Ecology
AP Biology 2010
Use textbook to: Compare/Contrast
Chaparral and Savannah Biomes
•
•
•
•
Temperature
Rainfall
Geographic Locations
General types of plants/animals (ex. Pine
forest)
• Special adaptations
Freshwater Aquatic Biomes
Zones: photic/aphotic; temperature
Oligotrophic versus Eutrophic lakes
Cultural Eutrophication
Input of nitrogen and phosphorous
Algal blooms followed by fish-kills
Marine Biomes
Zones: intertidal, neritic, oceanic/pelagic, benthic
Nertitic zone
Intertidal zone
Oceanic/pelgic
zone
Benthic Zone
How might we expect global climate change
to alter world biomes?
Population Ecology
Demography – Life tables & survivorship curves
Human Population Survivorship Curves
Life Histories
Semelparity: One-time reproduction
Iteroparity: repeated reproduction
Driving factor: how many offspring survive to
reproduce – determines how many offspring;
parental investment
Basic factors Affecting Population Size
• Number/Age of females
• Fertility rate of females
• Death rates of females
World fertility rates
Purple: 7-8; bottom blue:0-1
Age Structure:
Population Growth
In a restricted environment without immigration/emmigration:
Change in pop. Size = Births - Deaths for a time interval
N = B-D
t
b/d= per capita rate
r=b-d
N
t = rN
N
= bN-dN
t
OR
dN = rN
dt
Intrinsic rate of increase: rmax : exponential growth
Exponential Population Growth
Logistic Growth
K = carrying capacity
dN
K-N
dt = rmaxN( K )
Compare/Contrast
• Tundra/Desert
• Rainforest/Temperate deciduous forest
Geographic locations,Rainfall, temperature, unique adaptations,
overall types of plants/animals
Natural Populations have Limits to Growth
• Negative Feedback - intrinsic/extrinsic
• Density dependent factors: predation, disease
K – selection life history traits or r-selected life history traits
Community Ecology
• Species Richness – Biodiversity
• Historical theories: Gleason’s Individualistic hypothesis
versus Clements Interactive hypothesis
• Modern theories:
– Erlich’s Rivet Theory – tight association
– Walker’s Redundancy Model – loose web
Competition
• Interspecific – Competitive Exclusion Principle
• Ecological niche
• Resource partitioning
Ecological Niche
Sum of a species use of abiotic and biotic
resources in an environment.
Reflect and write a paragraph on the following
statement: Humans are responsible for all major
ecological issues.
Ecological Interactions
• Competition: inter and intra- specific
• Predator/Prey: camoflauge, mullerian,
batesian mimicry
• Mutualism
• Commensalism
• Parasitism
Batesian Mimicry
Mullerian mimicry
Primary Succession
Secondary Succession
Dominant versus Keystone species
• Dominant: highest abundance
• Keystone species: disproportional importance
for abundance. Removal Experiments
Trophic Organization
Secondary
production
Primary production - amount of light energy
converted to chemical energy (glucose) by
autotrophs
Net primary production – what is available to next
trophic levels: Primary-R
Bioaccumulation of Toxins in Food Chain:
Ex. Mercury (methylmercury)
Mercury in Tuna Sushi Higher
at Restaurants than Groceries
Nutrient Cycles
Water Cycle
Phosphorous Cycle
Carbon Cycle
Nitrogen fixation: Endocrine disrupters and flavonoid signalling
Jennifer E. Fox1,2, Marta Starcevic1, Kelvin Y. Kow1, Matthew E. Burow1,3
& John A. McLachlan1,3
Top of page
Abstract
Nitrogen fixation is a symbiotic process initiated by chemical signals from
legumes that are recognized by soil bacteria. Here we show that some
endocrine-disrupting chemicals (EDCs)1, 2, 3, so called because of their
effect on hormone-signalling pathways in animal cells, also interfere with the
symbiotic signalling that leads to nitrogen fixation. Our results raise the
possibility that these phytochemically activated pathways may have features
in common with hormonal signalling in vertebrates, thereby extending the
biological and ecological impact of EDCs.
Invasive Species
NUTRIA