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Ecology and Our Ecosystem
Characteristics of the Biosphere • Ecology is the study of organisms and their interactions with the environment. (eco-home) • The biosphere is the lifesupporting region of the earth. It includes all the land, air and water in which organisms live.
Parts of the environment • Abiotic factors- non- • Biotic factors- living parts of the environment. • A-without, bio-life • Ex: plants, animals and other organisms. • Ex: water, soil, light , temperature, wind, and physical space. 1. 43 Understand that and describe how organisms are influenced by a particular combination of living and non-living components in the environment.
Habitats • Every species in a habitat has characteristics that enable it to function in the unique abiotic and biotic factors. • It provides the members of a species with food, shelter, water, and whatever else they need to survive.
Species, Populations and Communities • Species are a group of • organisms so similar to one another, they can breed and produce fertile offspring. • Populations are all of the members of a single species • that live in one area. • Populations of different organisms share a living space and interact with one another. All of the populations that live and interact in one environment make up the community. Can you give an example of a species, population and community where you live?
The Ecosystem • All of the populations and abiotic factors in an area make up the ecosystem. • It can be a large (forest, ocean, desert) or small area (garden, pond. ) • Healthy ecosystems are very diverse.
Let’s Review the Organization of Life in Ecology From smallest to biggest 1. Organisms- ecologists study behaviors. 2. Populations- ecologists study the effects of them on the environment and growth rates. 3. Communities- study the effects on a community when new species are added or removed. 4. Ecosystem- ecologists are concerned with the stability of the ecosystem. 5. Biosphere- ecologists are concerned with all interactions.
Ecological Methods • Regardless of the tools they use, scientists conduct modern research using 3 basic approaches. • 1. Observing • 2. Experimenting • 3. Modeling.
How Organisms Interact: Feeding Relationships Autotrophs- use energy from the sun or stored energy to make their own food. They are also called producers. All organisms rely on autotrophs for food. Ex: plants. • Heterotrophs- depend on autotrophs and their source of nutrients and energy. They are also known as consumers. • They include animals.
Photosynthesis vs. Chemosynthesis • Photosynthesis- uses light to make food • Chemosynthesis • Hydrogen sulfide and 6 CO 2 + 6 H 20 C 6 H 12 O 6 oxygen combine to form sulfur compounds. Using + 6 O 2 chemical energy, cells make carbohydrates using CO 2 from sea water. • Where are these bacteria found?
Autotrophs • Get their energy from the • Chemosynthesis is sun through when organisms use photosynthesis. chemical energy to • Use light energy to power produce carbohydrates when there is no light chemical reactions that present. convert carbon dioxide and water into oxygen • Bacteria- vents at and sugar. bottom of ocean is an example. • 6 CO 2 + 6 H 2 O C 6 H 12 O 6 + 6 O 2
Photosynthesis vs. Cellular Respiration • Photosynthesis Captures energy Chloroplasts • Cellular Respiration Releases energy Mitochondria • 6 CO 2 + 6 H 2 O C 6 H 12 O 6 + 6 O 2 • C 6 H 12 O 6 + 6 O 2 6 CO 2 + 6 H 2 O 1. 3, 1. 4, 1. 9, 1. 43
Heterotrophs: Carnivores and Scavengers • Carnivores eat only “meat”. • What are some examples of carnivores? • Scavengers eat animals that are already dead, they don’t kill for food. • What are some examples? • Why are they important?
Herbivores • Eat Plants
Omnivores and Decomposers • Omnivores eat both plants and animals. • What are some examples? • Decomposers are organisms that break down and absorb nutrients from dead organisms. • Ex: bacteria, some protozoans, fungi. • Why are they important?
Detritivores • Feed on plant and animal remains and other dead matter called detritis • Earthworms, crabs, mites, snails
Matter and Energy in Ecosystems • When you pick an apple from a tree and eat it, you are consuming C, N and other elements, and well as energy. • Matter and energy are constantly cycling through the ecosystems. • Conservation of mass and energy laws: can’t be created or destroyed. They are transformed into different forms.
Food Chain • It is a simple model that scientists use to show matter and energy move through an ecosystem. • Nutrients and energy flow from autotroph to heterotroph to decomposers. • They consist of 3 links, but no more than 5 because the amount of energy by the 5 th link is only a small portion. Energy is lost as heat at each link. • Ex: Algae Fish Bird
Trophic levels • Each organism in a food chain represents a feeding step, or trophic level, in the passage of energy and materials. • They are many “routes”. • 1 st level- photosynthetic autotrophs- (producers. ) • 2 nd level- first order consumers (herbivores/omnivore) • 3 rd level- second order consumers (carnivores. ) • 4 th level- third order consumers (carnivores that feed on second order carnivores) 1. 44 Describe the flow of energy within ecosystems.
