Ecological Field Methods

Question 1

name 5 ways to record vegetation

Answer 1

1) species presence/ absence
2) no of specimen present per species
3) biomass per species
4) species presence within subplots of quadrat
5) % ground cover of species

Question 2

3 classification methods for % ground cover

Answer 2

braun-blanquet (1964

Domin (1923)

Londo (1976)

Question 3

disadvantages of biomass analysis

Answer 3

(destructive, difficult & only feasable for low vegetation)

Question 4

disadvantages of counting no of specimen per species

Answer 4

proves difficult for plants in the field; 1 tree = 1 fern?; often not clearly distinguishable

Question 5

what is passive sampling

Answer 5

Animals are being recorded without the use of any attractor (ideally gives the exact ratio of occurrence between different species - BUT most often reflects the activity spectrum of the different species)

Question 6

what is active sampling

Answer 6

Animals are actively attracted to the sampling device

Question 7

give examples of passive sampling

Answer 7

plot and line transects

sweep netting

mist net sampling

pitfall jars

fogging and misting

suction traps

Question 8

describe plot and line transects

Answer 8

All encounters with the group of interest (e.g. birds or their nests, mammals, reptiles, frogs, butterflies…) are recorded, ideally with respective distances along line transects or from certain points over a clearly defined period of time.

Question 9

describe sweep netting

Answer 9

A strong net is swept through the vegetation at regular intervals for a regular number of times; arthropods sitting in the vegetation are collected.

Question 10

describe mist net sampling

Answer 10

A net invisible for the animals is arranged to that the animals (birds/bats) are entangled in the net or automatically move into a special trapping area (butterflies).

Question 11

describe pitfall traps

Answer 11

A jar is arranged in a small hole so that it just reaches
surface level and filled with liquid; sometimes also with a small funnel to prevent escapes and/or a roof against rain may be added.

Question 12

describe fogging and misting

Answer 12

An insecticide (e.g.pyrethrin) is sprayed into the vegetation so that arthropods are knocked down and can easily be sampled in funnels/nets/ plastic sheets spread below the vegetation

Question 13

describe suction traps

Answer 13

An airflow is produced through a metal pole, and all insects sucked into the pole are filtered – widespread in the control
of aphids.

Question 14

4 examples of active sampling

Answer 14

light traps

bait traps

pheromone traps

water traps

Question 15

describe light traps

Answer 15

A light source attracts nocturnal insects which are either collected manually from a cloth or automatically trapped.
e.g.: lighttower

Question 16

describe bait traps

Answer 16

For insects, potential food sources (e.g. dead fish, rotten fruit) are put onto a plate and arranged below a net into which insects will move after feeding from the bait.
Typical mouse traps are another
example.

Question 17

describe pheromone traps

Answer 17

Pheromones attract male insects into trapping devices, e.g. sticky surfaces or sampling jars.

Question 18

describe water traps

Answer 18

Colourful bowls are filled with water and put on an elevated position – insects come to the trap and drown.

Question 19

Which questions should be considered when selecting parameters

Answer 19

1) What is the relevance of each parameter
2) How can we measure each parameter without interacting or disrupting other parameter
3) How much precision do we need? (time & money)
4) How will we evaluate results for each parameter

Question 20

What parameters exist when looking at habitat

Answer 20

habitat type, habitat size, coordinates, elevation, inclination, humidity, temperature, soil chemistry,, disturbance patterns (fire, flood), anthropogenic influence, connectivity to neighbouring ecosystems

Question 21

What parameters exist when looking at plant and animal species

Answer 21

population size, seasonal variation, difference in size or distribution between species

Question 22

what parameters exist when looking at vegetation

Answer 22

“species composition, structural composition (species type, not every individual species), connectivity

Autecological parameters
structural composition, life expectancy, phenology, reproduction, establishment”

Question 23

what parameters exist when looking at animal communities

Answer 23

“species composition, structureal characterization

Autecological parameters
habitat requirements (food, size etc), interspecific influences (predation, competition, mutualism, parasitism), reproduction, migration"

Question 24

what parameters exist when looking at threats to ecosystem

Answer 24

invasive species, degradation

Question 25

How to calculate minimum quadrat size

Answer 25

pick a square and count the no of species. Double the size and measure again. Do it again and again, and plot the number of species. Plot number against log area, and when it tapers off, that is the minimum size

Question 26

potential issues with quadrat size calculation

Answer 26

no real tapering off in forests, but it works for meadows!

Question 27

what is subplot frequency measurement

Answer 27

split quadrat into smaller squares, how many of those squares does each species occur in

Question 28

issues with subplot frequency measurement

Answer 28

small species with wide distribution vs a single giant tree

Question 29

problems when recording insects or animals that are mobile

Answer 29

cannot get a complete inventory (they leave or move or join), weather dependent, seasonal dependence, dependent on sampling effort

Question 30

problems with passive sampling

Answer 30

prefers most active species

Question 31

what are the sampling types

Answer 31

random, systemic, stratified random, stratified systematic