Download BIODIVERSITY: WHY IT MATTERS Should it matter to humans that

BIODIVERSITY: WHY IT MATTERS
Should it matter to humans that other life forms are disappearing? Many people think so.
Human populations depend on plants and animals for much of their food, medicines,
clothing, and shelter.
Perhaps even more important, intact ecosystems perform many vital functions, like
purifying the air, filtering harmful substances out of water, turning decayed matter into
nutrients, preventing erosion and flooding, and moderating climate. It is not known how
many species can be eliminated from an ecosystem without its functioning being impaired.
It is likely that an ecosystem with more species is more stable than one that has lost some
species. For example, research has shown that grassland plots with a greater number of
plant species are better able to withstand drought than those with less species diversity.
This stability may well be important in the future, as changes in precipitation brought on
by global warming stress ecosystems.
Some species are particularly important to the health of their ecosystems. These are
called "keystone species", because like the center stone in an arch, their removal can
greatly affect the entire system.
A classic example of the consequences of removing a keystone species occurred when fur
hunters eliminated sea otters from some Pacific kelp beds. Otters eat sea urchins, which
eat kelp. With its major predator gone, urchin populations exploded and consumed most of
the kelp. Fish and other animals associated with kelp beds disappeared.
In many cultures, humans value animals for reasons other than maintaining ecosystem
health. Animals play a prominent role in the religions or belief systems of many cultures.
Many people value other species for the enjoyment they give. Still others believe humans
have a moral obligation to live in harmony with other life forms. Whatever their reasons,
most people agree that it is important to try to prevent species extinction.
Not all people agree on how to do this, however, or what to do when human needs conflict
with needs of other species.
It is only recently that people have begun to be concerned about the decline of wildlife
that has no commercial value to humans. Wildlife laws originally were passed to control
exploitation of animals that people hunted. For example, international regulation of whaling
started after hunting had depleted many whale populations.
Whalers were worried that soon no more whales would be left and their livelihood would
disappear. In the United States, the first wildlife laws regulated hunting of game animals
to preserve populations large enough for people to continue hunting.
Now, our concern has expanded to include animals that have little or no obvious economic
value, like songbirds, as well as those we value for food or other uses.
Economic benefits of biodiversity
The notion that biodiversity has provided us with many benefits is well understood. Some
of these benefits come in the form of goods that can be directly valued because they
provide something that can be extracted and sold. These goods include everything from all
the domesticated agricultural crops that form the basis of the world's food supply, to
medicines that protect and cure us to the fibers that make up the clothes we wear. Thus
biodiversity is widely valued as food pantry, genetic storehouse for biotechnology and a
place to retreat to when we need to get away from our hectic urban existence.
Biodiversity also provides critical indirect benefits to humans that are difficult to
quantify because we have never had to put a price tag on them. These benefits encompass
ecosystem services, such as air and water purification, climate regulation, and the
generation of moisture and oxygen. A group of ecologists who recently attempted to
quantify the price of replacing these ecosystem services calculated that they would cost
over $33 trillion. That's greater than the entire global GNP! In other words, the world
cannot afford to replace these services; therefore we must work to protect our
ecosystems.
Natural communities maintain proper gaseous concentrations in the atmosphere and
prevent rapid climate changes. Drastic changes in the Earth's atmosphere can have
catastrophic effects. Such changes are believed to have led to the disappearance of
dinosaurs from Earth 65 million years ago. Much less drastic changes resulted in several
global ice ages, the last of which ended 10 thousand years ago.
Vegetation helps recycle moisture into the atmosphere. A single corn plant (1 lb dry
weight) can transfer 60 gallons of water from soil to atmosphere in a few months. A single
rainforest tree, in its 100 year lifespan can transfer approximately 2.5 million gallons of
water from soil to air. Their role in the hydrologic cycle is crucial.
A multiplicity of organisms is required to create soils and maintain fertility through
complex cycles and interactions. Plant roots break up rock to create soil particles; small
animals like earthworms, mites, insects and millipedes help give soil its texture and
fertility and are crucial to its aeration. Even tinier soil microorganisms and fungi are
responsible for cycling essential nutrients like nitrogen, phosphorus and sulfur and making
them available to plants. And their numbers are staggering. A gram of fertile agricultural
soil may contain 2.5 billion bacteria, 400 000 fungi, 50, 000 algae and 30, 000 protozoa. All
these organisms have particular functions and interact with each other and with their
physical environment to create the fertile soil that humans depend on for agricultural
production.
