Chapter 4 Ecosystems and Communities.

Chapter 4 Ecosystems and Communities

4-1 I. The Role of Climate Day to day conditions of Earth’s atmosphere in a particular place and time A. Weather = Average year after year conditions of temp. and precipitation in a particular region B. Climate = 1. Affected by: latitude, winds, ocean currents, trapping of heat in atmosphere, amount of precipitation 2. As a result of differences in latitude and thus the angle of heating Earth has three main climate zones: a. polar, temperate, and tropical.

The Effect of Latitude on Climate
90°N North Pole Sunlight Polar 66.5°N Arctic Circle Temperate Sunlight Tropic of Cancer 23.5°N Equator Most direct sunlight 0° Tropical Tropic of Capricorn 23.5°S Earth has three main climate zones. These climate zones are caused by the unequal heating of Earth's surface. Near the equator, energy from the sun strikes Earth almost directly. Near the poles, the sun's rays strike Earth's surface at a lower angle. The same amount of solar energy is spread out over a larger area, heating the surface less than at the equator. Sunlight Temperate Antarctic Circle 66.5°S Sunlight Polar 90°S South Pole Page 88

3. Heat Transport in the Biosphere
a. Warm air over the equator rises, while cooler air over the poles sinks toward the ground b. Upward and downward movement of air creates air currents/ winds, that move heat throughout the atmosphere. c. Similar patterns of heating and cooling occur in Earth’s oceans 1. Water is also moved at the surface by winds

Heat Transport in the Biosphere
Earth’s Winds WINDS Polar Easterlies 66.5°N Westerlies 23.5°N Northeast Trade Winds 0° Equator 23.5°S Southeast Trade Winds Earth's winds and ocean currents interact to help produce Earth's climates. The curved paths of some currents and winds are the result of Earth's rotation. Westerlies 66.5°S Polar Easterlies Prevailing winds Page 89

Heat Transport in the Biosphere
Ocean Currents OCEAN CURRENTS 66.5°N 23.5°N Equator 0° 23.5°S Earth's winds and ocean currents interact to help produce Earth's climates. The curved paths of some currents and winds are the result of Earth's rotation. 66.5°S Warm currents Cold currents Page 89

Page 87 II. Greenhouse Effect
Some heat escapes into space A. Atmospheric gases that trap the heat energy of sunlight and maintain Earth's temperature range include: carbon dioxide methane water vapor Greenhouse gases trap some heat Atmosphere Earth’s Surface

4-2 III. Shaping an Ecosystem A. Biotic Factors:
all the living things with which an organism might interact B. Abiotic Factors: Nonliving environment Ex. Temp., rain, wind, rocks, soil, air, sun C. Biotic and abiotic factors determine the survival and growth of an organism and productivity of the ecosystem in which the organism lives.

D. Habitat: area where an organism lives Conditions which an organism lives and how it uses it E. Niche: 1. No two species can share the same niche in the same habitat 2. Different species can occupy niches that are very similar

IV. Community Interactions
Occurs when organisms attempt to use the same resources A. Competition: 1. Competitive Exclusion Principle: no two species can occupy the same niche (role) in the same habitat at the same time Page 92

B. Predation: One organism captures and feeds on another a. Prey = organism being captured C. Symbiosis: two species living closely together (Page 93) 1. Mutualism: Both species benefit from relationship Ex. Flowers and bees 1 member benefits & the other is neither harmed/helped; rare 2. Commensalism: Ex. barnacles on whales; pilot fish with shark; egret on cattle 1 organism lives in/on another and harms it 3. Parasitism: Ex: Fleas/ ticks on dogs; sinus infection-bacteria & humans; athlete’s foot (fungus) & humans

V. Ecological Succession
A. Succession  predictable changes in an ecosystem 1. Primary Succession- “nothing there before” a. Occurs where no soil exists b. occurs on rock surfaces formed after volcanoes erupt c. The first species to populate the area are called pioneer species

Primary Succession Page 94

2. Secondary Succession (Page 95)-something was there before
a. Disturbance changes community without removing soil b. Forest fire, hurricane, tornado, human activities (subdivision, clear-cutting, mining)

3. Marine Succession a. whale dies and sinks to the ocean floor

b. Scavengers and decomposers eat the tissue within a year
c. decomposition enriches the sediments with nutrients d. heterotrophic bacteria decompose skeleton remains

