1. Population Ecology Biotic potential: -maximum possible growth rate for a species -depends on: -age at maturity -clutch size -how often and how long can reproduce -how well and how many offspring survive -never attained in nature! Why?

2. Limiting Factors: -space, light, water, food, nutrients, etc. Density-dependent factors -have an increasing effect as population density rises Density-independent factors -population size does not influence effect Growth Rate: r =births-death N

3. Patterns of Growth Exponential -rapid growth -frequent doubling -results in J curve *Occurs when: new habitat, new food source, decrease in predators, etc. Stabilization phase - # deaths = # births -S (sigmoid) curve *Carrying capacity: max. # of individuals a habitat can sustain Population cycles -lynx and snowshoe hare -gypsy moths

6. r strategists -many offspring  small, mature quickly -little or no parental care -often in unpredictable environments - “opportunists” k strategists -small # of large, slow maturing offspring -lengthy parental care -adapted to stable environments

11. Interactions between species (community ecology) Competition “Interspecific competition” – between members of different species; for limited resources Competitive Exclusion Principle -when 2 species compete for 1 limited resource  1 wins, the other is eliminated -only 1 species per niche

13. Realized niche -actual niche Fundamental niche -theoretical -larger -could be occupied by a species if no competitors present

14. Predator-Prey Complex, dynamic interactions Co-evolution: 2 species evolve in response to each other

15. 1. Plant structural defenses -thorns, spines, hairs, silica, sticky substances 2. Secondary compounds in plants -toxic to herbivores -therefore, plants are avoided eg. mustard oils, tannins, nicotine, poison ivy toxin

16. 3. Cryptic coloration 4. Aposematic (warning) coloration -conspicuous coloration -predators learn to avoid 5. Mimicry -1 or more species evolves to resemble another Batesian mimicry- unprotected species mimics protected species Muellerian mimicry- many protected species share a color pattern

19. Symbiosis -Parasitism botfly video -Commensalism which is this?

20. -Mutualism

21. Ecosystem Dynamics Energy – does it cycle? NO! it flows through ecosystems, gradually lost as heat Matter – (nutrients) do not leave ecosystem, they cycle Biogeochemical cycles: -water cycle -carbon cycle – CO 2 based -phosphorous cycle -nitrogen cycle -78% of air is N 2 but most organisms can not use N 2

22. Biogeochemical cycles (Nitrogen) 3 sources of useable N in ecosystems: 1. lightning - N 2  NO 3 - 2. Decomposition in soil 3. N-fixing bacteria - N 2  NH 4 + Nitrogen fixation – without it there would be virtually no life! *free living bacteria – in soil *symbiotic bacteria - in root nodules of legumes

23. Nitrification – bacteria in soil NH 4 +  NO 2 – NO 2 -  NO 3 - (nitrate) (plants take in through roots and use) Dentrification – bacteria NO 3 -  N 2 *N is often THE limiting factor in ecosystems Where does each get its N from? (and in what form?) AnimalsPlantsBacteriaAtmosphere

29. 500 bushels of wheat 1 cow What should they do to survive the longest? A.Eat the cow and then the wheat B.Drink the cow’s milk, then eat the wheat C.Don’t feed the cow but drink the milk, eat the cow when the milk stops, then eat the wheat D.Feed the wheat to the cow and drink the milk E.Feed the wheat to the cow, drink the milk, then eat the cow F.Eat the wheat, then the cow