4.1.3 Biodiversity Flashcards
What is Biodiversity
Biodiversity is the range and variety of different species of organisms on Earth, or within an ecosystem
Biodiversity considers not only the species richness but, what?
the variation within each species, its distribution and population size
What does species richness mean?
The number of different species represented in an ecological community. It does not take account the abundances of species or their relative abundance distributions
When would a high biodiversity be found?
high biodiversity would be found in an environment with lots of different species which show a lot of variation and are living in, all evenly distributed across the study area
Many human activities are reducing biodiversity in individual ecosystems and on a global level, give some examples
waste production, deforestation, and global warming
Different species depend on each other for, what?
- Food
- Shelter
- Maintenance of the physical environment (eg. tree roots provide stability for soils, ensuring they do not get washed away. This, in turn, provides a stable habitat for other plant species)
High biodiversity ensures, what?
the stability of ecosystems by reducing the dependence of one species on another for these three things
Populations with high levels of diversity are also more likely to, what?
to be resilient to sudden environmental impacts or disease
If the mouse population was suddenly wiped out, the fox and hawk populations might decrease, but would not be wiped out, why?
as mice are not their only food source
Exam Tip
When completing an ecological study, we must ensure that the data collected is random and representative of the survey area. We do this by selecting the position of the quadrat randomly and taking a minimum of 10 readings in each survey area.
