![]() This is geometrically equivalent to reflecting the plot centre through the tree (or object) itself and comparing its position with the boundary. In the boundary reflection method, the boundary is reflected through the tree (or object), and the position of the reflected boundary is assessed relative to the plot centre. The walkthrough method is really a simplification of the boundary reflection or mirage method, motivated by a simple insight by Ducey et al 2004. The method is very easy to apply in the field and does not require linear forest edges, so is commonly deployed where inventories are likely to experience irregular boundaries or where there are small mapped gaps. This is based on the inclusion areas for single trees, rather than a mirage of the entire plot. Interpine for several years now have been using for some types of forest inventories a method for edge correction called the “ walkthrough method” (introduced in collaboration with Brian Rawley). “move the plot till you find a straight forest edge to do a mirage“. ![]() “just do full mirages (half-circle everything counted twice), save’s time having to set up second mirage”.“don’t even try corners mirages, just pull it back on one side of the edge”.“if the plot falls on an edge just ignore it (remove from sample)”.“ just too hard to train correctly – just pull the plot into the stand”.These problems often result in erroneous use in practice with common things heard from practitioners in the field. Corners, or coincidence with more than one forest boundary inside the plot may mean placing more than one mirage plot centre resulting in some trees needing to be counted up to four times, while others are only counted once.
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