In prism plot sampling for a natural forest, how many trees should be measured?

In prism plot sampling for a natural forest, how many trees should be measured?

• A. 1-4 trees
• B. 13-20 trees
• C. 5-12 trees.
• D. 20-30 trees

Answer: (C)

In prism plot sampling, you aim to balance getting enough data to represent the stand with not overdoing field time. You use a fixed-angle sector to identify candidate trees, and then you measure a subset of those trees to estimate average size and the stand’s basal area. Five to twelve trees per prism plot is the practical range that provides reasonably precise estimates without wasting effort. Measuring too few (like one to four) leads to high sampling error and unreliable results, while measuring many more (thirteen or more, up to thirty) generally adds workload with diminishing gains in precision for typical natural forests.

In prism plot sampling, you aim to balance getting enough data to represent the stand with not overdoing field time. You use a fixed-angle sector to identify candidate trees, and then you measure a subset of those trees to estimate average size and the stand’s basal area. Five to twelve trees per prism plot is the practical range that provides reasonably precise estimates without wasting effort. Measuring too few (like one to four) leads to high sampling error and unreliable results, while measuring many more (thirteen or more, up to thirty) generally adds workload with diminishing gains in precision for typical natural forests.