Biodiversity within a community Flashcards
(13 cards)
What is biodiversity?
Biodiversity is the range and variety of genes, species, and habitats within a particular region. It can relate to a range of habitats, from a small local habitat to the earth.
What is the index of diversity?
The index of diversity puts a figure to biodiversity. So we can numerically compare values.
What is species richness?
Species richness is a measure of the number of different species in a community.
How can biodiversity be worked out?
Biodiversity can be worked out by taking random samples within a community and counting the number of different species.
What is species evenness?
Species evenness is the relative abundance of each species.
What is the diversity index equation?
d = (N (N - 1)) / (n (1 - 1))
N is total number of organisms of all species. n is the total number of organisms of 1 species.
What is the importance of the diversity index?
The diversity index can be used to compare biodiversity of different ecosystems, or to monitor change in biodiversity in a community overtime. Greater biodiversity = more healthy community.
How do farming techniques reduce biodiversity?
A growing human population results in more demand for
food so we maximise food production using farming techniques, at the expense
of biodiversity.
What are some farming techniques that are known to reduce biodiversjty?
Deforestation, removal of hedgerows, use of pesticides and herbicides, and monoculture.
How does deforestation reduce biodiversity?
Deforestation is done to increase area for farmland. It reduces the number of trees and tree species and destroys habitats, meaning species die/migrate.
How does removal of hedgerows reduce biodiversity?
Removal of hedgerows is done to increase size of fields, making farming more efficient. It reduces the number of trees and tree species and destroys habitats, meaning species die/migrate.
How does the use of pesticides and herbicides reduce biodiversity?
Pesticides kill pests & weeds which would compete with crops. Killing pests also affects organisms that feed on them as well, affecting the food chain. Same for herbicides, they reduce plant diversity and affects organisms which feed on them.
How does monoculture reduce biodiversity?
Monoculture refers to how it’s efficient to grow just one crop. This directly reduces diversity and can support fewer organisms as a habitat/food source as we have fewer niches.
