Semivariograms of L_LFOC (a, f), FR (b, g), SWC (c, h), NCP (d, i), and Q₁₀ (e, j) in 10-m grid squares of OF (left panel) and PP (right panel), respectively.

<p>Model for SWC are exponential models. The SWC were averaged over the 12 (OF) or 13 (PP) measurement campaigns.</p

General Linear Models for examine forest type effect on Q₁₀ values, where F test was conducted. <i>L_LFOC</i>, FR, SWC (averaged over 12 or 13 measurement campaigns), and NCP were taken as co-variables of the GLM respectively to examine which factor could exert influence on Q₁₀ value difference between forest.

<p>Abbreviations see <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0064167#pone-0064167-t001" target="_blank">Table 1</a>. None: No co-variable.</p><p>For all tests, df = 1 for fixed variable and co variables, and df = 67 for error.</p

Seasonal pattern of T₅ (up panel) and SWC (lower panel) for OF (left panel) and PP (right panel) for each subplot, as well as the seasonal pattern of the CV (up triangle) of T₅ and SWC among subplots.

<p>Seasonal pattern of T₅ (up panel) and SWC (lower panel) for OF (left panel) and PP (right panel) for each subplot, as well as the seasonal pattern of the CV (up triangle) of T₅ and SWC among subplots.</p

Isarithmic maps of the Q₁₀ in the 10-m grids of OF and PP are shown in the top and bottom panels respectively, interpolations were done by the inverse distance weighting method.

<p>White areas indicate high values and dark areas indicate low values.</p

Statistical analysis of soil parameters, fine root biomass, soil respiration rate, Q₁₀ values, and carbon pool lability (<i>L</i>_LFOC) for the oak forest and pine plantation.^a

a<p>S.D.: standard deviation; CV: coefficient of variance; R_S: soil respiration; SWC: soil water content; TOC: total organic carbon; TN: total nitrogen; LFOC: light fraction organic carbon; FR: fine root biomass; BD: bulk density; LAI: leaf area index; NCP: non-capillary porosity. <i>n = </i>35. The soil respiration rates R_S and SWC in this table were averaged over the 12 (OF) or 13 (PP) measurement campaigns.</p

Pearson correlation coefficients between Q₁₀ and variables in spatially.

<p>Abbreviations see <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0064167#pone-0064167-t001" target="_blank">Table 1</a>. n = 35 for each forest, n = 70 for pooled data of two forest types. The SWC in this table were averaged over the 12 (OF) or 13 (PP) measurement campaigns.</p

Comparison of accumulated methane flux balance for agriculturally managed peatlands and natural peatlands.

<p>Comparison of accumulated methane flux balance for agriculturally managed peatlands and natural peatlands.</p

The results of stepwise multivariable regression analysis between daily average CH₄ flux and abiotic variables including friction velocity (u*), vapor pressure deficit (VPD), photosynthetically active photon flux density (PPFD), air temperature (T_a), soil temperature at 10 cm and 50 cm (T₁₀, T₅₀), soil water content at 10 cm and 50 cm (SWC₁₀, SWC₅₀) and water table level (WT) and biotic variables such as gross primary productivity (GPP) and net ecosystem exchange (NEE).

<p>Only significant (P<0.05) variables were included in the equation. No significant interactions among the variables were found (P>0.05), and the variance inflation factor (VIF) for all variables in the model is less than 5.</p

The location of flux tower in the Robinsons pasture, western Newfoundland, Canada (48.264 N, 58.665 W).

<p>The image is similar, but not identical, to the original image, and therefore is only for illustrative purposes. The outline of the site was indicated by the red solid line and the red pin represents the location of eddy covariance (EC) tower (a); (b) a photo of the setup of EC measurement system.</p

The cumulative gap-filled CH₄ flux during the two study years (from May 2014 to April 2016).

<p>The cumulative gap-filled CH₄ flux during the two study years (from May 2014 to April 2016).</p