Title: This powerpoint is textdense to say the least, so it will serve as the lecture notes, too' Study que
1This powerpoint is text-dense to say the
least, so it will serve as the lecture notes,
too. Study questions follow on the last slide.
2BIOMES I. Climatic Determinants II. FORESTS A.
Tropical Rain Forest B. Tropical Dry Forest
3BIOMES I. Climatic Determinants II. FORESTS A.
Tropical Rain Forest B. Tropical Dry Forest 1.
Abiotic Conditions
4BIOMES I. Climatic Determinants II. FORESTS A.
Tropical Rain Forest B. Tropical Dry Forest 1.
Abiotic Conditions TEMP Uniformly warm annual
temp gt 20C little annual variation
5BIOMES I. Climatic Determinants II. FORESTS A.
Tropical Rain Forest B. Tropical Dry Forest 1.
Abiotic Conditions TEMP Uniformly warm annual
temp gt 20C little annual variation RAINFALL
Extreme seasonality, with a pronounced dry
season.
6BIOMES I. Climatic Determinants II. FORESTS A.
Tropical Rain Forest B. Tropical Dry Forest 1.
Abiotic Conditions TEMP Uniformly warm annual
temp gt 20C little annual variation RAINFALL
Extreme seasonality, with a pronounced dry
season. EVAPOTRANSPIRATIONAL STRESS high in dry
season water limiting.
7BIOMES I. Climatic Determinants II. FORESTS A.
Tropical Rain Forest B. Tropical Dry Forest 1.
Abiotic Conditions TEMP Uniformly warm annual
temp gt 20C little annual variation RAINFALL
Extreme seasonality, with a pronounced dry
season. EVAPOTRANSPIRATIONAL STRESS high in dry
season water limiting. LIGHT Never limiting,
neither seasonally nor beneath a canopy.
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9BIOMES I. Climatic Determinants II. FORESTS A.
Tropical Rain Forest B. Tropical Dry Forest 1.
Abiotic Conditions TEMP Uniformly warm annual
temp gt 20C little annual variation RAINFALL
Extreme seasonality, with a pronounced dry
season. EVAPOTRANSPIRATIONAL STRESS high in dry
season water limiting. LIGHT Never limiting,
neither seasonally nor beneath a canopy.
NUTRIENTS and CYCLING Cycling is seasonal.
Litter accumulates until rainy - then nutrients
recycled
10BIOMES I. Climatic Determinants II. FORESTS A.
Tropical Rain Forest B. Tropical Dry Forest 1.
Abiotic Conditions 2. Biota
11BIOMES I. Climatic Determinants II. FORESTS A.
Tropical Rain Forest B. Tropical Dry Forest 1.
Abiotic Conditions 2. Biota
Diverse, but less so than rain forests
12- BIOMES
- I. Climatic Determinants
- II. FORESTS
- A. Tropical Rain Forest
- B. Tropical Dry Forest
- 1. Abiotic Conditions
- 2. Biota
- Diverse, but less so than rain forests
- Structurally simple - four layers, fewer lianas,
no giant canopy trees or emergents
13- BIOMES
- I. Climatic Determinants
- II. FORESTS
- A. Tropical Rain Forest
- B. Tropical Dry Forest
- 1. Abiotic Conditions
- 2. Biota
- Diverse, but less so than rain forests
- This diversity perpetuates the evolution of
greater diversity (More niches for herbivores,
predators, pathogens, parasites, etc.) - Structurally simple - four layers, fewer lianas,
no giant canopy trees or emergents - Less remains, as a of original, than rainforest
because it is so easily converted to agricultural
land and soil fertility is better.
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15- BIOMES
- I. Climatic Determinants
- II. FORESTS
- A. Tropical Rain Forest
- B. Tropical Dry Forest
- C. Temperate Rain Forest
16- BIOMES
- I. Climatic Determinants
- II. FORESTS
- A. Tropical Rain Forest
- B. Tropical Dry Forest
- C. Temperate Rain Forest
- 1. Abiotic Conditions
17- BIOMES
- I. Climatic Determinants
- II. FORESTS
- A. Tropical Rain Forest
- B. Tropical Dry Forest
- C. Temperate Rain Forest
- 1. Abiotic Conditions
- TEMP seasonal but not extreme - moderated by
coastal currents. Cool - 10C mean.
