Chapter 14 – Ecosystems & Biomes 14.1 Ecosystems support life 14.2 Matter cycles through ecosystems 14.3 Energy flows through ecosystems 14.4 Biomes contain many ecosystems

14.1 Ecosystems Support Life Living things depend on the environment Ecology is the scientific study of how organisms interact with their environment and all the other organisms that live in that environment. Ecosystem is a particular environment and all the living things that are supported by it.

14.1 Biotic Factors Biotic Factor = all the living parts of an ecosystem Biotic factors interact with an ecosystem and influence it. Living things depend on the ecosystem for food, air, water, etc. for survival needs and they intern impact the ecosysstem. Ex: Plants (biotic) impact abiotic factors such as: Soil enrichment, depletion, retention, temperature, animals, etc. Animals (biotic) impact biotic and biotic (beaver building a dam, cattle overgrazing a grassland cause soil erosion - abiotic

14.1 Abiotic Factors Abiotic factors = non-living parts (physical as well as chemical) of the environment (oxygen, CO2, soil, water, sunlight, temperature, minerals & compounds, etc) Temperature affects plants (type & varieties), animals, available shelter, etc. Light impacts amount/variety of plants, how much photosynthesis Soil affects plant growth, water percolation, supply Water impacts carrying capacity (# of plants/animals an area can support) of all plant & animal life, variety of species, etc.

14.2 Matter Cycles All ecosystems need certain materials (matter) Cycle: movement of matter (living/nonliving) is a continuous process or cycle. Cycle = a series of events that happen repeatedly 3 Main Cycles are: Water, Carbon, Nitrogen

14.2 Water Cycle Water is constantly moving through the environment through the water cycle Water has two elements oxygen & hydrogen Water changes form as it cycles: solid (ice, snow), liquid, gas (water vapor), etc. Evaporation = change of state from liquid to gas form Plants release water as they breathe or respire & release more vapor through transpiration of vapor through their leaves.

14.2 – Carbon Cycle Carbon cycles through ecosystems in the carbon cycle. CO2 in our air has carbon in it. Plants use CO2 to produce sugars during photosynthesis. Carbon is re-released as plants/animals use energy or decompose. Earth’s oceans contain more carbon than the air. Algae & bacteria also use/release carbon

14.2 Nitrogen Cycle Four fifths of our air has nitrogen (a clear colorless gas), but we cannot use it in gas form. Nitrogen has to be “fixed” into a useable state by plants before they/we can use it. Plants take in nitrogen compounds through their roots. We get it when we eat the plants. Lightning breaks apart or fixes pure nitrogen as well Nitrogen fixing bacteria live in the oceans as well as in plants roots. Soybeans & alfalfa are good sources of nitrogen

14.3 Energy Flows Through Ecosystems We use chemical energy (from food; ultimately from the sun) and need to replace it with energy in our ecosystem. Producers – capture energy and store it in food as chemical energy. Plants are most common producers on land Photosynthetic bacteria and algae produce energy in the oceans (exception: deep ocean trench bacteria use heated chemicals released from vents in process called chemosynthesis) They make the energy available for themselves and the rest of the ecosystem.

14.3 Energy Flows – cont’d Consumers - organisms that get energy from eating/consuming other organisms. Classified by their position in a feeding relationship: Example 1st level consumers = primary consumers – feed on grasses & plants 2nd level consumers = secondary consumers feed on primary consumers 3rd level = tertiary consumers feed on secondary consumers Decomposers – break down dead plant/animal material into simpler compounds They release the last bit of energy from once living organisms.

14.2 Feeding Models Food Chain = Model of a feeding relationship between a producer and a single chain of consumers in an ecosystem. Food Web = model of the feeding relationships between many different consumers and producers in an ecosystem. Energy Pyramid = model that shows the amount of energy available at teach feeding level of an ecosystem. All show how organisms receive energy

14.4 Biomes contain many ecosystems Regions of Earth are classified into 6 biomes: Tundra & Taiga Dessert & Grassland Temperate Forrest & Tropical Forrest Mountain Zones & Polar Ic Biome = geographic area similar in climate (temp.-soil-water), plants, and animals

14.4 Biotic & Abiotic Biotic = living factors in an ecosystem. Abiotic (Non-living) factors in a particular biome are similar and impact the biotic.

14.4 Tundra Both are northernmost regions w/long cold winters and short cool summers Tundra = -50 – 18 degrees centigrade less than 25 cm. rain per year, yet wet Permafrost (deep layer of permanently frozen soil just below the surface; trees can’t root) Plants = mosses, lichens, grasses, shrubs Animals = rodents, caribou, musk oxen, grizzly bear, white fox, snowy owl, migrating birds

14.4 Taiga 30-60 cm rain per year -40 degrees to 20 degrees centigrade Cold winters and short cool summers; more snow No permafrost; soil low in nutrients Plants = coniferous (evergreen) trees w/needles that produce food all year long Animals = insects, deer, elk, snowshoe hare, beaver, lynx, owl, bear, wolf

14.4 Desert Found in middle latitudes Less than 25 cm of rainfall Dry, sandy soil; some are hot some cold Plants = cactus Animals = lizards, kangaroo rat, ground squirrel, snake, owl, fox

14.4 Grassland 50-90 cm rainfall Supports grasses, but No trees Found in middle latitudes often near desert; warm summers (30 degrees centigrade) but cold winters Plants = sun loving grasses Animals = bison, horse, gazelle, zebra, tiger, wolf, lion Wildfires/drought keep out invading trees/shrubs

Temperate Forest 75-150 cm water; enough to support trees Short winters Deciduous trees (drop their leaves) in fall & grow new leaves in spring (exception: Pacific Northwest has coniferous redwoods, spruce, fir) Most common plants: oak, birch, beech, maple, seed plants, fruiting plants Diverse animal variety: mice chpmunks, squirrels, raccoons, deer, wolf, bobcat, fox cougar

14.4 Tropical Forest Wet 200-450 cm rain 25 degrees year-round Soil is nutrient poor, but tree litter breaks down quickly to supply nutrients Diverse plants/animals; more than anywhere else on earth. More tree dwelling species (snakes, monkeys, etc)

14.4 Water Biomes Water covers ¾’s of Earth’s surface Two Broad Types = Fresh Water &Salt Water Freshwater Biomes: affected by land topography Runoff, lakes, rivers, streams, farms, etc. Plants may live in or near water; may root below & grow above water, etc. Phytoplanktons won’t grow in rivers due to moving h20