Chapter 15

1. Chapter 15

2. 15-1 climate and life. Climate- the temperature, the average annual precipitation, humidity and the amount of sunshine that a region typically experiences. * climate is a powerful factor in determining the types of living organisms that an area can support * climate, such as temp. and rainfall, will allow populations to grow, remain stable or vanish. temp. and rainfall can also affect the structure of foodwebs. climate is the interaction of the suns energy with the earths air, H20 and land. earths thermostat the earths atmosphere serves as a natural thermostat CO2 and H20 in the atmosphere allows solar energy to reach the earths surface, where it is absorbed and later converted into heat. these gasses (CO2&H20) keep the heat energy close to the earth for a period of time. This is called the greenhouse effect. Earths climate zone interactions between solar energy and the atmosphere are responsible for much more than the earths temp. – solar energy is responsible for global winds and ocean currents.

3. Environments and ecosystems an environment is a combination of physical and biological factors that influence life physical factors( called abiotic factors) 1. climate 2. soil(and its acidity) 3. nutrients. biological factors(biotic factors) all of the living things with which an organism might interact. Ecosystem is a collection of organisms, producers, consumers, and decomposers interacting with each other and with their physical enviornment. * an ecosystem is a combination of biotic and abiotic factors. Niche a full range of physical and biological conditions in which the organisms in a species can live and the way in which the organisms use those conditions. Habitat the type of surroundings in which a species lives and thrives.

5. 15-2 environments and life The biotic and abiotic factors of an environment continually interact with and affect each other these interactions as well as their capacity to change ecosystems usually operate slowly, over a long time scale. * ecosystems respond to change by undergoing more changes. Changes in ecosystems most ecosystems seem stable but many ecosystems are constantly changing because organisms alter their surroundings. - as a ecological system changes, older inhabitants gradually die out and new plants and animals move in. Ecological succession Rakata island (indonesia) was created by a violent eruption that destroyed the larger island of kraktoa in 1883 at first- only mosses, fungi, and grasses were able to grow on the newly cooled lava rock -over time these organisms causes the rock to break down, producing a thin layer or soil. - some plants and eventually trees were able to grow in this soil - animals soon flew, swam or drifted to the islans - within 100 years the island turned into a tropical rainforest

6. *Ecological succession- the process by which an existing ecosystem is gradually and progressivly replaced by another ecosystem. humans can causes ecological succession ex) an abondened clear cut field Climax community the relatively stable collection of plants and animals that result when an ecosystem reaches such a state. ex) natural disasters (floods,fires,etc) can alter an ecosystem causing ecological succession thus producing a climax community. Rakata island

8. 15-3 earths biomes ecosystems identified by their climax communities are called biomes. 6 terrestrial biomes4 aquatic biomes 1. tundra 1. open water 2. tropical rain forest 2. fresh water 3. desert 3. estuaries (river joins the sea) 4. grassland 4. rocky intertidal 5. temperate deciduous forest 6. taiga 3% of all water on earth is fresh. 98% of that is frozen.

10. 15-4 climate: a complex story global climate patterns are currently caused by the actions of winds and ocean currents -winds and ocean currents are in turn powered by solar energy. Winds. * since the earths surface is curved different parts of the surface receive different amounts of solar energy - near the equator , solar energy is more concentrated than it is in the north.south poles. * a result is that the surface of the earth is warmer at the equator than at the poles. * warm air rises, cool air sinks- there are three large circuits of rising/ falling air on each side of the equator. * as the earth rotates on its axis, the air flows move east or west –the surface air flows are called trade winds ocean currents oceans experience more solar heating at the equator -warmer H20 at the ocean surface moves from the equator toward the cooler H20 at the poles. - cold H20 near the poles sink to the bottom and travel toward the equator * again, the earths climate is caused by the interaction of air and H20 currents w/ the earths land masses. - as warm air moves over warm H20 it pickups moisture in the form of H20 vapor

11. - if the warm moisture rises and later cools, the H20 vapor condenses and falls to earth. The climate controversy The enhanced greenhouse effect- refers to the fact that human activities are adding greenhouse gases to the atmosphere; CO2 and gases are being added to the atmosphere causing the earth to retain more heat global warming- when the enhanced greenhouse effect is used to predict a significant rise in earths average temperature, the prediction is called global warming – 1 - 2 increase by 2050 * climate change includes any significant change in patterns of temperature, rainfall, humidity, storm activity and cloud formation that occurs in any part of the world. temperature is only one factor affecting climate Possible effects of global warming 1. melting of polar icecaps 2. rising sea levels 3. flooding 4. influence air/ H20 flows 5. decline of zooplankton( tiny marine organism that are part of marine food chains)

12. Ocean currents Winds Global warming