Distribution

Abiotic factors help determine both the abundance of a species—how many individuals are present—and its distribution—where those individuals are found. Each species is adapted to a particular range of conditions. Near its optimum, an organism is more likely to grow, survive and reproduce successfully.

Distribution analysis means recording which plants are affected and where they occur. Are damaged plants clustered in a patch, scattered among healthy plants, or affected uniformly across an area? A patch may suggest a local source such as contaminated soil; scattered cases may suggest a pathogen carried through the air.

Over time, this can change a species’ population size or distribution and therefore alter the whole community.

In a field investigation, distribution tells you where a species occurs, while abundance tells you how many there are. A patch of grass might contain daisies across its whole area but have far more in the sunny part than under a tree. To investigate this, first decide which species and area you will study.