Transcript ecology pp
Principles of Ecology Principles of Ecology • Ecology – Scientific study of interactions among organisms and their environments • Relationships among living –BIOTIC- and nonliving – ABIOTIC- parts Ecology • Biosphere: • Portion of the Earth that supports life; extends from the atmosphere to the bottom of the oceans • Ex. Compared to an apple would be the peel • Supports the diversity of organisms Levels of Organization p.397/361 • • • • Organism: an individual living thing Population: group of same species living in one area Community: group of different species living in one area Ecosystem: includes all the organisms as well as the climate, soil, and other ABIOTIC factors in one area • Biome: a major global community of organisms • Biosphere Biotic & Abiotic Factors • Abiotic factors – The nonliving parts of an organism’s environment – Ex. Plant growth – Ex: types of soil—sand, gravel, potting soil • Biodiversity: all of the varieties of life • Example of an ecosystem with lots of biodiversity? ______________________ Abiotic factors • • • • • Air currents Temperature Moisture Light Soil • Determine which species survive in a particular environment • Drought • Grasses grow more slowly • Wildflowers produce fewer seeds • Food supply shrinks BIOTIC FACTORS • All the living organisms that inhabit an environment – Animals, plants, microorganisms • Keystone species: a species that has an unusually HUGE effect on an ecosystem – Ex: a beaver – PIONEER SPECIES: 1st species to inhabit an area Pioneer Species (after lava flow) Population • In a population, organisms may compete for food, water, or other resources • competition occurs only if resources are in short supply Populations • Some species have made adaptations to reduce the competition within the species Community • A change in one population will change other populations and other species • EX: Mouse-eating hawks increase, the mice population will decrease Ecosystem • 3 types – Terrestrial ecosystems • Forests, meadows, and desert – Aquatic ecosystems • Fresh water –Ponds, lakes, streams – Marine ecosystems • Saltwater • 75% of Earth Habitat • The place where an organism lives out its life • Can change and disappear • Limiting Factors: -- “Limit” the size of the population – Human activities – human pop increasing • Agriculture • Air and water pollution • deforestation Niche • Role and position a species has in its environment – Ex: what an organism eats, where it lives, etc • Reduces the amount of competition between different species Niche -- examples DUNG BEETLE – SHAPES THE “DUNG” INTO A BALL **************************************************************************************** Symbiotic Relationships: • Close, permanent relationship between organisms of different species • Symbiosis: different species living close together • 3 types: – Commensalism – Mutualism – Parasitism ***Predation and Competition are also types of relationships*** A. Commensalism • ONE species benefits and the other species is neither harmed nor benefited – Falcon protect nesting areas – Geese choose areas that are close to falcon and are also protected from predators – Geese benefit ---falcon nothing Orchids grow on the branches of high trees. These orchids get more water and sunlight than those on the ground. The tree is unaffected by the orchid’s presence. This relationship is an example of… C. Mutualism • BENEFICIAL to BOTH species • Ex: Sucker fish cleaning sharks – sharks get cleaned and fish get food and a ride around the ocean • Ex: Man and his dog, etc In this photo the “cleaner fish” receives nourishment by dining off of the parasites and remaining food debris in the eel’s mouth. Is this an example of… B. Parasitism • ONE species BENEFITS (parasite) and the OTHER is harmed (host) • Parasite – HOST relationship • Ex: lampreys, TICKS, fleas, ROUNDWORMS, tapeworms • The parasite needs the host for food in order to survive. Lampreys are primitive fish with limited digestive systems. They attach to and feed on the body fluids of fish with more advanced digestive systems, often leading to the death of the host fish. This relationship is an example of… QSR #5 • 1. T or F…parasites usually do not kill the host, but they usually just harm them. • 2. T or F… Symbiosis is a close relationship between organisms of the same species. • 3. Provide 1 example of the following: – Commensalism – Mutualism – Parasitism – Predation Nutrition and Energy Flow • Producers: also called ___________________ • Make their own food from energy from the ______ usually thru the process of ____________ • Provide ____________ for