Over the years the ongoing studies at Holt Research Forest have generated large amounts of data at different scales and on different schedules. Much of the data looks something like this, from the 1996 file for the Timber Inventory study:
YEAR,SUBQUAD,TREENO,SPEC,FIASP,COND,DBH 1996,3E14,176,1,129,6,. 1996,3E14,177.1,17,660,1,15 1996,3E14,177.2,17,660,1,10 1996,3E14,177.3,17,660,0,15 1996,3E14,178,15,746,6,. 1996,3E14,179,15,746,1,19 1996,3E14,181,15,746,1,18 1996,3E14,183,1,129,0,38
…and so on for another 32,272 lines. This is good for statistical analyses and summaries but does not help much with understanding spatial patterns of distribution and growth.
This interactive map displays data from several HRF studies on the study area grid. Up to three tree species can be selected and represented in red, green or blue, with each study unit colored according to the presence of the selected species: If pine is red and oak is blue, a square containing equal numbers of each will be purple.
With the data displayed this way you can see at a glance how species composition is affected by land-use history or drainage; by clicking through the years you can see the changing patterns of regrowth.