Why Is Biodiversity Important? Who Cares?

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  • by Anup Shah
  • This Page Last Updated Saturday, June 14, 2008

At least 40 per cent of the world’s economy and 80 per cent of the needs of the poor are derived from biological resources. In addition, the richer the diversity of life, the greater the opportunity for medical discoveries, economic development, and adaptive responses to such new challenges as climate change.

The Convention about Life on Earth, Convention on Biodiversity web site.

Why is Biodiversity Important? Does it really matter if there aren’t so many species?

A diverse ecosystem is important. Biodiversity actually boosts ecosystem productivity where each species, no matter how small, all have an important role to play. It is this combination that enables the ecosystem to possess the ability to prevent and recover from a variety of disasters.

This is obviously useful for mankind as a larger number of plant species means a greater variety of crops. In addition, a larger number of species of animals ensures that the ecosystem is naturally sustained. And so, while we dominate this planet, we still need to preserve the diversity in wildlife.

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A healthy biodiversity offers many natural services

A healthy biodiversity provides a number of natural services for everyone:

  • Ecosystem services, such as
    • Protection of water resources
    • Soils formation and protection
    • Nutrient storage and recycling
    • Pollution breakdown and absorption
    • Contribution to climate stability
    • Maintenance of ecosystems
    • Recovery from unpredictable events
  • Biological resources, such as
    • Food
    • Medicinal resources and pharmaceutical drugs
    • Wood products
    • Ornamental plants
    • Breeding stocks, population reservoirs
    • Future resources
    • Diversity in genes, species and ecosystems
  • Social benefits, such as
    • Research, education and monitoring
    • Recreation and tourism
    • Cultural values

That is quite a lot of services we get for free! Now, as we erode ecosystems and reduce biodiversity, based on the above list of things we start to lose, the cost of replacing these (if possible) would be extremely expensive. It therefore makes economic and development sense to move towards sustainability.

A report from Nature magazine also explains that genetic diversity helps to prevent the chances of extinction in the wild (and claims to have shown proof of this). To prevent the well known and well documented problems of genetic defects caused by in-breeding, species need a variety of genes to ensure successful survival. Without this, the chances of extinction increases. And as we start destroying, reducing and isolating habitats, the chances for interaction from species with a large gene pool decreases. Side NoteUnfortunately the original link to the Nature.com article no longer works, since their site redesign, and I had not noted the publication details. However, for similar information, you could look at Consequences of changing biodiversity, Nature 405, 234 - 242, 11 May 2000 and Causes, consequences and ethics of biodiversity, Nature 405, 208–211, 11 May 2000.

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Species depend on each other

While there might be “survival of the fittest” within a given species, each species depends on the services provided by other species to ensure survival. It is a type of cooperation based on mutual survival and is often what a “balanced ecosystem” refers to.

As an example, consider all the species of animals and organisms involved in a simple field used in agriculture. As summarized from Vandana Shiva, Stolen Harvest (South End Press, 2000), pp 61–62:

  • Crop byproducts feed cattle
  • Cattle waste feeds the soil that nourish the crops
  • Crops, as well as yielding grain also yield straw
    • Straw provides organic matter and fodder
    • Crops are therefore food sources for humans and animals
  • Soil organisms also benefit from crops
    • Bacteria feed on the cellulose fibers of straw that farmers return to the soil
    • Amoebas feed on bacteria making lignite fibers available for uptake by plants
    • Algae provide organic matter and serve as natural nitrogen fixers
    • Rodents that bore under the fields aerate the soil and improve its water-holding capacity
    • Spiders, centipedes and insects grind organic matter from the surface soil and leave behind enriched droppings.
    • Earthworms contribute to soil fertility
      • They provide aerage, drainage and maintain soil structure.
      • According to Charles Darwin, “It may be doubted whether there are many other animals which have played so important a part in the history of creatures.”
      • The earthworm is like a natural tractor, fertilizer factory and dam, combined!
  • Industrial-farming techniques would deprive these diverse species of food sources and instead assault them with chemicals, destroying the rich biodiversity in the soil and with it the basis for the renewal of the soil fertility.

Shiva, a prominent Indian scientist and activist goes on to detail the costs associated with destroying this natural diversity and traditional farming techniques which recognize this, and replacing this with industrial processes which go against the nature of diversity sustainability.

Bees provide enormous benefits for humankind as another example. As reported by CNN, “One third of all our food—fruits and vegetables—would not exist without pollinators visiting flowers. But honeybees, the primary species that fertilizes food-producing plants, have suffered dramatic declines in recent years, mostly from afflictions introduced by humans.” (May 5, 2000).

An example from the seas (originally mentioned here years ago but removed because the link to the story no longer worked), was described by National Geographic Wild in a program called, A Life Among Whales (broadcast June 14, 2008).

It noted how a few decades ago, some fishermen campaigned for killing whales because they were apparently threatening the fish supply. A chain of events eventually came full circle and led to a loss of jobs:

  • The massive reduction in the local whale population meant the killer whales in that region (that usually preyed on the younger whales) moved to other animals such as seals
  • As seal numbers declined, the killer whales targeted otters
  • As otter numbers were decimated, the urchins and other targets of otters flourished
  • These decimated the kelp forests where many fish larvae grew in relative protection
  • The exposed fish larvae were easy pickings for a variety of sea life
  • Fishermen’s livelihoods were destroyed

But nature can often be surprisingly resilient, often without the need for human interventions. For example, a documentary aired on the BBC (I unfortunately forget the name and date, but in the 1990s) described two national parks in Africa where elephant populations had grown quite large within those artificial boundaries. The usual way to deal with this was to cull the population to try and keep the ecosystem in balance. Without this, elephants were stripping vegetation bare, affecting other animals, too.

A scientist pleaded with park management not to cull and let nature take its course. Being against prevailing thought, they would not agree. In the end they agreed to let one park have its elephants culled, while the other would be left alone.

A few years later, they found the park with the culled population had remained in poor condition. The park where things were left alone has naturally regenerated; the large elephant populations eventually reduced in number as they undermined their own resource base. The natural pace at which this happened allowed vegetation to grow back. Other wildlife grew in numbers and the ecosystem was generally back in balance.

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More important than human use or biological interest

Many people may support environmental causes to help preserve the “beauty” of Nature. However, that is in a strange way, not really a justifiable excuse as it is a subjective, human or anthropomorpahsized view. Instead, a logically sound reason based on ecological factors would help show that biodiversity is more important than people realize.

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Author and Page Information

  • by Anup Shah
  • Created: Monday, July 20, 1998
  • Last Updated: Saturday, June 14, 2008

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Document Revision History

DateReason
June 14, 2008Short examples added of how ecosystems rely on various species’ interactions and dependencies
July 29, 2007Add another link to more information about importance of biodiversity.
January 09, 2006Add another link to more information about importance of biodiversity. Rest is unchanged, for now, since January 1, 2001