43 Removals and Mortality
Removals are trees that for some reason are not included in the sample of assessed trees.
Mortality refers to sample trees which have died. A tree is defined as dead if all conductive tissues in the stem(s) have died.
Trees may have to be withdrawn or eliminated from sampling for several reasons. It is important to record this information so that the causes of changes in the numbers of assessment trees in each plot can be assessed and annual mortality rates can be derived.
If a tree has died, the cause must be determined (if possible).
Standing dead trees (classes 31–39) of Kraft classes 1–3 have to be reported with defoliation=100% and the cause of death (if possible) only during first assessment after their death.
When they have fallen or have been removed the dead tree is replaced by a new sample tree in case of a sampling design which is not area related.
Class 22 is only applicable in those countries that do not record trees with more than 50% crown damage.
Class 23 is only applicable to those countries that restrict sampling to Kraft classes 1, 2, 3.
In cases that more than one remark is needed, chose the most important remark and explain the second remark in the "Other observations":
a loop-sided ingrowth tree without height measurements would receive the code 21 – as no concerning data will be submitted and "Other observations" 02: ingrowth tree.
The yearly state of removals and mortality covers the assessment or derivation of an annual mortality rate.
This classification allows for reporting the reason why a tree has died or has been removed in broad categories only (e.g. biotic/abiotic reasons).
If more details are available, e.g. the exact cause of mortality of a tree was determined, this shall be reported by using the codes of the guidelines on assessment of damage causes.
Note: Mortality and the number of dead trees present in a plot are two different issues. Annual mortality can be calculated from the number of living trees that are dead the following year. The total number of dead trees in a plot at any one time provides no information on mortality rates, but provides information on the condition of a stand in the year of assessment.
Note: If trees in the plot have not been mapped, there may be some difficulty in identifying the fate of individual trees that have disappeared between surveys.