Chapter 52: AP Biology Notes Cornell Style

1. Chapter 52
An Introduction to Ecology and the Biosphere
I. The Scope of Ecology
• A. __________ is the study of interactions between organisms and their environment.
Includes:
– 1.____________ factors like climate, water, soil affect dispersal.
– 2.____________ factors include all living or once living things.
• B. _____________ are large areas of the earth that have similar climate and thus similar
life forms.
– Temperature
– Water
– Sunlight
– Wind (these first four determine the climate)
– Rocks and soil
– Periodic disturbances (fires, hurricanes, tornadoes, volcanic activity)
C. Major Earth Biomes:
1. ________ ________ ______: High rainfall amounts, little light penetrates the forest floor,
many epiphytes, high biodiversity.
2._________________: Found between TRF and desert. Characterized by seasonal drought,
grasses are plentiful, fires are an abiotic component. Many large herds of grazing animals
migrate with water supply.
3. ________________: Little water available(less than 30 cm/ year), high surface temperature.
CAM photosynthesis is common, plants well adapted for water retention.
4._________________: -Dense shrubs, rainy winters and hot, dry summers. Periodic fires have
driven evolutionary adaptations for survival after fire.

2. 5._____________ ___________: -Seasonal drought, fires and large grazing animals prevent the
establishment of trees and large shrubs.
6.________ _________ _______: Plentiful seasonal rainfall, trees lose their leaves in fall,
animals
hibernate over winter.
7.__________ ___________: Dominated by gymnosperms (cone-bearing trees). Northern Taiga
is the largest terrestrial biome.
8._______________: Soil is permafrost, low moisture,high winds, low temps= small plants
9.__________ __________: Most abundant biome on earth. Made up of freshwater and marine
• All aquatic biomes display vertical stratification:
– a._______ ______-photosynthetic-dissolved O2is high
– b.______ ____- no photosynthesis-dissolved O2 is lower
– c. _____ ______-at the bottom-dissolved O2 is low
• Covered in detritus-dead organic matter.(cell respiration)
• For lakes, there are two general types:
– A.________ __________ are deep, nutrient-poor and oxygen rich. They have
little phytoplankton.
– B._________ _________ are shallow, nutrient rich and oxygen poor. They
contain a lot of phytoplankton.
• The marine biomes include:
– _________ ______ where land and water meet.
– _______ _______-shallow water over continental shelf
– _______ _______-open blue water past the shelf
– _________ _______ created by cnidarians. (among the most productive biomes
on earth)