Dot Plots

Dot plots are a way to display every occurrence of a plant species, or group of species, along a single environmental gradient. We use dot plot to compare the elevational occurrence of single species or multiple species that may be related (in the same genus or family, for example). Data used to create the dot plots comes from three extensive botanical studies: the landscape scale vegetation monitoring program, the floristic inventory, and the Denali soils map and ecological site inventory, along with historical collection records – a dataset that includes over 85,000 plant occurrences at 5,900 sites!

elevational occurrences of conifer species

Shown here is the dot plot for the three coniferous trees in Denali – Larix laricinaPicea glauca, and Picea mariana. Note the much larger elevation range of Picea glauca as compared to the other two species, with occurrences (dots) as high as 1400m elevation. Note that in elevation zones with large numbers of occurrences for a species, the dots will blur into a solid black line.

Back to Understanding Data Presented