paper 2 Flashcards
what are sampling strategies used

collecting representative data 
describe the factors, influencing the sustainability of random sampoline 
size, ease of access, knowledge of the environment 
Selection bias 
occurs when the selection for the sample is not representative of the population 
why is random sampling used? 
to eliminate selection, bias 
measurement bias 
happens when there is faulty equipment 
Random sampling 
used for smaller data sets, each individual has an equal probability of being chosen 
systematic sampling 
select items using an interval, best when data doesn’t have patterns, and when covering a wide study area 
why do we study populations?
making good policy decisions, evaluating sources and impacts of threats, helps when designing protected areas, helps when deciding where to invest time and effort, provides empirical data to evaluate management strategies 
describe quadrat sampling

3 types- frame, grid, point
a square used to measure biodiversity
benefits to quadrant sampling
benefits-less harmful, simple and inexpensive, allows for population density of each species, allows to see changes over time
limitations to quadrant sampling
easy to introduce error, improper square size can lead to an innaxurate estimate
how to solve percent cover with quadrants
subtract the number of squares without the organism by 100,
divide that number by 100 and multiply by 100 to get percent cover
finding population abundance with quadrants
count number of each square for 10 squares, gwt the average by adding up and dividing by 10
then multiply that number by 100
estimating percent cover with a single species
count how many squares have the species and divide by 100
factors that could account for the distribution of a species

shade, soil, nutrients, water 
