Earth Systems – Ecosystem Analysis Intro.
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Environment
o Includes all conditions (biotic and abiotic)
o Biotic – living segment
o Abiotic – nonliving segment
 Might include external factors, i.e. ozone
o Habitat
 Portion of environment where organism lives
 Described by its features
 Geographic, physical, chemical, biotic
 Described as macrohabitat or microhabitat
 i.e. macrohabitat could be deciduous forest
 i.e. microhabitat might be rotting log
o Community
 Groups of interacting species within habitat
 Community Type
 Biome: largest geographic area with similar climax community
 Changes and variations within the larger community
o Usually caused by formation of microclimates
 Created by variations in light intensity/ solar radiation
 Resulting variations in temp/heat
 Changes available soil moisture/humidity
 Succession
o Slow predictable change in plant life
 Primary succession if area wiped clean
 Pioneer species are first species to populate
area
 Species change as conditions change
o i.e. soil moisture, shade
 Secondary succession if area partially disturbed
o Climax community eventually reached
 No further change allowed by conditions
 Altitude and Latitude
o Both cause gradual change in environment
 Altitude: drop 3 degrees every 1000ft
 Latitude: gradient exists, but not as predictable
 Evidence in Colorado mountains
o Two treelines, top and bottom
o Ecosystems change as altitude increases
 Grasslands on the plain
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Dry shrubs in the foothills
Trees, primarily conifers
 Ponderosa, douglas fir, limber pine, lodgepole
 Engelmann spruce, subalpine fir
 Colorado blue spruce throughout, (water)
Decrease in size of vegetation at the top
Tundra above treeline
Zonation
 Belts/zones in biotic community on smaller scale
o Caused by soil characteristics, light, moisture, slope
o Changes occur horizontally
 Stratification
 Layering of biotic conditions
o Changes occur over the vertical axis
o Caused by changes in light, moisture
 i.e. deciduous forest
o ground, herbaceous, shrub, understory-tree, canopy-tree
Ecosystem
 Community and its relationship with abiotic factors
Niche
 Functional role within an ecosystem
Dimensions of the Ecosystem
 Temporal
 Things with time component
 i.e. population growth, succession
 Spatial
 Geographical components
 i.e. location, topography, stratification
 Physical or chemical
 Atmosphere
 Lithosphere (land, substrate)
 Hydrosphere (aquatic)
 Biotic
 Biosphere
o Part of atmosphere, lithosphere, hydrosphere that can sustain
life
 Biomes
 Large regional interaction of similar communities
 Usually identified by major plant types and/ or climate
 Earth divided into “10” biomes excluding aquatic