Natural ecosystems also help absorb the wastes we create and render them nontoxic.
Wetlands are large filters which purify freshwater and remove heavy metals and other
contaminants from it. We often depend on rivers to flush away and break down the sewage
and effluents that we put into them, which again depends on the array of small and large
organisms that decompose and transform wastes in water. Soil organisms can slowly
decompose food items, paper products and other wastes produced by human activities.
Other Economic benefits: Recreation and Tourism
The Galapagos Islands show the mixed blessings of greenery
TOURISM has a long history in the Galapagos Islands. An early visitor was Charles Darwin
nearly 175 years ago, on a trip that inspired his theory of evolution by natural selection. A
lot has changed over the years. Visitors are now central to the future of the isolated
archipelago. Income is needed to raise standards of living and create incentives for local
people to conserve the fragile natural environment.
Between 1999 and 2005, gross domestic product increased by an estimated 78%, from a
base of $41m—giving the archipelago an annual growth rate of around 10% and making it
one of the world's fastest-growing economies. Tourism provided 68% of this growth.
Benefits of Parks and Recreation
•Availability
•Keeping kids off the streets
•Keeping kids occupied
•Community awareness
•Giving kids a place to go
•Feeling good because of being there
•Exercise, fitness & conditioning
•Good for kids
•Kids' enjoyment
•Having a place to go
Individual and family benefits identified by users of local parks and recreation services:
•Personal - 42%
•Social - 38%
•Facility/Activity - 12%
•Environmental - 6%
•Economic - 2%
•Personal Benefits:
◦Exercise, fitness & conditioning
◦Fun and entertainment
◦Learning and education
◦Relaxation
◦Health
•Social Benefits:
◦Getting to know people
◦Group participation
◦Interaction of adults and kids
◦Community awareness
◦Team spirit
•Facility Benefits:
◦Having instructional classes
◦The joy of playing
◦A place to go
◦A place for recreation
◦Exposure to arts
◦Crafts
◦Watching organized sports
•Environmental Benefits:
◦Fresh air
◦Nature
◦A place to be outdoors
•Economic Benefits:
◦Affordability
Benefits ranked by recreation and parks professionals in order of importance:
•Basic services to poorer residents
•Protection of natural environment
•Civic identity and pride
•Community visual appeal and function
•Develops strong communities
•Percent of population using regularly
•Individual growth and development
•Avoidance of costly damage due to mismanagement of the ecological system
•Prevents social problems
•Reduces health problems and costs
•Integrates disabled, disadvantaged and socially alienated
•Job creation
•Percent of population who might use
•Assists tourist industry
•Attracts industry
•Prepares individual to cooperate with others
•Increases property values and tax revenues
•Opportunities for underemployed
•Desire to replace volunteer effort
•Saves property owner expense
•Stimulates leisure retail industry
Medicines
A wide variety of plants, animals and fungi are used as medicine. Wild plant species have
been used for medicinal purposes since before the beginning of recorded history. Over
60% of world population depends on the plant medicines for their primary health care. For
example, quinine comes from the cinchona tree has been used to treat malaria, digitalis
from the foxglove plant treats chronic heart trouble, and morphine from the poppy plant
gives pain relief.
According to the National Cancer Institute, over 70 % of the promising anti-cancer drugs
come from plants in the tropical rainforests. It is estimated that of the 250,000 known
plant species, only 5,000 have been researched for possible medical applications.
You know those beautiful little tropical frogs with electric blue or orange markings? A
single touch of their skin could kill you.
Have you ever seen an elegant cone snail shell lying on the beach? Well, beware! It hides a
poison harpoon that is deadly. And watch out! Some snakes and lizards could be armed with
venom and toxic saliva. Amazingly, they may also hold cures to many human diseases.
Scientists have discovered that natural poisons, toxins, and venoms contain chemicals that
can be used to create an array of drugs for treating everything from chronic pain to
cancer. For instance, the cone shell’s venom, packed with nerve-debilitating conotoxins,
provides the basis for a new painkiller. Contortrostatin, a component found in copperhead
venom, is being used to attack breast cancer cells and to prevent cancer from spreading.