Ecology

1. Ecology

2. I. Ecosystem Components A. Ecology – from the Greek oikos (“house” or “place to live”) B. Ecology is the study of how organisms interact with one another and their environment.

3. C. An organism is a form of life. Organisms can be classified into species. Scientists have no concrete idea how many species exist on earth. Kinkajous (Honey Bear) Rainforest Mammal related to the raccoon

4. D. Estimates range between 4 million to 100 million species exist (most microscopicorganisms and insects) E. The best estimates are that there are 10-14 million species F. So far scientist have named and classified only about 1.8 millionspecies.

5. G. A population is a group of individuals of the same species occupying a given area at the same time Ex. Blue morpho butterflies Populations and Communities

6. H. In most populations individuals of the same species vary in their genetic make up – they don’t all look or act alike. I. This is called genetic diversity J. Genetic diversity is crucial if a population is to survive.

7. K. Populations of all the different species occupying a particular habitat make up a biological community.

8. L. An ecosystem is acommunityof different species interacting with one another and their non-living environment. Ecosystems include abiotic and biotic factors.

9. Diverse Ecosystems: Rainforest – Greatest species diversity of any ecosystem due to warm temperatures and abundant rainfall.

11. Cloud Forest – Rainforests in high elevation. Name comes from the constant clouds that envelop them – moist air all the time to feed

12. Dry Pacific Forest – Dry season, on which side of the mountains?

13. Mangrove swamps – Estuarine ecosystem on Pacific coast, provide the perfect habitat for juvenile species.

14. Coral Reefs

15. II. Species Interactions • Organisms interact with multiple other organisms of the same and different species. • Intraspecific Interactions – Interactions among members of the same species • Interspecific Interactions – Interactions between two or more members of different species

16. II. Species Interactions B. These interactions influence individual fitness, population density, species distribution, and even extinction levels or rates. C. When looking at interspecific species interactions, its helpful to ask if the interaction is beneficial or detrimental to each species involved.

17. II. Species Interactions D. The following chart shows the relationship between two species in each type of interspecific interaction. + = positive effect • = negative effect 0 = neutral

18. II. Species Interactions** From Hillis, Sadava, Heller, and Price

19. III. Interspecific Competition (-/-) • Interspecific competition is competition between members of two or more species. Usually multiple species are using the same resource and species are competing to get access to resource. • Remember that anytime an organism has to compete for something it expends energy and personal resources, even if it does “win” the competition.

20. III. Interspecific Competition (-/-) C. Again, intraspecific competition is competition between members of the same species (food, mates, etc). Think about how many ways human’s lives are dominated by intraspecific competition.

21. D. Niche – The set of physical and biological conditions a species requires to survive, grow, and reproduce.

22. III. Interspecific Competition (-/-) E. Both inter (between species) and intra (within species) competition often occurs over limiting resource – plants growing to get sunlight, competition among predators that depend on the same prey species, etc.

23. III. Interspecific Competition (-/-) F. Limiting Resource/Factor: Too much or too little of any factor in the environment can limit the growth of a population, even if all other factors are present. G. Limiting resources/factors in land ecosystems include: temperature, water, light, nutrients.

24. III. Interspecific Competition (-/-) H. Limiting resources/factors in aquatic ecosystems include: salinity, dissolved oxygen content, nutrients, light, and temperature.

25. I. Carrying capacityis the number of organisms an area can support based on the limiting factors present J. Competitive exclusion principle = two species competing for the same limiting resource in the same way can’t coexist. Either one species will go extinct or one species will adapt via resource partitioning.

26. III. Interspecific Competition (-/-) K. Resource partitioning will often occur between species in the same environment. Resource partitioning occurs when two species divide a resource based on differences in species behavior or morphology.

27. III. Interspecific Competition (-/-) L. If two species reduce competition by using the same resource at different times, it is called temporal resource partitioning. M. Many plants do this by flowering at different times of year, or day – some plants flower at night to attract different pollinators.

28. N. Wolves and coyotes are also an example of temporal resource partitioning. They are both top predators, but can live in the same region because wolves are more active in early to mid evening, coyotes are most active from midnight to dawn.

