Community Ecology PDF

Community Ecology MUIDS Biology 10 Ecological Levels of Organization 2 What is a Community? A community is a group of all populations living in the same location and interacting with each other. Community Structure Species richness and species diversit...

Community Ecology MUIDS Biology 10 Ecological Levels of Organization 2 What is a Community? A community is a group of all populations living in the same location and interacting with each other. Community Structure Species richness and species diversity allow us to compare different communities Species Richness Species richness is the number of different species present in an ecological community Only includes the count of species but not the information on abundance 4 different species of trees in community A and B Species Diversity Species diversity is the measure of diversity within a community. It includes both species richness and relative abundance. A: 25%; B: 25%; C: 25%; D: 25% A: 80%; B: 5%; C: 5%; D: 10% Let’s do it together: Find the species richness and species diversity in the two model communities shown below. Community 1 and 2 have the same species richness but different species diversity (percent of relative abundance) Bell-ringer Find the species richness and species diversity in the two model communities shown below. Each color represents different species. Community A: Community B: - 10 different species - 10 different species - 10% abundance for each species - 82% red, 2% each for pink, light gray, dark gray, blue, purple, yellow, green, brown, coral Today’s Objectives Students will be able to explain what competitive exclusive principle and resource partitioning is as well as give a few examples.  Community Structure Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. kinkajou squirrel monkey moose anteater snowshoe hare jaguar bear tapir red fox bat wolf sloth a. b. (forest): © Charlie Ott/Photo Researchers,Inc.; (squirrel): © Stephen Dalton/Photo Researchers,Inc.; (wolf): © Renee Lynn/Photo Researchers, Inc.; (rain forest): © Michael Graybill and Jan Hodder/ Biological Photo Service; (kinkajou): © Alan & Sandy Carey/Photo Researchers, Inc.; (sloth): © Studio Carlo Dani/Animals Animals 10  Community Interaction: Ecological Niche Each species occupy a particular niche in the community in terms of: Habitat 2. Niche – unique role that a species play in its community Adaptations An organism’s niche includes: Where the organism lives (habitat) What and how it eats (feeding activities) Interactions with other species Where it reproduces Organism’s activity pattern (time of the day they’re most active) Presence of other Physical How is niche different Activity organisms conditions patterns from habitat? Can any two species occupy the exact same niche? https://www.youtube.com/watch?v=rZ_up40FZVw Competition between Populations… Competitive Exclusion Principle No two species can indefinitely occupy the same niche at the same time Resource partitioning decreases competition between species Resource partitioning leads to niche specialization and less niche overlap between species 14 Finches on the Galápagos Islands Species coexist Percent of Sample Species coexist on Abingdon, Bindloe, James, and Jervis Islands 5 0 by adapting 3 0 1 different beak 0 small medium Beak Depth large types for Percent of Sample G. fortis exists alone 5 on Daphne Island 0 different food 3 0 1 sources 0 small medium large Beak Depth Percent of Sample G. fuliginosa exists alone 5 on Crossman Island 0 3 0 1 0 small medium large Beak Depth G. fuliginosa G. G. magnirostris fortis https://www.youtube.com/watch?v=0w5-UfEi470 16 Niche Specialization Among Five Species of Coexisting Warblers Reducing Niche Overlap When species with largely overlapping niches are allowed to compete, their niches may focus on a different part of the resource spectrum 17 Competition Between Resource Partitioning Two Species of Barnacles –Coexistence Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. high tide -No two species can coexist on the same Chthamalus limiting resource. area of competition -Species avoid Balanu competition by s partitioning resources and habitats among themselves. low tide 18  Bell-ringer 1. What will happen if two species occupy the same niche? a) The two species will compete with each other b) One species will out-compete the other. c) One species may go extinct. d) All of the above 2. Although three different butterfly species all inhabit the same flower garden in an area, competition between the butterflies rarely occurs. The most likely explanation for this lack of competition is that these butterflies A) have a limited supply of food B) B) are able to interbreed C) C) occupy different niches D) D) share food with each other 3. In a forest community, a shelf fungus and a slug live on the side of a decaying tree trunk. The fungus digests and absorbs materials from the tree, while the slug eats algae growing on the outside of the trunk. These organisms do not compete with one another because they occupy a. the same habitat, but different niches b. different habitats and different niches c. the same niche, but different habitats d. the same niche and the same habitat 3. True or False: Only 2 species at the most can have the same habitat. Today’s Objectives Students will be able to identify the types of interspecific interactions in the community as well as explain the difference between each type Types of interactions Intraspecific and Interspecific Intraspecific interactions include relationships between individuals of the same species Interspecific interactions include relationships with individuals of other species