Geoscience Reference
In-Depth Information
originator of the biological theory of evolution presented in his topic,
On the Origin
of Species (1859)
, and countless persons also credit him for his description of earth-
worm activity presented in another topic,
The Formation of Vegetable Mould
Through the Action of Worms, with Observations on Their Habits (1881)
, based on
his experiments in the garden at Down House when he was a young scientist. During
those times, the majority of humans thought earthworms were merely pests. His
experiments showed that earthworms were benefi cial for turning over the soil, tun-
neling through it while chewing it up and excreting it out, thereby making it more
fertile. It is remarkable that during his life, copies of his earthworm topic were sold
more frequently than his topic on evolution. But still more remarkable is the fact
that Darwin was not the fi rst to reveal the benefi cial activities of earthworms. A
century before Darwin's topic and even before Darwin's birth, Gilbert White wrote
not only statements but a topic near the end of the eighteenth century carefully
explaining the immensely benefi cial functions of earthworms in agriculture. Today,
we know that there are about 10-100 thousand pieces of earthworms under a soil
surface area of 1 m
2
and that their mass usually ranges between 1 and 50 g/m
2
.
Ants also play a special function in soils. They loosen the soil by forming fi ne
corridors and nests, they mix the soil, and they contribute to a regular distribution of
dead and decaying parts of edaphon in the mineral soil material. All their activities
improve the thermal isolation both inside the anthill and in its large surroundings.
They try to maintain an optimal soil water content for the biological processes in the
anthill that, in fact, acts positively for the soil-plant relationships in the great major-
ity of cultivated crops. Since ants modify the biochemical processes to the condi-
tions required by the life of the entire ant community, they act in a similar positive
way upon soil processes within the anthill.
Recognized as groups of “social” insects, termites are relatively abundant in the
tropics and subtropics and are classifi ed into seven families containing about 2,800
species. Recalling social communities of ants with a queen and king, nymphs, work-
ers, and soldiers, termites in spite of their organized behavior are not genetically
related to ants. Even so, they are commonly known among Australians as “white
ants.” Overall, their activities have positive effects - feeding on dead plant material,
wood, and soil, they mix the transformed matter together that contributes favorably
to the soil environment. But some of them can cause damage to buildings, house
equipment, or plantation forests. Termite workers undertake foraging, food storage,
and building the nest. They have special gut fl ora and enzyme productions that
enable them to digest cellulose. And here we fi nd why so many Europeans and
Americans curse termites after a stay in the tropics. When I (Mirek) returned to my
temporary home in Khartoum after enjoying a lovely vacation in Europe, I happily
entered my bungalow. Before leaving for Europe, I locked my clean shirts, etc., in a
wooden wardrobe. After arriving home from the Khartoum airport, I decided to
change into a fresh, clean shirt. To my surprise, when I attempted to merely unlock
the wardrobe, I pulled out its metallic lock. While staring and holding the metal in
my palm, the rest of the wooden door lost its shape and suddenly fell down as dust.
Immediately after that, the entire wooden cabinet disintegrated into a heap of dust
intermixed with my perfectly washed and ironed shirts, slacks, and linen.
