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36 Cards in this Set
- Front
- Back
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Define biomass |
the total dry weight of organic matter in organisms or ecosystems |
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How can energy converted into biomass be lost? |
* Inedible materials such as bones and hairs * Excretion of undigested materials * Heat from cellular respiration |
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What does feed conversion ratios measure? |
The efficiency of an animal in converting provided food into desirable output (meat/milk/etc) |
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How can a lower feed conversion ration be obtained? |
* restricting animal movement (battery hens) * slaughtering animal at young age (older animals grow slower and have higher FCR) |
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Define closed ecosystem |
A ecosystem that exchanged energy but not matter with its surroundings (mesocosm) |
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Define open ecosystem |
exchange both energy and material with surrounding (natural ecosystem) |
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Define ecosystem |
The interactions of living and non-living things within an area / a community and its abiotic enviorment |
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Define biome |
A geographical area with a particular climate that hosts a specific community of organisms |
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Outline the characteristics of tropical rainforests |
* Hot and humid environment near equator. * dense vegetation * high biodiversity |
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Outline the characteristics of Taiga/boreal forest |
* Coniferous forests near the poles with cold climate * little moisture (trapped as snow and ice) |
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Define net primary productivity |
The net of all energy produces by producers (plants) |
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How does climate effect primary productivity of energy? |
* warmer climate speeds up enzyme reactions for photosynthesis * High precipitation will increase photosynthesis as the hydrolysis of water is essential for non-cylic photo-phosphorylation |
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Define primary succession |
When communities develop on entirely new land without any established soil |
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Define pioneer species |
The organisms which first colonize a new set of land and establish the needed nutrients for other species to arrive |
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What is secondary succession? |
When one ecosystem is replaced by another (after the original was destroyed/disturbed) The succession starts on existing soil left by the previous ecosystem |
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How does deforestation disturb the regions nutrient cycling? |
* Less trees > less transpiration > less moisture * Less litter from trees > less humus > less soil nutrients * soil becomes acidic and nutrient poor > lower biodiversity * less trees > more light exposure > alter plant distribution |
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What methods can be used to control invasive species? |
Physical control - hunting, putting barriers Chemical - poison and pesticides Biological - using a living organism/virus to reduce invasive species population |
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Give an example of us of biological control elements for invasive species |
Cottony cushion scales (type of snail) are pests from Australia accidently introduced in California * They fed on all the citrus trees * predatory Australian beetle was introduced * Population of cottony cushion decreased |
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Define biomagnification |
When a chemical substance becomes more concentrated in each trophic level |
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Give an example for biomagnification |
The use of DDT as a chemical pesticide against malaria carrying insects * it was sprayed on crops and washed into waterways at low concentration * very high levels of DDT were found in birds that prey on fish * Birds with high DDT levels produced eggs with thinner/weaker shells |
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Give arguments for and against DDT use |
* Affordable and effective way to kills insects carrying disease * alternative strategies aren't as cost effective or efficient * DDT spraying is associated with cancer/birth defects/reduced fertility in humans * DDT persists in the environment for a long time (more than 15 years) |
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How is plastic degraded into microplastic? |
* UV radiation (from the sun) * the churning of waves |
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Define persistent organic pollutants |
Organic compounds that are resistant to environmental degradation |
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How does plastic pollute the water? |
* leaches chemical into the water * microplastic absorbs persistent organic pollutants, making them more poisonous |
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What are the effects of macro and microplastic on wildlife? |
* Plastic is ingested by marine animals who mistake it for food * plastic bioaccumulates which leads to biomagnification of POPs in wildlife * plastic damages the stomach causing animals to stop eating (by taking space in the digestive tract) |
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How does plastic debris affect the albatross? |
* Albatross nests on islands in the north pacific gyre, which accumulates a lot of plastic debris * Adult albatros can regurgitate swallowed plastic, but chicks cant * mortality rate in albatross chicks is very high |
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How does plastic debris affect sea turtles? |
* Sea turtles mistake plastic bags for jellyfish * the ingestion of plastic can be fatal and block the esophagus * Sea turtles can become entangled in plastic which restricts movement and developmental growth |
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Define indicator species |
Species that are sensitive to specific environmental conditions and have a limited range of tolerance |
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How do you calculate biotic indices? |
( Number of individuals of a species X tolerance rating ) % total number of organisms collected |
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What does the biotic indices indicate? |
* A high biotic index indicate many pollution sensitive organisms, meaning the environment is unpolluted * A low biotic index indicated a polluted environment do to a relative abundance of pollution-tolerant organisms |
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Define biodiversity |
The variety of species and abundance in a given area |
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Define species richness |
The number of different species in an area |
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Define Species evenness |
The relative abundance of different species more abundance = more evenness |
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Describe the edge effect |
The diversity of a species can increase in the edges of the ecosystem. Biodiversity can increase at the border between two ecosystem as different abiotic factors combine. * edges tens to have more competition, which would restrict survival of some * edges may be exposed to conditions such as more light or wind, in which certain species cant survive in |
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How does island size influence biodiversity? |
* larger islands support more habitats, more available niches * larger islands can sustain higher population numbers * larger islands have greater productivity at each trophic level, leading to longer, more stable food chains |
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What is the use of habitat corridors? |
Connects parts of a fragmented habitat which improves genetic diversity |
