2.3. 4: What is diversity
Diversity just means the amount of differences within a system or more illustrative it to think of it as how non-uniformed something is. The ethnic mix of the population of say a village in the Papua New Guinea highland is much less diverse than say the ethnic mix in a mega city such as New York.
When we consider ecosystems, diversity is sometimes used to mean how may different species there are in a community. However this is a very simple idea about what diversity is. Take two forest areas as an example of this. The first forest has 15 different species with 100 individuals of 1 species and 1 individual of each of the other 14 species. The second forest area also has 15 species, but this one has 7 individuals of each of the 15 species. The first forest has more individuals than the second one, BUT it is less diverse. In the second forest, the total number of individuals is spread more evenly between each species. If we think about diversity to include not just the number of species but relative number of individuals in each species as well, then spread of individuals between species is more important than the total number of individuals in a habitat.