Reconnaissance Temperature Experiment at the Puhimau Hot Spot

Mike Huddleston and Kim Bridges

June 18, 1999

 

For a general overview of the Puhimau Hot Spot, follow this link.

The purpose of this reconnaissance was to examine the soil and substrate temperatures in the Puhimau hot spot to see if there was any correlation between these temperatures and the distribution of the different species.

This temperature shows the temperature of the grassy area alongside the trail leading into the hot spot.  It is close to the ambient air temperature.
The species of primary interest is the endangered Portulaca sclerocarpa.  Individuals are rooted in the soil, so the probe was inserted approximately 2" into the substrate for individuals growing in several places.

Temperatures measurements included sites were in the open on soil (right) [temp: 115 F], open on "blue-green algal blocks" (below) [temp: 127 F], and on soil on a small hummock (below right) [temp: 121 F].
A broad examination of the temperatures was made across the hot spot.  One of the highest found was on an elevated prominance near the hot spot's center. The recorded temperature was 189 F.

This area is far from the Portulaca sclerocarpa distribution.