GEOG 1114 1stEdition Lecture 20Outline of Last Lecture-Cycles of the Biosphere -Flow of Energy: different cycles -Food Webs -Biogeography: concepts of biogeography -Four major environmental factors Outline of Current Lecture -Four major environmental factors -Adaptations of vegetation-11 Major Biomes Current Lecture Succession:A series of communities that come into being in disturbed ecosystems. Each succeeding community alters the local microclimate and surface conditions, making possible the appearance of anew community.-Occurs after catastrophic events -Primary species followed by secondary species -Brings back dynamic equilibrium Relating Vegetation Patterns of North America to the EnvironmentFour Major Environmental FactorsThese notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.Climate: -Temperature -Precipitation -Wind- drying; shape; destructive (windfall) -Light -Moisture Topographic ReliefElevational Microclimates:upslope vegetation: plants adapted to warmer, drier regions. Down slope vegetation: plants adapted to cooler, wetter areas Slope Aspect: compass direction a slope faces Example: Low hills of the eastern US have different microenvironment from the top to the bottom of slopes.South-Facing Slopes: receive more solar radiation tan north facing slopes; have higher temperatures, greater ET (warmer, drier)North-Facing Slopes: cooler, less EResults of slope aspect:Tall MountainsSmaller HillsSoil Characteristics: The medium for plant growth*Texture, Structure and Chemistry all play an important role in vegetation distributionWildfires: Certain vegetation biomes of N. America have evolved with fire as a major environmental factor. -Pine forests- Grasslands, Mediterranean -Result partial devastation of plant life and death or driving away of animals-Helpful for regrowth and maintaining of plant type Adaptations of vegetation-Fire-resistant bark-Fire-dependent cone opening mechanism: Lodge pole pine -Fire-stimulated seed germination-Ladder – pines-Vegetation changes that occur in areas where fires have been eliminatedCauses:Natural: lightening strikes under drought conditionsManmade: accident Fire suppression practices in ecosystems where fire is important can cause more damagewhen fire does occur Effectsare varied:Changes that occur in response to fire depend on a number of factors:-Type of vegetation, Season of the year, Time since last fire (if fire suppressed, fuel layer can build up, making the damage worse, loss of diversity, forests same age – old growth).The 11 Major Biomes:-Tropical Rainforest (Selva)-Tropical Deciduous Forest-Tropical Scrub-Tropical Savanna-Desert-Mediterranean Woodland and Shrub-Mid-latitude Grassland-Mid-latitude Deciduous Forest-Boreal Forest
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