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Principles of Ecology Test #3

Terms in this set (67)

Laboratory Experiment
Perturbations produced by experimentation in a laboratory.
Field Experiments
Perturbations produced by experiments in the field.
Natural Trajectory Experiments
Comparisons of the same community before, during, and after the perturbation.
Natural Snapshot Experiments
Comparisons of communities that have reached stead-state with relation to perturbation. (Comparing like-sites with different levels of perturbation).
Community Ecology
Community- association of populations which interact. (Occur together in time and space).
Biotic Interactions
The close association of two or more dissimilar organisms. (Symbiosis).
Mutualism
Both benefit from the association [++/--].
Commensalism
One of the species in benefited without harm to the other [+0/-0].
Parasitism, Predation, Herbivory
One species is benefited, the other is harmed [+-/-+]. This can however, evolve into mutualism.
Amensalism
Inhibition of one organism by another by the release of metabolic by-products into the environment.
Ex.
a. Passive interaction
b. Pines acid and tannins
c. Anti-herbivory chemicals, i.e. hormones
Chapparal
Release of chemicals that inhibit the germination of seeds.
Ex.
Fire releases the inhibition and ______ seeds germinate faster than others.
Competition
A negative effect of one species (or individual) upon the population size of another arising from their joint exploitation of environmental resources [--/++].
Law of Limiting Factor
Growth and distribution of a population is dependent on the one environmental factor most critically in demand.
Competition Exclusion
Two species cannot coexist on the same limiting resource.
Resource Partitioning
Each population will utilize a slightly different area or part of the same resource and coexist.
Interspecific Competition
Individuals of different species compete.
Intraspecific Competition
Individuals of the same species compete.
Diversity (Biodiversity)
Related to the number and distribution of species and is the product of richness and evenness.
Species Richness
The number of species in a community.
Species Evenness
Is the distribution of individuals; the number of other individuals of other species (max- all have the same number).
General Implications of Biodiversity
a. Supposedly characterizes complex communities.
b. Diversity increases in early succession but decreases in late succession.
c. In harsh environments populations are most affected by the environment; in less harsh environments populations are most affected by interactions with other populations.
d. Community Simplification (artificial) decreases stability.
Ecosystem
An ecological unit composed of interacting components of the biotic and abiotic worlds in a defined area.
a. Size- Biosphere to raindrop.
b. Boundaries must be defined.
1.) Natural boundaries with Transition Zones.
2.) Artificial Boundaries.
Biogeochemical Cycles:
a. 4th General Principle of Ecology
1. Minerals (and matter) cycule within ecosystem.
2. Minerals, such as nitrogen, carbon, water, etc. cycle between pools (storage compartments) such as geologic formations, oceans, the atmosphere, and living organisms.
b. Cycling Models (Compartments)
a. Spacial cycle and chemical cycle
b. Compartment (where the minerals reside) and flux arrows (movement) between compartments /pools.
c. Renewal Time- Time required to completely replace an element in a pool.
1. Atmospheric cycles are relatively fast.
2. Elements with a major pool in a geologic formation are very slow.
3. Organisms affect some cycles.
d. Water Cycle
Biomes
Earth's major kinds of terrestrial communities recognized by its dominant vegetation and defined by temperature patterns with sub biomes defined by moisture patterns (with one exception).
Tropical Biomes
Equator to 23.5 degrees north and south latitude, warm and hot year round.
(Tropical Rain Forest, Tropical Savanna)
Tropical Rain Forest
a. High rainfall year-round
b. Productivity is high
c. Diversity is high
d. Soils are thin and leached
e. Decomposition rate is very high
f. Nutrient pool in living organisms
Tropical Savanna
a. Grassland with mixed shrub/ forest areas.
b. South America and Africa
Temperate Biomes
Moderate year round temperature.
(Temperate Deciduous Forest, Temperate Evergreen Forest, Temperate Rain Forest [old growth]).
