biodiversity Flashcards
Species
Organisms belong to the same species if they are similar in their physical and biochemical make-up, and if they can breed together to produce fertile offspring.
Habitat.
The place where a particular organism lives.
Niche.
The “role” of an organism in an ecosystem e.g. what it eats, what eats it
(2 different species cannot occupy same niche as competition between them would be too fierce, once would out-compete the other.
What are the two components to species biodiversity?
Species richness - The number of different species living in an area.
Species evenness - The number of individuals of each species living in a given area.
Habitat biodiversity/ecological biodiversity.
-This is a measure of the number of different habitats found in a given area.
-The UK has a lot of different types of habit (meadow,woodland,stream), so has a large habitat biodiversity.
- The greater the habitat diversity - the greater the species biodiversity.
Genetic biodiversity.
This refers to the variation between individuals belonging to the same species.
- Genes can exist in many versions (alleles£ and this causes a huge amount of biodiversity within a species.
How to calculate biodiversity?
simpsons index of diversity
What’s simpsons index of diversity
D = 1 - sum (n/N)^2
N = total number of organisms of all species.
n = total number of organisms of a particular species.
Some habitats have very low biodiversity. Why do you think that it is important to conserve these?
The organisms surviving here will be rarer species, having genes allowing them to be specifically adapted to these harsh environments.
They might not be found anywhere else. The genes and alleles that these organisms possess may be useful to us in the future - if the climate changes, we could use these species for new breeding programmes or for generic engineering- to develop new crops for the future.
What is monoculture?
The growth of just one type of crop over a huge area.
What are the problems with monoculture?
- Growing just one type of crop = just one type of habitat. This will greatly reduce the different types of food available to other species. ( Insects, mammals, birds).
- It will also reduce the availability of nesting sites for other animals. If the crop fields are very large, there will be fewer hedgerows, again reduced habitats for other species.
Monoculture uses a lot of pesticides. What does this mean?
Herbicides- used to kill weeds in the crop, but will also kill many other wild- type plants that would provide habitats and food for other species.
Insecticides - used to kill insects on the crop. This causes 2 problems : fewer insects for birds and mammals to eat and also these may kill useful insects like bees (pollinators) and ladybirds.
Monoculture involves growing the same crop in the same area again and again. What does this mean?
Means that the same mineral ions are constantly being taken from the soil - it becomes lacking in nutrients, meaning other plant species struggle to grow there.
Since the crop is harvested to be eaten, mineral ions are not recycled back into the soil for future plant growth.
What is a keystone species and why is it important?
A keystone species is a plant or animal that plays a unique and crucial role in the way an ecosystem functions.
Without keystone species, the ecosystem would be dramatically different or cease to exist altogether.
