Biol234z pt 2 Flashcards

Question

leaf litter extraction tullgren funnel

Answer 1

random sample: take lots of samples of individuals at different places in a habitat good when time is limited if there is a structure to the habitat cluster sample: make an artifical area within a wider one systematic sample: putting traps in a fixed interval *arsenic mine in gunnislake

Answer 2

-not sampling randomly -collecting more then you need -change methodolgy -counting the same individual twice -understanding species biology -pseudo replication -not being honest about what was done -not knowing how you will analyse

Answer 3

what is a bioindicator what factors advan and dis of using terrestiral inverts as bioindictators general principles arising

Answer 4

using an invert species to show how a habitat/environment has changed. indicate overall levels of biodiversity monitor stress (detectors versus exploiters)

Answer 5

-found in lots of different environments -large quanitity of them -easy to sample -well studied- population dynamics -some amateur recording schemes (therefore change in range and abundance are easy to detect) -small size makes them sensitive to local conditions -generally mobile -short generation times- rapid numerical response -functionally important -cheap to do

Answer 6

disadvantages: -they are hard to identify -they might not indicate biodiversity of higher taxa -need a lot of under pinning ecological research

Answer 7

several taxa seperate abundance fluctuation from change of interest know about their history and phenology enviornmental tolerance knowledge

Answer 8

use dung beetles as indicators of habitat change: sand forest to mixed woodland -strong relationship wiht environmental characteristic -robustness of this should be tested -how specific and invert is to a environment type -ind/val approach test consistnecy of indicator values test whether dung beetles are a good test for change -using systematic pitfall grid sapling baited with elephant dung and sampled every 48 hours measured: specificity AiJ: mean number of species i across sites of group j Nindividualsi: sum of the mean number of species i over all groups fidelity bij: nsitesij: number of sites in habitat j where the species is present Nsitej: is the number of sites in that cluster indval= Aij x Bij x 100 indicator value= indval indicator values are higher depending on how high the abundance is what did they find? mixed woodland had more species with high indicator values investigated if there was a high fedelity value if there was a high abundance as the fedility goes up so does the abundance

Answer 9

set of species were found to be reliable indicators fidelity componenet of indval is affected by abundance detector species more prevalent in disturbed habitats and indicate direction of habitat change

Answer 10

tested a bioassay using chironomid mouthpart deformities as a measure of enviornmental stress taxonomy phylum: arthropoda class: insecta order: diptera features:one pair wings;halteres sediments absorb and bind toxins which may be bioavalible. bioassay also advantageous as chironomids can be hard to i.d what did they do? put midges in the river in a sealed-ish box came up with an overall toxicity score. left larvae out in the field. increase in abundace with stress the greater the sediment the greater the number of mouth part defomrities using inverts as bioindicators for environmental stress

Answer 11

looks at the question: can they use sets of butterfly species to indicators woukd be advantagoes but some groups are hard to detect located in the great basin of the USA sampling butterflies using the walking transect method. ruled out species that are super abundant thus using intermedaite species abundance. predciting community of resident butterflies all year round. the species richness predicted by the model was generally represented by observed species richness can the approach be extended to other groups.

Biol234z pt 2 Flashcards

(41 cards)