Bio 101 - Lecture 15

Bio 101 - Lecture 15 - Ecology Interactions in the real...

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Unformatted text preview: Ecology: Interactions in the real world Patterns of species abundance are the result of interactions Understanding interactions helps us: U d t d why ecosystems are lik they Understand h t like th are Helps us predict what might happen if we take (or don't take) certain actions Interactions Types of Interactions Within-species (=intraspecific) Within(=intraspecific) Niche all the biotic and abiotic resources used by a species Competition natural selection Sociality Cannibalism Competition (intraspecific) When individuals share a resource in short supply AND there are some losers as a result One basis for natural selection Not enough for everybody - those individuals that use resources the best, leave the most offspring (increased fitness) Sociality Animals living together in groups Division of labor Some individuals don t reproduce don't AND there are some losers as a result Social insects 1) Parental care of young (young couldn't survive without parental care) 2) Overlap of generations (essential for 1) 3) R Reproductive division of l b i d ti di i i f labor, i.e., th there are egg-laying females and other females, may be other castes Honey bees Reproductive Castes - queen and drone Queen - produces eggs to maintain the colony Drones - mate with new queens Worker Caste Sisters all daughters of the queen Sisters, Care for the eggs, larvae, queen and drones Maintain and defend the hive, and forage for food Queen Drone Worker 1 Cannibalism Ritual cannibalism (e.g., Black Widow spider, praying mantis female devours male after mating) Cannibalism True cannibalism eat the same species for energy as any other prey (e.g., walleye, pike) Occurs in fish hatcheries Cannibalism Infanticide Intentionally causing death of an infant of a species Occurs in many species: lions, hamsters, langurs Sometimes young are eaten, sometimes just killed Perhaps related to fitness Often unexplained phenomenon (e.g., dolphins) Interactions Types of Interactions Within-species (=intraspecific) Within(=intraspecific) Among-species ( Among- p g (=interspecific) or p ) symbiotic relationships Mutualism Parasitism Competition Predation Mutualism Both species benefit from the interaction Termites and flagellates g Termites SingleSingle-cell flagellate in guts of termite Produces cellulase to digest wood 2 Mutualism Both species benefit from the interaction Termites and flagellates g Lichens: fungi + algae Lichens Mutualism Both species benefit from the interaction Termites and flagellates g Lichens: fungi + algae Pollinators and plants Pollinator Mutualism Both species benefit from the interaction Termites and flagellates Lichens: fungi + algae Pollinators and plants Nitrogen-fixing bacteria and legumes NitrogenNitrogen-Fixing Bacteria NO3 N2 Nodule on a soybean root with Rhizobium 3 Mutualism Both species benefit from the interaction Termites and flagellates Lichens: fungi + algae Pollinators and plants Nitrogen-fixing bacteria and legumes Nitrogen- The Cleaner Wrasse (A parasite remover) "parasite removers" c. abc.net.au Parasitism (one species benefits, the other is harmed, but not too much) Parasitism lives on or in its host "worms" nematodes, tapeworms lice, parasitic plants diseases viruses, protozoa (malaria) Dwarf mistletoe Growing on Pine Witchweed On Corn Evolution favors stable relationship where host does not die (or not quickly) to allow spread of parasite Competition (among species) Niche separation Resource partitioning use of different abiotic and biotic diff t bi ti d bi ti resources in space and time Involves harm - there are losers Predation (one species benefits, the other is injured, killed, debilitated, compromised in some way) Herbivores - predators of plants Conversion efficiency of about 10-15% 10of energy stored in plants into herbivore biomass Carnivores predators that eat animals (meat) 4 Turning the tables.. Predatory plants "You know . . . I think I'd lik thi k like a salad." Pitcher Plants carnivorous plants If plants are such good food, why i th world still h is the ld till green? Why are all of the plants not consumed by herbivores? They are Predators eat herbivores Plants defend themselves against herbivores Density-dependent (e.g., disease) and Densitydensitydensity-independent (e.g., weather) factors regulating herbivore population size They are! Agriculture Deer overpopulation e g overgrazing of Carolinian e.g., forest by deer Rabbits in Australia Predators Eat Herbivores Control of orange scale in California orange groves Spread and eventual control of Klamath Weed in the Pacific NW 5 The herbivore: A "scale insect" feeding on orange trees in California The predator: A ladybird beetle introduced from Australia The pest: Klamath Weed or St. John's Wort, a major plague in grasslands of the Pacific NW Biological Pest Control The herbivore: A Chrysolina beetle introduced in 1946 How does a plant defend itself from herbivores? Spines, thorns, hairs How does a plant defend itself from herbivores? Spines, thorns, hairs Hide Lithops looks like a stone How does a plant defend itself from herbivores? Spines thorns hairs Spines, thorns, Hide Chemicals poison 6 Poison Plants? California ppy Poppy How does a plant defend itself from herbivores? Spines, thorns, hairs Hide Chemicals poison taste bad Spices Bad tasting stuff for which we acquire a taste Deadly Nightshade How does a plant defend itself from herbivores? Spines, thorns, hairs Hide Chemicals poison taste bad Tannins (and related chemicals) are handy things Make leaves indigestible Used for tanning leather Basis for health claims for red wine, dark beer, and black tea Produce "tea-stained" water in "tealakes, rivers, and bogs indigestible parts (like tannins) What's an herbivore to do? The evolutionary "arms race" Herbivores eat plants -plants are damaged Plants with defenses grow and reproduce more Herbivores that can feed on plants with defenses grow and reproduce more Plants that evolve different kinds of defenses grow and reproduce more And so on . . . Feed on something else Overcome defenses caterpillars that feed on oak tolerate/eliminate the poison 7 Predation (one species benefits, the other is injured, killed, debilitated, compromised in some way) Herbivores - predators of plants Carnivores predators that eat animals ( i l (meat) t) How does something defend itself from carnivores? Run, hide Fight Taste and/or smell bad Look like something that tastes or smells bad Chemical warfare Spines, shells, armor Mimicry How does something defend itself from carnivores? Run, hide Warning coloration Fight stinging insects Taste and/or smell T d/ ll bad Look like something that tastes or smells bad Chemical warfare Yellowjacket Spines, shells, armor Camouflage How does something defend itself from carnivores? Run, hide Fight Taste and/or smell Warning coloration g bad Look like something that tastes or smells bad Chemical warfare Spines, shells, armor How does something defend itself from carnivores? Run, hide Fight Taste and/or smell bad Look like something that tastes or smells bad or fights Chemical warfare Spines, shells, armor Mimicry 8 How does something defend itself from carnivores? Run, hide Fight Taste and/or smell bad Look like something that tastes or smells bad or fights Chemical warfare Spines, shells, armor Some beetles spray a noxious chemical How does something defend itself from carnivores? Run, hide Fight Taste and/or smell bad Look like something that tastes or smells bad or fights Chemical warfare Spines, shells, armor Population regulation Population regulation Density-dependent factors - Increased Densitycompetition and diseases in populations when there are too many animals Population regulation DensityDensityindependent factors Factors not related to numbers of organisms that limit populations (e.g., weather, fire) Ecological Interactions within-species & withinamongamong-species keep ecological communities in a dynamic balance (unless something or someone screws it up) Hot, dry weather 9 Overpopulation Industrial pollution Habitat destruction Exploitation of natural resources Invasive species 10 ...
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This note was uploaded on 04/18/2008 for the course BIO 101 taught by Professor Lanno during the Winter '08 term at Ohio State.

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