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Effects of Increased Summer Precipitation and Nitrogen Addition on Root Decomposition in a Temperate Desert.

Zhao H, Huang G, Li Y, Ma J, Sheng J, Jia H, Li C - PLoS ONE (2015)

Bottom Line: Water and N addition had no significant effect on root mass loss and the N and phosphorus content of litter residue.Results from this study indicate that small and temporary changes in rainfall and N deposition do not affect root decomposition patterns in the Gurbantunggut Desert.Root decomposition rates were significantly different between species, and also between fine and coarse roots, and were determined by carbon components, especially lignin content, suggesting that root litter quality may be the primary driver of belowground carbon turnover.

View Article: PubMed Central - PubMed

Affiliation: Xinjiang Key Laboratory of Soil and Plant Ecological Processes, College of Grassland and Environmental Sciences, Xinjiang Agricultural University, Urumqi, China.

ABSTRACT

Background: Climate change scenarios that include precipitation shifts and nitrogen (N) deposition are impacting carbon (C) budgets in arid ecosystems. Roots constitute an important part of the C cycle, but it is still unclear which factors control root mass loss and nutrient release in arid lands.

Methodology/principal findings: Litterbags were used to investigate the decomposition rate and nutrient dynamics in root litter with water and N-addition treatments in the Gurbantunggut Desert in China. Water and N addition had no significant effect on root mass loss and the N and phosphorus content of litter residue. The loss of root litter and nutrient releases were strongly controlled by the initial lignin content and the lignin:N ratio, as evidenced by the negative correlations between decomposition rate and litter lignin content and the lignin:N ratio. Fine roots of Seriphidium santolinum (with higher initial lignin content) had a slower decomposition rate in comparison to coarse roots.

Conclusion/significance: Results from this study indicate that small and temporary changes in rainfall and N deposition do not affect root decomposition patterns in the Gurbantunggut Desert. Root decomposition rates were significantly different between species, and also between fine and coarse roots, and were determined by carbon components, especially lignin content, suggesting that root litter quality may be the primary driver of belowground carbon turnover.

No MeSH data available.


Residual mass for two diameter size classes of E. oxyrrhynchum (A) and S. santolinum (B) roots decomposing in the field over a period of 1.7 years (experiment II).Water and N addition treatments have been averaged by root size class within each species. ** indicate significant differences between fine and coarse roots within each species (P<0.01). Vertical bars represent standard errors (n = 12). Insets show decomposition rates for fine and coarse roots of E. oxyrrhynchum and S. santolinum, respectively.
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pone.0142380.g007: Residual mass for two diameter size classes of E. oxyrrhynchum (A) and S. santolinum (B) roots decomposing in the field over a period of 1.7 years (experiment II).Water and N addition treatments have been averaged by root size class within each species. ** indicate significant differences between fine and coarse roots within each species (P<0.01). Vertical bars represent standard errors (n = 12). Insets show decomposition rates for fine and coarse roots of E. oxyrrhynchum and S. santolinum, respectively.

Mentions: Residual mass did not differ significantly between diameter classes in E. oxyrrhynchum (F = 0.10, P = 0.75), and was significantly lower in fine roots than in coarse roots in S. santolinum after 1 year of decomposition (F = 5.41, P = 0.02, Fig 7). Also, fine roots of S. santolinum had significantly lower decomposition rates than the coarse roots (F = 13.69, P = 0.001, Fig 7). Consistently, four-way ANOVA showed that the decomposition rate was only significantly affected by species and slightly affected by diameter class (Table 2). There were, however, no interactive effects of species × treatments and root diameter × treatments on rates of decomposition, which indicated that the effects of water and N addition on decomposition dynamics were independent of species and diameter class (Table 2).


Effects of Increased Summer Precipitation and Nitrogen Addition on Root Decomposition in a Temperate Desert.

Zhao H, Huang G, Li Y, Ma J, Sheng J, Jia H, Li C - PLoS ONE (2015)

Residual mass for two diameter size classes of E. oxyrrhynchum (A) and S. santolinum (B) roots decomposing in the field over a period of 1.7 years (experiment II).Water and N addition treatments have been averaged by root size class within each species. ** indicate significant differences between fine and coarse roots within each species (P<0.01). Vertical bars represent standard errors (n = 12). Insets show decomposition rates for fine and coarse roots of E. oxyrrhynchum and S. santolinum, respectively.
© Copyright Policy
Related In: Results  -  Collection

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getmorefigures.php?uid=PMC4636258&req=5

pone.0142380.g007: Residual mass for two diameter size classes of E. oxyrrhynchum (A) and S. santolinum (B) roots decomposing in the field over a period of 1.7 years (experiment II).Water and N addition treatments have been averaged by root size class within each species. ** indicate significant differences between fine and coarse roots within each species (P<0.01). Vertical bars represent standard errors (n = 12). Insets show decomposition rates for fine and coarse roots of E. oxyrrhynchum and S. santolinum, respectively.
Mentions: Residual mass did not differ significantly between diameter classes in E. oxyrrhynchum (F = 0.10, P = 0.75), and was significantly lower in fine roots than in coarse roots in S. santolinum after 1 year of decomposition (F = 5.41, P = 0.02, Fig 7). Also, fine roots of S. santolinum had significantly lower decomposition rates than the coarse roots (F = 13.69, P = 0.001, Fig 7). Consistently, four-way ANOVA showed that the decomposition rate was only significantly affected by species and slightly affected by diameter class (Table 2). There were, however, no interactive effects of species × treatments and root diameter × treatments on rates of decomposition, which indicated that the effects of water and N addition on decomposition dynamics were independent of species and diameter class (Table 2).

Bottom Line: Water and N addition had no significant effect on root mass loss and the N and phosphorus content of litter residue.Results from this study indicate that small and temporary changes in rainfall and N deposition do not affect root decomposition patterns in the Gurbantunggut Desert.Root decomposition rates were significantly different between species, and also between fine and coarse roots, and were determined by carbon components, especially lignin content, suggesting that root litter quality may be the primary driver of belowground carbon turnover.

View Article: PubMed Central - PubMed

Affiliation: Xinjiang Key Laboratory of Soil and Plant Ecological Processes, College of Grassland and Environmental Sciences, Xinjiang Agricultural University, Urumqi, China.

ABSTRACT

Background: Climate change scenarios that include precipitation shifts and nitrogen (N) deposition are impacting carbon (C) budgets in arid ecosystems. Roots constitute an important part of the C cycle, but it is still unclear which factors control root mass loss and nutrient release in arid lands.

Methodology/principal findings: Litterbags were used to investigate the decomposition rate and nutrient dynamics in root litter with water and N-addition treatments in the Gurbantunggut Desert in China. Water and N addition had no significant effect on root mass loss and the N and phosphorus content of litter residue. The loss of root litter and nutrient releases were strongly controlled by the initial lignin content and the lignin:N ratio, as evidenced by the negative correlations between decomposition rate and litter lignin content and the lignin:N ratio. Fine roots of Seriphidium santolinum (with higher initial lignin content) had a slower decomposition rate in comparison to coarse roots.

Conclusion/significance: Results from this study indicate that small and temporary changes in rainfall and N deposition do not affect root decomposition patterns in the Gurbantunggut Desert. Root decomposition rates were significantly different between species, and also between fine and coarse roots, and were determined by carbon components, especially lignin content, suggesting that root litter quality may be the primary driver of belowground carbon turnover.

No MeSH data available.