San Francisco
18- BIOMES
- I. Climatic Determinants
- II. FORESTS
- A. Tropical Rain Forest
- B. Tropical Dry Forest
- C. Temperate Rain Forest
- 1. Abiotic Conditions
- TEMP seasonal but not extreme - moderated by
coastal currents. Cool - 10C mean. - RAINFALL High but seasonal - dry summer
moderated by fogs
19- BIOMES
- I. Climatic Determinants
- II. FORESTS
- A. Tropical Rain Forest
- B. Tropical Dry Forest
- C. Temperate Rain Forest
- 1. Abiotic Conditions
- TEMP seasonal but not extreme - moderated by
coastal currents. Cool - 10C mean. - RAINFALL High but seasonal - dry summer
moderated by fogs - EVAPOTRANSPIRATIONAL STRESS low for most the
year hot summer
20- BIOMES
- I. Climatic Determinants
- II. FORESTS
- A. Tropical Rain Forest
- B. Tropical Dry Forest
- C. Temperate Rain Forest
- 1. Abiotic Conditions
- TEMP seasonal but not extreme - moderated by
coastal currents. Cool - 10C mean. - RAINFALL High but seasonal - dry summer
moderated by fogs - EVAPOTRANSPIRATIONAL STRESS low for most the
year hot summer - LIGHT Seasonally limiting in winter and under
closed canopies.
21- BIOMES
- I. Climatic Determinants
- II. FORESTS
- A. Tropical Rain Forest
- B. Tropical Dry Forest
- C. Temperate Rain Forest
- 1. Abiotic Conditions
- TEMP seasonal but not extreme - moderated by
coastal currents. Cool - 10C mean. - RAINFALL High but seasonal - dry summer
moderated by fogs - EVAPOTRANSPIRATIONAL STRESS low for most the
year hot summer - LIGHT Seasonally limiting in winter and under
closed canopies. - SOILS deep, rich humus layer, rich A horizon.
Slower decomposition and shallower bedrock keep
nutrients at surface
22- BIOMES
- I. Climatic Determinants
- II. FORESTS
- A. Tropical Rain Forest
- B. Tropical Dry Forest
- C. Temperate Rain Forest
- 1. Abiotic Conditions
- TEMP seasonal but not extreme - moderated by
coastal currents. Cool - 10C mean. - RAINFALL High but seasonal - dry summer
moderated by fogs - EVAPOTRANSPIRATIONAL STRESS low for most the
year hot summer - LIGHT Seasonally limiting in winter and under
closed canopies. - SOILS deep, rich humus layer, rich A horizon.
Slower decomposition and shallower bedrock keep
nutrients at surface - DISTURBANCE winter, treefalls, storms
23- BIOMES
- I. Climatic Determinants
- II. FORESTS
- A. Tropical Rain Forest
- B. Tropical Dry Forest
- C. Temperate Rain Forest
- 1. Abiotic Conditions
- TEMP seasonal but not extreme - moderated by
coastal currents. Cool - 10C mean. - RAINFALL High but seasonal - dry summer
moderated by fogs - EVAPOTRANSPIRATIONAL STRESS low for most the
year hot summer - LIGHT Seasonally limiting in winter and under
closed canopies. - NUTRIENTS and CYCLING stalled by winter and dry
summer, but otherwise wet .
24- BIOMES
- I. Climatic Determinants
- II. FORESTS
- A. Tropical Rain Forest
- B. Tropical Dry Forest
- C. Temperate Rain Forest
- 2. Biota
25- BIOMES
- I. Climatic Determinants
- II. FORESTS
- A. Tropical Rain Forest
- B. Tropical Dry Forest
- C. Temperate Rain Forest
- 2. Biota
- Lower diversity, but tallest trees on the planet,
in NA, hemlock and spruce in north give way to
redwoods and sequoia in south
26Redwood
27- BIOMES
- I. Climatic Determinants
- II. FORESTS
- A. Tropical Rain Forest
- B. Tropical Dry Forest
- C. Temperate Rain Forest
- 2. Biota
- Lower diversity, but tallest trees on the planet,
in NA, hemlock and spruce in north give way to
redwoods and sequoia in south - Also found in southern Chile and in SE
Australia/New Zealand - tallest eucalyptus are
tallest angiosperms.
28Sequoia semperviren
Eucalyptus regnans
29- BIOMES
- I. Climatic Determinants
- II. FORESTS
- A. Tropical Rain Forest
- B. Tropical Dry Forest
- C. Temperate Rain Forest
- 2. Biota
- Lower diversity, but tallest trees on the planet,
in NA, hemlock and spruce in north give way to
redwoods and sequoia in south - Also found in southern Chile and in SE
Australia/New Zealand - tallest eucalyptus are
tallest angiosperms. - Structurally simple dark understory retards
growth of understory except mosses... heavy
epiphyte load
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31- BIOMES
- I. Climatic Determinants
- II. FORESTS
- A. Tropical Rain Forest
- B. Tropical Dry Forest
- C. Temperate Rain Forest
- D. Temperate Deciduous Forest
32- BIOMES
- I. Climatic Determinants
- II. FORESTS
- A. Tropical Rain Forest
- B. Tropical Dry Forest
- C. Temperate Rain Forest
- D. Temperate Deciduous Forest
- 1. Abiotic Conditions
33- BIOMES
- I. Climatic Determinants
- II. FORESTS
- A. Tropical Rain Forest
- B. Tropical Dry Forest
- C. Temperate Rain Forest
- D. Temperate Deciduous Forest
- 1. Abiotic Conditions
- TEMP Seasonality is more extreme, with more
severely cold winters but moist spring and
summer.
