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Cards In This Set
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What are the 2 formations of deserts?
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Warm and cold and semideserts
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Where is this biome located
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Located on most continents except antartica
Warm deserts: 25-30 latitude, subtropical west coasts cold semi deserts: 30-50 latitude, continental rainshadows (A region having little rainfall), transition to desert or grassland |
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Climate?
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Temperature:
-hot summers, moderate winters, highest annual/ daily ranges -cold deserts= high elevation or continental ppt: -low ppt, seasonal, highly variable -coastal deserts-advection fog from cold ocean currents -rely on this for ppt Water balance Ep>>>>>Ea, huge annual water deficit (200-300cm/yr) |
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Draw the soil moisture balance
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 See figure |
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What are the types of soils
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Coarse sandy soils- large particles, smaller surface area, lower water hold capacity, high percolation, low run-off and evaporation
these are better than fine clay soils because small particles= large SA, high water holding capacity, less percolation of ppt, more surface run-off and evaporation |
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What are the vegetation characteristics
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Productivity: low relative to other biomes
life forms: herbs, shrubs, tree-like cacti |
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What are the adaptations of this biome
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Xerophytes= plants adapted to drought
phreatophytes= well plants -have tap roots to access ground H2O water storage: -succulents (cactus) -tolerant coating to desiccation (water loss) -spines to protect losing H2O to herbivores reduce water loss from tissues: -produce small leaves to conserve water -waxy surfaces=hold H2O -shiny surfaces or white hairs = high albedo to reduce temp -deciduous leaves -reisin has odor to prevent animals from eating it. ephemerals or annuals: -persist through drought as seeds -life cycke is triggered by ppt to germinate and grow nurse plants: -drought tolerant plants creat microclimate suitable for other species -important for succession |
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What are disturbances?
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-high stress environments in which natural disturbance are rare
fire- exceptionally rare -hot dry environment is conducive to fir BUT not enough plant cover |
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What are some human impacts
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Introduced exotic grasses from other areas for the purpose of live stock
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Why is introducing another plant bad?
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Not have natural competitors + will succeed to run out native species
this will increase plant cover therefore increasing fires which the native species are not adapted to (positive feedback =increased plant desity will cause increased cheat grass but overall negative effect on native species |
