Organisation of an ecosystem - AQA

Question 1

Predators and prey

Answer 1

In a healthy, balanced ecosystem the numbers of predators and prey 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 factors, like water or sunlight, or biotic factors, like a new predator or pathogen. This would result in a less healthy, balanced ecosystem.