1 Nature Climate Change 2013 Vol: 3(3):187-194. DOI: 10.1038/nclimate1692

Greenhouse-gas emissions from soils increased by earthworms

Earthworms play an essential part in determining the greenhouse-gas balance of soils worldwide, and their influence is expected to grow over the next decades. They are thought to stimulate carbon sequestration in soil aggregates, but also to increase emissions of the main greenhouse gases carbon dioxide and nitrous oxide. Hence, it remains highly controversial whether earthworms predominantly affect soils to act as a net source or sink of greenhouse gases. Here, we provide a quantitative review of the overall effect of earthworms on the soil greenhouse-gas balance. Our results suggest that although earthworms are largely beneficial to soil fertility, they increase net soil greenhouse-gas emissions.

Mentions
Figures
Figure 1: Percentage effect of earthworm presence on N2O and CO2 emissions from soil and SOC.Effect sizes in all meta-analyses were weighted by the inverse of the pooled variance. Error bars denote the 95% confidence intervals. Numbers of observations are in parentheses. Figure 2: Percentage effect of earthworm presence on the net GWP of the soil for each observation that included both N2O and CO2 flux measurements and the average for all observations.The effect size was weighted by the inverse of the pooled variance. The error bar denotes the 95% confidence interval. For every observation, the earthworm effects on CO2 and N2O emissions are reported in the four columns on the right. The first and second column denote the effect of earthworm presence on the two individual gases; the third and fourth columns report the contributions of earthworm-induced CO2 and N2O emissions to the net GWP, respectively.
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References
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