RAINFOR GEM Intensive Plots Manual (pdf) - University of Oxford

Two rhizotron transparencies following protocol #2 (example above from the SAFE plots, Malaysia; method C. Girardin). Roots aretraced onto a transparency held against the rhizotron screen (a different one each time). Different diameter classes are indicated bycolour (black-blue-red-green convention), but a new transparency is used each session and all roots are redrawn, which allows tickmarks and session numbers to be omitted (exclude roots/segments which branch after contacting the rhizotron screen). Note thetransparency ID top now includes the date (plot code/date of session/rhizotron no.). The right-hand transparency was drawn 2.5months after the left-hand one, showing that (unusually) many fine roots have died between these two time points.Both protocols described here work well in the field so it is up to you which you follow. The advantage ofprotocol #1 is that much less time is spent drawing roots each session. The advantage of protocol #2 is that (a)transparencies can be simply scanned and therefore the image analysis step should be much quicker e.g. usingWINRHIZO software http://www.regent.qc.ca/ 53 ) and (b) roots moving within the soil between sessions are nolonger a problem as they are when following protocol #1.53 See examples at http://www.plantstress.com/methods/Root%20Methods%20PORTAL/Root%20length%20method%20PSU.htm.Other alternatives are RootLM (http://digital.cs.usu.edu/~xqi/RootLM/) or ImageJ (http://rsb.info.nih.gov/ij/, see §4.3).42