MonocultureMonoculture involves the culture of a single species with or without the
addition of fertilizers or feeds. Only a few applications of organic
fertilizers without appropriate instructions have been conducted by the
farmers in central and northeast Thailand to increase fish production.
Fertilizers commonly used by local fish farmers are manures from cows,
buffalo, pigs, and chickens. Inorganic fertilizers are not commonly used.
A typical example of controlled stocking monoculture with the addition of
organic fertilizers is the culture of Nile Tilapia, Sarotherodon nilotica.
With a stocking density of 2 fish per m2 of pond surface area, production
of 25000kg per ha at least twice as many as fish as can be produced from
naturally occurring organisms, is possible after four months of rearing by
adding pig manure everyday for five days a week at the rate of 75 kg per
ha per day.
Supplementary feeding is another means that can increase the
production of fish culturing in ponds. At present, some commercial fish
farmers use rice bran and broken rice to feed fish. Water spinach,
duckweed, and other aquatic weeds, soybeen, cake, peanut cake, fish meal,
and fresh or frozen trash fish are also used.
It is unfortunate that the word "monoculture" has been borrowed from
agriculture and applied to forestry as if it meant the same thing.
In farming, a monoculture means that you remove the entire natural
ecosystem, pile the roots and debris and burn them, plow the soil and
plant seeds of a food or fibre crop, usually exotic in origin. This kind
of monoculture never happens in nature in the absence of human
In forestry, a monoculture forest refers to a forest that is dominated by
a single species of tree. This is a very common feature in forests that
grow back after natural disturbances such as fire, flood, landslide, or
insect attack. Natural monocultures are common in northern coniferous
forests such as the temperate rainforests and boreal forests of North
America, Europe, and Russia.
The forest depicted above may be technically a monoculture as the word is
used in forestry. But it is a fully functioning forest ecosystem
containing thousands of species of mosses, ferns, fungi, herbs, shrubs,
birds, insects, reptiles, amphibians, and mammals.
Rather than viewing forests as either "natural" or "monoculture" it makes
much more sense to consider the broad gradation of forest types, some
greatly influenced by human activity and others not so influenced. Some
natural forests are rich in tree species while others are dominated by a
single tree species. Pioneer tree species such as lodgepole pine, poplar,
some of the spruces, etc. often form natural monocultures in the wake of
wildfire. Managed forests can contain a wide variety of tree species while
others are similar to natural monocultures. In British Columbia, for
example, where forest management is based on native tree species, the new
forests growing back after logging are slightly higher in tree species
diversity than the original forests*. This is because the pioneer hardwood
species such as alder, birch and maple are more abundant in young forests
than in older ones.
Of course there are monoculture plantation forests that are truly tree
farms, with monocultures of exotic, hybridized trees planted in rows.
These forests are often established on land that has already been cleared
of its original forest for agriculture. In Brazil, many of the eucalyptus
plantations are on land that had been burned out by inappropriate farming
practices. They represent a form of ecological restoration compared to
what was there previously. In addition, it is the practice in these
plantations to restore at least 20% of the land to native forest,
particularly the riparian (river-side) areas. There is a good example of
this in the State of Espirito Santo on the Atlantic coast north of Rio de
Janeiro. Here the Aracruz Cellulose company is working with the World
Wildlife Fund to re-introduce native animals, plants, and trees to the
region. 150 native tree species are grown in the nursery and planted out
in the network of natural areas amidst the eucalyptus plantations.
I would rather see the land covered with native forest, young or old, than
an exotic monoculture plantation. On the other hand I will choose the
monoculture forest over a field of sugar-cane or wheat any day. And so
will most of the birds and animals and insects. In my opinion, any forest
is better than no forest.
see "British Columbia's Forests: Monocultures or Mixed Forests? Province
of British Columbia, Ministry of Forests, May 1992.