%0 Research article
%T Non-destructive estimation of sapwood and heartwood width in Scots pine (Pinus sylvestris L.)
%A Bieker, Dirk
%A Rust, Steffen
%D 2010
%J Silva Fennica
%V 44
%N 2
%R doi:10.14214/sf.153
%U https://silvafennica.fi/article/153
%X Accurate estimates of the water conducting sapwood area are necessary to  scale sapflow measurements to tree and stand level transpiration. We  tested a non-destructive method, electric resistivity tomography (ERT),  to estimate the area of conductive sapwood in 9 Pinus sylvestris L.  trees in lower Saxony, Germany. Tomograms were compared to  cross-sections stained with benzidine after harvesting. All tomograms  displayed a distinct pattern of low resistivity at the stem perimeter  and high resistivity in the stem centre with a steep increase in  resistivity in between, assumed to indicate the transition from sapwood  to heartwood. The tomograms showed a sapwood width 2 cm smaller than the  staining method. This indicates that staining methods overestimate the  amount of active sapwood because when heartwood is formed, moisture  content decreases before extractive contents reach levels visible by  staining. The ERT method is a new powerful method for the  non-destructive estimation of sapwood and heartwood width.