Open AccessThe effect of a dry spring on seasonal carbon allocation and vegetation dynamics in a poplar bioenergy plantation
Author(s) -
Broeckx Laura S.,
Verlinden Melanie S.,
Berhongaray Gonzalo,
Zona Donatella,
Fichot Régis,
Ceulemans Reinhart
Publication year - 2014
Publication title -
gcb bioenergy
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.378
H-Index - 63
eISSN - 1757-1707
pISSN - 1757-1693
DOI - 10.1111/gcbb.12087
Subject(s) - primary production , environmental science , leaf area index , growing season , productivity , biomass (ecology) , agronomy , ecosystem , bioenergy , vegetation (pathology) , water use efficiency , water use , soil water , ecology , biology , soil science , renewable energy , irrigation , medicine , pathology , economics , macroeconomics
In this study the seasonal variation in carbon, water and energy fluxes as well as in net primary productivity ( NPP ) of different tree components is presented for a 2‐year‐old poplar ( P opulus spp.) plantation. A thorough ecophysiological study was performed at ecosystem scale, at tree and at leaf level, in this high‐density bioenergy plantation. Seasonal variation in NPP and fluxes was analysed in relation to meteorological parameters at the field site. The growing season length in terms of carbon uptake was controlled by leaf area development until the maximum leaf area index ( LAI max ) was reached. Afterwards, a shift to belowground carbon allocation was observed. A dry period in spring caused a reduced leaf area production as well as a decrease in net ecosystem exchange and gross primary production ( GPP ) due to stomatal closure. Water use efficiency and fine root growth increased in response to limiting soil water availability in the root zone. When soil water availability was not limiting, GPP was controlled by a decrease in solar radiation and air temperature. The results of this study indicate that the productivity of recently established bioenergy plantations with fast‐growing trees is very sensitive to drought. The interaction between soil water availability and factors controlling ecosystem GPP is crucial in assessing the CO 2 mitigation potential under future climate conditions.