To understand the magnitudes of temporal variation in soil respiration (R_s) and its spatial heterogeneity, and the effect of abiotic and biotic factors to cause the variation in a young plantation recovering after the clear-cutting of a mature forest, we analyzed 8 year R_s, microclimate, and vegetation data obtained in a young hybrid larch plantation with dense undergrowth of dwarf bamboo Sasa in northern Japan during snow-free periods from 2004 to 2014. R_s was measured by a multichannel automated chamber system and was resolved into two components, temperature sensitivity of respiration, Q₁₀, and temperature-normalized basal respiration at 10°C, R₁₀. Volumetric soil water content affects both seasonal and inter-annual variation of R_s by suppressing R₁₀, whereas soil temperature affects only its seasonal variation. Vegetation recovery had significant effect on both temporal variation and spatial heterogeneity in R_s, although the tree and undergrowth Sasa had different contribution to these variations. Increase in the undergrowth Sasa PAI (plant area index) recovering after clear-cutting increased the R_s through the increase in Q₁₀, whereas the spatial heterogeneity in R_s was increased by the increase in the tree PAI through the increase in R₁₀. These results reveal that the soil water and vegetation has strong effect on the inter-annual variation of R_s and its spatial heterogeneity in the recovering young plantation, in spite of the strong exponential relationship of R_s with T_s in their seasonal variation. Although our results were obtained under the limited range in the inter-annual variation in seasonal mean T_s ( < 2°C), this may not be the unique case only in our study site and gives us a caution when predicting R_s in future warmer environment.

中文翻译：

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日本北部冷温落叶松人工林土壤呼吸的年际变化及其空间异质性

为了了解土壤呼吸的时间变化幅度（R _s）及其空间异质性，以及非生物和生物因素对成熟林砍伐后幼林恢复的影响，我们分析了8年ř_小号，气候，和植被用矮竹的茂密下层年轻混合落叶松人工林获得的数据纱纱期间无雪周期日本北部从2004年到2014年ř_小号通过多通道自动腔室系统测定，并分解为两个成分，呼吸温度敏感性，Q ₁₀和在10°C时温度标准化的基础呼吸，R ₁₀。土壤体积水含量通过抑制R _10来影响R _s的季节变化和年际变化，而土壤温度仅影响其季节变化。植被恢复对R _s的时间变化和空间异质性都有显着影响，尽管树木和灌木丛Sasa对这些变化具有不同的贡献。采伐后恢复的林下Sasa PAI（植物面积指数）的增加通过Q _10的增加而使R _s增加，而R _s的空间异质性通过增加R ₁₀来增加树PAI来增加。这些结果表明，尽管R _s与T _s在季节变化中具有很强的指数关系，但土壤水和植被对R _s的年际变化及其空间异质性在恢复的年轻人工林中具有很强的影响。尽管我们的结果是在季节性平均值T _s（<2°C）的年际变化的有限范围内获得的，但这可能并非仅在我们的研究地点才是唯一的情况，并且在将来预测R _s时应谨慎行事_。温暖的环境。