eco lab Flashcards
Identify initial concerns regarding collecting a representative sample of a population.
how big of a sample should you have, is the sample random, is it representing the area well enough, and can it be replicated.
Explain why descriptive statistics are necessary in ecological studies.
Reporting every single measurement in a data table would be truthful, but not very useful, because the human mind cannot easily take in long lists of numbers. A more fruitful approach is to take all the measurements of our fish and systematically construct a composite numerical description, or statistic, which conveys information about the population in a more concise form . (this is what the lab manual said)
Standard Deviation
to measure the amount of variation around the mean, this helps determine if the data is normally distributed
Investigate fundamental issues of experimental design (e.g., how many samples?)
1) what sampling method can be used to collect the needed data, 2) how do we select sampling locations to limit potential bias and obtain best estimates of target parameters, and 3) how can we minimize the number of samples we take while still providing an accurate estimate of parameters?
Precision
How clumped together/close they are
Accuracy
how close to the target are they
what are the three different types of sampling
Plot sampling
pointer-quarter
belt transect
plot sampling
Counting the number of organisms of interest in a defined area (quadrant).
what are the problems with plot sampling
size of sampling plot, how plots will be placed, and number of plots to be sampled.
Plants in a long leaf pine forest
wire grass
longleaf pine tree
bracken fern
oak tree
what are the three types of dispersion
random
even( uniform)
clumped
why does clump happen
Indicate that a species responding to the fine gradient in the environment or that it has a form of reproduction that keeps juveniles near adults also this clumped pattern is a result of distribution of resources (think about tree and its seed and how it germinates close to its parent, also think of a wolf and its pack)
why does Uniform
Territory, or interaction between organisms
Why are control fires important
gets rid of organic matter on the forest floor. They also do controlled fires because it prevents uncontrolled fires from happening. (Low intensity fires occur naturally in these systems, but due to human development we now conduct controlled fires to reduce extreme wildfires. Also, without periodic fires, hardwood trees such as oaks would grow tall enough to form a canopy over the pine trees and inhibit them from receiving a sufficient amount of sunlight.)
Normal distribution
is a typical bell curve with the peak of the curve corresponding to the mean
What are some important things to know about a t-test
p-value at .05
if the value is at .00-1 then it will be significant and you accept your hypothesis
D.f
observed groups - 1
Important thing to know for a chi square test
if alpha is .05 then the significant level is 3.84
if value is great than 3.84 then?
you reject your null hypotheses and accept your hypothesis
if its less than 3.84 then?
you accept your null
What are the steps for mark and recapture
- Portion of population captures
- The organisms are marked
- Organism is released
- Another portion of pop is captured at a later time and any marked ones are counted
what are the assumptions for mark and recapture
- After capture, mark and release- can’t have a higher mortality rate, free to interact within the pop, appropriate time between capture, Can’t be “ trap-happy” or “trap-shy”
- Tags do not become lost or unrecognized
- There is no emigration or death of tagged individuals
what the equation for mark and recapture
N1=(M1N2)/M12
what does N1 stand for
number of individuals in that population
what does M1 stand for
number of individuals capture the first time and marked
N2
number of individuals that are capture the second time
M12
number of individuals in the second same that were marked during the first sample
What are two techniques that are use to estimate pop size
direct and indirect
Direct
strip censuses
point surveys
roadside count
Indirect
assume things based on what you see and hear
EX: pellets, tracks, tree markings, feeding stations, etc
Species composition
All the species in a defined area along with some measure of abundance.
Species area curve
As you increase the area, you increase the number of species.
Net range of species change
Immigration - Extinction
Plants in wetland setting
Pond Pine, Jessamine, Red Bay, Loblolly Bay, Sweet Bay, Bull Bay, Greenbrier, Gallberry, Water Oak
Identify the three distinguishing attributes used to delineate a wetland habitat from other habitat types.
Hydrology- the degree of flooding or soil saturation (surface water, high water table, ordinary high water mark.)
Dominance of wetland plants
Hydric soil- Soils saturated long enough during the growing season to produce oxygen deficient conditions in the upper part of the soil
Ecology
the scientific study of the relationships b/w organism and their environment
What the steps for the scientific method
observe research hypothesis experiment observe and record data share results
what is a sample
a small part or quantity intended to show what the whole is like
why use indirect measures to estimate pop size
difficult to capture
cannot be easily marked
endangered
relative change in pop size equation
initial pop size (N1)
what are the ecological functions of wetlands
filtering system
help with runoff
flood protection
home to many animals
what are the two wetlands at UNCW
Mccrory’s bog
Green House Bay
species richness
the number of different species in a region but does not take into account abundance
what are the assumptions for island lab
- Immigration decreases with the number of species on the island
Individuals of each species have a constant and identical probability of arriving at the island
The probability of extinction of any species is constant
Total rate of extinction for an island will increase with the number of species
