YAY!!!!!!!!!!!!!!!!!!!!! Organisms and their Environment • Ecology: The study of organisms, their environment, and how they interact with each other. – Includes studying things living.
Download ReportTranscript YAY!!!!!!!!!!!!!!!!!!!!! Organisms and their Environment • Ecology: The study of organisms, their environment, and how they interact with each other. – Includes studying things living.
YAY!!!!!!!!!!!!!!!!!!!!! Organisms and their Environment • Ecology: The study of organisms, their environment, and how they interact with each other. – Includes studying things living and non-living, but is still a large part of Biology. http://www.nps.gov/ever/eco/gator.htm 2 Levels of Organization • Ecologist study organisms ranging from the various levels of organization: – Individual – Population – Community – Ecosystem – Biome – Biosphere Organisms and their Environment • Biosphere: The part of the Earth that sustains life. – All living things on Earth are found in the biosphere. – If you shrank the Earth to the size of an apple, the biosphere would be the thickness of the peel. – Includes from high in the sky to deep in the oceans. 4 Organisms and their Environment • Interactions – Species: A group of organisms so similar to each other they can mate and produce fertile offspring – Populations: Group of organisms in the same species that live in the same place and interbreed. http://animals.mongabay.com/crabs.html – Community: Many groups of different populations (different species as well) that live together. • A collection of interacting populations http://www.cs.unca.edu/nfsnc/ 5 Organisms and their Environment • The interactions between organisms and the • abiotic factors around them forms an ecosystem. Different ecosystems: – Terrestrial – Aquatic • Marine • Freshwater Biomes: a group of ecosystems that have a climate and dominant communities http://www.oceanfutures.com/gallery/gallery _archive.asp#october http://www.borealforest.org/world/world_m anagement.htm http://www.cfra-nc.org/acfrb.htm 6 Autotrophs/Producers • Sunlight is the main energy source for life on earth. • Autotrophs/Producers take sunight and make sugar.Plants, some algae,some protists like euglenas and volvox, and certain bacteria can capture energy from sunlight or chemicals and use that energy to produce food. Plants, and unicellular critters like some Algae, protists and Photosynthetic Bacteria • Photosynthesis – set of chemical reactions that convert carbon dioxide and water into energy-rich carbohydrates (food) and oxygen. Chemosynthetic Bacteria • Organisms which use chemical energy (inorganic molecules; hydrogen sulfide) to produce highenergy carbohydrates (food). Consumers/Heterotrophs • Organisms that rely on other organisms for their energy and food supply. – Herbivores – eat plants – Carnivores – eat other animals or insects – Omnivores – eat plants and animals – Detritivores (Decomposers and Scavengers) – feed on plant and animal remains and dead matter Herbivores Omnivores Detritivores Energy Flow • All of the earth’s energy comes from the sun!!! Except for chemosynthetic bacteria • And of all the sun’s energy only about 1% is used by living things. • Energy flows through an ecosystem in one direction, from the sun or inorganic compounds to autotrophs (producers) and then to various heterotrophs (consumers). Quiz • Define – Species • A group of organisms so similar to one another that they can breed and produce fertile offspring. – Population • A group of individuals that belong to the same species and live in the same area. – Community • Assemblages of different populations that live together in a defined region. Quiz • 1. What are the two main forms of energy that power living systems? – Light energy, through photosynthesis and chemical energy through chemosynthesis • 2. Briefly describe the flow of energy among organisms in an ecosystem. – Energy flows in one direction, from autotrophs to heterotrophs and on down the food chain. • 3. Show the following as a food chain: omnivore, autotroph, herbivore. – Autotroph -> Herbivore -> Omnivore Food Chain • series of steps in an ecosystem in which organisms transfer energy by eating and being eaten. What is the highest organism in all food chains? Food Webs • network of complex interactions formed by the feeding relationships among the various organisms in an ecosystem Trophic Levels • step in a food chain or food web Ecological Pyramids • diagram that shows the relative amounts of energy or matter within each trophic level in a food chain or food web. – Energy Pyramid – Biomass Pyramid – Pyramid of Numbers Energy Pyramid • Only about 10% of the energy available within one trophic level is transferred to organisms at the next trophic level. Biomass Pyramid • Biomass - total amount of living tissue within a given trophic level. Pyramid of Numbers • What if we looked at a tree in a forest? • The pyramid would look upside-down Ecosystems and Communities What factors shape ecosystems? Biotic and Abiotic factors determine the survival and growth of organisms and the productivity of ecosystems in which organisms live. • Habitat - the area where an organism lives, including the biotic and abiotic factors that affect the organism. • Resources - any necessity of life, such as water, nutrients, light, food, or space. Habitat + Resources = ????? • Niche - full range of physical and biological conditions in which an organism lives and the way in which the organism uses those conditions. Warbler Niches • Can you have two separate organisms occupying the same exact niche??? How do these terms fit together? • Habitat • Resources • Niche • Competitive Exclusion