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Spatial heterogeneity of soil CO2 efflux at ADVEX site Norunda in Sweden

Khaled, Bahzad (2011) In Lunds universitets Naturgeografiska institution - Seminarieuppsatser
Dept of Physical Geography and Ecosystem Science
Abstract
This study investigates the spatial variation in soil carbon dioxide (CO2) efflux in a boreal mixed forest mainly dominated by Scots pine (Pinus sylvestris L.) and Norway spruce (Picea abies L.) in the ADVEX expermental site in Norunda, in central Sweden. Soil CO2 efflux measurements were performed in 72 collars around the main tower by using a portable LI-6250 infrared gas analyzer connected to a home-made dark chamber. The average soil CO2 efflux normalized to temperature of 10 oC (R10) from the forest floor in Norunda as calculated from 72 collars was 2.09±1.36 [μmol m-2 s-1]. This was the sum of the total soil respiration mainly originating from root respiration (autotrophic), microbial respiration (heterotrophic) in addition to the... (More)
This study investigates the spatial variation in soil carbon dioxide (CO2) efflux in a boreal mixed forest mainly dominated by Scots pine (Pinus sylvestris L.) and Norway spruce (Picea abies L.) in the ADVEX expermental site in Norunda, in central Sweden. Soil CO2 efflux measurements were performed in 72 collars around the main tower by using a portable LI-6250 infrared gas analyzer connected to a home-made dark chamber. The average soil CO2 efflux normalized to temperature of 10 oC (R10) from the forest floor in Norunda as calculated from 72 collars was 2.09±1.36 [μmol m-2 s-1]. This was the sum of the total soil respiration mainly originating from root respiration (autotrophic), microbial respiration (heterotrophic) in addition to the respiration from forest floor vegetation which was not removed from the upper soil layer during the measuring of soil CO2 efflux. Measurements were performed between the 7th and 12th of June 2007 during the daytime between 11 am and 4 pm. The spatial heterogeneity of soil respiration as expressed by coefficient of variation (CV) was 65%, which reflects inconsistency in soil CO2 efflux among the 72 collars in the study area. In order to investigate the reasons for spatial variation in soil CO2 efflux, a number of variables were measured in each collar directly after CO2 efflux was measured. First, depth of the soil layer above boulders showed a significant relationship with R10 (R2=0.48). Second, humus thickness also showed a significant relationship with R10 (R2=0.21). Third, there was a significant difference in R10 with micro-topography (between normal and elevated points). Fourth, a weak negative correlation was found between R10 and weight of the dry mosses with R2=0.06. Fifth, a non- significant relationship between R10 and distance, diameter and species of the nearest three trees to the collar was found. The variables that measured in the field account about 50% the reasons behind spatial variation in soil CO2 efflux, therefore others variables are suggested to investigate for future studies. (Less)
Abstract (Swedish)
Denna studie undersöker den rumsliga variationen i markens koldioxid-utflöde (CO2) i en boreal blandskog, huvudsakligen dominerad av tall (Pinus sylvestris L.) och gran (Picea abies L.) i ADVEX experimentsite i Norunda, centrala Sverige. Mätningar av markens CO2 gjordes i 72 collars omkring huvudtornet med hjälp av en LI-6250 infraröd gasanalysapparat kopplad till en hemmagjord mörkkammare. Medelvärdet för markens CO2-utflöde vid en normaliserad temperatur på 10oC (R10) i Norunda, som beräknats från 72 collars, var 2.09±1.36 [μmol m-2 s-1]. Detta var summan av den totala markrespirationen, som huvudsakligen kom från rot-respiration (autotrofisk), mikrobiell respiration (heterotrofisk) utöver den respiration som kom från skogsmarken som... (More)
