TY - JOUR
T1 - Plant respiration
T2 - controlled by photosynthesis or biomass?
AU - Collalti, Alessio
AU - Tjoelker, Mark G.
AU - Hoch, Günter
AU - Mäkelä, Annikki
AU - Guidolotti, Gabriele
AU - Heskel, Mary
AU - Petit, Giai
AU - Ryan, Michael G.
AU - Battipaglia, Giovanna
AU - Matteucci, Giorgio
AU - Prentice, Iain Colin
PY - 2020/3
Y1 - 2020/3
N2 - Two simplifying hypotheses have been proposed for whole-plant respiration. One links respiration to photosynthesis; the other to biomass. Using a first-principles carbon balance model with a prescribed live woody biomass turnover, applied at a forest research site where multidecadal measurements are available for comparison, we show that if turnover is fast the accumulation of respiring biomass is low and respiration depends primarily on photosynthesis; while if turnover is slow the accumulation of respiring biomass is high and respiration depends primarily on biomass. But the first scenario is inconsistent with evidence for substantial carry-over of fixed carbon between years, while the second implies far too great an increase in respiration during stand development—leading to depleted carbohydrate reserves and an unrealistically high mortality risk. These two mutually incompatible hypotheses are thus both incorrect. Respiration is not linearly related either to photosynthesis or to biomass, but it is more strongly controlled by recent photosynthates (and reserve availability) than by total biomass.
AB - Two simplifying hypotheses have been proposed for whole-plant respiration. One links respiration to photosynthesis; the other to biomass. Using a first-principles carbon balance model with a prescribed live woody biomass turnover, applied at a forest research site where multidecadal measurements are available for comparison, we show that if turnover is fast the accumulation of respiring biomass is low and respiration depends primarily on photosynthesis; while if turnover is slow the accumulation of respiring biomass is high and respiration depends primarily on biomass. But the first scenario is inconsistent with evidence for substantial carry-over of fixed carbon between years, while the second implies far too great an increase in respiration during stand development—leading to depleted carbohydrate reserves and an unrealistically high mortality risk. These two mutually incompatible hypotheses are thus both incorrect. Respiration is not linearly related either to photosynthesis or to biomass, but it is more strongly controlled by recent photosynthates (and reserve availability) than by total biomass.
KW - biomass accumulation
KW - carbon use efficiency
KW - gross primary production
KW - maintenance respiration
KW - metabolic scaling theory
KW - net primary production
KW - nonstructural carbohydrates
KW - plant respiration
UR - http://www.scopus.com/inward/record.url?scp=85074644765&partnerID=8YFLogxK
U2 - 10.1111/gcb.14857
DO - 10.1111/gcb.14857
M3 - Article
C2 - 31578796
AN - SCOPUS:85074644765
SN - 1354-1013
VL - 26
SP - 1739
EP - 1753
JO - Global Change Biology
JF - Global Change Biology
IS - 3
ER -