Principle Direct competition (two organisms trying to occupy the same niche) in nature usually results in a winner and a loser. The competitive exclusion principle states that no two species can occupy the same niche. All ecosystems everywhere follow this rule. Community Interactions • Predation – interaction when one organism feeds on another Community Interactions • Symbiosis – any relationship in which two species live closely together. – There are three types of symbiosis • Mutualism • Commensalism • Parasitism Community Interactions • Mutualism – occurs when both species benefit from the relationship. Community Interactions • Commensalism – occurs when one member of the association benefits and the other is neither helped nor harmed. Community Interactions • Parasitism – occurs when one organism lives on or inside another organism and harms it. Science/Art Activity • Draw and explain in detail an energy pyramid and a biomass pyramid for any two ecosystems? • 1. How does the way matter flow through an ecosystem differ from the way that energy flows? – Energy flows just one way through an ecosystem: from producers to consumers. Matter moves through the water, carbon, nitrogen, and phosphorus cycle. • 2. Name two of the four biogeochemical cycles. – Hydrologic cycle (water cycle), carbon cycle, nitrogen cycle, and phosphorus cycle Biogeochemical Cycles • Unlike the one-way flow of energy, matter is recycled within and between ecosystems. • Elements, chemical compounds, and other forms of matter are passed from one organism to another and from one part of the biosphere to another through biogeochemical cycles. The Hydrologic (Water) Cycle • Evaporation – the process by which water changes from its liquid state to its gaseous state. • Transpiration – evaporation from the leaves of plants. Nutrient Cycles • Every living organism needs nutrients (materials, building blocks) to grow and carry out life’s processes. • Like water, nutrients are passed between organisms and the environment through biogeochemical cycles. Carbon Cycle Carbon Cycle • Carbon cycles between various components of the biosphere. • There are four different processes involved in the carbon cycle. 1. Biological Processes 2. Geochemical Processes 3. Mixed Biogeochemical Processes 4. Human Activity Carbon Cycle Biological Processes • Photosynthesis • Respiration • Decomposition Carbon Cycle Geochemical Processes • Volcanoes • Ocean Vents Carbon Cycle • Biogeochemical Processes – Fossil fuels • Coal • Oil • Natural gas Carbon Cycle Human Activity • Mining • Burning of Fossil • Fuels Cutting and Burning of Forests How many of these processes actually take carbon out of the atmosphere? • How does the hydrologic cycle work? • What processes are involved in the carbon cycle? How do they affect the carbon cycle? Nitrogen Cycle Nitrogen Cycle • All organisms require nitrogen to make amino • acids (building blocks of proteins) Nitrogen exist in different forms: – Nitrogen Gas (N2) – Makes up 78% of Earth’s Atmosphere – Ammonia (NH3); Nitrate (NO3-) and Nitrite (NO2-) ions which are all found in decaying organisms and organic waste (poop) – Nitrogen also exists in many forms in the ocean – Fertilization also adds nitrogen into the atmosphere is the form of Nitrite Nitrogen Cycle Nitrogen coming out of the atmosphere • 1. Only certain bacteria called legumes can use nitrogen gas directly. – These bacteria convert N2 gas into ammonia – This process is known as nitrogen fixation • 2. Other bacteria convert ammonia into nitrates and nitrites. • 3. Plants then absorb the nitrates and nitrites and then they are passed down the food chain. Nitrogen Cycle Nitrogen going back into the atmosphere • Now that organisms (plants, animals) have nitrogen, how does it get back into the atmosphere – When organisms die decomposers break down the remains putting ammonia back into the soil. Some of this ammonia is converted into nitrates. – Other bacteria convert nitrates back into nitrogen gas Nitrogen Cycle Phosphorus Cycle • Phosphorus is essential to form parts of ATP, DNA, and RNA. • Phosphorus is not as common in the biosphere as nitrogen and carbon. – The reason for this is because phosphorus does not enter the biosphere. – Phosphorus (in the form of phosphate) remains mostly in rocks, soil, and ocean sediments. Phosphorus Cycle • 1. Plants absorb • • phosphate from the soil or water. 2. Phosphate is dissolved and runs through rivers into oceans where it is absorbed by marine organisms 3. When organisms die the phosphate returns to the soil. • Explain, in detail, how the nitrogen cycle works. • Explain, in detail, how the phosphorus cycle works. Limiting Nutrient • Primary Productivity - rate at which organic matter is created by producers in an ecosystem. • Limiting Nutrient - single nutrient that either is scarce or cycles very slowly, limiting the growth of organisms in an ecosystem. Algal Bloom • an immediate increase in • the amount of algae and other producers that results from a large input of a limiting nutrient. Eutrophication – the process of depleting oxygen levels in an environment. This can lead • What does the word ecology mean to you? Weather and Climate • Weather – the day-to-day condition of Earth’s • atmosphere in a given time and place. Climate – the average year after year conditions of temperature and precipitation at a given place. Sunlight and Latitude What also affects the temperature in the biosphere? What are the three major climate zones? • Polar zone – between 66.5° and 90.0° • Temperate zone – between the polar and tropical • zones Tropical zone – between 23.5° north and 23.5° south What also affects