1. G2: Ecosystems & Biomes
(4 hours)

3. G.2.1 Define
gross production
Total amount of energy trapped in organic matter produced by plants per area per time (kJ)
net production
Gross production – energy lost through respiration
Biomass
Dry weight of an organism (g m-2 yr -1)

4. gross production – respiration = net production GP – R = NP
G.2.2 Calculate values for gross production and net production using the equation:
gross production – respiration = net production
GP – R = NP
Sample question!!
Calculate % of energy moving up to herbivores

9. Food webs give more realistic image of ecosystem
G.2.3 Discuss the difficulties of classifying organisms into trophic levels.
Food webs give more realistic image of ecosystem
Omnivores especially difficult--
Depending on what eating, can be 1/2/3 consumer at different times

11. Higher trophic levels: low total biomass per unit area of ecosystem
G.2.4 Explain the small biomass and low numbers of organisms in higher trophic levels.
Top predators must be large enough to overwhelm their prey, so can only be relatively few of them
Higher trophic levels: low total biomass per unit area of ecosystem
Biomass lost during each TLevel
Cell respiration: biomass of glucose is lost, CO2, Water excreted
Each successive level loses more and more biomass

14. Trophic Level Energy Flow (kJ m–2 yr–1) producers 20,810
G.2.5 Construct a pyramid of energy, given appropriate information. (Xref- pyramid of energy )
Trophic Level Energy Flow (kJ m–2 yr–1)
producers 20,810
primary consumers 3,368
secondary cons
tertiary consumers

18. G.2.6 Distinguish between primary & secondary succession, using an example of each.
CHANGE in abiotic and biotic factors in ecosystem over time...some species gradually replace others in a particular area
Primary:
Previously barren, lifeless area
Newly created volcanic island
Pioneer species usually lichens—tolerant to extreme temp changes and little/no soil; they decompose rock...soil forms
moss can survive  seeds germinate  coconuts wash ashore, germinate; animals may swim/fly/carried on floats from other islands

19. Secondary: follows natural or artificial “upheaval” of the primary succession
MUCH faster b/c soil already present, may be existing seeds & roots
Ex. Forest fire
Primary
Secondary
Begins with no life
Follows a disturbance of primary succession
No soil
Soil present
New area (volcanic island)
Old area (following forest fire)
Lichen & mosses pioneers
Seeds & roots already present
Biomass low
Biomass higher
Production low (few plants)
Production higher

22. Pioneer species to those that compete with others for nutrients
G.2.7 Outline the changes in species diversity and production during primary succession.
OVERALL TRENDS:
Few species to many
Pioneer species to those that compete with others for nutrients
Little to high diversity (mature forest is home to 100s species)
Simple relationships to more complex (mutualism, competition, predation)
More & more biomass at each stage of succ.

23. G.2.7 Outline the changes in species diversity and production during primary succession.
Foredune: no soil, only sand, p.succ. Starts here—lyme grass very salt tolerant, fast growing, roots stabilize dune; marram grass too, wide roots. LITTLE PLANT DIVERSITY
Yellow dune: developing thin layer of soil b/c yrs of m.grass; more plants invade (sedge, etc); rabbits here, nutrients from poop ; summer dandelions/thistle. Humus builds as pioneers decay. MORE COMPLICATED, MORE SPECIES, SOIL BEING FORMED

24. Mature dune: final stage of succession. Can support a forest
G.2.7 Outline the changes in species diversity and production during primary succession.
Grey dune: yrs of plants dying/decomposing, so layer of humus; it holds water; dune farther inland, less salt; thick shrubs eventually grow here
Mature dune: final stage of succession.
Can support a forest
Wild flowers, trees, mosses/ferns in shade
Thick humus b/c 200 yrs of plants; high moisture content
Many insects, birds, mammals
Cooler temp than foredune; less wind/blowing sand

25. Death/decay of plants/animals  humus
G.2.8 Explain the effects of living organisms on the abiotic environment with reference to the changes occurring during primary succession.
soil development
Death/decay of plants/animals  humus
Quickly absorbs and releases water, good for plants
Leaf litter creates more org matter, mixes with sand, creates deep, well-draining soil; can support tall trees
accumulation of minerals
Sand doesn’t hold moisture but humus & soil do, takes time to get structure to hold moisture and minerals to allow aeration of roots (structure IMPROVES)
Bacteria, fungus (decomposers) active in recycling nutrients in soil w/humus (recycling INCREASES)
reduced erosion
Roots stabilize dune/soil, reduces erosion

27. G.2.9 Distinguish between biome & biosphere.
Biosphere: living part of earth (where organisms live)
Crust, atmosphere
Biomes: divisions of biosphere
Each is part of biosphere
Defined by community structure and vegetation

28. PLOTS temp and rainfall in a region
G Explain how rainfall and temperature affect the distribution of biomes.
A climograph showing the biomes in G.2.11 can be used to illustrate the interaction between these two factors.
PLOTS temp and rainfall in a region
Tundra: organisms adapted to cold, dry
Conif forest: plants conserve water when ground frozen, animals heavy coats in winter (summer-shed)
Temp forest: wide range of conditions (many deciduous to reduce water loss in winter)
Desert: specific adaptations for extreme heat and dryness (kangaroo rat’s specialized kidney; cacti’s spines)
Trop forest: high temp, high rainfall

29. G.2.11 Outline the characteristics of six major biomes.
Temp
Moisture
Vegetation
Desert
Mostly very hot. Soil temps >60C (140F) daytime
Low precip, <30cm/yr
Cacti, shrubs w/water storage tissues, thick cuticles & other water-loss adaptations
Grassland
Cold winter temps;
hot summers
Seasonal drought; occasional fires; medium moisture
Prairie grasses hold soil w/long roots; occasional fires prevent trees/shrubs from invading...and don’t forget the dead zebras. 
Shrubland
Mild winter temps;
Long, hot summers
Rainy winters, dry summers
Dry woody shrubs killed by periodic fires; shrubs store food in fire-resistant roots; regrow quickly, produce seed that germinates only after fire!

30. G.2.11 Outline the characteristics of six major biomes.
Temp
Moisture
Vegetation
Temp Decid Forest
Very hot summer, very cold winter
High rainfall evenly throughout yr. Winter: water may freeze for short time
Deciduous trees (oak, hickory, maple) dominate. Warmer seasons—wide range of herbaceous plants on forest floor
Tropical rainforest
Very warm
Very high precip (>250cm/yr)
Plant diversity very high. Canopy of top layer, next layer is shrubs; ground layer is herb.plants and ferns. Vines, orchids, bromeliads on trees.
Tundra
Very cold;
Summer-upper layer of soil thaws, but lower frozen (permafrost)
Little precipitation
Low-growing plants (lichen, mosses) and few grasses, shrubs. Permafrost prevents roots from growing deeply. Continuous daylight in summer allows plant growth & reproduction.