II. The Living World (10-15%) 1. *Ecosystem Structure (Biological populations and communities; ecological niches; interactions among species; keystone species; species diversity and edge effects; major terrestrial and aquatic biomes) 2. *Energy Flow (Photosynthesis and cellular respiration; food webs and trophic levels; ecological pyramids) 3. *Ecosystem Diversity (Biodiversity; natural selection; evolution; ecosystem services) 4. *Natural Ecosystem Change (Climate shifts; species movement; ecological succession) 5. Natural Biogeochemical Cycles (Carbon, nitrogen, phosphorus, sulfur, water, conservation of matter)

mft Tropical rain forest Coniferous forest Deciduous forest Thorn forest Tall-grass prairie Short-grass prairie Desert scrub Thorn scrub Terrestrial Communities

Latitude Effects on Richness Species Diversity 1, Latitude 80ºN ºN ºS60 Latitude (a) Ants(b) Breeding birds

MacArthur and Wilson Study done comparing small and large island biodiversity. Conclusions: –Small islands have less animals coming to it because it is a small target to immigrate to. –Smaller islands have higher extinction rates because of fewer resources and habitats –Islands closer to mainlands will have higher immigration of animals.

Species Native: species that normally live in an area. In Iowa: whitetail deer, squirrel, bass, etc. Non-native: AKA invasive or alien. Brought into an area intentionally or accidentally. Can often overtake native species. Asian beetle, water milfoil, zebra mussel, etc. Indicator: species that will be affected first by environmental change. Trout (temperature), frogs, birds. Keystone: species that have an effect on a large number of other species. (pollination, predation, etc)

Why we love Kermit the Frog Amphibians are excellent indicator species. Why? –Lifecycle puts it in contact with land and water –Vulnerable to a wide variety of chemicals, radiation, pollutants Frog species loss –Habitat loss –Pollution –Hunting (frog legs) –UV radiation

Number of individuals Resource use Species 1Species 2 Region of niche overlap Species 1Species 2 Resource Partitioning © 2004 Brooks/Cole – Thomson Learning Hawks and Owls = same prey. Hawks – hunt by day Owls – hunt by night

Resource Partitioning

Prey Defense Mechanisms Avoidance: Hedgehogs (rollup/spines), lizards tails that break off, turtle (shell), Camouflage: coloring, patterns, etc to help blend in. Deer, frogs, etc. Poison: Oleander plants, some frogs Foul smell/taste: Monarchs, skunks, etc. Warning color: bright color to show poisonous nature. Mimicry: Look like a poisonous animal, act like another (bull snake “rattling”)

Span worm Bombardier beetle Viceroy butterfly monarch butterfly Poison dart frog snake caterpillar Prey Defense Mechanisms Wandering leaf insect io moth Camouflage Foul smell Mimicry Foul taste Mimicry Poison/Warning Color

Relationships Predator-Prey: “eat or be eaten” Parasitism: one organism lives off of another. Host is often weakened, but not killed. Examples: tapeworms, wood ticks, cowbird eggs. Mutualism: both species in relationship will benefit. Example: clown fish/sea anemone. Commensalism: one organism benefits, the other is not affected. Some doubt this exists as “some effect” must occur. Example: seeds traveling on animals Review clip for visual

ECOLOGICAL SUCCESSION Changes in the biotic characteristics in an area over time. Primary Succession Secondary Succession

Two types of ecological succession Primary succession: occurs on a surface where no ecosystem existed before (no soil) Secondary succession: occurs on a surface where an ecosystem has previously existed but has been disturbed (soil is present)

Primary Succession Starts with: barren rock (land) or rock bottom of lake, river, stream. Examples: area after volcanic eruption, glacier retreat. Pioneer species: usually lichen and moss. Begins to break down rock to make soil. Early successional plants: annuals, low growing, short lives. Midsuccessional plants: herbs, taller grasses, shrubs. Late successional plants: mostly trees. Climax community (succession completed) View clip

Time Small herbs and shrubs Heath mat Jack pine, black spruce, and aspen Balsam fir, paper birch, and white spruce climax community Exposed rocks Lichens and mosses Primary Succession Review soil formation

Succession in the boreal forest (for example in Canada) – climax species are fir, spruce, hemlock For example, eastern U.S. - climax species are oak, hickory, maple

Secondary Succession Starts with: disaster or human activity that destroys environment, but soil remains. Follows same process as Primary succession, but lengthy soil making process gets to be “skipped” First to re-grow: small grasses, plants then leads to larger shrubs and trees.

Time Annual weeds Perennial weeds and grasses Shrubs Young pine forest Mature oak-hickory forest Secondary succession

© 2003 John Wiley and Sons Publishers Ecological Succession can occur in aquatic ecosystems

 Starts with : newly formed pond/lake  Typically from glacial retreat  Bottom is rocky.  Sediment is brought in by runoff, erosion.  Plants able to grow on edges only.  Plant growth, death, decay leads to more nutrients.  Normal eutrophication can lead to wetland, then meadow.  Succession would end with grassland or meadow

Aquatic Succession Starts with: newly formed pond/lake Typically from glacial retreat Bottom is rocky. Sediment is brought in by runoff, erosion. Plants able to grow on edges only. Plant growth, death, decay leads to more nutrients. Normal eutrophication can lead to wetland, then meadow. Succession would end with grassland or meadow

Aquatic Succession

Even in one location, the climax community depends on many factors

© 2003 John Wiley and Sons Publishers Changes in Biota

© 2003 John Wiley and Sons Publishers Changes in Abiotic Factors

II. The Living World (10-15%) 1. *Ecosystem Structure (Biological populations and communities; ecological niches; interactions among species; keystone species; species diversity and edge effects; major terrestrial and aquatic biomes) 2. *Energy Flow (Photosynthesis and cellular respiration; food webs and trophic levels; ecological pyramids) 3. *Ecosystem Diversity (Biodiversity; natural selection; evolution; ecosystem services) 4. *Natural Ecosystem Change (Climate shifts; species movement; ecological succession) 5. Natural Biogeochemical Cycles (Carbon, nitrogen, phosphorus, sulfur, water, conservation of matter)