Automatic detection of onset and cessation of tree stem radius increase using dendrometer data

Dendrometers are devices, which measure continuously the stem radius of a tree. In this work, we studied the use of cumulative sum (CUSUM) charts for automatically and, thus, objectively determining the onset and cessation dates of radial increase based on dendrometer data. We used data measured in two forest stands in southern Finland to demonstrate the idea and to test the performance of the CUSUM chart. In order to produce reliable results, one has to choose suitable parameter values for the chart. Once configured properly, the method produced results similar to those determined by an expert.