Biodiversity Flashcards
What is biodiversity
The variety of living organisms in an area
What is habitat
The place where an organism lives, e.g. a rocky shore or field
What is a community
All the populations of different species in a habitat
What is local biodiversity
You could consider the variety of different species loving in a small habitat that’s local to you. E.g.ba pond or meadow, or even your back garden. Some habitats will be more biodiverse than others
Global biodiversity
You could also consider the variety of species on earth. Recent estimates put the total number of species on earth at about 8.7 million. Biodiversity varies in different parts of the work
It is greatest at the equator and decreases towards the poles
What is species richness
Species richness is a measure of the number of different species in a community. It can be worked out by taking random samples of a community and counting the number of different species
What is species richness also a measure of apart from the number of different species in a community
Species richness is also a measure of biodiversity. But the number of different species in a community isn’t the only thing that affects biodiversity. The population sizes of those species do too
Species that are in a community in very small numbers shouldn’t be treated the same as those with bigger populations.
What is an index of diversity
It is another way of measuring biodiversity. It’s calculated using an equation that takes both the number of species in a community (species richness) and the abundance of each species
Why is woodland clearance practiced
This is done to increase the area of farmland. It directly reduces the number of trees and sometimes the number of different tree species.
It also destroys habitats, so some species could Los their shelter and food source. This means that species will die or be forced to migrate to another suitable area, further reducing biodiversity
Why is hedgerow removal practiced
This is also done to increase the area of farmland by turning lots of small fields into fewer larger fields. This reduces biodiversity for the same reasons as woodland clearance
What are pesticides
These are chemicals that kill organisms (pests) that feed on crops. This reduces diversity by directly killing the pests. Also any species that feed on the pests will lose a food source, so their numbers could decrease too
What are herbicides
These are chemicals that kill unwanted plants (weeds) . This reduces plant diversity and could reduce the number of organisms that feed on the weeds
What is monoculture
This is when farmers have fields containing only one type of plant. A single type of plant reduces biodiversity directly and will support fewer organisms (e.g. as a habitat or food source) which further reduces biodiversity.
What are some examples of conservation schemes
Giving legal protection to endangered species
Creating protected areas such as SSSIs (sites of species scientific interest) and AONBs (areas of outstanding natural beauty). These restrict further development, including agricultural development
The environmental stewardship scheme which encourages farmers to conserve biodiversity, e.g. by replanting hedgerows and leaving margins around fields for wild flowers to grow