the temperature in the biosphere? Atmospheric Gases CO CO2 CH4 H2O(g) Heat Transfer Water currents above Wind currents right Ecological Succession • Ecosystems are constantly in flux. – What causes changes in ecosystems? • Ecological Succession – is the series of predictable changes that occurs in an ecosystem over time. Primary Succession • Occurs on surfaces where no soil exists, usually after a volcanic eruption. – 1. Bare rock community is populated by an pioneer species (first species to populate an area). Usually lichens (fungus and alga). – 2. Pioneer species help to form soil and puts nutrients into soil. – 3. Plants begin to grow then off to the races Primary Succession Secondary Succession • Occurs in an community where everything has • been removed but the soil. What could start primary succession? Succession in a Marine Ecosystem Whale fall Community • Large whale dies, such as a blue or fin whale, and sinks to the normally barren ocean floor. The whale attracts scavengers and decomposers, including amphipods, hagfishes, and sharks, that feast on the decaying meat. • Within a year, most of the whale’s tissues have been eaten. The decomposition of the whale’s body, however, enriches the surrounding sediments with nutrients, forming an oasis of sediment dwellers, including many different species of marine worms. • When only the whale’s skeleton remains, a third community moves in. Heterotrophic bacteria begin to decompose oils inside the whale bones. They release chemical compounds that serve as energy sources for other bacteria that are chemosynthetic autotrophs. The chemosynthetic bacteria support a diverse community of mussels, limpets, snails, worms, crabs, clams, and other organisms that live on the bones and within the nearby sediments. Biomes • Are groups of ecosystems that have the same climate and dominant communities. • There are 10 major land biomes in the world which are defined by a unique set of abiotic factors—particularly climate—and has a characteristic ecological community. Aquatic Ecosystems • Aquatic ecosystems are determined primarily by the depth, flow, temperature, and chemistry of the overlying water. Freshwater Ecosystems • Can be broken into two types. – Flowing-water ecosystems – Standing-water ecosystems Flowing-Water Ecosystems • Rivers, streams, brooks, creeks – Close to source, high oxygen but little nutrients. – As the water flows it pulls nutrients from eroding rocks and sediments – Plants are more plentiful downstream – Animals are more plentiful when current slows – Organism are well adapted • Hooks on larvae, suckers on fish (catfish), streamlined fish (trout, salmon) Flowing-Water Ecosystems Standing-Water Ecosystem • Organisms that would normally be washed away are able to thrive. – Plankton - tiny, freefloating, weakly swimming organisms that occur in aquatic environments. • Phytoplankton • Zooplankton Freshwater Wetland • ecosystem in which water either covers the soil, or is present at or near the surface of the soil for at least part of the year – Three types • Bogs • Marshes • Swamps Bogs • Formed in depressions left from melting ice • • sheets thousands of years ago Lots moss (sphagnum) Water tends to be very acidic Marshes • Shallow wetlands along rivers • Under water for most if not all the time • Tall grasses and cattails Swamp • Water flows very slowly • Looks like flooded forest Estuaries • wetlands formed where rivers meet the ocean. • Affected by tides • Usually shallow, photosynthesis and • • • chemosynthesis Detritus powers the ecosystem High level of biomass Great spawning and nursery area – Two types • Salt marsh • Mangrove Swamps Salt Marshes • Temperate zone estuaries Mangrove Swamps • Located in tropical zone • Mangrove trees – salt tolerant trees • Ecosystems are constantly changing in response to natural and human disturbances. As an ecosystem changes, older inhabitants gradually die out and new organisms move in, causing further changes in the community. • Explain how primary succession occurs on newly exposed surfaces, such as recently deposited volcanic ash and rock. • Succession can occur in any ecosystem- even in the permanently dark, deep ocean. Explain the three stages in the succession of a whale-fall community. • What is the difference between primary succession and secondary succession? Marine Ecosystems • Photic Zone – upper layers of the ocean where sunlight is present down to about 200m. • Aphotic Zone – permanently dark chemosynthetic bacteria • The ocean is also divided into zones based on the depth and distance from shore: the intertidal zone, the coastal ocean, and the open ocean. Marine Ecosystems Intertidal Zone • Located at the shore between the High Tide Mark and Low Tide Mark • Submerged part of the time, and exposed part of the time • Crashing waves and strong currents • Seaweed, barnacles, starfish, urchins, snails • Zonation - prominent horizontal banding of organisms that live in a particular habitat. Intertidal Zone Coastal Ocean • Extends from the low tide mark to the edge of the continental shelf. • Falls mostly in the photic zone Coastal Ocean • Kelp Forest – Can grow 50cm a day – Cold temperate seas • Coral Reefs – Tropical seas – Within 40m of the surface Open Ocean • Oceanic Zone • Starts at the end of the • • continental shelf Ranges from 500m to 11000m deep Productivity is low by producers due to low levels of nutrients – But, oceans are so large that 90% of the earth’s productivity comes from the ocean Benthic Zone • The ocean floor • Organisms that live in the benthic zone are often refered to as the BENTHOS. • Photosynthetic Organisms • And Chemosynthetic Organisms