Download Biodiversity Frequently Asked Questions

Biodiversity Frequently Asked Questions
What is biodiversity?
Biodiversity is the shortened form of two words "biological" and "diversity." It refers
to all the variety of life that can be found on Earth (plants, animals, fungi and microorganisms) as well as to the communities that they form and the habitats in which
they live.
The Convention on Biological Diversity gives a formal definition of biodiversity in
its article 2: "biological diversity means the variability among living organisms from
all sources including, inter alia, terrestrial, marine and other aquatic ecosystems and
the ecological complexes of which they are part; this includes diversity within
species, between species and of ecosystems".
Biodiversity is not only the sum of all ecosystems, species and genetic material.
Rather, it represents the variability within and among them. It can be distinguished
from the expression "biological resources", which refer to the tangible components of
ecosystems. Biological resources are real entities (a particular species of bird, a wheat
variety growing in a field, oak wood, etc.) while biological diversity is rather an
attribute of life (the variety of bird species, the genetic variability of wheat around the
world, forest types, etc.).
Biological diversity is often understood at three levels:
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species diversity refers to the variety of different species (plants, animals,
fungi and micro-organisms) such as palm trees, elephants or bacteria;
genetic diversity corresponds to the variety of genes contained in plants,
animals, fungi and micro-organisms. It occurs within a species as well as
between species. For example, poodles, German shepherds and golden
retrievers are all dogs, but they all look different;
ecosystem diversity refers to all the different habitats - or places - that exist,
like tropical or temperate forests, hot and cold deserts, wetlands, rivers,
mountains, coral reefs, etc. Each ecosystem corresponds to a series of complex
relationships between biotic (living) components such as plants and animals
and abiotic (non-living) components which include sunlight, air, water,
minerals and nutrients.
How much biodiversity is there?
Estimates of the total number of species range from 7 to 100 million, with a probably
good estimate being about 13 to 15 million species. Up to this day, only about 1.75
million living species have been identified and described scientifically. Many new
species continue to be discovered each year, most of them invertebrates. During the
nineties, the number of newly described species averaged 13.000 per year.
The table below shows approximate numbers of species in major groups (UNEP,
Global Biodiversity Assessment, 1995):
Group No. of described species
Estimated total no. of species
Viruses
4 000 400 000
Bacteria
4 000 1 000 000
Fungi 72 000 1 500 000
Protozoa
40 000 200 000
Algae 40 000 400 000
Plants 270 000
320 000
Nematodes 25 000 400 000
Crustaceans 40 000 150 000
Arachnids
75 000 750 000
Insects
950 000
8 000 000
Mollusks
70 000 200 000
Vertebrates 45 000 50 000
Others 115 000
250 000
Totals 1 750 000
13 620 000
Why is biodiversity important?
The natural environment provides the basic conditions without which humans could
not survive. This seems intuitive enough: we need to breathe, eat, drink and shelter
ourselves and we get all this from the natural world.
Ecological importance:
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trees provide habitat and food for birds, insects, other plants and animals,
fungi, and micro-organisms;
insects, bats, birds, and other animals serve as pollinators;
parasites and predators act as natural population controls;
various organisms, such as earthworms and bacteria, are responsible for
recycling organic materials and maintaining the productivity of soils;
green plants remove carbon dioxide from the atmosphere and replenish it with
oxygen. Forests, for example, are particularly important "sinks" for the
absorption of carbon dioxide and thus are key factors in reducing global
climate change;
wetlands serve as sponges to reduce the impacts of floods and to cleanse
streams by filtering sediments, nutrients, and contaminants from inflowing
waters.
The interaction of all these natural processes forms a complex web of life. If any part
of this web suffers or breaks downs, the future of the other parts is threatened.
Humans are in many cases degrading and destroying the ability of biological diversity
to perform the services mentioned above.
Economical importance:
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food: species are hunted (e.g. antelopes, birds), fished (e.g. cod, tuna fish), and
gathered (e.g. fruits, berries, mushrooms), as well as cultivated for agriculture
(e.g. wheat, corn, rice, vegetables) and aquaculture (e.g. salmons, mussels). It
is interesting to know that, of the about 80,000 available comestible plants,
humans use less than 30 to satisfy 90% of our planet's alimentary needs;
fuel: timber and coal are only two examples of natural resources used to
produce energy;
shelter and warmth: timber and other forest products (e.g. oak, beech, pine) are
used as building materials and for shelter. Fibers such as wool and cotton are
used to make clothes;
medicines: both traditional medicines and processed drugs are obtained from
biodiversity: penicillin is produced by a mould, codeine is obtained from
poppies, digitalis from foxglove and quinine from the bark of cinchona trees;
other goods such as paper and pencils come from raw materials provided by
the Earth's diversity.
Indirect services:
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clean and drinkable water: only a small amount - about 1% - of the water on
our planet is usable directly. The rest is either salty (97%) or frozen (2%).
Forests around the world filter our usable water again and again, constantly
replenishing the water we use for drinking, bathing, and growing crops;
air to breathe: plants around the world take carbon dioxide out of the air and
put oxygen into it - oxygen that almost all creatures need to breathe;
fertile soils: micro-organisms recycle the soil's organic matter and maintain its
fertility;
pollination: insect, bird and bat species carry pollen from one plant to another
(or from one part of a plant to another), thus fertilising fruit crops and flowers.
Cultural importance:
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plants and animals are often used as symbols, for example in flags, paintings,
sculptures, photographs, stamps, songs and legends.
finally, biodiversity is also beautiful: it is a pleasure to see and smell flowers
in a field, to listen to birds singing, etc.