Distribution and Abundance

Distribution and Abundance

Defining Distribution and Abundance

• Distribution refers to the geographical area within which that species can be found.
• Abundance is the number of individuals of each species within a given distribution.

Factors Affecting Distribution

• Physical factors: These include temperature, water availability and light intensity. For example, cacti have a wide distribution in dry, desert-like conditions due to their ability to conserve water.
• Biotic factors: These involve other living organisms within the ecosystem, for example food availability, predation or competition.

Investigating Distribution and Abundance

• Quadrat sampling: A random sampling technique often used to estimate abundance and distribution of organisms in an area. Quadrats are typically square and outlined using a simple structure, such as a metal or wood.
• Transect sampling: An approach to gather data along a gradient. A line (the transect) is made across the habitat and samples are taken along the line at regular intervals.

Applications and Impacts

• Understanding distribution and abundance of organisms can have important applications in conservation efforts.
• Such understanding can help in formulating effective strategies to protect endangered species, control pests, and manage the sustainable exploitation of resource species.
• Changes in distribution and abundance might signal an onset of climate change effects on an ecosystem.