LEARNING OUTCOME B1. Biomes. Biomes. Factors Creating Biomes 26/10/2011. Section Biomes. Factors Creating Biomes

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1 Section Biomes LEARNING OUTCOME B1 Key Terms abiotic adaptation biome biotic climate climatograph Science 10 Biology Biomes Biomes are the largest division of the largest division of the biosphere. Every environment has both abiotic (nonliving) and biotic (living) components. Example biotic components within an ecosystem are animals, plants, microorganisms. These biotic components all interact with one another and the physical and chemical environments in which they live. Example abiotic components within an ecosystem are things like sunlight, moisture and temperature Biomes A biome includes large regions that have similar biotic and abiotic components. Temperature and precipitation are the two most important abiotic factors. They determine what biotic factors can survive. Example mosses cannot survive in the dessert because they need lots of water. Factors Creating Biomes Latitude is another abiotic factor that can influence the characteristics and distribution of biomes because it affects precipitation and temperature. Latitude is the distance measured in degrees north or south from equator. At the equator the rays of sun shine from directly overhead, and this means the equator received 12 hours of sunlight each day year-round. The Tropic of Cancer is located above the equator and the Tropic of Capricorn is located below the equator. The zone between these two lines is known as the Tropical Zone. The sun s rays are less intense further away from the equator, which means the temperature in these zones is lower than the temperature at the equator. Factors Creating Biomes Latitude also impacts precipitation. At the equator, the direct sunlight heat moist air, this quickly rises, and cools the atmosphere. This cool air falls back to the Earth s surface as rain. The land and ocean one the equator receive the largest amount of rainfall on Earth. In Polar Regions, little moisture can be picked up and be carried in cold air. This means clouds cannot form easily and there is very little precipitation. 1

2 Factors Creating Biomes Factors Creating Biomes Elevation is the height of a land mass above sea level. Temperate changes at different elevations because the atmosphere becomes thinner at higher elevations and a thinner atmosphere retains less heat. Elevation also has an effect on precipitation patterns On the windward side of the mount, clouds fill with moisture rise and cool, then release rain and snow. On the leeward side of the mountain, which is the side sheltered from the wind, the air warms again which allows it to absorb water, creating a dry land area. Since elevation affects both temperature and precipitation, the type of biome found at a high altitude can be different from the type of biome found at very low elevations. Ocean currents are another abiotic factor that affects temperature and precipitation. Climate Adaptation and Biomes Temperature and precipitation are two important facts that determine climate. Climate is the average pattern of weather conditions that occur within a region. Climatograph - is a graph of climate data for a specific region and it s generated from data usually obtained over 30 year from weather observation stations. A climatograph includes monthly temperature and an average of the total monthly precipitation for each month. Certain type of plants and animals are characteristics of certain biomes because they are better adapted for survival in those biomes. There are three types of adaptation: structural, physiological and behavioural. Types of Adaptations Section 1.2 Ecosystems Structural Adaptation is a physical feature of an organism s body having a specific function that aids in its survival. Physiological Adaptation a physical or chemical event that occurs within the body of an organism that enables survival. Behavioural Adaptation refers to what an organism does to survive. Key Terms commensalism competition ecosystem mutualism niche parasitism predation 2

3 An ecosystem has abiotic components such as oxygen, water, nutrients, light that interacts with biotic components such as plants, animals and microorganism. Biomes contain many types of ecosystem, within each ecosystem there are many different habitats. Habitats are places where organisms can live. Nutrients are chemical required for plants and animal growth. Example nitrogen and phosphorus Photosynthesis is a chemical reaction that converts solar energy to chemical energy that can be used by plants. Species is a group of closely related organisms that can reproduce with one another. Community is all the populations of different species that interact in a specific area or ecosystem. Symbiosis - refers to the interactions between members of two different species that live in close association with one another. The three types of symbiotic relationship are: Commensalism one species benefits from the other and the other species is neither harmed nor benefits from the interaction. Mutualism is when both organisms benefit from the relationship. Parasitism is when one species benefits and the other species are harmed. Population refers to all members of a particular community within an ecosystem. Example in an ecosystem of Williams Creek, near Terrace, many populations interact, such as speckled frogs, mosquitoes, grizzly bears, moose, mountain goats, bald eagles, salmon, red cedar trees and western hemlock trees. Ecological Hierarchy is when biotic factors are ordered in the following way: organism, population, community and ecosystem Niches refers to how an organism contributes to and fits into its environment. All physical, chemical and biological interactions required for a species to survive, grow and reproduce are part of the organism s niche. Competition is a harmful interaction between two or more organisms that can occur when organism compete for the same resource at the same time. Predation is a term used to describe predator-prey interactions in which one organism eats all or part of an organism. As a result, one organism benefits and the other organism is harmed. Predatory animals have adaptations thatmake them effective predators. Predator adaptations may include highly developed senses such as very good eye sight or a keen sense of smell. Prey animals also have adaptations that keep them from being eaten. Prey may be spines, hard shells or produce poisonous substances. 3

