Ecology is the study of
how organisms interact with each other and their environment
Environment includes
biotic and abiotic factors
Abiotic factors are
light, water, air, mineral nutrients
Biotic factors are
predation, competition, mutualism
predation
An interaction in which one organism kills another for food.
competition
the struggle between organisms to survive in a habitat with limited resources
mutualism
A relationship between two species in which both species benefit
terrestrial refers to
Land
Aquatic refers to
water
Population ecology
ways of describing a population
population size
the number of organisms in a population
population density
Number of individuals per unit area
age structure
number of organisms in various age categories of a population
populations change due to
births, deaths, immigration, emigration.
Life history traits
1. time to reach reproductive age 2. frequency of reproduction 3. number of offspring 4. amount of parental care given to offspring
opportunistic life history
many small offspring in a short amount of time
equilibrial life history
pattern of developing and reaching sexual maturity slowly and producing few, well-cared-for offspring
limiting factors keep populations from
continuing to grow
examples of limiting factors
competition, predation, parasitism, disease, natural disasters, weather, long-range environmental changes
Algae
phytoplankton & Seaweed
seaweeds
large, multicellular marine algae
brown algae examples
kelp
How do populations change
exponential growth, logistic growth, population cycles
exponential growth
the rate of population increase under ideal conditions
logistic growth
Growth pattern in which a population's growth rate slows or stops following a period of exponential growth
population cycles
fluctuations in population size in response to varying effects of limiting factors
biological control
the intentional release of a natural enemy to attack a pest population
methods of reducing pest populations
chemical pesticides, biological control, cultural methods (agriculture)
resource management goal
maximize harvest while maintaining population for future harvests
examples of resource managment
Deer and other game animals, fish, trees harvested for lumber
kudzu
A quick-growing vine with large leaves often found in the Southern United States
Why is Kudzu so bad?
it overtakes and kills native species
herbivory
animal consumes plants or algae
parasites & pathogens
parasites that live IN or ON another organism
pathogens include
viruses, bacteria, fungi, parasites and some protists
Producers
make their own food
Consumers
obtain energy by eating other organisms
Herbavore
plant eater
carnivore
eats other animals
omnivores
eat both plants and animals
scavengers
eat dead animals
detritivores
eat detritus (plant and animal waste)
decomposers
fungi and bacteria that are absorbing biological molecules
Top to bottom of the food chain
1. Carnivores
2. Herbivores
3. Plants
4. consumers
5. producers
6. aquatic mammals
7. larger fish
8. small fish
9. Zooplankton
10. phytoplankton
species diversity of a community hold two components
number of species & 2 relative abundance of species present
Disturbances and examples
Fires, droughts, storms tornados, floods, human activity
examples of human activity
mining and burning of fossil fuels, manufacture and use of fertilizer
in the event of an environmental disturbance,
organisms are killed and resource availability changes
small scale disturbances can
increase species diversity of a community
ecological succession
follows large scale disturbances
energy flows
enters in the form of light (most ecosystems)
Nutrient Cycle
non living environment to living things back in a continuous loop
Nutrients in biological molecules include:
carbs, lipids, proteins and nucleic acids
chemical energy in herbivores
available to carnivores
chemical energy in producers
available only to herbivores
light energy is only available to
producers
Carbon Cycle
From CO2 to Carbon Fixation to Carbon in Biological molecules to combustion back to CO2
Fossil fuels are
coal, petroleum, natural gas
differences in abiotic factors determine what?
where organisms live
Examples of abiotic factors
light, water, temperature, inorganic nutrients, salinity, available oxygen, currents, tides, etc.
other abiotic factors in terrestrial ecosystems include:
wind, fire, storms
Climate is determined by
latitude, proximity of large bodies of water, mountains
World regions include
Polar regions, temperate regions, tropics
Tropic of Cancer
23.5 degrees North
Tropic of Capricorn
23.5 degrees south
rain shadow effect
one side of a mountain receives all the rain while another does not due to moisture falling on the windward side of the mountain
9 phyla
sponges, cnidarians, mollusks, flatworms, annelids, nematodes, arthropods echinoderms, chordates
what do Sponges do?
sessile, always live in water, filter bacteria
cnidarians are
coral - sea anemones, jellies, always live in water
plankton are
drifting organism, protists, prokaryotes
examples of Mollusks
snails, slugs, gastropods, shell-like
Flat worms lack
respiritory system
blood flukes
parasites that live in blood cells
more examples of flat worms
blood flukes, planarians, tapeworms, (all mostly parasites)
annalids
segmented worms (earthworms, leaches, polychaetes)
roundworms
nematodes
echinoderms
sand dollars, sea stars, sea urchins, sea cucumbers (all marine)
arthopod characteristics
external exoskeleton, chitin, jointed legs, segmented body, insects, arachnids
Chordates
have a notochord during atleast part of their life cycle
bottleneck effect
a population's size is reduced for at least one generation
mechanisms of evolution
natural selection, artificial selection, genetic drift, gene flow, dna mutation
adaptive evolution
increase in frequency of traits that are well suited for the environment in a population over generation
artificial selection
Selection by humans for breeding of useful traits from the natural variation among different organisms
genetic drift
allele frequencies fluctuate unpredictably from one generation to the next
DNA mutations
Changes to genes due to changes in nucleotide base sequences.
gene flow
exchange of genes between populations
Protists are
Eukaryotes
protists can be
mostly single celled and sometimes multicellular
where do protists live
water
how do some protists obtain energy?
ingest and digests other prokaryotes
examples of protists
Paramecium, Euglena, Amoeba
protists that obtain energy from photosynthesis
algae
protists that obtain energy by absorption
fungi
Phytoplankton
Microscopic, free-floating, autotrophic organisms that function as producers in aquatic ecosystems
Phytoplankton single celled or multicellular?
single celled
Coccolithophores
microscopic algae with calcium carbonate shells, form the base of many marine food webs
diatoms
cell walls reinforced with silica
dinoflagellates
cell wall made of cellulose plates, two flagella located in grooves between the plates
what percentage of the bacterial pop is susceptible to antibiotics?
99.9%
polypeptide
chain of amino acids