Chapter 3 Flashcards
Flashback to Ch3. List the 4 types of keystone species
pollinators
predators
modifier of physical environment
continuous food providers
Where are the two most diverse ecosystems one earth (that the book picked)
tropical rain forest
coral reefs
What two variation styles are theorized to result in diversity patterns on earth?
variation in climate/environment
variation in topography, geological age, and habitat size.
Describe the rain forests
occupy 7% of land area
contain over half of the world’s species
based mainly on samping of arthropods
reasonable estimates range from 5-10 million species
maybe up to 30 million
40% of plants are found in rainforests (275k sp total)
30% of birds are found here. (of about 2600 species)
What physical aspect of the rainforest lends itself to diversity?
the layering of foliage and communities within the canopy
Trends in rainforest availability
around the equator is the most dense, but in general we just have been killing it.
Describe coral reefs
marine equivalent to tropical rain forests in species richness and complexity
high productivity
-sunlight penetrates deeply through the clear water
How do cruise boats and resorts hurt coral reefs?
pollution. Clear water is essential to coral reef functioning/productivity
Facts about the great barrier reef
349000 square km (0.1% of ocean surface) 400 species of coral 1500 species of fishes (8% of world's fish species) 4000 species of mollusks 6 spcies of turtles
What are the differences between tropical rain forests and coral reefs
very few reef species have narrow distributions like rain forests
widely dispersed during juvenile phase.
only isolated islands like Hawaii have endemic species
Most biodiversity is found ONLY in the oceans.
(Diversity is spread over broad range of phyla and classes)
Diversity is spread over broad range of phyla and classes. Give some specific stats.
32 of 34 extant animal phyla are found in marine systems
13 of these exist only in marine environment (not fresh water or land)
1 phylum is found exclusively in terrestrial environments.
0 phyla are found exclusively in freshwater environments.
Patterns of diversity that vary in climate and environment show that species richness increases with what 3 factors mainly?
3 main factors:
- decreasing elevation (mts vs valleys)
- increasing solar radiation (equator)
- increasing precipitation
What factors cause species diversity to increase with variation in topography, geological age, and habitat size? Why?
-complexity of topography (diff habitat types)
- greater geological age
- -coral sp. richness is greater in indian and west pacific ocean vs Atlantic which is younger
-habitat size
Why: It allows genetic isolation, local adaptation, and speciation.
What correlations exist among types of organisms in distribution of species richness?
The amount of diversity among these groups is correlated.
Amphibians, birds, mammals, and plants in South America:
- most in western amazon
- secondary concentration in highlands of NE South America.
Birds, amphibians, and mammals in africa.
Hot spots
areas of species diversity that are very important to conserve.
