1 Ecosystems & Biomes Chapter 13

2 What are the Energy Roles in an Ecosystem?Each organism has a role in the movement of energy through its ecosystem. Each of the organisms in an ecosystem fills the energy roll of producer, consumer, or decomposer.

3 Producers Energy enters most ecosystems as sunlight.Some organisms, such as plants, algae, and some bacteria, capture the energy of sunlight and store as food energy. (through photosynthesis). An organism that can make its own food is a producer. Producers are the source of all food in an ecosystem.

4 Consumers Some members of an ecosystem cannot make their own food.An organism that obtains energy by feeding on other organisms is a consumer.

5 Consumers Consumers are classified (grouped) by what they eatHerbivores Carnivores Omnivores Scavenger Herbivores are consumers that only eat plants. Ex: caterpillars, rabbits, deer Carnivores are consumers that only eat animals. Ex: wolves, walruses, snakes Omnivores are consumers that eat both plants and animals. Ex: crows, bears, humans Scavengers are carnivores that feed on bodies of dead organisms. Ex: catfish, vultures

6 Decomposers Decomposers break down biotic wastes and dead organisms and return the raw materials to the ecosystem. They are nature’s recyclers They obtain energy for their own needs, they also return simple molecules to the environment, which can be used again by other organisms. If an ecosystem had only producers and consumers, the raw materials of life, such as carbon and nitrogen would stay locked up in wastes and bodies of dead organisms. Decomposers prevent this from happening. A simple molecule is O2, CO2, H2O Examples: mushrooms, bacteria, mold

7 How Does Energy Move Through an Ecosystem?Energy moves through an ecosystem when one organism eats another. This movement of energy is shown as food chains, food webs, and energy pyramids.

8 Plant  Grasshopper  Bird  Snake  OwlFood Chain Energy must constantly flow through an ecosystem for it to remain stable. One of the ways that energy flows through an ecosystem is via consumption. Food chains are models that depict direct predator/prey relationships between organisms. The arrows between organisms in a food chain model shows which organism is “giving” energy to another. The arrow points from the organism being eaten to the organism that eats it. Plant  Grasshopper  Bird  Snake  Owl A plant to a grasshopper shows that the grasshopper eats the leaves. Energy is moving from the plant to the grasshopper. Next, a bird might prey on the grasshopper, a snake may eat the bird, and then an owl might eat the snake.

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11 Trophic Levels Trophic levels identify an organisms position within an ecosystem. In Ecology, trophic levels are used to identify the health and stability of an ecosystem. Producers are organisms that convert the sun’s energy to sugar (a usable energy) through the process of photosynthesis. The producers are ALWAYS at the beginning or base of the food chain and provide energy to other organisms in the ecosystem. Examples: Examples: phytoplankton, plants

12 Trophic Levels Primary consumers are made up of herbivores such as elephants and butterflies and gain energy from producers. Secondary consumers are generally carnivores and gain energy from primary consumers. Tertiary consumers are similar to secondary consumers in the fact that they are carnivores and gain energy from primary and secondary consumers. Quaternary consumers are at the top of the food chain and are generally carnivores. They gain energy by consuming anything in the levels below them.

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14 Food Webs Each organism can eat and be eaten by many different types of organisms. Scientists combine food chains together to create a more accurate model of the flow of energy within and ecosystem. A food web shows the feeding relationships between many organisms in an ecosystem. Food webs depict interconnectedness of an entire ecosystem.

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16 Energy Pyramid A diagram called an energy pyramid shows the amount of energy that moves from one feeding level to another in a food web. The most energy is available to the producer level of the pyramid. As energy moves up the pyramid, each level has less energy available than the level below. When an organism eats it obtains energy. They use some of this energy to move, grow, reproduce, and carry out other life activities. These activities produce heat, a form of energy, which is then released into the environment. When heat is released, the amount of energy that is available to the next consumer is reduced.

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20 Cycles of Matter

21 The Water Cycle Water is essential for lifeThe water cycle is the continuous process by which water moves from the Earth’s surface to the atmosphere and back. The process of evaporation, condensation, and precipitation make up the water cycle. Recycling is important for ecosystems because matter is limited. Matter cycles through the ecosystem. Matter is made up of tiny particles called atoms. Two or more atoms that are joined together and act as a unit make up a molecule. For example, a water molecule consists of two hydrogen atoms and one oxygen atom.

22 The Water Cycle Evaporation is the process by which molecules of liquid water absorb energy and change to gas. The energy for this process comes from the heat of the sun. How water is evaporated: Liquid water evaporates from oceans, lakes, and other sources and forms water vapor, a gas, in the atmosphere. Smaller amounts evaporate from living things. Plants release water vapor from their leaves. You release liquid water in your wastes as water vapor when you exhale.

23 The Water Cycle Condensation is the process by which gas changes to a liquid. As water vapor rises higher in the atmosphere, it cools down. The cooled vapor then turns back into tiny drops of liquid water. The water collects around dust particles and form clouds.

24 The Water Cycle Precipitation – rain, snow, sleet, or hailAs more water vapor condenses, the drops of water in the clouds grow larger. Eventually, heavy drops fall to Earth in the form of rain, snow, sleet, or hail. Precipitation that falls on land may soak into the soil and become ground water, or run off the land, flowing back into a river or ocean.

25 What are the three processes of the water cycle?

26 Carbon & Oxygen Cycles Carbon & oxygen are necessary for life.Carbon is an essential building block in the bodies of living things. Most organisms use oxygen for their life processes. In ecosystems, the processes by which carbon and oxygen are recycled are linked. Producers, consumers, and decomposers all play roles in recycling carbon and oxygen.

