Transcript Community
Review: Species: groups of organisms that are similar enough to breed and produce fertile offspring Review: Population: groups of organisms of the same species living in a particular place Review: Community: group of organisms of different species living in a particular place (includes all living things— plants and animals) Review: Ecosystem: all of the living AND nonliving things in a particular area ◦ Example: plants, animals, water, climate, soil, rocks, etc. Review: Biome: group of ecosystems with the same climate and similar communities ◦ Example: Desert, Tundra, Savanna, Tropical Rainforest Review: Biosphere: area on earth where all life exists Review: The Role of Climate Two major factors affecting ecosystems and biomes are climate and weather. Temperature, precipitation, and other environmental factors combine to produce weather and climate. What is the difference? Climate vs. Weather Weather= day-to-day conditions in an area ◦ Example: Is it raining? Is it sunny or cloudy? Is it windy? Is it foggy? Climate= average yearly conditions of temperature and precipitation in a region ◦ Example: What is the avg. yearly temperature? Are there different seasons? What is the avg. yearly humidity and precipitation? Factors that Contribute to Climate Trapping of heat by the atmosphere Transport of heat by wind and water currents Amount of precipitation Latitude (how far north or south a place is) The Effect of Latitude on Climate Earth is a sphere tilted on its axis and receives sunlight at different angles throughout the year Different latitudes = different angles of heating by the sun Creates 3 Climate Zones Polar: cold and dry; sun’s rays hit at low angles Temperate: between polar and tropical; most changes in light; temperature varies from hot to cold Tropical: near equator; direct or nearly direct light year around; hot and wet The Greenhouse Effect Gases in the atmosphere (H2O, Co2, and methane) trap heat and warm the earth. Heat Transfer in the Biosphere Heat is moved by wind and air currents Warm air/water rises and cool air/water moves in. This creates currents. What Shapes an Ecosystem? Ecosystems are influenced by biological and physical factors. Biotic factors = living (biological) influences on an organism Abiotic factors = nonliving (physical) influences on an organism What Shapes an Ecosystem Habitat = the biotic and abiotic factors where an organism lives Habitat is like an organism’s address. What Shapes an Ecosystem? Niche = all biotic and abiotic factors where an organism lives AND the way in which it uses those factors Niche includes WHERE an organism lives PLUS things like… ◦ What it eats? Any predators? Where in the habitat does it live…tree, pond, underground? ◦ The organisms actions…hibernating, migrating, when and how it reproduces? Habitat vs. Niche Habitat is like the organism’s address. Niche is like the organism’s occupation. What Shapes an Ecosystem? Resources = anything needed by an organism for life Examples: Nutrients, water, light, space Community Interactions There are several ways species interact with each other: ◦ ◦ ◦ ◦ Competition Predation Cooperation Symbiosis Competition Between SAME or DIFFERENT species Compete with each other for available resources Competition Organisms in an ecosystem have to compete with each other for available resources such as FOOD. Competition Organisms in an ecosystem have to compete with each other for available resources such as SHELTER. Competition Organisms in an ecosystem have to compete with each other for available resources such as MATES. Competition Organisms in an ecosystem have to compete with each other for available resources such as SPACE/TERRITORY. Competition Organisms in an ecosystem have to compete with each other for available resources such as LIGHT. Especially plants! Competition If resources are scarce, some organisms will starve and populations will decrease. If resources become more plentiful, populations will increase. Competition in nature often results in a winner and a loser…with the loser failing to survive! Competition If a nutrient is in short supply OR cycles slowly through the ecosystem, it will LIMIT the growth of a population. This is called a LIMITING FACTOR (or limiting nutrient). During this drought, there was not enough food available and many kangaroos starved. Competition Limiting Nutrient ◦ The short supply of a limiting nutrient keeps the population in check. ◦ When an ecosystem receives a LARGE input of limiting nutrient (Ex. Fertilizer) the population increases dramatically. ◦ Example: Algal bloom Predation Between different kinds of organisms Predator = organism that hunts and kills other organisms to supply their energy needs Predation Prey = Organisms in an ecosystem that get eaten by a predator Cooperation Between SAME kind of organisms Live together and help each other Example: Monkeys helping clean each other Cooperation Same species live together in groups Example: herds, packs, colonies, families Share food and childcare responsibilities Groom each other Take care of sick Cooperation Same species live together in groups Example: herds, packs, colonies, families Hunt in packs Provide Protection Symbiosis Between DIFFERENT species Two species living closely together Symbiosis 3 Types: Mutualism, Commensalism, Parasitism 3 Types of Symbiosis Mutualism: both organisms benefit Commensalism: one organism is helped; other organism is NEITHER helped nor harmed Parasitism: one organism benefits (the parasite); other organism (host) is harmed in some way MUTUALISM “Good for me - Good for you” http://www.providence.edu/bio/faculty/adams/LECTUREProvCollegeMutualism.html Insects transfer pollen between plants as they gather nectar for food. http://www.yksd.com/DistanceEdCourses/YKSDbiology/lessons/SecondQuarterLessons/Chapter5/5-5/images/3-way-mutualism.jpg PARASITISM “Good for me - Hurts you” Tapeworms absorb food by living inside host intestine; host is harmed http://www.biology.ucok.edu/AnimalBiology/Platyhelminthes/tapeworms.jpg MUTUALISM “Good for me - Good for you” Clown fish gets protection from enemies by hiding out in poisonous sea anemones http://www.zahnersatz.com/english/library/symbiosis.jpg Sea anemone gets scraps of leftover food dropped by fish COMMENSALISM “Good for me - Doesn’t bother you” http://www.abyssal.com/meeks/images/hermit_crab.jpg Hermit crabs make homes in shells abandoned by snails; Snail is not harmed by crab MUTUALISM “Good for me - Good for you” Birds eat parasites living on the hides of giraffes and rhinos while enjoying protection from predators. Groomed animals lose their pests. http://www.imbt.org/science.htm http://www.hugheshome.net/jon/africa02/images/rhino_bird_JPG.jpg PARASITISM “Good for me - Hurts you” Ticks are blood sucking insects that attach to a dog’s skin. The ticks feed on the dog’s blood, and the dog has discomfort and can get diseases. COMMENSALISM “Good for me – Doesn’t bother you” http://www.geology.wmich.edu/gillespie/g322/Chapters/C16shark.gif Pilot fish receive scraps of food dropped by shark; Shark is neither harmed nor helped Ecological Succession Series of predictable changes that occur in a community over time Caused by: ◦ Slow environmental changes OR ◦ Sudden natural disturbances Succession is basically things “growing back” after something happens (or growing for the first time) Ecological Succession Caused by slow environmental changes Ecological Succession Or caused by sudden natural disturbances Ecological Succession Two types: ◦ Primary Succession ◦ Secondary Succession Primary Succession Happens on surfaces where NO SOIL exists Example: volcanoes, glaciers melting, etc. If there is no soil, how can something grow?? Primary Succession Some plants can grow on bare rock without any soil ◦ Example: Lichens and mosses Primary Succession The first species to populate an area = pioneer species In primary succession, lichens and/or moss are the pioneer species. Primary Succession Steps in Primary Succession When lichens and mosses die, their remains turn into soil. Wind and rain cause weathering and erosion which break down some of the rock surface and turn it into soil. Grasses and small plants can start to grow in the soil that has been created. Then bigger plants can begin growing. Eventually a climax community will be reached. Climax Community Climax community = a mature stable community in which there is little change in the number of species Secondary Succession Occurs on areas where SOIL IS present Occurs after natural disturbances that do not remove soil Example: after a forest fire, or after farmland is plowed then left alone Secondary Succession Goes through the same steps as primary succession, EXCEPT soil is already there in beginning Pioneer species comes in FIRST (can be a plant that requires soil, not just lichens/mosses). Bigger plants start to grow until climax community reached. Secondary Succession REMINDERS! Not all ecosystems will reach the climax community stage. Sometimes another disturbance can happen and ecological succession has to start over. REMINDERS! Plants are not the only thing that “come back” when succession happens. Animals inhabit these areas too once there is enough food! The type of food available determines which animals will come back and when.