We have been collaborating with USGS research scientists to study the effects of climate change on Joshua trees in the Mohave desert. In doing so, we have randomly established several permanent study plots that measure 50 meters square.

All of the Joshua trees within the square are then numbered; assigned a GPS co-ordinate; measured for height, girth, and number of terminal buds(branches); noted whether the tree has bloomed; and given a overall health status of 1 to 5 with 5 being the healthiest. 

Every couple of years we review and update the data on each study plot.  All the information gathered on all study plots is saved for inclusion in the USGS study which is ongoing.