Food Webs • Food Webs represent a network on interconnected food chains. • They express all the possible feeding relationships at each trophic level in a community.
Ecological Pyramids- show the relative amounts of energy or matter contained within each trophic level. • Energy Pyramid- • Biomass Pyramid- shows total amount of living only 10% of the tissue within a given energy available trophic level. within one trophic level is transferred • Pyramid of Numbersto organisms at the shows relative numbers of next. individual organisms at each trophic level.
Which pyramid is shown? Some pyramids of energy use numbers to represent the number of animals/plants there are for each level. If you had a tree that fed 50, 000 insects, what would the pyramid look like? Others use grams.
Cycling Maintains Homeostasis • Energy is lost as heat to the environment by body processes at each level. It flows one way. • Sunlight is the source of all energy. • Matter also moves through the trophic levels, but can’t be replinished like sunlight. • Matter is constantly recycled. • Biological systems do not use up matter, they transform it into living tissue, or passed out as waste. 1. 44 Describe the flow of matter and nutrients within ecosystems.
Why do we need the following? • • Water Carbon Nitrogen Phosphorus
• Water- liquid or solid on Earth and gas in the atmosphere.
The water cycle • Evaporation of water from water bodies, animals and plants. (liquid to gas) • Condensation- gas to liquid in form of precipitation. • Transpiration- loss of water vapor from plants. • Respiration- gaseous exchange of oxygen and carbon dioxide between organisms and environment. (Organisms also lose water through excretion. ) • After an organism dies, decomposition releases water back into the environment.
The Carbon Cycle
Carbon Cycle • Carbon is found in the environment in the form of CO 2 in the atmosphere and ocean. • From the atmosphere, CO 2 moves to aquatic and terrestrial producers. • Producers use CO 2 in photosynthesis to make sugar, a higher energy form. • Organisms eat C when they consume “plants”. • Respiration returns C to atmosphere in form of CO 2 and decay returns C to the environment. • If decay occurs without O, the C can be bound up in a fossil fuels that are burned and returned to the atmosphere.
Fossil Fuels Formation • Fossil fuels are made when plants and other organic organisms die and decompose in the ground. Layers upon layers are formed over many years. Through chemical processes and pressure, fossil fuels are made. • 1. 42 Sometimes, the environmental conditions are such that plants and marine organisms grow faster than decomposers can recycle them back to the environment. Layers of energy rich organic material thus laid down have gradually been turned into great coal beds and oil pools by the pressure of the overlying earth. Burning these fossil fuels, people are passing most of the stored energy back into the environment as had and release large amounts of CO 2.
Nitrogen Cycle • Atmospheric N 2 makes up nearly 78% of air. • Living things can’t use N in atmospheric form. • Lightning and some bacteria convert atmospheric N 2 into usable N-containing compounds. (nitrogen-fixing bacteria) • Plants take up nitrates made from bacteria and lightning and convert them into N-compounds. • Herbivores eat the plants and convert N-plant proteins into N animal proteins. During digestion, plant and animal proteins are made into human proteins. • Organisms return N to the atmosphere when they die and decay. (denitrification) • Fertilizers from farming are taken up by plants or runoff into body of waters.
Phosphorus Cycle • Plants use P from the soil in their body tissues. • Animals get P by eating plants. • When the animals die, they decompose and the P is returned to the soil to be used again. (Short-term cycle. ) • Phosphate washed into the sea become incorporated into rock as insoluable compounds. Millions of years later, as the environment changes, the rock is exposed and made part of the ecological system. (long-term cycle. )
Nutrient Limitation • Primary productivity is the rate at which organic matter is created by producers. • Controlled by amount of available nutrients. • When an organism is limited by a single nutrient that is scarce or cycles slowly, the substance is a limited nutrient. • Why would this be important to ecologists?
Algal Bloom • If there is too much of a limiting nutrient (ie. Fertilizer from field) that flows into water, this can cause an immediate increase in the amount of algae and other producers called an algal bloom. • Why do they occur? • This increases the number of producers, and disrupt the ecosystem, if not enough consumers. • Eutrophication- too much algae, takes up all of the oxygen things die
Invasive Species • In 1988, small freshwater zebra mussels were introduced to Lake Erie from Europe. • They spread to all great lakes in less than 10 years. • They compete with other species for food. • They clog up waterintake pipes and farmirrigation pipes. • One benefit- filterfeeding action h as made water cleaner. • Gypsy moths 1. 38
Biosphere Review • Click on the following link and choose your text book. Review the links and take the self-test. • Ch. 3 Review