss and lichens |
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Climax Community |
Endpoint of succession, final stable community Woodland |
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Quadrat |
Square frame, used to study an ecosystem |
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What data can you collect from a quadrat? |
1. Presence or absence of each species- distribution 2. Can estimate or count the number of individuals if each species- abundance. Ecologist can then calculate percentage cover. |
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How to avoid bias when taking a sample? |
1. Randomly position quadrat across habitat using random coordinates. 2. Take samples at regular distance across the habitat, so every part of the habitat is sampled. |
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Line transect |
Make a note of which species us touching the tape at regular intervals |
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Belt transect |
Placing a quadrat next to the line (interrupted belt transect) Moving quadrat along the line after studying the quadrat (continuous belt transect) both at regular intervals |
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Intra specific competition |
Competitions between members of the same species |
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Interspecific competition |
Competition between members of different species |
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Allelopathy |
Plants have a mechanism in which they release chemicals into their habitat. It stops neighbouring plants from using resources in the habitat. Chemicals may inhibit growth, germination and nutrient uptake. Chemicals can be released into the soil by the roots or leave by the leaves and fruit. |
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Modern sustainable forestry |
1. Any tree which is harvested is replaced by another 2. Even with the extraction of timber the forest must maintain its ecological function regarding biodiversity, climate, mineral and water cycles 3. Local people must benefit from forest. |
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How to supply more wood without more trees being harvested |
1. Control pests and pathogens 2. Only plant trees that are guaranteed to grow well 3. Position trees optimum distance apart. If close they compete and grow this and tall produces poor quality timber. |
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How are humans threatening biodiversity? |
1. Over exploitation of wild populations for food, sport and commerce species are harvested faster then they can replenish. 2. Habitat disruption and fragmentation because of more intensive agricultural practices, population or widespread building. 3. Introduction of species can out compete native species |
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Managing small scale timber production Coppicing Rotational coppicing |
Cutting the tree trunk of deciduous trees close to the ground to encourage new shoot growth from the cut surface and mature into stems. Rotational coppicing provides a continuous supply of wood. Manager divide a wood into sections and cut one section each year. Depends on time taken for stem to mature and dimension of woods required |
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Managing large scale production of timber. |
Clear felling all the trees in one area. Destroys habitats. Reduces soil mineral levels. Soil way run off into waterways and pollutes them. |
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Managing small scale timber production |
Cutting tree trunk higher up. It is useful so species cannot eat the shoots |