in the community In community ecology, we will be focusing on interspecific interactions Mutualism In mutualism, both species benefit (+/+) The cattle egret eats off the bugs The butterfly consumes nectar on the rhino’s body. The rhino’s from the flower, while also body is cleaned of bugs while the transferring pollen into the flower. cattle egret gains access to food. The flower becomes fertilized. Both of them benefit. Both of them benefit. https://www.youtube.com/watch?v=Xm2qdxVVRm4 Commensalism In commensalism, one species benefits while the other species is not affected (+/0) The clownfish lives in the tentacles of sea When the cattle graze, the insects in anemone. The clownfish benefits from grass are disturbed. Cattle egrets eat the having the sea anemone as a habitat, but disturbed insects and benefit from this the sea anemone is neither benefited nor action, but the cattle is not affected by harmed this. Commensalism  Parasitism Parasites live in or on a host organism. The host is always harmed by the parasite, but not necessarily killed. (+/-) Parasites may live externally on the host as ectoparasites, or inside the host’s body as endoparasites https://www.youtube.com/watch?v=vMG-LWyNcAs Parasitism Summarizing the Three Symbiosis Types https://www.youtube.com/watch?v=zTGcS7vJqbs Competition Can occur within (intraspecific) and between different species (interspecific) Competition between animals for mates or food are dominated by the largest and most aggressive individual Individuals compete for resources such as food, space, and mates. Both competitors are harmed by the interaction (-/-) Neighboring plants compete for light, nutrients, and water  Predation Predation is an interaction where a predator (an organism that is hunting) feeds on its prey (the organism that is attacked) Benefits the predator but harms or kills the prey (+/-) Presence of predators can decrease prey densities, and vice-versa Symbiosis – close, long term interaction between two different species Type of interaction Scenario Positive/Negative Mutualism Both species benefit (+/+) Commensalism One species benefits (+/0) while the other species is not affected Predation One species (predator) (+/-) benefits while the other species (prey) is harmed Parasitism One species (parasite) (+/-) benefits while the other species (host) is harmed Competition Both species are (-/-) harmed Bell-ringer: Identify whether the following is mutualism, commensalism, parasitism, competition, or predation 1. Lion eating warthog 2. A mosquito sucks blood out of human’s finger 3. A bird making a nest on the tree 4. Tick living on a dog 5. Remoras attach themselves to a shark’s body. They travel with the shark and feed on the leftover food scraps after the shark has finished its meal 6. Bacteria in human’s intestines 7. Birds and mammals eating berries and fruits from the plant 8. Two species of birds on the same tree Answers! 1. Predation 2. Parasitism 3. Commensalism 4. Parasitism 5. Commensalism 6. Mutualism 7. Mutualism 8. Competition Today’s Objectives Students will be able to identify types of prey defense mechanism as well as compare primary and secondary succession.  Prey defenses Some prey may have adaptations that help them avoid predators Camouflage Poisonous chemicals Warning coloration Flocking behavior Speed Protective armor Protective spines or thorns Mimicry Identify the following type of defenses  You cannot see me! I’m going to hide here, no one can see me. Camouflage Camouflage – blends in with the sourroundings (color, pattern, etc) Just keep swimming. Together, we stand. Flocking behavior I hope I’m not the slowest one. Flocking Behavior: Live in group in order to increase chance of survival Protective Spines or Thorns Protective spines or thorns – have spine or thorns that can injured the predator Protective armor Protective armor – have a hard shell or skin as a protection Look at my coloration, you should stay away! Warning Coloration Warning Coloration: use very bright color to warn off the predator I am her sister, so I am an owl, not a butterfly don’t eat me! Mimicry I’m going to pretend to be the bees. Mimicry – a harmless species LOOK like a harmful, poisonous, or bad-tasting species or make itself LOOK like a harmful species 47 https://www.youtube.com/watch?v=Y9Ll5P6qeNU We are the skunk. Stay away from us You can try to eat me, but I don’t Poisonous promise you’ll live. Chemicals Poisonous Chemicals – some prey produce poison to make predator sick or produce smell Speed – Outrun the predator Community Development Ecological succession is a change within a community over time that involves a series of species replacements. Usually occurs after a disturbance. There are two types of succession: Primary Succession Secondary Succession Primary Succession Initiated when a new area that has never previously supported an ecological community is colonized by plants and animals. This could be on newly exposed rock surfaces from landslides or lava flows. Secondary Succession An area that has previously had an ecological community is so disturbed or changed that the original community was destroyed and a new community moves in. More common than primary succession Often a result of natural disasters such as flood, fire, and winds, as well as human interference such as logging and clear-cutting. Pioneer species is the first species that grows in an area after a disturbance. First to return after the disturbance Their presence will increases diversity in the region Most of the time – plants not animals Help establish plant growth in damaged region Animals then slowly come in to eat the plant, flower, or the nectar