biological communities: the biome concept
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Assignment: Read Chapter 4: Variations in the Physical Environment Next week ONLY: Monday AM lab = Tues 5-8 Monday PM lab = Wed 5-8 Please turn cell phones off + put away. 1st row seats = saved for later-comers…. - PowerPoint PPT PresentationTRANSCRIPT
Assignment: Read Chapter 4:Variations in the Physical EnvironmentNext week ONLY: Monday AM lab = Tues 5-8 Monday PM lab = Wed 5-8Please turn cell phones off + put away. 1st row seats = saved for later-comers…
Biological Communities: The Biome Concept
OBJECTIVES• What are large-scale distributions of plant
life forms?• aquatic• terrestrial• What is the proximal cause of their
distribution?• How does climate differ among biomes?• Whittaker’s scheme• Walter’s climagrams• Do form and function converge in regions
with similar climate?
Concept Map… *** Which physical factor separates habitats?
A water availability B movement of water USE EACH ONCE C medium of gas exchange D amount of salinity
Biome
Terrestrial Aquatic
Wetlands Desert Freshwater Marine
Rivers Lakes
1
2
3
4
Aquatic habitats
River continuumDownstream drift
High gradient vs.Low gradient
River: where precipitation > evaporation
photic
aphotic
A lake can be divided into vertical and horizontal zones.
Lakes can be poor or rich in nutrients.
Oligotrophic Eutrophic
Limnology = study of freshwater habitats
Abyssal zone
Ocean zones differ in temperature, depth, light, and tides.
Ocean habitats
OceanographyMarine biology
Estuary: where ariverreaches the ocean but isimpeded bylandforms
The terrestrial-aquatic interface…
The terrestrial-aquatic interface
rocky freshwater estuary marine
woody herbaceous woody herbaceous
swamp bog/fen marsh mangrove salt marsh
tropical temperate
Another concept map…
Concept map *** What 4 variables distinguish biomes?
Herbaceous/graminoids Shrubs Trees (grasses, sedges)
Shrublands Forests Grasslands Deserts
Tundra Evergreen Deciduous
Conifers Broadleaf Temperate Trop.
Temperate Tropical
Biome: a major type of terrestrial community categorized by its 1) dominant plant form, 2) seasonality of leaves, 3) leaf morphology, 4) location.
Tropical rain forestTropical seasonal (deciduous) forest / savannaSubtropical desertWoodland/shrublandTemperate rain forestTemperate seasonal (deciduous) forestTemperate grasslandBoreal forest (taiga)Tundra
***Review of major biomes…(write these down)
***What biomes do
you see in a cross-
country trip from E to W?
***Write down the letter that corresponds to the name of the biome:
Pictures not in this PP…go to book to see them.
A Tropical rain forestB Tropical seasonal forest/savannaC Subtropical desertD Woodland/shrubland Temperate rain forestE Temperate grassland/desert F Temperate seasonal forest G Boreal forestH Tundra
Answers
A
BC
D E
FG
H
I*** Which biome is found at each indicated
letter?
H Tropical rain forestG Tropical seasonal forest/savannaF Subtropical desertD Woodland/shrublandI Temperate rain forestC Temperate seasonal forestE Temperate grasslandB Boreal forestA Tundra
Answers
***Proximate/functional approach…
• What is the major factor determining biomes?
• In one sentence: Why isn’t there a single biome for the
earth?
Most species have limited tolerance; hence small ranges and biomes develop.
***In one sentence: Compare the ranges of birds/plants.
Climate is the major determinant of plantdistributions. Other factors are soil, fire, grazing, topography.
Whittaker’s scheme: biomes delineated by average temperature and precipitation.
Walter’s climate diagrams allow comparisons among localities.
20 mm monthly rainFor each 10ºC in temp= enough water for growth
(wherever precip line is above temp line)
growing season
What is clue that this is a desert?
Climatic zones and biomes separated first on basis oftemperature, then precipitation and its seasonality.
Boreal + polar climate zones:average annual T=< 5C
Temperate climate zones: average annual T = 5-20C
Equatorial + tropical climate zones: average T = > 20C.
Each climate zone has a typical seasonal pattern of temperature and precipitation.
When is itsdry season?
***What type of biome would you expect to develop with each climate?
Explain.
A B
***What type of vegetation would you expect at each locality? Explain.
A B
***Summarize in one sentence the main conclusion about biomes based on these figures and legends.
Localities worldwide with similar climate have the same biome.
Observation:Plant growth form is similar in widely separated areas. I wonder why?
Mexico Kenya
***Hypothesis:If form and function match the environment,then…?
Prediction: then unrelated organisms in similar environments will evolve similar form and function = Convergent evolution
Mexico Kenya
Unrelated African and South American rainforest mammals show striking convergence.
Example of exam question…A. Which biome would occur in each climate?
B. What is the limiting climatic factor(s) for each biome?
C. Where is each biome located in the Western (New World) and Eastern (Old World) hemisphere? Put letters on map.
OBJECTIVES• What are large-scale distributions of plant
life forms?• aquatic• terrestrial• What is the proximal cause of their
distribution?• How does climate differ among biomes?• Whittaker’s scheme• Walter’s climagrams• Do form and function converge in regions
with similar climate?
Chapter 5 Biological Communities: The Biome Concept
biomes* growth form forbsecological tolerances edaphic optimumspecializations specialists generalistsclimate zone growing season prairiessteppes rhizomes sclerophylloustaiga permafrost canopyemergent trees understory lianasepiphytes streams rifflespools allochthonous riparian zoneautochthonous river continuum lakeslittoral zone limnetic zone benthic zoneestuaries littoral zone zonationneritic oceanic zone benthic zonephotic zone aphotic zone coral reefs
Vocabulary
lotic lentic plant formherbaceous graminoids topographycontinental drift rain shadow middenecotone marine swampcypress mangrove bog/fenmarsh salt marsh estuaryoligotrophic eutrophic oxbow lakedeep sea vent kelp forest inter-tidal community zone
More vocabulary…Chaper 5/ Lecture 2: