Decomposition of Norway spruce needles and fine roots : production of CO2 and DOC

The relative amounts of CO2 and DOC lost during decomposition of spruce needles and fine roots are poorly known. However, knowledge about this division is crucial for our understanding of carbon cycling in boreal forest ecosystems. In this paper, decomposition of Norway spruce needles and fine roots...

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Main Author: Larsson, Hanna
Format: L3
Language:Inglés
Swedish
Published: SLU/Dept. of Soil and Environment 2008
Subjects:
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author Larsson, Hanna
author_browse Larsson, Hanna
author_facet Larsson, Hanna
author_sort Larsson, Hanna
collection Epsilon Archive for Student Projects
description The relative amounts of CO2 and DOC lost during decomposition of spruce needles and fine roots are poorly known. However, knowledge about this division is crucial for our understanding of carbon cycling in boreal forest ecosystems. In this paper, decomposition of Norway spruce needles and fine roots has been studied in a three-week-long column incubation experiment. Five different substrates were used; fresh needle litter, aged needles from the litter layer, seven-year-old roots from litterbag studies, fresh roots from mineral soil, and dead roots from mineral soil. Production of CO2 and DOC from the substrates, DOC quality and adsorption of DOC to ferrihydrite was studied. Respiration rate was highest for needles and fresh material, while DOC production was highest from needles in a later decomposition stage and from fresh roots. Most carbon was lost as CO2 from fresh needle litter, while DOC dominated carbon losses from seven-year-old roots from litterbag studies. The fraction of hydrophobic compounds in DOC and the proportion of DOC adsorbed to ferrihydrite were largest for substrates in late decomposition stages. Respiration rate seemed to be dependent on substrate origin (needle or root) while DOC production, DOC quality and adsorption were independent of origin.
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spelling RepoSLU122202017-11-02T09:43:38Z Decomposition of Norway spruce needles and fine roots : production of CO2 and DOC Larsson, Hanna decomposition CO2 DOC needles fine roots carbon The relative amounts of CO2 and DOC lost during decomposition of spruce needles and fine roots are poorly known. However, knowledge about this division is crucial for our understanding of carbon cycling in boreal forest ecosystems. In this paper, decomposition of Norway spruce needles and fine roots has been studied in a three-week-long column incubation experiment. Five different substrates were used; fresh needle litter, aged needles from the litter layer, seven-year-old roots from litterbag studies, fresh roots from mineral soil, and dead roots from mineral soil. Production of CO2 and DOC from the substrates, DOC quality and adsorption of DOC to ferrihydrite was studied. Respiration rate was highest for needles and fresh material, while DOC production was highest from needles in a later decomposition stage and from fresh roots. Most carbon was lost as CO2 from fresh needle litter, while DOC dominated carbon losses from seven-year-old roots from litterbag studies. The fraction of hydrophobic compounds in DOC and the proportion of DOC adsorbed to ferrihydrite were largest for substrates in late decomposition stages. Respiration rate seemed to be dependent on substrate origin (needle or root) while DOC production, DOC quality and adsorption were independent of origin. Kunskaper om hur stor andel av kol som försvinner som CO2 respektive löst organiskt kol (DOC) från barr och finrötter under nedbrytning är nödvändiga för att förstå kolomsättningen i boreala skogsekosystem. Dessa kunskaper saknas dock fortfarande i hög grad. Denna uppsats bygger på en tre veckor lång studie där fem olika substrat från gran (barr från fallförna, barr från markförna, sju år gamla rötter från förnapåsar, färska rötter från mineraljord samt döda rötter från mineraljord) inkuberades i glaskolonner. Produktion av CO2 och DOC, DOC-kvalitet samt adsorption av DOC till ferrihydrit mättes för de olika substraten. Respirationshastigheten var högst för barr och färska substrat, medan produktionen av DOC var högst för barr i senare nedbrytningsstadier och för färska rötter. De största kolförlusterna från barr från fallförna skedde som CO2 medan DOC dominerade kolförlusterna från de sju år gamla rötterna från förnapåsar. Andelen hydrofoba föreningar i producerat DOC samt andelen DOC adsorberat till ferrihydrit var störst för substrat i sena nedbrytningsstadier. Respirationshastigheten påverkades av om substratet var barr eller finrot, medan DOC-produktion, DOC-kvalitet samt DOC-adsorption var oberoende av ursprung. SLU/Dept. of Soil and Environment 2008 L3 eng swe https://stud.epsilon.slu.se/12220/
spellingShingle decomposition
CO2
DOC
needles
fine roots
carbon
Larsson, Hanna
Decomposition of Norway spruce needles and fine roots : production of CO2 and DOC
title Decomposition of Norway spruce needles and fine roots : production of CO2 and DOC
title_full Decomposition of Norway spruce needles and fine roots : production of CO2 and DOC
title_fullStr Decomposition of Norway spruce needles and fine roots : production of CO2 and DOC
title_full_unstemmed Decomposition of Norway spruce needles and fine roots : production of CO2 and DOC
title_short Decomposition of Norway spruce needles and fine roots : production of CO2 and DOC
title_sort decomposition of norway spruce needles and fine roots : production of co2 and doc
topic decomposition
CO2
DOC
needles
fine roots
carbon