34- BIOMES
- I. Climatic Determinants
- II. FORESTS
- A. Tropical Rain Forest
- B. Tropical Dry Forest
- C. Temperate Rain Forest
- D. Temperate Deciduous Forest
- 1. Abiotic Conditions
- TEMP Seasonality is more extreme, with more
severely cold winters but moist spring and
summer. - RAINFALL More even throughout year no
pronounced drought period.
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36- BIOMES
- I. Climatic Determinants
- II. FORESTS
- A. Tropical Rain Forest
- B. Tropical Dry Forest
- C. Temperate Rain Forest
- D. Temperate Deciduous Forest
- 1. Abiotic Conditions
- TEMP Seasonality is more extreme, with more
severely cold winters but moist spring and
summer. - RAINFALL More even throughout year no
pronounced drought period. - EVAPOTRANSPIRATIONAL STRESS low for most the
year hot summer but dry winter (frozen precip)
37- BIOMES
- I. Climatic Determinants
- II. FORESTS
- A. Tropical Rain Forest
- B. Tropical Dry Forest
- C. Temperate Rain Forest
- D. Temperate Deciduous Forest
- 1. Abiotic Conditions
- TEMP Seasonality is more extreme, with more
severely cold winters but moist spring and
summer. - RAINFALL More even throughout year no
pronounced drought period. - EVAPOTRANSPIRATIONAL STRESS low for most the
year hot summer - LIGHT Seasonally limiting in winter and under
closed canopies.
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39- BIOMES
- I. Climatic Determinants
- II. FORESTS
- A. Tropical Rain Forest
- B. Tropical Dry Forest
- C. Temperate Rain Forest
- D. Temperate Deciduous Forest
- 1. Abiotic Conditions
- TEMP Seasonality is more extreme, with more
severely cold winters but moist spring and
summer. - RAINFALL More even throughout year no
pronounced drought period. - EVAPOTRANSPIRATIONAL STRESS low for most the
year hot summer - LIGHT Seasonally limiting in winter and under
closed canopies. - NUTRIENTS and CYCLING Slow but efficient deep
litter layer.
40- BIOMES
- I. Climatic Determinants
- II. FORESTS
- A. Tropical Rain Forest
- B. Tropical Dry Forest
- C. Temperate Rain Forest
- D. Temperate Deciduous Forest
- 1. Abiotic
- 2. Biota
41- BIOMES
- I. Climatic Determinants
- II. FORESTS
- A. Tropical Rain Forest
- B. Tropical Dry Forest
- C. Temperate Rain Forest
- D. Temperate Deciduous Forest
- 1. Abiotic
- 2. Biota
- Deciduous trees dominate growing season long
enough to grow new ones and still make enough
photosynthetic profit to overwinter.
42- BIOMES
- I. Climatic Determinants
- II. FORESTS
- A. Tropical Rain Forest
- B. Tropical Dry Forest
- C. Temperate Rain Forest
- D. Temperate Deciduous Forest
- 1. Abiotic
- 2. Biota
- Deciduous trees dominate growing season long
enough to grow new ones and still make enough
photosynthetic profit to overwinter. - Simple four-layer structure to forest.
CANOPY UNDERSTORY SHRUB HERB
43- BIOMES
- I. Climatic Determinants
- II. FORESTS
- A. Tropical Rain Forest
- B. Tropical Dry Forest
- C. Temperate Rain Forest
- D. Temperate Deciduous Forest
- 1. Abiotic
- 2. Biota
- Deciduous trees dominate growing season long
enough to grow new ones and still make enough
photosynthetic profit to overwinter. - Simple four-layer structure to forest.
- herbs flower in in spring when light abundant
also when wind-dispersed canopy trees pollinate
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45- BIOMES
- I. Climatic Determinants
- II. FORESTS
- A. Tropical Rain Forest
- B. Tropical Dry Forest
- C. Temperate Rain Forest
- D. Temperate Deciduous Forest
- 1. Abiotic
- 2. Biota
- Deciduous trees dominate growing season long
enough to grow new ones and still make enough
photosynthetic profit to overwinter. - Simple four-layer structure to forest.
- herbs flower in in spring when light abundant
also when wind-dispersed canopy trees pollinate - Biota varies dramatically with climate, from
northern hardwoods of Beech and Maple to Southern
Poplar-Oak (moist) and Oak-Hickory (dry).
