Why is Biodiversity Important?

 

In some respects our own "success" as a species shows the best reason for safeguarding biodiversity. As a species we inhabit the most diverse environments on the planet from the Arctic to the desert we have "adapted" to survive and flourish in all these places. It is this ability to "adapt" that is provided by biodiversity. If we have the widest possible pool of "genetic" material from which to draw then earth's' ecosystem has the greatest chance to continue to adapt and survive. If we reduce the amount of genetic material available to us then the environment around us becomes less able to evolve, loses flexibility, and is more at risk from change.

Maintenance of ecosystems

Ecosystem relationships resemble a web of connections from one living thing to many other living and non-living things. They not only allow survival, but also maintain a balance. Vegetation for example is integral to the maintenance of water and humidity levels and is essential for the maintenance of the oxygen/carbon dioxide balance of the atmosphere.

Due to the complex nature of ecosystem relationships, the removal or disturbance of one part of the ecosystem could affect the functioning of many other components of the ecosystem. Our knowledge of these relationships is incomplete, and the results of disturbance are thus to some extent unpredictable.

The Aeroplane Analogy: Too many loose screws?

The concept of biodiversity may appear to be complex, but it can be illustrated simply.

Imagine you are on holiday and you look out of the aircraft window and notice a small leak of oil. Now, how important is this? Perhaps later you notice one small screw has become loose, after all it's only one small screw. Let us say that the screw falls off and nothing appears to happen, perhaps later in the journey another small screw comes loose, when are you going to go to the captain? Perhaps the screw simply holds something unimportant in place; perhaps it just looks good. After all we're talking about two small screws in an entire aeroplane, (or two apparently unimportant species in billions).

Ecosystems interconnect and losing one part that appears to have no particular purpose may be just as dangerous as losing that last rivet that holds the wing on or the engine in place! So how many screws can we loose before the plane crashes?
Protection of water resources
Natural vegetation cover in water catchment areas (e.g. river basins) helps to maintain hydrological cycles and acts as a buffer against extreme events such as flood and drought. Vegetation also helps to regulate underground water tables, preventing dryland salinity.
Soils formation and protection
Biological diversity helps in the formation and maintenance of soil structure and the retention of moisture and nutrient levels. Soil protection through the maintenance of biological diversity can preserve the productive capacity of the soil, prevent landslides, safeguard coastlines and riverbanks, and prevent the degradation of coral reefs and river and coastal fisheries by protecting against siltation.
Pollution breakdown and absorption
Ecosystems and ecological processes play an important role in the breakdown and absorption of many pollutants created by humans and their activities. These include wastes such as sewage, garbage and oil spills.

Plants and Agriculture
Loss of genetic diversity can threaten the food on which we all rely. Since the 1950s, the spread of modern varieties of corn, wheat, rice, and other crops has rapidly squeezed out native species. Almost 80% of rice that is now grown in the Philippines, Indonesia and some other countries are the same variety. The diversity has been reduced and the countries are reliant on just a few species of rice. The impact of this kind of loss of diversity can be devastating for example;

  • In 1991, the genetic similarity of Brazil's orange trees opened the way for the worst outbreak of citrus canker recorded in the country.
  • In 1970, U.S. farmers lost $1 billion to a disease that swept through the corn industry,
  • Similarly, the Irish potato famine in 1846,
  • The loss of a large portion of the Soviet wheat crop in 1972,
  • The citrus canker outbreak in Florida in 1984

All of the above stem from reductions in genetic diversity. In such countries as Bangladesh, where some 62 percent of rice varieties come from a single maternal plant, Indonesia (74 percent), and Sri Lanka (75 percent), such outbreaks could occur at any time.

Society has learned a tremendous amount about techniques to maximise crop yields important to feed the growing world population. These advances rely in part on biodiversity, and our ability to cross breed and develop hardy healthy new strains. The conservation of diversity is also essential for finding effective biological control organisms and for breeding disease resistant species.
Medicines
Four out of every five of the top 150 prescription drugs used in the U.S. have had their origins in natural compounds. Aspirin for example was developed from the bark of willow trees. Today aspirin and many other drugs are synthesised more efficiently than they can be extracted from the wild, but they were first discovered in naturally occurring compounds
  Task 4 What is taxol ?, where did it come from, find three other similar examples of how biodiversity has helped humankind.
Other Products
Products that may be derived from biological resources include sunscreens from corals, light and high tensile fibres from spider silk and instant adhesives from velvet worms or barnacles. Micro-organisms are important in the production of extensive ranges of agrochemicals, protein for animal feed enzymes and biopolymers. Genetic engineering of micro-organisms promises further advances in the production of new compounds and processes. There is also potential for further development of natural pesticides, and other useful products such as fats, and oils.