McDougal Littel Biology Nowicki California Ed.: Unit 6 Chapter 15 Notes
UNIT 6: ECOLOGY
Chapter 15: The Biosphere
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I. Life in the Earth System (15.1)
A. The biosphere is the portion of the Earth that is inhabited by life
1. Biosphere- part of Earth where life . exists
a. Includes all living . and non . -living parts
b. Biota- collection of just living things in biosphere
2. Earth has four . major connected systems
b. Hydrosphere . -all of Earth’s water, ice, water vapor
c. Atmosphere . -the air blanketing Earth’s solid and liquid surface
d. Lithosphere . -features of Earth’s surface (continents, rocks, sea floor, and everything below Earth’s surface
B. Biotic and Abiotic factors interact . in the biosphere
1. All four of Earth’s systems are connected . to another
2. Gaia . hypothesis- Earth itself is kind of a “living organism”
II. Climate (15.2)
A. Climate is the prevailing weather of a region .
1. day . -day to day conditions
2. Climate- long .term pattern of weather conditions
B. Key factors that shape an area’s climate
1. temperature . -key factor
2. sunlight .
3. water . (moisture)- key factor
4. wind .
C. microclimate . -climate of a small specific place within larger area.
1. Can be very important . to living things
2. Can be very small . or large . area
D. Earth has three main three . zones
1. Use average temperature . and precipitation . to categorize
a. Polar zone -in far northern and southern regions
b. Tropical zone- surrounds the equator .
c. Temperate zone- wide area between polar . and tropical . zones
2. Influence of sunlight
a. Earth’s surface heated . unevenly
1). Hottest portion where sun . strikes directly
2). Curved shape causes uneven . heating
3). Earth tilts . on its axis and this also plays a role in seasonal changes
3. Air and Water Movemen
a. Sun also warms water . and air .
b. Uneven heating causes wind . and water currents .
c. Warm air (and water) rised . and
cold air (and water) sinks .
d. Also affects amount of precipitation (warm air holds more water than cold air)
4. Landmasses- also shape . climate
a. Coastal areas tend to have smaller changes in temperature . moderated by oceans .
b. Mountains have large effect on climate- causes precipitation .
5. Adaptation to Climate- Many organisms adapted to survive . in specific climate
III. Biomes (15.3)
A. Earth has 6 major biomes- Each biome characterized by certain set of abiotic .
factors, ecosystems .
1. Tropical Rain Forest Biome- warm . temperatures, abundant precipitation .all year, lush forests
2. Grassland Biome- primary plant life is grass . Occurs in variety of climates .
3. Desert Biome- arid . environment, little . precipitation, four types: hot, semi-arid, coastal, and cold
4. Temperate Forests- Include deciduous forests and rain forests. Temperate deciduous forests have deciduous . summers and cold . winters. Deciduous trees are the dominant plant species
5. Taiga- Found in cool northern climates. northern . winters, short summers. Small amount of precipitation
6. Tundra- Far northern latitudes with long winters (10 months) limited precipitation, permafrost .
7. Minor biomes- example: chaparral . -hot, dry summers and cool, moist winters
B. Polar ice caps and mountains are not . considered biomes
1. Polar ice caps- have no soil . and do not have specific plant . community
a. Found at poles . (north and south)
b. Most animals depend on sea . for food
IV. Marine Ecosystems (15.4)
A. The ocean can be divided into zones
1. Ocean Zones
a. Divided into open sea ( pelagic .) and ocean floor ( benthic . zone)
b. Divided between areas that receive light ( photic . zone) and those that do not ( apothic .zone)
c. Ocean also separated into zones using distance . from shore line and water depth
1). intertidal . zone- between high and low tide lines
2). neritic . zone-extends from intertidal out to edge of continental shelf
3). bathyal . zone- extends from edge of neritic zone to base of continental shelf
4). nerritic . zone- lies below 2000 meters and is in complete darkness
d. Life in Neritic Zone- only 1/10th of ocean but contains majority of biomass . (Most biomass consists of plankton .)
B. Coastal waters contain unique habitats
1. coral . Reefs- found within tropical zone and contains large diversity
2. Kelp Forests- found in cold ., nutrient rich waters
V. Estuaries and Freshwater Ecosystems (15.5)
A. Estuaries are dynamic . environments where rivers flow into the ocean .
1. Estuary- partially enclosed body of water formed where a river . flows into the ocean.
a. Mix of fresh . and salt . water
b. River carries lots of nutrient .
c. Large numbers of species thrive and are highly productive . ecosystems
d. Provide refuge for many species and spawning . grounds
e. Over 80 . % of estuaries have been lost to land development
B. Freshwater ecosystems include moving and standing water
1. Freshwater ecosystems- rivers, streams, wetlands
2. among most productive . ecosystems on Earth
C. Ponds and lakes share common features
1. Smaller in size than oceans, but also divided into zones
a. littoral . zone- between low and high water marks
b. limnetic . zone- open water farther out from shore
c. benthic . zone- bottom of lake or pond where less sunlight . reaches