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47- BIOMES
- I. Climatic Determinants
- II. FORESTS
- A. Tropical Rain Forest
- B. Tropical Dry Forest
- C. Temperate Rain Forest
- D. Temperate Deciduous Forest
- 1. Abiotic
- 2. Biota
- Deciduous trees dominate growing season long
enough to grow new ones and still make enough
photosynthetic profit to overwinter. - Simple four-layer structure to forest.
- herbs flower in in spring when light abundant
also when wind-dispersed canopy trees pollinate - Biota varies dramatically with climate, from
northern hardwoods of Beech and Maple to Southern
Poplar-Oak (moist) and Oak-Hickory (dry). - Pines dominate early in succession, or on dry
slopes, sandy soils, or other nutrient poor
substrates.
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49- II. FORESTS
- A. Tropical Rain Forest
- B. Tropical Dry Forest
- C. Temperate Rain Forest
- D. Temperate Deciduous Forest
- E. Boreal Forest(Taiga)
50- II. FORESTS
- A. Tropical Rain Forest
- B. Tropical Dry Forest
- C. Temperate Rain Forest
- D. Temperate Deciduous Forest
- E. Boreal Forest(Taiga)
- 1. Abiotic Conditions
51- II. FORESTS
- A. Tropical Rain Forest
- B. Tropical Dry Forest
- C. Temperate Rain Forest
- D. Temperate Deciduous Forest
- E. Boreal Forest(Taiga)
- 1. Abiotic Conditions
- TEMP A cold climate limits the growing season
no "time" for broad leaved trees to make leaves
and grow conifers dominate.Freeze-thaw cycles
keep roots shallow
52- II. FORESTS
- A. Tropical Rain Forest
- B. Tropical Dry Forest
- C. Temperate Rain Forest
- D. Temperate Deciduous Forest
- E. Boreal Forest(Taiga)
- 1. Abiotic Conditions
- TEMP A cold climate limits the growing season
no "time" for broad leaved trees to make leaves
and grow conifers dominate.Freeze-thaw cycles
keep roots shallow - RAINFALL Precip. is low (40-100 cm/year).
53- II. FORESTS
- A. Tropical Rain Forest
- B. Tropical Dry Forest
- C. Temperate Rain Forest
- D. Temperate Deciduous Forest
- E. Boreal Forest(Taiga)
- 1. Abiotic Conditions
- TEMP A cold climate limits the growing season
no "time" for broad leaved trees to make leaves
and grow conifers dominate.Freeze-thaw cycles
keep roots shallow - RAINFALL Precip. is low (40-100 cm/year).
- EVAPOTRANSPIRATIONAL STRESS Severe in long
winter due to low water availability
54- II. FORESTS
- A. Tropical Rain Forest
- B. Tropical Dry Forest
- C. Temperate Rain Forest
- D. Temperate Deciduous Forest
- E. Boreal Forest(Taiga)
- 1. Abiotic Conditions
- TEMP A cold climate limits the growing season
no "time" for broad leaved trees to make leaves
and grow conifers dominate.Freeze-thaw cycles
keep roots shallow - RAINFALL Precip. is low (40-100 cm/year).
- EVAPOTRANSPIRATIONAL STRESS Severe in long
winter due to low water avaiability - LIGHT Seasonally limiting in winter and under
closed canopies.
55- II. FORESTS
- A. Tropical Rain Forest
- B. Tropical Dry Forest
- C. Temperate Rain Forest
- D. Temperate Deciduous Forest
- E. Boreal Forest(Taiga)
- 1. Abiotic Conditions
- TEMP A cold climate limits the growing season
no "time" for broad leaved trees to make leaves
and grow conifers dominate.Freeze-thaw cycles
keep roots shallow - RAINFALL Precip. is low (40-100 cm/year).
- EVAPOTRANSPIRATIONAL STRESS Severe in long
winter due to low water avaiability - LIGHT Seasonally limiting in winter and under
closed canopies.
56Bogs - water accumulates at surface
Permafrost reduces root growth and plant growth
57- II. FORESTS
- A. Tropical Rain Forest
- B. Tropical Dry Forest
- C. Temperate Rain Forest
- D. Temperate Deciduous Forest
- E. Boreal Forest(Taiga)
- 1. Abiotic Conditions
- TEMP A cold climate limits the growing season
no "time" for broad leaved trees to make leaves
and grow conifers dominate.Freeze-thaw cycles
keep roots shallow - RAINFALL Precip. is low (40-100 cm/year).
