distribution of organisms

• Scientists use keys to identify organisms based on their physical appearance.
• Scientists take samples from ecosystems to find out the variety and number of organisms living there.
• Quadrats are used to measure the variety and abundance of plant species.
• To achieve a reliable sample, many quadrats should be used and thrown randomly.
• Pitfall traps are used to sample the variety and abundance of invertebrates living on the soil surface.
• Traps should be checked regularly to prevent invertebrates being eaten or escaping.
• Traps should be camouflaged with leaves or a raised cover to disguise the trap from predators.
• Traps should be below the level of the soil so the invertebrates fall into the trap.