Ecology Flashcards
Biome
A geographical area (abiotic) that has an identifiable group of living forms (biotic).
- identified by climate
- more producers–>more consumers(diversity)
Ecology
The study of surroundings (house).
Geographical areas
Physical constraints biosphere in a given area determine WHAT WILL LIVE THERE. typically look first at plants (bottom of food chain
How is climate determined?
How close you are to equator. More sun–more light—more hot.
Weather vs. climate
Weather: current conditions
Climate: annual average conditions
Physical abiotic constraints
pH Oxygen Pressure Light Mineral content Salinity Soul type
Climate abiotic constraints
Temperature Precipitation Humidity Wind Sun
Population
A group of individuals of the same species living in the same general area.
-will typically rely on same resources, influenced by same environmental factors and are likely to breed with one another
Change causes ______
Change at ALL levels
Ultimate for population
How they evolved
Proximate for population
What’s happening now
Characterized by dynamic (changing) (4)
Density, dispersion, population size, demographics
Characterize by density
of individuals within a given area
Characterize by dispersion
How are they spread out in a given area?
-uniform, random, and clumped (most common, aka patchy, tend to go where resource is.)
Characterize by population
How many in a given area
Demographics
Vital stats of a population and how they change
Birth-death model
Change in population over time
N_t+1=N_t+B-D
N=size of pop/t=time/b=birth rate/d=death rate
Life-table
Age specific summary of survival pattern of a population
Cohort
Age specific group within a population
Survivorship curve
A plot of the proportion or numbers in a cohort still alive at each age.
-leaf graph
Exponential growth model
(dN)/(dt)=r_max(N)
d=death rate/time
Logistic growth model
(dN)/(dt)=(rN(K-N))/K
K=carrying capacity
d=death rate/time
Carrying capacity
of individuals that can be supported within the given area.
Allee effect
The fitness of individuals in a small population is less than those individuals in a large population
______ of organisms will reflect the type of reproduction model seen
Life histories
Natural history
All of the traits an organism exhibits in it’s schedule of reproduction and survival from birth to death (infant-toddler-child) trade-offs btw survival and traits such as frequency of reprod., parental care, # of offspring….(cost/benefit) description of life (reflects evolution)
Natural selection has molded to basic strategies to……
Solve the problem of getting an individuals DNA into the future
R-selected
Lots of babies like fish
K-selected
Fewer young, more parental care and investment
Density-independent
Population size is not influenced by size of population (r-grows exponentially)
Density-dependent
Point when the population reaches k and levels off
- factors due to pop size(density) that limits pop growth
- space, competition(food, mates,resources), disease
- k(logistic growth)
Community
Interacting group of various sp. w/in a given area
- an assemblage with unity(how they work together/identifiable)
- focuses on biotic interactions
Ecosystem
The sum of all the organisms living w/in its boundaries and all the abiotic factors w/which they interact
- (smallbig)
- log vs. forest
Each species within a system has a specific _____\
Niche
Niche
- set of environmental tolerances of a sp. which defines where it can live.
- way a sp. obtains it’s energy and it’s patterns of interactions w/other sp.(it’s role)
- how it conducts its business (makes its living)
Energy interactions
Organize interactions by how they contribute to the flow of energy and materials
- abiotic
- consumer resource (trophic interactions)
Trophic levels
1) Primary producers (autotrophs)
2) Heterotrophs
- -primary consumers (herbivores)
- -secondary consumers(omnivores)
- -tertiary consumers (carnivores)
- -decomposers(detritivores->dead material)
Modeling
Food chain, good web, food pyramid, bio magnification pyramids, 10% rule, trophic cascades
1st law of thermodynamics
- matter/energy cannot be created or destroyed
- matter cycled/energy flows(lost to heat)
- therefore we need constant input of energy (sun)
Second law of thermodynamics
For every transfer of energy some is going to be lost to heat (10% rule).
Biomagnification
As you go from 1 level to another matter builds up (pesticide->algae->fish->eagles eggs were thin and cracked)
Carbon cycle
6O[2]+C[6]H[12]O[6]—>6CO[2]+H[2]O
-first part: respiration, burning fossil fuels, decomposition
GPP
Gross primary production
-Producers:light energy(J/m^2/yr)——->chemical (g/m^2/yr) (dry biomass)
NPP
Net primary production
- primary consumers
- NPP=GPP-R[producer]
- ——-R=energy lost due to respiration
(Typically 1/2 is lost)
Community
Populations (diff. species) within a given area interacting.
Ecological niche
Considering abiotic/biotic interactions.
-general (I serve food)
Fundamental niche
Considering where the species can potentially exist (law of tolerances)
-what type of restaurant (burgers)
Realized niche
Where one actually observes the species within the community
-compete with other burgers (charbroiled)
Interspecific interactions (fundamental niche)
\+mutualism+ O commensalism+ (cattle bugs) O amensalism- (elephant travel) -competition- \+pred/prey- \+herbivory- \+parasitism-
Law of competitive exclusion principle
No 2 species will occupy the same niche
Batesian
Mimic the bad ( monarch tastes bad, mimics look like monarch)
Müllarian
All bad tend to look same (bees, hornets, etc./poisonous frogs)
Succession
Series of events in which life comes back (reestablishes itself) in a predictable way
–predictable because set of abiotic conditions tend to be the same
Primary succession
No soil
Secondary succession
What follows after a disturbance
-soil
Pioneer species
First organisms after succession (mosses, lichens)
-r selected because they haven’t evolved for competition so they crash
Climax community
Organisms after life stabilizes
- mostly k selected
- greatest diversity/ max. Niches filled
- endures change better than pioneer species because it’s more developed
- associated with biome
- dynamic(changing) climate isn’t stable which determines producers
Shannon’s index of species diversity
The proportion of individuals in an area indicate their importance to diversity
Keystone species
Organism that is vital to a community
- prairie must have prairie grass
- can’t have ponds w/o beavers
Invasive species
Came in and outcompeted native species
Exotic species
Not normally found there (may/may not outcompete–>could coexist)
Limiting factors
- density dependent (biotic)
- density independent (abiotic) catastrophic events
More diverse communities are found where?
Towards the equator
Why is a species absent from an area?
Look at dispersal and distribution
What does it mean for a dispersal to be limited?
Area is inaccessible or not enough time.
- natural range(where historically originated and lived)
- species transplants:when a species gets transplanted into another community
Why species occur where they do: behavior limits distribution
Habitat selection
-behavior
Why species occur where they do: biotic factors limit distribution.
Predation, parasites, competition, disease
-biotic constraints
Why species occur where they do: abiotic factors limit
Abiotic constraints (chemical or physical factors)—–>law of tolerances
