TY  - JOUR
AU  - Windt, Carel
AU  - Blumler, P.
TI  - A portable NMR sensor to measure dynamic changes in the amount of water in living stems or fruit and its potential to measure sap flow
JO  - Tree physiology
VL  - 35
IS  - 4
SN  - 1758-4469
CY  - Victoria, BC
PB  - Heron
M1  - FZJ-2015-00941
SP  - 366-375
PY  - 2015
AB  - Nuclear magnetic resonance (NMR) and NMR imaging (magnetic resonance imaging) offer the possibility to quantitatively and non-invasively measure the presence and movement of water. Unfortunately, traditional NMR hardware is expensive, poorly suited for plants, and because of its bulk and complexity, not suitable for use in the field. But does it need to be? We here explore how novel, small-scale portable NMR devices can be used as a flow sensor to directly measure xylem sap flow in a poplar tree (Populus nigra L.), or in a dendrometer-like fashion to measure dynamic changes in the absolute water content of fruit or stems. For the latter purpose we monitored the diurnal pattern of growth, expansion and shrinkage in a model fruit (bean pod, Phaseolus vulgaris L.) and in the stem of an oak tree (Quercus robur L.). We compared changes in absolute stem water content, as measured by the NMR sensor, against stem diameter variations as measured by a set of conventional point dendrometers, to test how well the sensitivities of the two methods compare and to investigate how well diurnal changes in trunk absolute water content correlate with the concomitant diurnal variations in stem diameter. Our results confirm the existence of a strong correlation between the two parameters, but also suggest that dynamic changes in oak stem water content could be larger than is apparent on the basis of the stem diameter variation alone.
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:000354778300004
C6  - pmid:25595754
DO  - DOI:10.1093/treephys/tpu105
UR  - https://juser.fz-juelich.de/record/187268
ER  -