SORTIE-ND
Software for spatially-explicit simulation of forest dynamics

Self thinning

Self-thinning is a behavior that uses a pseudo-density dependent function designed to increase the death rate in dense uniform-age stands. You specify a maximum DBH at which to apply it - above this DBH a tree will not die.

Trees killed by this behavior will have a mortality reason code of "natural".

Parameters for this behavior

Parameter nameDescription
Self-Thinning InterceptIntercept of the self-thinning linear function.
Self-Thinning SlopeSlope of the self-thinning linear function.
Maximum DBH for Self-ThinningMaximum DBH at which self-thinning applies. Above this value, no mortality occurs.

How it works

Self-thinning uses a simple linear function of probability of mortality as a function of DBH, assuming the tree is below the maximum DBH at which to apply self-thinning. After evaluating this function for a tree, it uses a random number to determine whether the tree dies.

How to apply it

This behavior can be applied to seedlings, saplings, and adults of any species.