![]() ![]() For data selection, daytime was taken as the period when photosynthetically active radiation ( PAR) >5 μmol m −2 s −1. ∆ D/∆ t was calculated as the difference in diameter at the start and at the end of a day‐ or night‐time period divided by the duration of that period. (a) ET (b–d) ∆ D for four trees per genotype and (e) ∆ D/∆ t for genotypes Skado (grey dot), Oudenberg (white dot) and Grimminge (black triangle) during the period 19 August ( DOY 231)–23 August ( DOY 236) 2011. Time course of evapotranspiration ( ET) measured using eddy covariance (a), of stem diameter variations (∆ D) (b–d), of day‐ and night‐time stem diameter variation over time (∆ D/∆ t n = 4 per genotype) (e) and of daytime maximum daily shrinkage ( MDS) (f). Future studies on the prediction of SRC water use, or efforts to enhance the biomass yield of SRC genotypes, should consider intergenotypic differences in transpiration water losses at tree level as well as the SRC water balance at stand level.īioenergy evapotranspiration poplar sap flow short‐rotation coppice stand water balance. Besides differences in growth, the significant intergenotypic differences in daily ∆ D (due to stem shrinkage and swelling) suggested different water use strategies among the three genotypes which were confirmed by the sap flow measurements. Canopy transpiration based on sapwood area or leaf area scaling was 43.5 and 50.3 mm, respectively, and accounted for 74%, respectively, 86%, of total ecosystem ET measured during the intensive field campaign. Daily stem diameter variation (∆ D) was monitored simultaneously with F s to understand water use strategies for three poplar genotypes. stand scale eddy covariance flux data during a 39-day intensive field campaign in late summer 2011. Secondly, we compared leaf area scaled and sapwood area scaled sap flow ( F s) measurements on individual plants vs. Measured ET and modelled ET were lower as compared to the ET of reference grassland, suggesting that the SRC only used a limited amount of water. Transpiration represented 59% of evapotranspiration (ET) at stand scale over the whole year. First, we used the AquaCrop model and eddy covariance flux data to analyse the different components of the stand-level water balance for one entire growing season. To this end, we quantified the water use of a commercial scale poplar ( Populus) SRC plantation in East Flanders (Belgium) at tree and stand level, focusing primarily on the transpiration component. Short-rotation coppice (SRC) has great potential for supplying biomass-based heat and energy, but little is known about SRC's ecological footprint, particularly its impact on the water cycle.
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