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Connecting soil organic carbon and root biomass with land-use and vegetation in temperate grassland.

McGranahan DA, Daigh AL, Veenstra JJ, Engle DM, Miller JR, Debinski DM - ScientificWorldJournal (2014)

Bottom Line: Pastures with a recent history of severe grazing had reduced root biomass and greater bulk density.Ordination suggests greater exotic species richness is associated with lower root biomass but the relationship was not apparent when an invasive species of management concern was specifically tested.We discuss how unexplained variability in belowground properties can complicate measurement and prediction of ecosystem processes such as carbon sequestration.

View Article: PubMed Central - PubMed

Affiliation: School of Natural Resource Sciences Range Science Program, North Dakota State University, Fargo, ND 58108-6050, USA.

ABSTRACT
Soils contain much of Earth's terrestrial organic carbon but are sensitive to land-use. Rangelands are important to carbon dynamics and are among ecosystems most widely impacted by land-use. While common practices like grazing, fire, and tillage affect soil properties directly related to soil carbon dynamics, their magnitude and direction of change vary among ecosystems and with intensity of disturbance. We describe variability in soil organic carbon (SOC) and root biomass--sampled from 0-170 cm and 0-100 cm, respectively--in terms of soil properties, land-use history, current management, and plant community composition using linear regression and multivariate ordination. Despite consistency in average values of SOC and root biomass between our data and data from rangelands worldwide, broad ranges in root biomass and SOC in our data suggest these variables are affected by other site-specific factors. Pastures with a recent history of severe grazing had reduced root biomass and greater bulk density. Ordination suggests greater exotic species richness is associated with lower root biomass but the relationship was not apparent when an invasive species of management concern was specifically tested. We discuss how unexplained variability in belowground properties can complicate measurement and prediction of ecosystem processes such as carbon sequestration.

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Related in: MedlinePlus

Relationships among 13 belowground properties with respect to first two Principal Components from Principal Components Analysis. For description of plotted text codes and quantified loadings for each variable, see Table 4.
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fig2: Relationships among 13 belowground properties with respect to first two Principal Components from Principal Components Analysis. For description of plotted text codes and quantified loadings for each variable, see Table 4.

Mentions: Although the ordination of soil and root data highlighted several patterns among belowground properties, we did not observe patterns that indicate associations between belowground properties, land-use, and vegetation. The PCA revealed three general trends in variation within the soil and root data along which correlated variables clustered (Figure 2): one following root biomass, another SOC, and a third combining clay content and bulk density. Variables related to SOC loaded most heavily along PC1 while variables related to root biomass contributed in greater proportion to PC2 (Table 5). The first three axes of the PCA accounted for 72% of the variation in belowground properties, but there was no association between the PCA and factors that might explain variation in belowground properties, including historical and current grazing, tall fescue abundance, soil series, and slope (P > 0.1). We did not expect current management to affect either root biomass or SOC given the low severity and brief time span of the experimental disturbance regime [18, 54].


Connecting soil organic carbon and root biomass with land-use and vegetation in temperate grassland.

McGranahan DA, Daigh AL, Veenstra JJ, Engle DM, Miller JR, Debinski DM - ScientificWorldJournal (2014)

Relationships among 13 belowground properties with respect to first two Principal Components from Principal Components Analysis. For description of plotted text codes and quantified loadings for each variable, see Table 4.
© Copyright Policy - open-access
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC4221899&req=5

fig2: Relationships among 13 belowground properties with respect to first two Principal Components from Principal Components Analysis. For description of plotted text codes and quantified loadings for each variable, see Table 4.
Mentions: Although the ordination of soil and root data highlighted several patterns among belowground properties, we did not observe patterns that indicate associations between belowground properties, land-use, and vegetation. The PCA revealed three general trends in variation within the soil and root data along which correlated variables clustered (Figure 2): one following root biomass, another SOC, and a third combining clay content and bulk density. Variables related to SOC loaded most heavily along PC1 while variables related to root biomass contributed in greater proportion to PC2 (Table 5). The first three axes of the PCA accounted for 72% of the variation in belowground properties, but there was no association between the PCA and factors that might explain variation in belowground properties, including historical and current grazing, tall fescue abundance, soil series, and slope (P > 0.1). We did not expect current management to affect either root biomass or SOC given the low severity and brief time span of the experimental disturbance regime [18, 54].

Bottom Line: Pastures with a recent history of severe grazing had reduced root biomass and greater bulk density.Ordination suggests greater exotic species richness is associated with lower root biomass but the relationship was not apparent when an invasive species of management concern was specifically tested.We discuss how unexplained variability in belowground properties can complicate measurement and prediction of ecosystem processes such as carbon sequestration.

View Article: PubMed Central - PubMed

Affiliation: School of Natural Resource Sciences Range Science Program, North Dakota State University, Fargo, ND 58108-6050, USA.

ABSTRACT
Soils contain much of Earth's terrestrial organic carbon but are sensitive to land-use. Rangelands are important to carbon dynamics and are among ecosystems most widely impacted by land-use. While common practices like grazing, fire, and tillage affect soil properties directly related to soil carbon dynamics, their magnitude and direction of change vary among ecosystems and with intensity of disturbance. We describe variability in soil organic carbon (SOC) and root biomass--sampled from 0-170 cm and 0-100 cm, respectively--in terms of soil properties, land-use history, current management, and plant community composition using linear regression and multivariate ordination. Despite consistency in average values of SOC and root biomass between our data and data from rangelands worldwide, broad ranges in root biomass and SOC in our data suggest these variables are affected by other site-specific factors. Pastures with a recent history of severe grazing had reduced root biomass and greater bulk density. Ordination suggests greater exotic species richness is associated with lower root biomass but the relationship was not apparent when an invasive species of management concern was specifically tested. We discuss how unexplained variability in belowground properties can complicate measurement and prediction of ecosystem processes such as carbon sequestration.

Show MeSH
Related in: MedlinePlus