4 Energy Flow Energy Flow Producer produces foods in the form of carbohydrates during photosynthesis (plants). Consumer is an organism that feeds on plants. A consumer may also become an energy source if it is eaten by another consumer. Example insect Organisms continue to contribute to the energy flow in an ecosystem even after they die, in a process called decomposition. Biodegradation is the when living organisms such as bacteria break down dead organic matter. Decomposers are organisms that change wastes and dead organisms into usable nutrients. The nutrients are then made available to other organisms in the soil and water. Decomposers are the link between the biotic and abiotic factors within an ecosystem. Decomposition is the breaking down of organic wastes and dead organisms. Key Terms Section 2.1 Energy Flow in Ecosystems biodegradation consumer decomposer food chain food pyramid food web producers trophic level How Energy Flows in Ecosystems? Every organism within an ecosystem interacts with that ecosystem in two ways: The organism obtains food energy from the ecosystem. The organism contributes energy to the ecosystem. Energy Flow is the flow of energy from an ecosystem to an organism and from one organism to another. You are part of the flow of energy when you eat the food energy stores in plants and animals. Energy Flow & Energy Loss in Ecosystems There are several different models used to help show energy flow and loss within an ecosystem: Food Chains and Food Webs Food Chains are models that show the flow of energy from plant to animal and from animal to animal. Each step in a food chain is called a tropic level. Trophic levels in a food chain show the feeding and niche relationships among organisms. Since plants and phytoplankton such as algae are the producers, they are the first trophic level and are referred to as primary producer. Primary Consumers are in the second trophic level, and these organisms obtain their energy by eating primary producers. Example grasshoppers, Secondary Consumers are in the third trophic level and they obtain their energy by eating primary consumers. Example spotted frog or crab 4

5 Tertiary Consumers are in the fourth trophic level and they obtain their energy by feeding on secondary consumers. Example red tail hawk or sea otter Detrivores are consumers that obtain their energy and nutrients by eating the bodies of small dead animals, dead plant matter, and animal wastes. Feed at every trophic level and make up their own important food chains. Example earthworms or beetles Herbivores primary consumers that east plants. Example grasshoppers Carnivores are secondary consumers that eat primary consumers. Also eat other secondary consumer and are often at the tertiary level of the food chain. Carnivores at this level are often referred to as top carnivores, top consumers or top predators. Many animals are part of more than one food chain and eat more than one kind of food in order to meet their energy requirements. Omnivores are consumers that eat both plants and animals. Food Webs are models of the feeding relationships within an ecosystem Food Pyramids Food Pyramid is a model that shows the loss of energy from one trophic level to another. Often referred to as ecological pyramids There are several types of food pyramids such as pyramids of biomass, numbers and energy. The amount of life that an ecosystem can support is determined by the amount of energy captured by producers A desert or tundra ecosystem with little vegetation cannot support many organisms. 5

6 Section 2.2 Nutrient Cycles in Ecosystems Nutrients are chemical that are required for plant and animal growth and other life processes. Nutrients accumulate for short of long periods of time in the Earth s atmosphere, ocean and on land masses (example carbon, nitro and phosphorus). Nutrient cycle is the flow of nutrient into and out of stores (accumulation in the ocean, atmosphere or land masses). Humans affect nutrient levels by ruining habitats though clear cutting. The main nutrients are nitrogen, carbon (makes up organic molecule living things), phosphorus, hydrogen and oxygen Phosphorus enters the environment from sedimentary rock. Carbon, hydrogen, oxygen make up DNA and in the body they makeup protein and genetic information. They also make carbohydrate and proteins Nitrogen is found in proteins and DNA Three important nutrient cycles are: carbon cycle nitrogen cycle phosphorus cycle All living thing contain carbon. Essential component in the chemical reaction that allow life (cellular respiration). The Carbon Cycle The Carbon Cycle How is carbon stored? Found in land and in vegetation, decaying organic material, carbon dioxide in the atmosphere and as a layer on the ocean. Dissolved CO 2 can also be found deep in the ocean, in cold water the carbon will sink to the ocean floor. Carbon can also be found in coal, oil and gas deposits. All are known as fossil fuels that are formed from dead plants and animals. Sedimentation is the building of sedimentary rocks. Soil particles and dead decaying organic matter accumulate in layer on the ground or in the bottom of the ocean. Some sedimentary rocks form shells of marine organisms such as coral and clams. These shells contain calcium carbonate CaCo 3. These shells accumulate on the ocean floor when the organism dies and form carbonate rich deposits, which over time change into limestone which is a sedimentary rock. Photosynthesis cycles carbon and oxygen through an ecosystem. Occurs in plants, trees and microscopic organism such as cyanobacteria Make carbohydrates Cellular Respiration Both plants and animals release CO 2 back into the atmosphere by converting carbohydrates and oxygen into CO 2 and water. Energy is released during cellular respiration; which is used by organisms for growth, reproduction and repair. CO 2 into the atmosphere is a waste product. Decomposition - is the process that breaks down dead organic matter, and releases Co 2 back into the atmosphere. The Carbon Cycle Mixing Ocean CO 2 is dissolved in cold water sinks and moves slowly in deep ocean currents towards the tropics. In the tropics (warm water), CO 2 is mixed and released back into the atmosphere. Volcanoes release CO 2 through the melting of sedimentary rocks. Decomposing trees and forest fires also release CO 2 into the atmosphere. How Human Activities Impact the Carbon Cycle Industry motorized transportation, land clearing; urban expansion and agriculture have changed carbon cycles. CO 2 in the atmosphere has increased by 30% due to burning of fossil fuels. 6