29. O. Spatial resource partitioning – species reducing competition by using different habitats. Top predators often do this by having different hunting territories. P. Desert plants often do this as well by having different root systems – some have a wide area of very shallow roots, while others have very small area of deep tap roots.

30. Q. Morphological resource partitioning – the evolution of differences in body size or shape to exploit different resources in the same area.

31. R. Darwin’s Galapagos finch classic example – 14 different finch species with differences in beak morphology allowed them to eat different types of seeds.

32. IV. Consumer/Resource Interactions (+/-) • Consumer/resource interactions are the interactions between species that are commonly thought of as predator/prey type interactions.

33. IV. Consumer/Resource Interactions (+/-) B. Predation – organism kills another non-plant organisms C. Herbivory – organism consumes plants D. Parasitism – organism consumes nutrition/tissue (blood) from another organism, usually not killing.

34. III. Interactions Between Species E. Keystone Species – Organism that is more important for ecosystem maintenance than would be evident by the raw numbers of organisms or biomass in the ecosystem. F. Removal of keystone species often substantially alters the food chain of an area.

35. G. The classic examples of a keystone species is otter in a kelp-forest marine food web. The sea otter eats sea urchins, which in turn eats the kelp. When sea otters are removed the sea urchin population explodes and overgrazes the kelp, causing complete loss of the kelp. Kelp forms a forest which provides food and shelter for a wide range of organisms.

36. H. Usually keystone species in ecosystems are top predators.

37. IV. Consumer/Resource Interactions (+/-) I. Consumer/Resource interactions drive an “evolutionary arms race” between consumer and resource. J. “Prey continually evolve better defenses and predators continually evolve better offenses and neither gain any lasting advantage over each other.”

38. Evolutionary Arms Race Weapons K. Predator: Speed, size, weapons, strength, sharp senses, armor piercing/crushing tools, means of detoxifying poisons. L. Prey: camouflage, speed, size, weapons, mimicry, thick armor, poisonous

39. V. Mutualism (+/+) A. Symbiosis “living together” B. Mutualism is a type of symbiosis 1. Mutualism - both species benefit • Ex. Ants and the Acacia Tree • Ants protect the tree • Tree provides nectar and home for ants

40. C. Examples: • flowers and pollinators (bees, bats, flies, hummingbirds) • Humans and bacteria living in digestive system

41. V. Mutualism (+/+) D. Mutualistic relationships are an exchange between two or more organisms that positively benefit the fitness of both species involved E. Fitness = An individual’s ability to survive and reproduce

42. V. Mutualism (+/+) F. Species aren’t altruistic – they don’t purposely do nice things for others. They are acting in their own self interest and usually accidentally benefit other species. 1. Bees visit flowers to get nectar, when they are at the flower the pollen rubs off on bee, then pollen is taken to another flower as bee tries to get more nectar.

43. V. Mutualism (+/+) G. Lots of cheating is involved in mutualism – some flowers don’t actually provide nectar, some bees bite the bottom of the flower to get nectar and the pollen doesn’t rub off on them.

44. VI. Commensalism ( +/ 0) • Commensalism – one organism benefits while the other is neither helped nor harmed (no effect on the fitness of second species). • Usually commensalism happens when a species’ feeding behavior makes food more available to another species.

45. VI. Commensalism ( +/ 0) C. Example 1: Brown- headed cowbirds follow herds of cattle, eating insects flushed out by cows eating and tromping around in grass (don’t eat the insects OFF of cows). D. Dung beetles – Use animal poo to eat and lay eggs in. Animals not affected in any way by dung beetle behavior.

46. E. The classic example… Clownfish and Sea Anemones -the clownfish is protected by the nematocysts of the sea anemone - the sea anemone is neither helped or harmed However… sea anemone may Benefit from N compounds in Fish waste, or the fish may eat Some of the anemone’s food….

47. VII. Amensalism (-/0) • Amensalism = one species harmed, one species unaffected • Mostly accidental relationships – big animals step on insects, humans kill worms when plowing fields, etc.