4.2- Reasons to maintain biodiversity Flashcards
What are keystone species?
One that has a disproportionate effect upon its environment relative to its abundance. A prey keystone species is an important food source for organisms in the ecosystem. If a prey keystone species disappeared, it would cause a food shortage in the ecosystem. A plant keystone species provides food or shelter for important herbivores and pollinators. The loss of these plant species could lead to a population decrease in various organisms that depend on them.
What does soil depletion mean?
The loss of soil fertility caused by removal of minerals by continuous cropping.
What are ecological reasons to maintain biodiversity?
- Interdependence of organism
- Genetic resource
Why is interdependence of organism a reason to maintain biodiversity?
Natural ecosystems are complex. They have developed over millions of years as species have evolve to live with each other and depend upon one another. All the organisms in a habitat are linked together in a food chain or food web. The range of relationship between organisms includes predator- prey, intra and inter species competition and parasitic and mutualistic relationships.
What happens if one spices is affect by human activities?
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When one species is affected by human activity and its numbers decline, this will affect other species. In some cases, the effect may not be great. For example, if birds feed on a variety of insets and one insect’s species falls in number, the birds may be able to eat more of the other insects. This is why habitats with higher species diversity tent to be more stable. They can withstand a certain amount of changes. However, in a simple habitat with lower species diversity, the loss in numbers of one prey-insect species may mean that the bird has less food and will itself decline in numbers
What will happen if the number of keystone species reduce?
Some species have a disproportionate effect upon their environment relative to their abundance. The decline of such a keystone species will have a dramatic or catastrophic effect on their habitat. Keystone species may be predators that limit the populations of herbivores so that the vegetation is not overgrazed.
Give an example of a keystone species:
For example, during the early part of the 20th century the mountain lions of Kaibab Plateaus Arizona were hunted in order to protect the deer population. As a result, the deer population increased dramatically, ate all the vegetation, and then the population plummeted as the deer starved.
How do plants have an effect on the interdependence of organisms?
Many plants are also keystone species. A plant that is dominant in the habitat has many effects upon other species in the habitat, for example the sugar maple tree in the forest of northern USA. The sugar maple tree is a large tree with deep roots. Its roots access water deep in the soil and transfer the water to shallower regions that are dry, making it available to other plants. The foliage produces a covering canopy, which keeps the soil cool and moist.
What does the foliage and shade of maple tree allow?
This allows many soil organisms to thrive, including earthworms and many soil-dwelling insects. The shades also prevent excess undergrowth, which allows other tree species to take root and grow. The sap is very sweet and provides food for a variety of insects (and manufacture of maple syrup). Many insects and birds can live in the tree canopy.
What does decline biodiversity (genetic resource) mean?
Allowing biodiversity to decline means that genetic diversity also declines. This means that we could lose the natural solutions to some of our problems.
How are wild animals and plants part of genetic resource in maintaining biodiversity?
Wild animals and plants may hold the answers to some problems caused by climate change. Populations of wild plants growing in an area have had thousands of years to evolve. They have adapted to overcome the problems presented by the environment. They may also have adapted to the pests and diseases found in that area.
How can careful selection and breeding help plants and animals in maintaining biodiversity?
By careful selection and breeding from wild strains and wild species, we may be able to breed new crop varieties that can cope with the new conditions created by climate change. Genetic engineering to produce transgenic species could also be used to good effect.
How is genetic resources an ecological reasonmaintain biodiversity in terms of medicine?
The number of potential new medicines and vaccines to be found in nature, plants, animals, fungi and bacteria is unknown. Plants have evolved a wide range of molecules that combat diseases and fungi have evolved molecules that help them compete with bacteria in the soil. Any of these molecules could be of value in developing new and effective pharmaceutical product. It is important to main the genetic diversity of wild species because if the potential that exists in the wide range of species currently extant.
Why are economic reasons to maintain biodiversity?
In 1997, an international l team of economists and environmental scientists attempted to quantify the economic value of natural ecosystem. They came up with a figure of $33 *10^12. They looked at all the ways in which a natural ecosystem perform processes that are of value to humans
What advantages does the natural ecosystem have to humans?
-economic reasons
- Regulation of the atmosphere and climate
- Purification and retention of fresh water
- Formation and fertilization of soil
- Recycling of nutrients
- Detoxification and recycling of wastes
- Crop pollution
- Growth of timber, food and fuel
- Discovery of molecules with potential as medicines
What impact do the factors have on humans?
-economic reasons
All of the factors have an impact on food production. One of the most immediate effects the loss of biodiversity has on food production is the depletion of soil. Soil that are subject continuous monoculture become less and less fertile. As a result, agricultural yields decline.
