4.2.8 Reasons for Maintaining Biodiversity Flashcards
What are the reasons?
Biodiversity is the range and variety of genes, species and habitats within a particular region
It is made up of three components:
Genetic diversity
Species diversity
Ecosystem diversity
Global biodiversity has a major impact on humans and all other species on the planet
There are many reasons for maintaining biodiversity:
Ecological
Economic
Aesthetic
Social
Moral/ethical
Environmental
Agricultural
What are the ecological reasons?
Biodiversity has a major effect on the stability of an ecosystem
A more diverse ecosystem is better able to survive and adapt to environmental changes or threats
For example, if the temperature of a species-rich lake rises due to global warming:
Some species of fish in the ecosystem are unable to cope with the change while others can
The fish that are able to cope will survive, reproduce and keep contributing to the ecosystem
Within communities there are keystone species that have a larger impact on the ecosystem than others
When these species are lost there are several knock-on effects
Bush elephants in the African savannah are a keystone species
They graze in a very extreme way, knocking over and eating several species of tree
This destruction of vegetation actually helps to maintain the ecosystem
Elephant dung also provides a habitat for many important fungi and insect species
When elephants were legally hunted for their ivory, their numbers reduced and scientists observed a major negative impact on the savannah
What are the economic reasons?
Ecosystems have a lot of economic value
Many of the medicines used today have originated from plants, fungi and bacteria
For example the cancer-fighting drug paclitaxel is sourced from Pacific and Himalayan Yew Trees
The Himalayan Yew has declined in numbers due to over-harvesting for fuel and medicine
Due to the large number of drugs that have already been sourced from nature it is reasonable to assume that there are other drugs, yet to be found in nature, that could be used in the future
Ecotourism a major source of income for many countries
Many tourists travel to and spend money in National parks so they can see wildlife
Increased tourism in a country contributes to the economy and provides jobs
Ecosystems have also made major contributions to the field of science and technology
The specific enzyme used in DNA sequencing was first discovered in thermophilic bacterium found in a hot spring in Yellowstone National Park, USA
What are the aesthetic reasons?
Humans find great joy and pleasure in the beauty of nature
It provides inspiration for creatives such as photographers, poets, musicians and artists
There is a strong argument for preserving biodiversity because of its aesthetic benefits
What are the social reasons?
Many people enjoy spending time in the natural environment
There are many activities that people can do together in nature, e.g. birdwatching, walking, climbing
Such environments may be lost if they are not conserved, with the loss of the social benefits that they can bring
What are the moral and ethical reasons?
Many people believe that humans have a moral obligation to prevent the loss of biodiversity that results from human activities
Humans share the planet with millions of others species and they have no right to cause the extinction of other species
As humans are the most intelligent species on the planet the responsibility falls upon their shoulders to protect and value all of the organisms on the planet
What are the environmental reasons?
Humans need diverse ecosystems because of the essential environmental services they provide
Plants absorb carbon dioxide from the atmosphere and help to reduce the greenhouse effect and climate change
Microorganisms digest and break down the masses of organic waste that are produced by larger organisms
Humans have irrigation and drinking water thanks to the transpiration of plants and their contribution to the water cycle
Different fungi and bacteria species are a major part of the nutrient cycle that allows for nutrients to reenter the soil for further plant growth
Plants are producers in food webs. They are both a direct and indirect energy source for humans through fruit, vegetables and meat
What are the agricultural reasons?
Most of the crops that humans grow are very uniform with low genetic diversity
The wild relatives of crops can provide a source of genetic diversity to rescue crops that are affected by disease or other disasters
Many of the wild relative species are under threat due to habitat destruction and climate change
All of the world’s potato crop comes from a single species
This lack of species diversity makes the crop highly susceptible to disease
There are over 100 species of wild potatoes that grow in the Andes
These Andean species act as a source of alleles for disease resistance
These alleles have been introduced to the potato crop through gene technology and interbreeding
