How are populations affected by conditions in an ecosystem?Predators and prey
The abundance of organisms in an ecosystem is dependent upon biotic (living) and abiotic (non-living) factors. Abundance and distribution are estimated using techniques such as transects and quadrats.
In a healthy, balanced ecosystem close ecosystem The living organisms in a particular area, together with the non-living components of the environment. the numbers of predators close predator An animal that hunts, kills and eats other animals for food. and prey close prey Organisms that predators kill for food. remain fairly constant. They can go up and down during each year but generally over the years, these increases and decreases remain fairly constant.
If numbers of either predators or prey increase or decrease it could be due to a change in the abiotic close abiotic Non-living elements of an ecosystem, such as climate, temperature, water, and soil type. factors, like water or sunlight, or biotic close biotic Living elements of an ecosystem, such as plants and animals. factors, like a new predator or pathogen close pathogen Microorganism that causes disease. . This would result in a less healthy, unbalanced ecosystem.
The numbers of predators and prey for certain ecosystems such as the Canadian Lynx (wild cat) and hare have been recorded over many years and found to change in a regular cycle. A similar example is shown in the graph below and shows characteristic repeating patterns called predator-prey cycles.
