| How do you catch termites?
What is the nature of your work with termites?
My present work focuses on how important
termites, as well as other soil creatures such as earthworms and ants are in maintaining the actual health of our northern tropical
environments by recycling nutrients, revitalising the soil, providing important
food sources. All the animals running around in the soil play a really important
role in keeping the soils healthy. And if the soils are healthy, that’s a good
start for the environment to be in a healthy state.
How do you catch termites with small tweezers?
We do! That’s one of the easiest, or least
difficult, ways to collect termites. Unlike a lot of other insects, termites
are very difficult to sample in the environment. For such creepy crawlies as
ants, for example, we bury plastic jars in the soil with the lids off, and put
the preservative agent in the bottom. The ants just run along the surface and
drop into these vials a really easy way of catching them. For grasshoppers we
sweep nets like big butterfly nets through the grass, collecting spiders at the
same time.
But termites are really difficult, because
they live in a variety of habitats: in mounds, in dead wood, under the soil. So
you need a variety of techniques to sample them in the environment. For
example, we do open up mounds and I pick the termites out with the tweezers; I
get an axe, break open any dead wood on the ground and pick them out with
tweezers. And we use a range of baits, putting wooden stakes and even toilet
rolls (which they love) on the ground for them to feed on.
An offer too good to refuse: attracting termites into degraded landscapes
I understand there is an exciting possibility of using termites to rehabilitate
land. How might that work?
One aspect of my research at the moment is
looking at whether we can use termites as a management tool, to kick-start the
restoration process in degraded landscapes like disused mine sites, or very
bare areas that have been so severely overgrazed that when the cattle are
removed, the system can’t bounce back even with sufficient rainfall and no
grazing, the system is still in a degraded state. You have hard soils,
there’s no grass, the trees are gone, the area is in quite an unhealthy state.
So the idea is to try and introduce termites into that landscape to start
increasing its health.
But because it’s really hard to physically
go out and collect termites and dump them into a landscape, we have to attract
them there by using their food resources. There is quite a range of feeding
strategies amongst the termites. Most people think of them as wood feeders, but
we also have termites that feed on grass, on litter or on soil, and the idea is
that we put patches of attractive food resources down in the bare, degraded
landscape. I am using straw to try and attract grass-feeding termites, and bits
of wood to attract wood-feeding termites.
Termites that are attracted in to start
feeding on all that dead plant material the straw and the wood help to
recycle the energy and nutrients that are locked up in it: unless something
comes along and breaks it down, those nutrients remain inaccessible to the rest
of the system. And as the termites start burrowing and creating tunnels through
the soil and setting up nests, that starts aerating the soil, a bit like
earthworms in your garden at home breaking up the soil and reconditioning it.
Then, because the nutrients are cycling through and the termites are creating
lots of holes in the soil, water can get into the soil more easily, rather than
running off the surface, and a much more attractive environment is created for
plants to start growing. And if the plants start growing, that attracts other
insects in. So we have a flowthrough effect, from the termites conditioning the
environment and improving its health, up through the food chain. You get other
insects moving in and then lizards come in, and birds and so forth.
Have you actually set up some test sites to work on this?
Yes. For a year now I have been setting up
some really basic test sites, the first in Australia for this type of work. (A
couple of preliminary studies have been done on the African savanna systems,
which have a lot of similarities with the Australian ones.) And I’ve found
already that termites are actually moving into the areas where the food
resources have been put out, so it’s looking good.
Vital steps toward a sustainable Australia
Would you say that ecosystems research is an important component in developing a
sustainable Australia?
Yes, particularly in the north. In northern
Australia we are lucky that many of our landscapes are quite pristine or at
least in very good condition compared with southern Australia, so it is a
golden opportunity for us to understand how these ecosystems work. Such an
understanding is essential if we want to come up with management practices that
can utilise that land in a sustainable way. In southern Australia it is
obvious, from the level of degradation and the salinity that we see, that a lot
of mistakes have been made. If we’d understood beforehand a bit more about how
these ecosystems work, it might have helped us to improve and maintain the
sustainability of these systems. In the north, where the land is in much better
condition, we’ve still got that chance.
But the challenge for us is to tell people
the significance of our research, when often people want instant results. We
can’t come up with appropriate land management practices unless we know how the
system works to start with.
In my case, I need to know how all the
creatures in the soil are helping keep the environment healthy. We know in
general that termites and ants and earthworms are important for a healthy
environment, but we don’t know whether the termites help in one particular way,
perhaps as a food source, the earthworms in another way, perhaps in keeping the
soil healthy, and the ants in a different way again. They all may help in
slightly different ways, but we don’t know yet. We need to understand the particular
contributions of all those little creatures in the soil, and how
they work together to keep the environment healthy, before we can go on to
understand how cattle grazing or any other disturbances fire, for example
may affect groups of termites or earthworms or ants and how the whole system is
affected. And then, hopefully, we can come up with ways to keep those
landscapes sustainable and to conserve the biodiversity the diversity of
insects, birds, spiders, animals in general, and plants in that system.
An edited transcript of the full interview can be found at http://www.science.org.au/scientists/tdg.htm.
Focus questions
- Do you agree with Dawes-Gromadzki in thinking that healthy soils are essential for a healthy environment?
- How would you describe a ‘sustainable environment’?
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