Temperate Deciduous Forest
PPT throughout the year and cold winters.
a. Productivity is moderate
b. Diversity is moderate
c. 9 regional associations
Temperate Evergreen Forest
1. Mountains
2. Productivity is low
3. Diversity is low
4. High frequency of drought and fire.
Temperate Rain Forest
1. Cool mountain climate
2. Winter ppt is very low
3. Redwoods and Sequoias
Capture-Recapture Method
A method used to determine the size of a species population. This is done by marking captured individuals and then releasing them back into the environment. Smaller populations have more recaptured species. While larger populations have less recaptured species.
Temperate Grasslands (Prairie, steppe, pampas, veldt)
Too little moisture for a forest, but more than a desert.
a. Less than 60 cm ppt , decreasing east to west.
b. Largest formation in North America.
c. Continental Climate (huge extremes in temperature).
d. Summer drought.
e. Fire and grazing climax.
Perennial Bunchgrasses
Produce stolons for many years. (Stolons are above ground horizontal-stems).
Perennial Sodgrasses
Spread by rhizomes (below ground horizontal stems).
Tall Grass Prairie
Bunchgrasses
Mixed Grass Prairie
Bunch and Sodgrass
Desert Grassland
Plateaus above 1000m at the edge of western desert in the USA
Taiga (Boreal Forest)
Latitude type Gymnosperm forest survives extreme cold weather.
a. Canada to Siberia
b. PPT as snow
c. Low species diversity
d. Forest floor 100% covered with cryptograms (lichens, moss, and algae)
e. White Spruce, Balsem Fir, and Larch
Tundra
Treeless due to the extremely cold temperatures.
Arctic Tundra
a. High latitudes at low elevation.
b. Permafrost- snow covered.
Alpine Tundra
a. High elevations at low latitudes
b. No permafrost (Colorado, etc.)
Timberline [Krummholz Zone- twisted wood] Found between Taigas and Tundras.
a. Broad ecotone in arctic, narrow in alpine biomes.
b. Dwarf, twisted trees.
Deserts
Extremely dry areas.
a. PPT is less than 200 mm per year. (Less than 7 inches)
b. Productivity is low
c. Diversity is very low (except reparations areas-near rivers or streams).
d. Large daily temperature changes
Subtropical or Hot Deserts
a. mainly between 20-30 latitude
b. Drought resistant deciduous trees: Shrubs and succulents
d. Sonoran Desert in Arizona
e. Chihuahuan Desert in New Mexico
Temperate Deserts
a. Mainly due to Rain Shadow Effect
b. Warm desert (Mohjore Desert)
c. Cold desert (Great Basin Desert)
Arctic Desert
No vegetation.
Desertification
Previously productive land becoming a desert.
a. overpopulation
b. overgrazing
c. 1,000,000 hectare per year
Productivity
Measure of the total amount of energy made by photosynthesis for a given unit of land surface for a given unit of time.
Standing Crop
Dry weight of plant material at a given time.
Cellular Respiration
Use of energy to preform life functions.
Anaerobic Respiration
Does not use oxygen.
Glycolysis
Breaks down glucose into Pyuvic Acid (PA) molecules.
Fermentation
(Type of Anaerobic Respiration)
a. Lactic Acid Fermentation
b. Alcohol
Aerobic Respiration
Uses Oxygen
a. Glycolysis
b. Krebs Cycle
c. Electron Transport Chain System (9 times more efficient than anaerobic).
d. Respiration
Gross Primary Productivity (GPP or Pc)
Total amount of chemical energy fixed by photosynthesis (per unit area, per unit time).
Net Primary Productivity (NPP or Pa) = GPP
Energy lost through respiration.
Second Law of Ecology
Energy flows through ecosystems. Organisms may be arranged in groups or levels, as to how they obtain energy.
Producers (Autotrophs)
Use inorganic Carbon (CO2) as their carbon source.
Photoautotrophs
Use light energy via photosynthesis. (Plants, algae, cyanobacteria, and some bacteria).
Chemautotrophs
Inorganic energy. (bacteria)
Consumers (Heterotrophs)
Use organic carbon as their carbon source.
Chemoheterotrophs
Use organic molecules for energy.
Photoheterotrophs
Bacteria
Reducers
Feed on dead organic matter.
Third General Principle of Ecology
The graphic representation of the trophic levels is represented in a pyramid.
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