all other organisms Autotrophs/Producers • Organisms that convert _____________ or chemicals to energy – Plants – Bacteria – THINK...THEY “AUTOMATICALLY” MAKE THEIR OWN ______________. Heterotrophs • Consumers: – Organisms that must consume food for energy • 1. Herbivores: eat __________________ • 2. Omnivores: eat __________________ • 3. Carnivores: eat __________________ • 4. Detritivores – (including scavengers and ___________) Heterotrophs • Scavengers – They eat animals that have already ___________. • • • • Vultures Buzzards Ants beatles Heterotrophs • Decomposers – a type of _____________ – Break down and absorb nutrients from dead organisms • Protozoans • Bacteria • Fungi(mushrooms) YUM YUM Pathways for energy • 1. Food chain – A simple model used to show how ______ and _________move through and ecosystem – Autotrophs to heterotrophs to decomposers – MADE OF ONE SINGLE PATHWAY PATHWAYS • 2. Food Web: – Made of several different food ______________. – **NOT in a single pathway Pathways for energy • 3. Ecological pyramid: – A pyramid that shows the different “trophic” or ____________levels of a food chain – The bottom layers are larger, representing more _____________at the bottom than at the top – What constitutes the most BIOMASS of the whole Earth?_______________________ QSR #6 • 1. ______ ________ are the levels of nourishment in a food chain. • 2. List three examples of decomposers. • 3. If an animal eat both seeds and insects, which type of consumer would it be? • 4. What is the difference between a food chain and a food web? • 5. ____________ return valid nutrients to the environment by breaking down dead organisms. Succession • The gradual re-growth of a community of species in an area – EX: Hawaiian Islands!!! Primary Succession • The establishment of an ecosystem that was previously UNINHABITED (NOT lived in) – Pioneer species: the 1st organisms to inhabit an area Secondary Succession • The RE-ESTABLISHMENT of an ecosystem that has been destroyed by: – Forest fires – Volcanoes – glaciers PRIMARY SUCCESSION SECONDARY SUCCESSION Limiting factors • Any factor that can “limit” the size of a population. – Ex: Timberline • High elevations, temperatures are too low, winds too strong, and soil too thin to support growth of large trees – Vegetation is limited to small mosses, ferns, and lichens Limiting Factors • Density-Dependent Limiting Factors: – Limiting factors that ARE AFFECTED by the number of species in an area • Competition, predation, parasitism, disease • Density-Independent Limiting Factors: – Factors that limit the population size regardless of the density of species in an area – Population size DOES NOT MATTER • Unusual weather, natural disasters, human activities density DEPENDENT limiting factors Population size DOES MATTER!!!!!! density INDEPENDENT limiting factors Population size DOES NOT matter Cycles in nature • Matter and nutrients can be recycled • 3 main elements MUST move through an ecosystem – 1. water – 2. carbon – 3. nitrogen Water or Hydrologic cycle • Cells are 70-90 % water • Water is needed for most metabolic processes • Steps in the water cycle: – 1.Evaporation:____________________ or Transpiration: ____________________ – 2. Condensation: water vapor forms ______________ – 3. _________________: water returns to earth as sleet, rain, snow… – 4. Surface Runoff: returns water to bodies of water or to groundwater Steps of CARBON CYCLE These steps are numbered on your diagram • 1. Plants take ___________from the air – Plants store the Carbon as carbohydrates or starches (photosynthesis) – fruits and ______________ • 2. Animals and __________eat the carbon from the plants • 3. Plants and animals release the CO2 back into the air (respiration) • 4. Carbon can also be trapped in ______________(oil, gasoline,coal,etc.)—when these burn, releases ______ back to air Nitrogen Cycle • Needed by all _____________________ • Used to make proteins and nucleic acids -- DNA, and RNA...REMEMBER __________ BASES??? • N gas makes up 78% of the air • Cannot be metabolized by plants or animals • Only bacteria called nitrogen fixers (Cyanobacteria) are the organisms that convert N2 to a ___________form Steps of the Nitrogen Cycle (Number on your diagram) • 1. Cyanobacteria take___________ from the air (nitrogen fixation) • 2. convert it to ____________ • 3. Bacteria in the soil change ammonia into nitrates • 4. Plants can now use the nitrates to make _____________ N-Cycle Contin. • 5. Consumers eat _________ and get the proteins containing the _____________ • 6. Decomposers break down ________organsims and return nitrogen back to the __________.