Southern Research Station

Title: Substituting root numbers for length: Improving the use of minirhizotrons to study fine root dynamics

Author: Crocker, Tracey L.; Hendrick, Ron L.; Ruess, Roger W.; Pregitzer, Kurt S.; Burton, Andrew J.; Allen, Michael F.; Shan, Jianping; Morris, Lawrence A.

Date: 2003

Source: Applied Soil Ecology 23: 127-135

Description: Minirhizotrons provide a unique way to repeatedly measure the production and fate of individual root segments, while minimizing soil disturbance and the confounding of spatial-temporal variation. However, the time associated with processing videotaped minirhizotron images limits the amount of data that can be extracted in a reasonable amount of time. We found that this limitation can be minimized using a more easily measured variable r(i.e. root numbers) as a substitute of root length. Linear regression models were fitted between root length versus root number for production and mortality of seven sample datasets of varying tree species and treatments. The resulting r² values ranged from 0.79 to 0.99, suggesting that changes in root numbers can be used to predict root length dynamics reliably. Slope values, representing the mean root segment length (MRSL), ranged from 2.34 to 8.38 mm per root segment for both production and mortality. Most treatments did not alter MRSL substantially, the exceptions being C0₂ treatments and a girdling treatment that altered plant community composition and, consequently, root morphology. The high r² values demonstrated a robust relationship between variables irrespective of species or treatments. Once the quantitative relationship between root lengths and numbers has been established for a particular species-treatment combination, quantifying changes in root number through time should substantially decrease the time required to quantify root dynamics.

Keywords: Fine roots, minirhizotrons, mortality, production

View and Print this Publication (558 KB)

Pristine Version:  An uncaptured or "pristine" version of this publication is available. It has not been subjected to OCR (Optical Character Recognition) and therefore does not have any errors in the text. However it is a larger file size and some people may experience long download times. The "pristine" version of this publication is available here:

View and Print the PRISTINE copy of this Publication (1.0 MB)

Publication Notes: 

• We recommend that you also print this page and attach it to the printout of the article, to retain the full citation information.
• This article was written and prepared by U.S. Government employees on official time, and is therefore in the public domain.

 Get the latest version of the Adobe Acrobat reader or Acrobat Reader for Windows with Search and Accessibility

Citation

Crocker, Tracey L.; Hendrick, Ron L.; Ruess, Roger W.; Pregitzer, Kurt S.; Burton, Andrew J.; Allen, Michael F.; Shan, Jianping; Morris, Lawrence A.  2003.  Substituting root numbers for length: Improving the use of minirhizotrons to study fine root dynamics .   Applied Soil Ecology 23: 127-135