Plot design examples

Revision as of 07:27, 23 September 2011

These are some self-stuy exercises that might be relevant in context of planning a suitable plot design in national forest inventories:

1. Explain why a major statistical planning criterium for the choice of a plot design is to capture as much of the given variability of the target variable as possible!

1. List some target variables that could be estimated based on one dimensional lines as observation units!
2. Explain the rational of a nested plot design, in which trees of different diameter classes are included in sub-plots of different area size (smaller trees in small plots, large trees in large plots)!

1. What sources of information might be a suitable basis for the decision on plot design options if you carry out a NFI for the first time?

1. Planning for field protocols and plot designs is very much a compromise between statistical considerations and feasability in practical field implementation. Explain why compact circular (sub-) plots are common, even if elongated rectagular plots might be more suitable from a pure statistical point of view!
2. You are responsible to allocate a limited budget for the implementation of a national forest inventory. Would you rather opt for a small number of large plots or a large number of rel. small plots? Explain!

1. A decision maker is arguing on your report: „you observed only 0.05 % of the forest area of our country in the field, i can‘t believe that these results are reliable!“ How can you defend your results? (describe how sampling intensity and sample size are affecting precision)