5 Sampling Techniques – Sampling techniques can be used to sample living and non-living parts of an ecosystem. Factors related to living things such as amount of food, number of predators, incidence of disease and competition are called biotic factors Non-living factors such as temperature, rainfall, intensity and pH are called Abiotic factors. Biotic Used to How to use Source of Error Minimising Error Technique sample Place randomly on Plants the ground Not placed Place randomly randomly Slow moving Quadrat the number of Sample larger organisms e.g. squares the organism Small sample area area limpets, snails. is found in Place small container Lip not with Ensure lip with in the ground ground ground Small animals/ Disguise opening Bird eat Pitfall Trap insects e.g. Disguise opening trapped animals / centipedes Leave overnight and Set up multiple trapped animals collect and identify traps eat each other organisms found a large tray/sheet under Some organisms Take several sample area fly away samples Tree Small Gently hit a branch Small sample area Beating animals/insects Use larger Collect organisms Some organisms tray/sheet that fall onto sheet remain in the tree and identify
5 – Sampling Techniques Sampling techniques can be used to sample living and non-living parts of an ecosystem. Factors related to living things such as amount of food, number of predators, incidence of disease and competition are called biotic factors Non-living factors such as temperature, rainfall, intensity and pH are called Abiotic factors. Biotic Technique Used to sample How to use Source of Error Minimising Error Quadrat Plants Slow moving organisms e.g. limpets, snails. Place randomly on the ground the number of squares the organism is found in Not placed randomly Small sample area Place randomly Sample larger area Pitfall Trap Small animals/ insects e.g. centipedes Place small container in the ground Disguise opening Leave overnight and collect and identify organisms found Lip not with ground Bird eat trapped animals / trapped animals eat each other Ensure lip with ground Disguise opening Set up multiple traps Tree Beating Small animals/insects a large tray/sheet under sample area Gently hit a branch Collect organisms that fall onto sheet and identify Some organisms fly away Small sample area Some organisms remain in the tree Take several samples Use larger tray/sheet
National-5-Environmental-Science-Unit-1-Notes.docx