1 Biomes • What defines a biome? • Where are the ‘lines’ drawn? • What are the major controlling factors? • What about aquatic ‘biomes’ Biomes • Animals and plants have narrow ranges of tolerance to abiotic factors • This in part determines the biotic components of biomes . These are broad geographic regions determined by temperature and rainfall , and described by their plant communities Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Tolerance limits Figure 3.2 3-1 Figure 50.2 Patterns of distribution in the biosphere Figure 50.3 A climograph for some major kinds of ecosystems (biomes) in North America Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. World biome map Figure 5.3 5-1
Welcome message from author
This document is posted to help you gain knowledge. Please leave a comment to let me know what you think about it! Share it to your friends and learn new things together.
Transcript
1
Biomes
• What defines a biome?• Where are the ‘lines’ drawn?• What are the major controlling factors?• What about aquatic ‘biomes’
Biomes• Animals and plants have narrowranges of tolerance to abiotic factors
• This in part determines the bioticcomponents of biomes. These arebroad geographic regions determinedby temperature and rainfall, anddescribed by their plant communities
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
Tolerance limitsFigure 3.2
3-1
Figure 50.2 Patterns of distribution in the biosphere
Figure 50.3 A climograph for some major kinds of ecosystems (biomes) in NorthAmerica
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
World biome mapFigure 5.3
5-1
2
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
Biome climate graphsFigure 5.4
5-2
Figure 50.16a-d Examples of terrestrial biomes: maps
Figure 50.16e-h Examples of terrestrial biomes: maps Figure 50.16b Savanna
BiomesFigure 50.16c Desert. Organ Pipe State Park (top), Joshua Tree National Park
(bottom left), Death Valley (bottom right)
3
Figure 50.16a Tropical forests Figure 50.16h Tundra. Denali National Park (left), reindeer (right)
Figure 50.16e Temperate grassland Figure 50.16f Temperate deciduous forest, Great Smokey Mountains National Park
Figure 50.14 Marine biomes Figure 50.9 The distribution of major aquatic biomes
4
Figure 50.13 Zonation in the marine environment
Biomes
Figure 50.8 Lake stratification and seasonal turnover Figure 50.10 Zonation in a lake
Figure 50.11 Freshwater ecosystems. Oligotrophic lake (left), eutrophic lake (right)
Sea surface temperature
5
Salinity Currents
Aquatic Biomes
• Temperature• Currents• Nutrients• Salinity• Oxygen• Depth• Sunlight
• Physical as well as chemical boundaries
Some Key Points• Animals interact with biotic and abiotic factors in ways which shape
their survival and distributions• Biomes are delineated by abiotic factors, but biotic factors play a role
too.• Biomes are described by plant communities which are ‘controlled’ by
temperature and precipitation• Oceans are different: currents and salinity/oxygen distribution have a
major impact - productivity• Organisms have tolerance ranges to abiotic factors - both long term
and short term effects.
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
Biodiversity “hot spots”Figure 5.20
5-6
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
Natural medicinal products
5-7
6
Biodiversity
• Species diversity: number of differentspecies
• Genetic diversity: ensuring a healthygene pool-problems with bottlenecks
• Ecological diversity: numbers of ‘habitattypes’ - relates directly with speciesdiversity
• But WHY is it important??
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
Human disturbance
5-9
Extinction
Natural extinction• Extinction is a natural process. As
earth changes, so does it’s flora andfauna.
• Periods of mass extinctions andradiations (diversity)
• Extinction has to keep up w/speciation. (~1 per 1000 yrs.)
Extinction
Human accelerated extinction• Most major mass extinction in the last 65 mill yrs
is now (cretaceous), by us.• 40-100 sp. going extinct every day: unparalleled• 1000-10000 times natural background rate -
what’s cause?• possibly 20% of current species extinct in next 30
yrs - more than have been named yet!• Fastest moving aspect of global change• Irreversible
Extinction What causes extinctions?• Natural events - climate change, etc.• Habitat loss and disturbance• Commercial hunting and poaching• Predator and pest control• Pets/decorative plants• Introduction of non-natives• Population growth, affluence and
poverty
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
Mass extinctions
5-8
7
Extinction
What makes a species extinction prone?
• Critical population size• Specialists vrs. Generalists• Animal size (large)• Range (small)• Trophic position (high)• Tolerance to humans• Behavioral patterns
Passenger pigeon-now extinct
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
Reproductive strategies
3-10
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
U.S. wetland acreageFigure 5.24
5-10
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
Endangered species
5-13
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
Protected landsFigure 5.33
5-14
Related Documents