- EVAPOTRANSPIRATIONAL STRESS Severe in long
winter due to low water avaiability - LIGHT Seasonally limiting in winter and under
closed canopies. - NUTRIENT CYCLING Slow and inefficient organic
debris and water trapped at surface by ice,
creates bogs
58- II. FORESTS
- A. Tropical Rain Forest
- B. Tropical Dry Forest
- C. Temperate Rain Forest
- D. Temperate Deciduous Forest
- E. Boreal Forest(Taiga)
- 1. Abiotic Conditions
- 2. Biota
59- II. FORESTS
- A. Tropical Rain Forest
- B. Tropical Dry Forest
- C. Temperate Rain Forest
- D. Temperate Deciduous Forest
- E. Boreal Forest(Taiga)
- 1. Abiotic Conditions
- 2. Biota
- Slow growing (but evergreen) conifers dominate
spruce, fir, pine. Birch and Aspen are only
deciduous trees to make it.
60- II. FORESTS
- A. Tropical Rain Forest
- B. Tropical Dry Forest
- C. Temperate Rain Forest
- D. Temperate Deciduous Forest
- E. Boreal Forest(Taiga)
- 1. Abiotic Conditions
- 2. Biota
- Slow growing (but evergreen) conifers dominate
spruce, fir, pine. Birch and Aspen are only
deciduous trees to make it. - Communities grade from sparse forest/tundra
boundary with lichens, moss, and an occasional
spruce to conifer forest to the white pine
/hemlock/ northern hardwood transition with the
deciduous forest. - dense brush in gaps otherwise no shrub layer to
speak of
61- II. FORESTS
- A. Tropical Rain Forest
- B. Tropical Dry Forest
- C. Temperate Rain Forest
- D. Temperate Deciduous Forest
- E. Boreal Forest(Taiga)
- 1. Abiotic Conditions
- 2. Biota
- Slow growing (but evergreen) conifers dominate
spruce, fir, pine. Birch and Aspen are only
deciduous trees to make it. - Communities grade from sparse forest/tundra
boundary with lichens, moss, and an occassional
spruce to conifer forest to the white
pine/hemlock/northern hardwood transition with
the deciduous forest. - dense brush in gaps otherwise no shrub layer to
speak of - dramatic seasonality to many animal populations
62BIOMES I. Climatic Determinants II. FORESTS III.
Grasslands
63III. Grasslands A. Shrub Forest Savannah
(Tropics) 1. Abiotic Conditions TEMP Uniformly
warm annual temp gt 20C a bit more seasonality
due to warmer temps during arid dry season
RAINFALL seasonal - closer to tropical margins
rainfall determines tree density, from shrub
forest ot tropical savannah with a few trees to
true grassland EVAPOTRANSPIRATIONAL STRESS
high, especially in dry season selects for C4
grasses LIGHT Never limiting, no winter and no
big trees creating shade NUTRIENTS and CYCLING
Most nutrients bound in biomass rapid
decomposition and rapid absorption. Little litter
accumulation.
64III. Grasslands A. Shrub Forest Savannah
(Tropics) 1. Abiotic Conditions 2. Biota
65III. Grasslands A. Shrub Forest - Savannah 1.
Abiotic Conditions 2. Biota Arid conditions and
fire select for C4 grasses
66III. Grasslands A. Shrub Forest - Savannah 1.
Abiotic Conditions 2. Biota Arid conditions and
fire select for C4 grasses In "C3" metabolism,
the metabolism we have already learned, CO2 is
first bound to a C5 molecule - making an unstable
C6 molecule that splits into two C3
molecules...glucose is produced and the C5's are
recycled...
6(CO2)
6(C6)
6(C5)
C6 (Glucose)
5(C6)
67III. Grasslands A. Shrub Forest - Savannah 1.
Abiotic Conditions 2. Biota Arid conditions and
fire select for C4 grasses In "C3" metabolism,
the metabolism we have already learned, CO2 is
first bound to a C5 molecule - making an unstable
C6 molecule that splits into two C3
molecules...glucose is produced and the C5's are
recycled...
6(CO2)
But there is a big problem when things get dry.
The plants close the pores in their leaves to
reduce water loss ('cuz it's dry!), and this
stops gas exchange, too. So no more CO2 gets
into the leaf, and no O2 can get out.
6(C6)
6(C5)
C6 (Glucose)
5(C6)
68III. Grasslands A. Shrub Forest - Savannah 1.
Abiotic Conditions 2. Biota Arid conditions and
fire select for C4 grasses In "C3" metabolism,
the metabolism we have already learned, CO2 is
first bound to a C5 molecule - making an unstable
C6 molecule that splits into two C3
molecules...glucose is produced and the C5's are
recycled...
6(CO2)
But there is a big problem when things get dry.
The plants close the pores in their leaves to
reduce water loss ('cuz it's dry!), and this
stops gas exchange, too. So no more CO2 gets
into the leaf, and no O2 can get out. And so, as
photosynthesis proceeds in a closed leaf, CO2
decreases and the O2 increases.
6(C6)
6(C5)
C6 (Glucose)
5(C6)
69III. Grasslands A. Shrub Forest - Savannah 1.
Abiotic Conditions 2. Biota Arid conditions and
fire select for C4 grasses In "C3" metabolism,
the metabolism we have already learned, CO2 is
first bound to a C5 molecule - making an unstable
C6 molecule that splits into two C3
molecules...glucose is produced and the C5's are
recycled...
O2
(CO2)
This is bad because the C5 molecule can only bind
CO2 when it's in high concentration. As the
CO2 drops, the C5 molecules bind to oxygen and
are metabolized... and glucose production
STOPS... (this is BAD).
6(C6)
6(C5)
C6 (Glucose)
5(C6)
C5 BREAKDOWN
70III. Grasslands A. Shrub Forest - Savannah 1.
Abiotic Conditions 2. Biota Arid conditions and
fire select for C4 grasses In "c4" metabolism,
the C3 pathway is isolated in special cells, in
which the CO2 concentration can be kept high (so
that glucose production will continue).
6(CO2)
6(C6)
6(C5)
C6 (Glucose)
5(C6)
71III. Grasslands A. Shrub Forest - Savannah 1.
Abiotic Conditions 2. Biota Arid conditions and
fire select for C4 grasses The CO2 conentration
is kept high by "pumping it in"... PEP is a C3
molecule that binds CO2 even at low
concentratrations (making a C4 molecule.
6(CO2)
CO2
6(C6)
C4
PEP (C3)
6(C5)
C6 (Glucose)
5(C6)
72III. Grasslands A. Shrub Forest - Savannah 1.
Abiotic Conditions 2. Biota Arid conditions and
fire select for C4 grasses This C4 molecule is
transferred and broken releasing CO2 and
recycling PEP. So CO2 is high in the special
cell and glucose production continues.
6(CO2)
CO2
6(C6)
C4
6(C5)
C6 (Glucose)
PEP (C3)
PEP (C3)
5(C6)
73III. Grasslands A. Shrub Forest - Savannah 1.
Abiotic Conditions 2. Biota Arid conditions and
fire select for C4 grasses SO, CO2 fixation is
spatially separate from Glucose production.
6(CO2)
CO2
6(C6)
C4
6(C5)
C6 (Glucose)
PEP (C3)
PEP (C3)
5(C6)
74- III. Grasslands
- A. Shrub Forest - Savannah
- 1. Abiotic Conditions
- 2. Biota
- Arid conditions and fire select for C4 grasses
- Large grazers dominate harvest energy by
processing huge amounts of forage quickly, or by
ruminating (bacterial gut flora). Migratory
75Cows are "foregut fermenters"... food goes
straight to a fermentation sac (rumen) with
bacteria....they regurgitate food and chew it
several times (chewing cud) before it passes to
the intestine for the extraction of nutrients...
76Horses are "hindgut fermenters"... food goes to
the stomach and then to the intestine, with no
regurgitation. The large intestine a caecum
(blind sac) have bacteria that break down the
cellulose. They must eat pretty continuously
because they don't ectract as many nutrients from
the food they eat.
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78III. Grasslands A. Shrub Forest - Savannah B.
Temperate Grassland (Prairie)
79III. Grasslands A. Shrub Forest - Savannah B.
Temperate Grassland (Prairie) 1. Abiotic
80III. Grasslands A. Shrub Forest - Savannah B.
Temperate Grassland (Prairie) 1. Abiotic TEMP
seasonal extremes - continental climate limits
growing season to 120-300 days depending on
latitude and temperature extremes. RAINFALL
Summer rain is predictably seasonal. Rainfall is
too low to leach cations from soil but can be
high enough to support significant plant
productivity. EVAPOTRANSPIRATIONAL STRESS high,
especially in dry season selects for C4 grasses
but C3 grasses still plentiful LIGHT Never
limiting, no winter and no big trees creating
shade NUTRIENTS and CYCLING moist grasslands
are richest soils on Earth, rich in nutrients and
organics
81III. Grasslands A. Shrub Forest - Savannah B.
Temperate Grassland (Prairie) 1. Abiotic 2.
Biota
82III. Grasslands A. Shrub Forest - Savannah B.
Temperate Grassland (Prairie) 1. Abiotic 2.
Biota The height and density of grasses
correlates with rainfall, which changes the soil
conditions.
increasing rainfall
83III. Grasslands A. Shrub Forest - Savannah B.
Temperate Grassland (Prairie) 1. Abiotic 2.
Biota The height and density of grasses
correlates with rainfall, which changes the soil
conditions. Perennial C4 grasses dominate.
84III. Grasslands A. Shrub Forest - Savannah B.
Temperate Grassland (Prairie) 1. Abiotic 2.
Biota The height and density of grasses
correlates with rainfall, which changes the soil
conditions. Perennial C4 grasses dominate.
Again, large grazers and predators dominate the
food webs.