27 The Carbon Cycle Most producers take in CO2 gas from the air during photosynthesis and use the carbon to make food. As consumers eat producers they take in the carbon-containing molecules. Both producers and consumers then break down the food to obtain energy. As the food is broken down they release CO2 and water into the environment. When they die decomposers break down their remains and return carbon molecules to the soil. Some decomposers also release CO2 into the air.

28 The Oxygen Cycle Oxygen cycles through ecosystems.Producers release oxygen as a result of photosynthesis. Most organisms take in oxygen from the air or water and use it to carry out their life processes. What affect do humans have on the levels of carbon and oxygen in the atmosphere?

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30 The Nitrogen Cycle Nitrogen is also a necessary building block that make up living things. In the nitrogen cycle, nitrogen moves from the air into the soil, into living things, and back into the air or soil. Even though the air around us is 78% nitrogen organisms cannot use nitrogen gas. Most organisms can use nitrogen only after it has been “fixed” or combined with other elements to from nitrogen- containing compounds. So, if we need it so much how do we get it?

31 The Nitrogen Cycle Nitrogen fixation is the process of changing free nitrogen into a usable form of nitrogen. Most nitrogen fixation is performed by certain kinds of bacteria, which live in bumps called nodules on the roots of legumes. These plants include clover, beans, peas, alfalfa, peanuts, and some trees. What type of relationship is between the bacteria and the legumes? Mutualism; the bacteria feed on the plants’ sugars, and the plants are supplied with nitrogen in a usable form.

32 The Nitrogen Cycle Once nitrogen is fixed, producers can use it to build proteins and other complex compounds. Nitrogen can cycle from the soil to producers and then to consumers many times. At some point, bacteria break down the nitrogen compounds completely in which the bacteria then release the free nitrogen back into the air, causing the cycle to continue.

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34 Cycles of Matter How does this picture show the water cycle, oxygen cycle, nitrogen cycle, and food chain?

35 Biomes

36 What are the 6 major biomes?A biome is a group of ecosystems with similar climates and organisms. 6 major biomes: Desert Rain forest Grassland Deciduous forest Tundra The climate – the average annual temperature and amount of precipitation – in an area that determines its biome.

37 Desert Biomes Characteristics of a desert biomeAn area that receives < 25cm of rain per year. Large shifts in temperature during the day. Examples Organisms in the desert must adapt… To little or no rain To extreme temperatures The Namib desert in Africa cools rapidly each night when the sun goes down. The Gobi in Central Asia, have a yearly avg. temperature that is below freezing. The stem of the saguaro cactus has folds that are similar to the pleats in an accordion. The stem expands to store water when it is raining. Gila monsters can spend weeks at a time in their cool underground burrows. Many other animals are active at night when the temperatures are cooler.

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39 Rain-Forest Biomes Characteristics of the rain-forestForest in which large amounts of rain fall year-round. Little sunlight reaches the ground Plants are everywhere such as vines hanging from tree limbs. Some are a warm, humid “jungle” in the tropics. The Pacific Northwest is also considered a rain-forest because it receives more than 300cm of rain per year. Scientists refer to this area as a temperate rain-forest – “having moderate temperatures.” Temperate – huge trees, U.S. Pacific Northwest, Moderate temperatures Tropical – Humid: tree layers, hot temperature, near equator Both – wet, lots of plants, lots of animals

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41 Tropical Rain Forests What are the four distinct layers of the tropical rain forest?Emergent layer – tallest layer that receives most of the sunlight. Canopy – a leafy roof Understory – plants grow well in the shade formed by the canopy Forest floor – nearly dark, only a few plants live there.

42 Grassland Biome Characteristics of grasslandsAlso called the prairie A grassland is an area that is populated mostly by grasses and other nonwoody plants. Receive 25 to 75cm of rain each year. Home to many large animals such as elephants, bison, and kangaroos. Grasslands located closer to the equator are known as the savannas. Receives as much as 120cm of rain Scattered shrubs and small trees grow here, along with grass.

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44 Deciduous Forest BiomeCharacteristics of deciduous forest Deciduous trees are trees that shed their leaves and grow new ones each year. Receive at least 50cm of rain per year. Temperatures vary greatly throughout the year. Variety of plants creates many different habitats. Birds, and mammals such as chipmunks, and skunks live her

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46 Boreal Forest Biome Boreal means “northern” Also known as taigaCharacteristics of Boreal Forest Dense forest in the upper regions of the Northern Hemisphere Coniferous trees - trees that produce their seeds in cones and have leaves shaped like needles. Have thick waxy leaves to prevent water loss Winters are very cold; summers are rainy and warm Animals such as red squirrels, insects, moose, and beavers live here.

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48 Tundra Biome Characteristics of the Tundra Extremely cold and dryReceives no more rain than the desert Frozen soil is called the permafrost. Shallow ponds and marshy areas in the summer Mosses, grasses, and dwarf trees; grow during the short summer season Mammals in the tundra are caribou, foxes, and wolves

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50 Mountains & Ice Not classified as a biome.Because the organisms in these areas vary, mountain ranges and land covered with thick ice sheets, they are not considered biomes. Greenland and Antarctica fall into this category. Biomes are classified by their abiotic and biotic factors

51 Aquatic Ecosystems

52 Two Major Aquatic EcosystemsFreshwater ecosystem and Marine (saltwater) ecosystem. ½ of all oxygen produced on Earth comes from floating algae called phytoplankton. All aquatic ecosystems are affected by the same abiotic factors Sunlight Temperature Oxygen Salt content

53 Freshwater ecosystem 3% of the Earth’s water is freshwaterStreams and rivers Examples Ponds and lakes

54 Marine Ecosystem Estuary is found where the fresh water of a river meets the salt water of an ocean. Algae and plants provide food and shelter for animals, such as crabs and fish. Many animals use the calm waters of the estuary for breeding grounds.