4-3 VI. Biomes A. Group of ecosystems with same climate and dominant communities B. Plants and animals exhibit variations in tolerance = ability to survive and reproduce under conditions that differ from their optimal conditions Climate within a small area that differs significantly from the climate around it C. Microclimate: Ex: Oasis in a desert

Desert (Cold and Hot Deserts) Temperate Grasslands
VII. Ten Major Terrestrial Biomes Tropical Rain Forest Tropical Dry Forest Savanna-Grassland Desert (Cold and Hot Deserts) Temperate Grasslands Temperate Woodland/Shrubland-Chapparral Temperate (Deciduous) Forest-GA Northwest Coniferous Forest- Washington State, Seattle Taiga (Boreal) Tundra

VII. Ten Major Terrestrial Biomes-HONORS
A. Tropical Rain Forest °C; greater than 200cm rain yearly; warm temps, wet weather and lush plant-life; near equator B. Tropical Dry Forest C. Savanna-grassland; long, dry winter, wet summer; Africa °C; 100 to 150 cm-10 to 30 in. D. Desert- 30 °C cool deserts; °C in hot deserts; less than 25 cm rain yearly; extreme dryness (arid) w/ hot-cold temps E. Temperate Grassland- 10 –25 °C; cm rain yearly; limited rain; grasses and nonwoody plants

F. Temperate Woodland/ Shrubland-chaparral
G. Temperate (Deciduous) Forest -10 to 25 ° C; cm rain yearly; 4 seasons; GEORGIA H. Northwest Coniferous Forest- needle-like leaves; moderate temps, lots of precipitation, Washington State, Seattle I. Taiga (Boreal)- (-30) to 20 °C; cm rain yearly; cold forest; cone-bearing evergreens; mostly snow precipitation; northern US, southern Canada J. Tundra- PERMAFROST-(-40) to 10 ° C; less than 25 cm rain yearly; cold, dry, treeless; little precipitation, but ice-covered; long, cold winters; short, lush summers; Alaska

Reg Ed- FOR BIOME BOOKLETS:
---- Tropical Rain Forest °C; greater than 200cm rain yearly --- Savanna °C; 100 to 150 cm-10 to 30 in. --- Desert °C cool deserts; °C less than 25 cm rain yearly --- Temperate (Deciduous) Forest -10 to 25 °C; cm rain yearly --- Taiga (Boreal)- (-30) to 20 °C; cm rain yearly ---Tundra- PERMAFROST-(-40) to 10 °C; less than 25 cm rain yearly

The Major Biomes Page 99 60°N 30°N 0° Equator 30°S 60°S
Tropical rain forest Temperate grassland This map shows the locations of the world’s major biomes. Other parts of Earth’s surface are classified as mountains or ice caps. Each biome has a characteristic climate and community of organisms. Temperate forest Northwestern coniferous forest Tropical dry forest Desert Temperate woodland and shrubland Boreal forest (Taiga) Tropical savanna Tundra Mountains and ice caps

4-4 VIII. Aquatic Ecosystems
A. Determined by depth, flow, temp., and chemistry of the overlying water IX. Freshwater A. Flowing-Water Ecosystem 1. Rivers, streams, creeks, and brooks are freshwater ecosystems that flow over land 2. originate in mountains or hills B. Standing-Water Ecosystem 1. Lakes and ponds 2. water circulates within, this helps to distribute heat, oxygen, and nutrients

3. Still waters provide habitats for organisms such as plankton  free-floating organisms
Unicellular algae i. Phytoplankton = Unicellular and small animals that feed on phytoplankton ii. Zooplankton = C. Freshwater Wetland 1. water covers the soil or is present at or near the surface of the soil at least part of the year 2. Can be flowing or standing and fresh, salty, or brackish

3. Three Types of Freshwater Wetlands:
i. Bogs are wetlands that typically form in depressions where water collects ii. Marshes are shallow wetlands along rivers iii. Swamps, which often look like flooded forests, water flows slowly

X. Estuaries A. Where rivers meet the sea B. mixture of fresh and salt water, and are affected by the ocean tides C. Salt marshes occur in estuaries along seacoasts in the temperate zone D. Mangrove swamps are coastal wetlands that occur in bays and estuaries across tropical regions, including southern Florida and Hawaii