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86III. Grasslands A. Shrub Forest - Savannah B.
Temperate Grassland (Prairie) C. ArcticTundra
ALPINE
ARCTIC
87III. Grasslands A. Shrub Forest - Savannah B.
Temperate Grassland (Prairie) C. Arctic Tundra 1.
Abiotic
88III. Grasslands A. Shrub Forest - Savannah B.
Temperate Grassland (Prairie) C. Arctic Tundra 1.
Abiotic TEMP Cold most of the year, with a
growing season less than 100 days. The summer
does have long days, but light intensities are
still low due to oblique angle. RAINFALL
Precipitation is very low, less than 25cm/year.
EVAPOTRANSPIRATIONAL STRESS high, largely due
to desiccating effects of dry, strong cold winds
and water frozen as ice most of year. LIGHT
Limiting most of year growing season very short
SOILS shallow just above permafrost boggy in
summer very slow decomposition - mats of peat
that transfer little nitrogen to soil
89(No Transcript)
90III. Grasslands A. Shrub Forest - Savannah B.
Temperate Grassland (Prairie) C. Arctic Tundra 1.
Abiotic TEMP Cold most of the year, with a
growing season less than 100 days. The summer
does have long days, but light intensities are
still low due to oblique angle. RAINFALL
Precipitation is very low, less than 25cm/year.
EVAPOTRANSPIRATIONAL STRESS high, largely due
to desiccating effects of dry, strong cold winds
and water frozen as ice most of year. LIGHT
Limiting most of year growing season very short
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92III. Grasslands A. Shrub Forest - Savannah B.
Temperate Grassland (Prairie) C. Arctic Tundra 1.
Abiotic TEMP Cold most of the year, with a
growing season less than 100 days. The summer
does have long days, but light intensities are
still low due to oblique angle. RAINFALL
Precipitation is very low, less than 25cm/year.
EVAPOTRANSPIRATIONAL STRESS high, largely due
to desiccating effects of dry, strong cold winds
and water frozen as ice most of year. LIGHT
Limiting most of year growing season very short
SOILS shallow just above permafrost boggy in
summer very slow decomposition - mats of peat
that transfer little nitrogen to soil
DISTURBANCE winter, freez-thaw cycles, storms,
exposure NUTRIENTS and CYCLING soils nutrient
poor and shallow
93peeling back the soil and vegetation to the top
of the permafrost
94- III. Grasslands
- A. Shrub Forest - Savannah
- B. Temperate Grassland (Prairie)
- C. Arctic Tundra
- 1. Abiotic
- 2. Biota
- No trees - above treeline.
95III. Grasslands A. Shrub Forest - Savannah B.
Temperate Grassland (Prairie) C. Arctic Tundra 1.
Abiotic 2. Biota No trees - above treeline.
Perennial grasses, mosses, and lichens dominate
the growing season is even too short for annual
herbs to really get going.
96- III. Grasslands
- A. Shrub Forest - Savannah
- B. Temperate Grassland (Prairie)
- C. Arctic Tundra
- 1. Abiotic
- 2. Biota
- No trees - above treeline.
- Perennial grasses, mosses, and lichens dominate
the growing season is even too short for annual
herbs to really get going. - Mammals tend to remain all year, relying on thick
fur to weather winters. Some migration into the
boreal forest does occur.
97- III. Grasslands
- A. Shrub Forest - Savannah
- B. Temperate Grassland (Prairie)
- C. Arctic Tundra
- 1. Abiotic
- 2. Biota
- 3. Alpine Tundra
98- III. Grasslands
- A. Shrub Forest - Savannah
- B. Temperate Grassland (Prairie)
- C. Arctic Tundra
- 1. Abiotic
- 2. Biota
- 3. Alpine Tundra
- Elevational treelines vary with latitude, being
900m at 65N, 2100m at 49N, 3300m at 40N, and
4200m at 19N.
99- III. Grasslands
- A. Shrub Forest - Savannah
- B. Temperate Grassland (Prairie)
- C. Arctic Tundra
- 1. Abiotic
- 2. Biota
- 3. Alpine Tundra
- Elevational treelines vary with latitude, being
900m at 65N, 2100m at 49N, 3300m at 40N, and
4200m at 19N. - Soils lack permafrost but are thin and "new".
Well drained (water runs downslope and does not
pool) and summer droughts can occur. - Dominant plants are perennial grasses and cushion
plants.