Denna studie undersöker den rumsliga variationen i markens koldioxid-utflöde (CO2) i en boreal blandskog, huvudsakligen dominerad av tall (Pinus sylvestris L.) och gran (Picea abies L.) i ADVEX experimentsite i Norunda, centrala Sverige. Mätningar av markens CO2 gjordes i 72 collars omkring huvudtornet med hjälp av en LI-6250 infraröd gasanalysapparat kopplad till en hemmagjord mörkkammare. Medelvärdet för markens CO2-utflöde vid en normaliserad temperatur på 10oC (R10) i Norunda, som beräknats från 72 collars, var 2.09±1.36 [μmol m-2 s-1]. Detta var summan av den totala markrespirationen, som huvudsakligen kom från rot-respiration (autotrofisk), mikrobiell respiration (heterotrofisk) utöver den respiration som kom från skogsmarken som inte var borttagen från det översta jordlagret under mätningarna av mark-CO2-utflöde. Mätningar utfördes mellan den 7:e och 12:e Juni 2007, dagtid mellan 11 på förmiddagen och 4 på eftermiddagen. Den rumsliga heterogeniteten för markrespiration som uttrycks av variationskoefficienten (CV) var 65%, vilket reflekterar inkonsekvensen i CO2-utföde mellan de 72 collars i studieområdet. För att undersöka orsakerna bakom den rumsliga variationen mättes ett antal variabler i varje collar direkt efter att CO2-flödet var uppmätt. Markdjup visade ett signifikant samband med R10 (R2=0.48). Humustjocklek visade också ett signifikant samband med R10 (R2=0.21). Det var en signifikant skillnad i R10 med mikro-topografi (mellan normala och upphöjda punkter). En svag negativ korrelation på R2=0.06 upptäcktes mellan R10 och den torra mossans vikt. . Ett icke signifikant samband mellan R10 och avstånd till, diameter på och art på det närmsta trädet hittades. Variablerna som mättes i fält förklarade inte den rumsliga variationen i mark-CO2-utflöde och således föreslås att andra variabler undersöks i framtida studier. (Less)
Please use this url to cite or link to this publication:
author
Khaled, Bahzad
supervisor
organization
year
type
H2 - Master's Degree (Two Years)
subject
keywords
soil CO2 efflux, spatial variation, depth of the soil, humus thickness, micro topography, stand and forest floor characteristics, mark-CO2-utflöde, rumslig variation, markdjup, humustjocklek, mikrotopografi, trädbestånd, skogsmarkskaraktäristik
publication/series
Lunds universitets Naturgeografiska institution - Seminarieuppsatser
report number
222
language
English
id
2162045
date added to LUP
2012-03-20 11:02:50
date last changed
2012-03-20 11:02:50
@misc{2162045,
  abstract     = {This study investigates the spatial variation in soil carbon dioxide (CO2) efflux in a boreal mixed forest mainly dominated by Scots pine (Pinus sylvestris L.) and Norway spruce (Picea abies L.) in the ADVEX expermental site in Norunda, in central Sweden. Soil CO2 efflux measurements were performed in 72 collars around the main tower by using a portable LI-6250 infrared gas analyzer connected to a home-made dark chamber. The average soil CO2 efflux normalized to temperature of 10 oC (R10) from the forest floor in Norunda as calculated from 72 collars was 2.09±1.36 [μmol m-2 s-1]. This was the sum of the total soil respiration mainly originating from root respiration (autotrophic), microbial respiration (heterotrophic) in addition to the respiration from forest floor vegetation which was not removed from the upper soil layer during the measuring of soil CO2 efflux. Measurements were performed between the 7th and 12th of June 2007 during the daytime between 11 am and 4 pm. The spatial heterogeneity of soil respiration as expressed by coefficient of variation (CV) was 65%, which reflects inconsistency in soil CO2 efflux among the 72 collars in the study area. In order to investigate the reasons for spatial variation in soil CO2 efflux, a number of variables were measured in each collar directly after CO2 efflux was measured. First, depth of the soil layer above boulders showed a significant relationship with R10 (R2=0.48). Second, humus thickness also showed a significant relationship with R10 (R2=0.21). Third, there was a significant difference in R10 with micro-topography (between normal and elevated points). Fourth, a weak negative correlation was found between R10 and weight of the dry mosses with R2=0.06. Fifth, a non- significant relationship between R10 and distance, diameter and species of the nearest three trees to the collar was found. The variables that measured in the field account about 50% the reasons behind spatial variation in soil CO2 efflux, therefore others variables are suggested to investigate for future studies.},
  author       = {Khaled, Bahzad},
  keyword      = {soil CO2 efflux,spatial variation,depth of the soil,humus thickness,micro topography,stand and forest floor characteristics,mark-CO2-utflöde,rumslig variation,markdjup,humustjocklek,mikrotopografi,trädbestånd,skogsmarkskaraktäristik},
  language     = {eng},
  note         = {Student Paper},
  series       = {Lunds universitets Naturgeografiska institution - Seminarieuppsatser},
  title        = {Spatial heterogeneity of soil CO2 efflux at ADVEX site Norunda in Sweden},
  year         = {2011},
}