XI. Marine Ecosystems A. well-lit upper layer of the ocean = photic zone 1. Algae and other producers can grow only in this thin surface layer B. aphotic zone which is permanently dark is below the photic zone 1. Chemosynthetic autotrophs are the only producers that can survive here C. Ocean is divided into zones based on the depth and distance from shore: The intertidal zone, coastal ocean, open ocean

Continental slope and continental rise
Marine Ecosystems Photic zone Land 200 m 1,000 m Intertidal zone Coastal ocean Open ocean 4,000 m Aphotic zone Benthic zone 6,000 m The ocean can be divided into zones based on light penetration and into zones based on depth and the distance from shore. Each zone contains a characteristic assemblage of organisms. Ocean trench 10,000 m Continental slope and continental rise Abyssal plain Continental shelf Page 109

4-1 The Earth’s polar zones are cold because
A. they are never heated by the sun. B. at the poles, the sun's rays are at a very low angle. C. the greenhouse effect does not occur at the poles. D. heat is transported from the poles to the equator.

4-1 The upward movement of warm air and the downward movement of cool air creates A. upwellings. B. air currents. C. ocean currents. D. the greenhouse effect.

4-1 Earth's temperature range is maintained by
A. the greenhouse effect. B. climate zones. C. ocean currents and winds. D. latitude differences.

4-1 Variation of temperature in the temperate zone is due primarily to
A. air and ocean currents. B. the greenhouse effect. C. variation in the sun’s energy production. D. latitude and season.

4-1 The tropical zone is warm all year long because
A. the sun’s angle changes the most in that part of Earth. B. ocean water is warmest near the equator. C. it receives direct or nearly direct sunlight year-round. D. landmasses in the tropic latitudes hold on to heat.

4-2 Which of the following is a biotic factor in a bullfrog's niche?
A. water B. a heron C. climate D. day length

4-2 An organism’s niche is different from its habitat because
A. The niche does not include the place where the organism lives. B. the niche includes all the conditions under which the organism lives. C. the niche includes only abiotic factors. D. the niche includes only biotic factors.

4-2 The attempt by organisms of the same or different species to use a resource at the same time in the same place is called A. competition. B. predation. C. symbiosis. D. cooperation.

4-2 An association between two species in which one species benefits and the other is neither helped nor harmed is called A. symbiosis. B. mutualism. C. commensalism. D. parasitism.

4-2 When a volcano erupts and completely destroys an ecosystem, the first species to populate the area are usually A. grasses and shrubs. B. pioneers such as lichens. C. small plants such as mosses. D. small animals such as rodents.

4-3 When the climate in a small region of a biome is different from the overall climate of the biome, the region’s climate is called A. tolerance. B. a harsher climate. C. a microclimate. D. a local variation.

4-3 The ability of an organism to survive under conditions that differ from its optimal condition is called A. niche. B. tolerance. C. variation. D. succession.

4-3 Which of the following biomes is characterized by less than 25 centimeters of annual precipitation? A. tropical savanna B. desert C. boreal forest D. temperate grassland

4-3 Which of the following biomes is characterized by a mixture of deciduous and coniferous trees? A. temperate woodland and shrubland B. boreal forest C. temperate forest D. tropical dry forest

4-3 Which of the following biomes is characterized by the presence of permafrost? A. boreal forest B. temperate grassland C. northwestern coniferous forest D. tundra

4-4 Which of the following factors is important in determining the type of aquatic ecosystem found in a specific area? A. geographic location B. amount of dissolved chemicals C.the percentage of land covered by water D. the kinds of organisms in the water

4-4 The two types of freshwater ecosystems are distinguished by whether or not they have A. high oxygen content or low oxygen content. B. phytoplankton or zooplankton. C. high temperature or low temperature. D. flowing water or standing water.

4-4 Coastal wetlands that are widespread in tropical regions such as southern Florida and Hawaii are known as A. detritus. B. bogs. C. mangrove swamps. D. benthos.

4-4 Coral animals cannot grow in water that A. contains salt.
B. contains oxygen. C. is cold. D. receives sunlight.

4-4 The zone that covers the ocean floor is the A. benthic zone.
B. abyssal plain. C. continental shelf. D. continental rise.