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101- III. Grasslands
- IV. Deserts
102- III. Grasslands
- IV. Deserts
- 1. Abiotic
- TEMP Temperatures can vary dramatically,
depending on time of day, time of year, and
latitude. Below freezing temperatures are
possible in high latitude deserts. - RAINFALL The common limiting variable is water -
deserts have less than 25cm/year, on average. In
warm deserts, the potential evaporation is much
greater than the precipitation. In Phoenix, AZ,
potential evapotranspiration is 130 cm a year,
but rainfall is only 18 cm/year. - EVAPOTRANSPIRATIONAL STRESS very high
desiccating conditions exceed rainfall - LIGHT not limiting during growing season
- SOILS little vegetation cover and slow
decomposition mean little organic inputs - very
patchy (under bushes). Otherwise, mineral soil is
exposed (lithosol). Rainfall does not generate
enough soil mositure to leach cations capillary
action may even bring them near to surface and
form a calcium and magnesium hardpan called
caliche. These salts exacerbate desiccation. - DISTURBANCE desiccation, temperature extremes,
severe drought, fire - NUTRIENTS and CYCLING very poor
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104- III. Grasslands
- IV. Deserts
- 1. Abiotic
- 2. Biota
105- III. Grasslands
- IV. Deserts
- 1. Abiotic
- 2. Biota
- Xerophyllic plants adapted to extreme drought
stress dominate (CAM plants)
106III. Grasslands IV. Deserts 1. Abiotic 2.
Biota CAM plants (cacti). In deserts where it's
REALLY dry, you can't even have your stomates
open AT ALL during the day... as son as the sun
comes up, it's hot. So, CAM plants keep their
stomates closed in the day, and they only use CO2
stored from the previous evening.
NIGHT - Stomates open, CO2 absorbed and ficed
into a C4 molecule
6(CO2)
6(C6)
6(C5)
C4
C6 (Glucose)
C3
5(C6)
107III. Grasslands IV. Deserts 1. Abiotic 2.
Biota NIGHT - Stomates open, CO2 absorbed and
fixed into a C4 molecule DAY Stomates closed, C4
is used and CO2 is released and Glucose is
made....this can only be done in the daylight
when ATP ans NADP are made with the light
reaction.
6(CO2)
6(C6)
6(C5)
C4
C6 (Glucose)
C3
C3
5(C6)
108- III. Grasslands
- IV. Deserts
- 1. Abiotic
- 2. Biota
- Xerophyllic plants adapted to extreme drought
stress dominate (CAM plants) - strong diurnal patterns in animal and plant
activity (CAM)
109- III. Grasslands
- IV. Deserts
- 1. Abiotic
- 2. Biota
- Xerophyllic plants adapted to extreme drought
stress dominate (CAM plants) - strong diurnal patterns in animal and plant
activity (CAM) - Plant density tightly linked to water
availability.
110- III. Grasslands
- IV. Deserts
- V. Summary - Terrestrial Biomes
- NET PRIMARY PRODUCTIVITY (total photosynthesis -
respiration)
111- III. Grasslands
- IV. Deserts
- V. Summary - Terrestrial Biomes
- NET PRIMARY PRODUCTIVITY (total photosynthesis -
respiration) - Take home messages....
- 1) per unit area, forests are more productive
than grasslands, which are more productive that
the open ocean (though REEFS are very
productive!!)
112- III. Grasslands
- IV. Deserts
- V. Summary - Terrestrial Biomes
- NET PRIMARY PRODUCTIVITY (total photosynthesis -
respiration) - Take home messages....
- 2) multiplying by the area of the biome, we see
the whole productivity of the biome as a
percentage of the Earth's productivity...
113- III. Grasslands
- IV. Deserts
- V. Summary - Terrestrial Biomes
- NET PRIMARY PRODUCTIVITY (total photosynthesis -
respiration) - Take home messages....
- 2) Rainforests and the open ocean are responsible
for over 40 of the planet's productivity.... why
is this important?
114- III. Grasslands
- IV. Deserts
- V. Summary - Terrestrial Biomes
- NET PRIMARY PRODUCTIVITY (total photosynthesis -
respiration) - Take home messages....
- ... because humans and all other organisms are
dependent on the NET PRIMARY PRODUCTIVITY... it
is the base of our food pyramids...
carnivores
HERBIVORES
NET PRIMARY PRODUCTIVITY
115Study Questions 1. Why do deciduous trees
dominate where there are cold winters and long
summers? 2. Why do conifers dominate at high
latitudes, high altitudes and in sandy soils? 3.
Why do grasses dominate some habitats? (climatic
reasons.) 4. Why are desert soils poor? 5.
Explain why tropical habitats are more
productive, on average, than temperate habitats.
6. How does C4 photosynthesis work, and why is
it adaptive for plants living in dry
environments? 7. How does CAM photosynthesis work
and why is it adaptive for plants in deserts? 8.
Why are temperate rain forests where they are? 9.
What are the most productive habitats, per unit
area, on the planet? 10. Which biomes contribute
the most to the Earths total NPP? 11. What is
NPP? Why is it an important ecologically to an
ecosystem? 12. Why is the melting of permafrost a
climatic concern?