Biol234z pt 2 Flashcards
ecological sampling of terrestiral inverts
lo:
analytical and sampling techniques
scientific hypotheses.
RICT, distributions, monitoring.
why care about inverts?
*cryptobiosis: dormancy
*chemical bombs: quinone and hydrogen peroxide weapon from beetles
*mites: male mites creating a garden to lure in females.
*yora insect protein dog food
*the insect apocalpyse: 75% decline in insect biomass.
-Molase trapping
-habitat loss etc
*decline of insects video
what are the major groups of terrestrial inverts?
protostomia (mouth develops before the anus)
2 branches lohptrochozoea
eodzosza
panarthropods
terestrial arthropods
*tardigrades
*onychohora (velvet worms, shoot slim webs to catach prey, tend to live at lower latitudes)
*arthropods
arthropods
chelicerates (spiders, scorpions)
crustaceans
myriapods (cenitpedes, millipedes)
hexapods & insects (6 legs)
wingless insects: apterygotes
major forms of development
metamorphises
invasive species of anthropods:
annelids
polychaetes: ragworm
lie up against each other to reproduce
molluscs
50k spp
gastropods (slugs/ snails)
microcorphia
thysanura
phitraptera
pscoptera* (book bugs)
odonatab (dragonfly)
dermaptera (ear wigs)
traumatic insemination: bedbugs- stabs into female to mate
megaloptera
hymenoptera (wasps, parasitic wasps)
coleoptera
how to sample terrest inverts
why and then sampling?
*estimation population size
*Access diversity
*environmental consultancy
*academic research
*species distributions
*
direct search
*timed search by looking
advantages:
disadvantages: not a systimatic way of catching, only catch whats there at that time.
device:
pooter: pot with 2 tubes
netting method
sweep net
vegetation
catch flying insects
semi-quantitive only
disadvantages:
net wont keep things in, when opened.
aerial kite net
catching flying insects
used for direct capture
barrier trap
flying insects
typical orders captured
perpex mounted on a frame
malaise trap
disadvantges:
collects a lot of insects
advantages:
good for different groups
light trap
skinner trap
heath trap
treacling
pitfall traps
arboreal pitfall trap (in the canopy)
avoids harm to other wildlife
pan traps
beating
whack tree with stick and see what comes out
kick sampling
put net downstream of where standing and kick the floor of the stream
RIVPACS/RICT- river invert
bait traps
often useful for pest organisms
will draw insects in from a wider area
pheromone trap
suction sampling
leaf litter extraction
tullgren funnel
how can i collect a robust data set?
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
sampling sins
-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
what are appropriate methods for curation and preservation?
lecture 2
terrestrial inverts as bioindicators
what is a bioindicator
what factors
advan and dis of using terrestiral inverts as bioindictators
general principles arising
paper: doi-10.1007
what is a bioindicator?
using an invert species to show how a habitat/environment has changed. indicate overall levels of biodiversity
monitor stress (detectors versus exploiters)
why are terrestrial inverts advantageous as bioindicators?
-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
why are terrestrial inverts disadvantageous bioindicators?
disadvantages:
-they are hard to identify
-they might not indicate biodiversity of higher taxa
-need a lot of under pinning ecological research
how to select terrestiral inverts as bioindicators?
several taxa
seperate abundance fluctuation from change of interest
know about their history and phenology
enviornmental tolerance knowledge
case study:
dung beetles as bioindicators
paper
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
outcome
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
case study 2
chironomids as indicators of stress
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
river invert classification tool
case study 3:
inverts as indicators of species richness and diversity
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.
RICT
excellent indicators of water quality
(aquatic inverts)
quiz:
