Sub-sampling scheme

All existing CCHA vegetation surveys were sub-sampled from the existing effort of sample plots every half meter. The plot below shows an example of the sub-sampling scheme, where effort was reduced in increments of a half meter, starting from the complete survey to an upper limit of sampling every ten meters. For simplicity, the plot shows sub-sampling up to every three meters for a hypothetical 30 meter transect (transect exceed 100 meters at all site).

The existing surveys were sub-sampled at the specified meter interval for every unique subset (or replicate) that was possible. For example, two unique replicates can be created with sub-sampling every one meter, three every 1.5 meters, etc.

The large red points show which of the existing survey points were sub-sampled for the specified sub-sample distance. For each site and sample year, the vegetation transect was sub-sampled following the scheme below (sub-sampling up to ten meters) and relevant habitat summaries were estimated. The top row represents the complete transect, or the “truth”.

Note: Although it appears that the entire original transect is sampled across all replicates, the results from each replicate are averaged as independent samples appropriate for the selected effort.