21054435
not annotated - annotated - LINNAEUS only
Seasonal dynamics in the stable carbon isotope composition delta^1^3C from non-leafy branch, trunk and coarse root CO2 efflux of adult deciduous (Fagus sylvatica) and evergreen (Picea abies) trees.
Respiration is a substantial driver of carbon (C) flux in forest ecosystems and stable C isotopes provide an excellent tool for its investigation. We studied seasonal dynamics in delta^1^3C of CO2 efflux (delta^1^3C(E)) from non-leafy branches, upper and lower trunks and coarse roots of adult trees, comparing deciduous Fagus sylvatica (European beech) with evergreen Picea abies (Norway spruce). In both species, we observed strong and similar seasonal dynamics in the delta^1^3C(E) of above-ground plant components, whereas delta^1^3C(E) of coarse roots was rather stable. During summer, delta^1^3C(E) of trunks was about -28.2% (Beech) and -26.8% (Spruce). During winter dormancy, delta^1^3C(E) increased by 5.6-9.1%. The observed dynamics are likely related to a switch from growth to starch accumulation during fall and remobilization of starch, low TCA cycle activity and accumulation of malate by PEPc during winter. The seasonal delta^1^3C(E) pattern of branches of Beech and upper trunks of Spruce was less variable, probably because these organs were additionally supplied by winter photosynthesis. In view of our results and pervious studies, we conclude that the pronounced increases in delta^1^3C(E) of trunks during the winter results from interrupted access to recent photosynthates.
Ann file
T1 Species 146 161 Fagus sylvatica
N1 Reference T1 Taxonomy:28930
T2 Species 178 189 Picea abies
N2 Reference T2 Taxonomy:3329
T3 Species 521 536 Fagus sylvatica
N3 Reference T3 Taxonomy:28930
T4 Species 538 552 European beech
N4 Reference T4 Taxonomy:28930
T5 Species 569 580 Picea abies
N5 Reference T5 Taxonomy:3329
T6 Species 582 595 Norway spruce
N6 Reference T6 Taxonomy:3329