Monitoring Flashcards
Vad är NILS förnågot?
landskapsövervakning på nationell nivå
Beskriv “the living planet index”
Describes trends in population sizes for different species
*bias - counts natural fluctuation as a decline in population sizes
Describe “accidental” monitoring
Historical records, used today to allow us to get a picture how the landscape looked like before
Can be valuable, but also challenging:
- details of method unclear
- potential to describe “change” due to changes in method/location
- changes in species names etc
Examples of how to detect change - measurements
- population size
- population spatial structure
- species diversity (richness/diversity)
- species heterogeneity (beta-diversity)
describe species evenness
equitability/distribution of individuals
describe species richness
number of species
describe diversity indices
combines evenness & richness, ex simpsons (D = 1- n(n-1)/(N(N-1))
what does beta diversity measure?
spatial heterogeneity, change in species composition from place to place
ex,
- all sites have the same species –> low b-diversity
- different sites have different species –> high b-diversity
What are the 4 different sampling strategies?
- Slumpvis stickprovstagning
not biased, need a large sample size to make sure its representative - Stratifierad slumpvis stickprovstagning
not biased, but need take count that your stratify might not be equally representative - Systematiskt stickprovstagning
easy to decide sampling location, not best choice if there are systematic patterns in the community/species you monitor - Selektiv stickprovstagning
efficient, defo biased