7 The Nitrogen Cycle This is an important component of DNA/proteins which are essential for life. In plants nitrogen is important for growth. How is nitrogen stored? In the atmosphere, where it exists as N 2 gas Also stored in oceans and as organic matter in soil Organisms, lakes and marshes also store nitrogen Nitrogen Fixation Process in which N 2 gas is converted to NO - 3 or NH 4+ ; both of these compounds are useable by plants. Nitrogen fixation occurs in three ways: Atmosphere: N 2 is converted to NO - 3 by lightening Soil: N 2 is converted into NH + 4 by bacteria Water bodies: Fixes N 2 gas into NH + 4 Nitrification Coverts NH 4 _ to NO 3 - Takes place in two stages and involves nitrifying bacteria. Certain species of nitrifying bacteria convert NH 4 + to NO 2 - A different species of nitrifying bacteria converts NO 2 - to NO 3 - Once nitrates are made available they can enter plant roots and eventually be incorporated into plant proteins. Other types of decomposers (bacteria and fungi) are able to take nitrogen trapped in proteins and DNA of dead organisms and covert it back to NH 4+. Some bacteria species decompose urea (waste products) that are excreted by animals and then converted to NH 4 (ammonia) Denitrification Process of how nitrogen is returned back to atmosphere. Involves denitrifying bacteria which converts NO - 3 back into N 2 gas Nitrogen is also returned to the atmosphere as ammonia (NH 3 ) in volcanic ash and nitrogen oxides. How is nitrogen removed from an ecosystem? Excess nitrate or ammonium that is not taken up by plants mix with rainwater and are washed from the soil into ground water and streams. This unused nitrogen may settle in lakes, rivers or ocean bottoms as sediment. Eventually these sediments will form rock, and nitrogen will not be available. Only after centuries of weathering will the nitrogen be released. Human Impact on the Nitrogen Cycle Increased N 2 gas in the atmosphere due to burning of fossil fuels, and in the treatment of sewage plants Clearing forests/grasslands by burning also release trapped nitrogen into the atmosphere. These compounds eventually return to aquatic and terrestrial environments as acid rain. Fertilizers also impact the nitrogen cycle, because not all NO - 3 and NH + 4 are used by plants so they return to the atmosphere as N 2 gas or can be washed or leached from the soil by rain water or irrigation. Ground water that contains these compounds enters lakes and streams and dissolved. This results in eutrophication, which is when the presence of excess nutrients causes increased plant growth and decay. This may cause excessive algal growth which deprives other aquatic plants of sunlight and O 2. When the algae die and decompose it also deprives other aquatic plants of O 2. Also crops such as soybeans, peas, alfalfa and rice increase the rate of nitrogen fixation with an area. The Phosphorus Cycle Phosphorus is an essential element in a molecule that carries energy to plant and animal cells. In plants phosphorus contributes to root development, stem strength, and seed production. Humans have large amounts of phosphorus in their bones, which help with the development of strong bone tissue. How is phosphorus stored? It is trapped in phosphate rock and sediment on the ocean floor. How is phosphorus cycled? Weathering of rocks releases phosphate. On land plants take up phosphate through their roots and animals obtain phosphate through eating plants. Decomposers break down organism waste so phosphorus can be released. Phosphate from run-off settles in lakes and ocean bottoms, and will not enter the biotic community unless the sediment is disturbed. 7

8 Human Activity and its Impact on the Phosphorus Cycle Commercial fertilizers and detergents release excess phosphate into the environment. Too much nitrogen in the ecosystem results in eutrophication and algal blooms can occur (causes same problems as excess nitrogen). Human activity has also released phosphorus supplies due to slash-and-burn methods which release phosphate in the form of ash. Ash accumulates in soil and phosphate leaches from the ash and runs off into the water supply and settles at the bottom of lakes and ocean. This phosphorus is not longer available to organisms. The Carbon Cycle Occurs in oceans as a result of geological and natural events Carbon is moved through the oceans and atmosphere (see figure 2.25). CO 2 may be released from volcanoes, because sedimentary rocks melt. CO 2 may also be released from decomposing trees. CO 2 is released during a forest fire. Humans impact the carbon cycle through vehicle pollution. This pollution contains carbon which puts more carbon into the air. 8