Soil Biology and Ecology
36 | Unit 2.3
TUllGREN FUNNElS
Collect samples from various habitats and care-
fully place in funnels. If too much sample material
falls through funnel, add more screens, or a piece of
coarse cheesecloth.
Place a wide-mouth jar containing liquid under the
funnel. Use water if you want to keep animals alive.
Use alcohol (70%) with some glycerin added if you
want to preserve specimens. Do not shake or disturb
funnels, in order to keep sample jars as free of soil
as possible. Let samples stand in funnels with no
light for 1 day. Turn lights on and leave them on
from second to seventh day.
Samples can be collected and extracted in advance
of demonstration, although as with pitfall traps, it
would be useful to demonstrate for students how
samples were collected, and how extraction funnels
work.
PrOcedUre
Observe collections under magnification. If live col-
lections are made, students have the opportunity to
observe behavioral adaptations of the animals (e.g.,
springing springtails, fast-moving predators like
centipedes, or mesostigmatid mites, slower-moving
fungal grazers like oribatid mites and millipedes).
Have simple keys available for help with identifica-
tion. For a quantification exercise, have students
count species, or functional groups, and calculate a
diversity index for comparing habitats.
PreParatiOn tiMe
1 hour or more, depending on which exercises
are followed, and what materials are available
or need to be obtained.deMOnstratiOn tiMe
From just 0.5 hour for a brief show-and-tell,
where students observe samples previously col-
lected, to 1 to 2 hours if students are involved in
collecting samples, observing, and quantifying.discUssiOn QUestiOns- Can you guess which animals might be
predators? Which ones might be grazers? - What effects do each habitat that the
samples were collected from have on the soil
organisms found there? Think about sizes of
creatures, diversity, food-web interactions,
pigmentation, and so on. - Which habitats had greatest abundance?
Which has greatest diversity? Why? - What effects do you think different
soil management practices have on soil
arthropods? Besides the various effects of
organic matter inputs, think also about the
influence of physical disturbance.
Instructor’s Demonstration 4 Outline