Transcript A. Ecology

CHAPTER 50 – AN
INTRODUCTION TO
ECOLOGY AND THE BIOSPHERE
Objectives of Learning:
1. Interactions between organisms and their environments
determine the abundance and distribution of organisms
2. Ecology and Evolutionary Biology are closely related
3. Species dispersal, behavior, habitat, abiotic and biotic factors
contribute to the distribution of organisms
4. Temperature and water are major climatic factors that
determine distribution of organisms
5. Biomes are determined by yearly temperature, rainfall, and
geography
Themes: Interaction with the environment, Unity and
Diversity, Evolution
Root Words
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ABioAbyssBenthoEstuarEuTrophGeoHydroThermInter LimnLittor-
• Oligo-
• Meso• Micro• Pelag-
• Perman• -photo
• Profund-
• -clin
IMPORTANT IDEAS:
A. Ecology – study of the interaction of organisms & their
environment.
Organism
Organism
Environment
1. Abiotic Factors – nonliving factors (Temp. pH, rainfall etc.)
2. Biotic Factors – living factors.
B. Levels of Organization in Ecology – (in order of least to most
inclusive)
Individual
Population
Community
Ecosystem
Biomes
Biosphere
Population – Group of the SAME species (Given area/given time).
Community – Group of different populations.
Ecosystem – All organisms in an area as well as the ABIOTIC
factors.
Biome – World’s major communities.
Key Factors – climate, topography which determines
predominant vegetation, which in turn determines type of
organisms and their adaptations to their environment.
Climate – average daily weather conditions in an area.
( Controlled by: Temp, precipitation, winds, and
light.)
Microclimate – climate within climates.
Topography – Physical features of the land. (Mountains, plains,
valleys etc.)
Biosphere – entire portion of the earth inhabited by life.
Other Terms:
1. Acclimation – physiological adjustment to a change in an
environmental factor.
2. Morphology – Study of anatomical features.
3. Phytoplankton – Plankton (microscopic) that are plants.
4. Temperature – has the most influence on the metabolic rates of
plants and animals
5. Convergent Evolution – species from different evolutionary branches
may come to resemble each other if they live in
similar roles in the environment.
Example – wings of birds and insects. (these are called
analogous structures – have similar function,
but not necessarily the same shape)
Ecotone – an area where different terrestrial biomes grade into each
other.
Fires – Many plants and animal communities adapt to these. Fires
also can change species composition within biological communities.
Principle of Allocation – Organisms have limited amounts of energy,
so they must allocate their energy for such things as: Getting nutrients;
escaping predators; hunting; growth; reproduction etc.
Evolutionary Adaptation – is the slowest of all ways organisms
respond to environmental changes. (migration is the fastest).
Fig. 50.11 pg. 1101 Solar Radiation and Latitude
Fig. 50.12 pg. 1102 The Cause of the Season
Fig. 50.13 (A)
Air Circulation
and Precipitation
near the Equator
Question: If the earth was
knocked off its axis and
became perpendicular,
what is the most obvious
effect this would be have?
Elimination of seasonal
variation.
Zonation in a Lake
Fig. 50.18 pg. 1107
NOTE: Nutrient-rich runoff into freshwater ecosystems can result in
“eutrophication” (nutrient enrichment of a body of water which leads to
excessive growth in algae, then depletion of dissolved oxygen as dead
algae is consumed by decomposition).
Most
phytoplankton
Bottom dwelling area –
the organisms here eat
detritus (dead organic
material).
50.22 Zonation in Marine Environment
Phytoplankton
mostly found.
Lowest level where
photosynthesis
occurs
Species – most have small ranges in which they live.
Introduced species – often fail to colonize the new area; may
become common pests; can disrupt the balance of native species
Land Biomes
As you travel toward the poles Temperature becomes the major
factor in determining biomes. Near the equator, precipitation is the
major factor.
Deserts – are located in places where air masses are usually falling.
Aquatic Biomes
• Hydrophytes – plants that like to live in very
moist soils (grow best in bogs and swamps)
• Lake Turnover – in temperate lakes, surface water
is replenished with nutrients during turnovers in
the spring and fall.
Practice Questions:
1. Biome that would support large animals with moderate rainfall?
SAVANNA
2. Phytoplankton is found in which zone?
PHOTIC (marine).
3. What terrestrial biomes are best adapted to frequent fires?
Temperate grasslands, savanna, & chaparral.
4. Different Photoperiods which biome (community) is best adapted?
Temperate forest (deciduous)
5. Biome most likely to have a mild climate, rainy winters and hot
dry summers?
Chaparral