Abstract How and why spatial patterns of soil respiration (SR) emerge and change or persist over time, and what makes spatial patterning of SR and environment variables interdependent or non-interdependent, is poorly understood. Our objectives were to quantify temporal changes in spatial patterns of SR for a grassland dominated by Leymus chinensis and to explore the underlying ecological mechanisms. We conducted simultaneous measurements of SR, along with a suite of other aboveground and belowground properties, for 75 sampling points in May, July (when SR was measured twice due to a distinct temporal fluctuation in soil water content and higher temperatures) and September. No spatial structure was detected for SR in May. The degree of spatial dependence of SR in September was lower than on 17 July and 23 July, while the autocorrelation range for SR in September (7.2 m) was higher than on 17 July (1.7 m) and 23 July (3.8 m). SR was explained by soil physicochemical properties (soil organic carbon content, organic carbon:total nitrogen ratio and soil pH) in May, and soil pH was the most influential factor at this time. On 17 July, SR was explained by the combination of soil water content, bulk density, aboveground biomass, soil fungal:bacterial biomass ratio and C acquiring enzyme activity. Soil temperature, bulk density, soil electrical conductivity and aboveground biomass explained 53% of the spatial variability in SR on 23 July. SR was mostly controlled by soil temperature (positively) in September. These results indicated that the spatial patterns of SR varied remarkably across the four observations and evolved temporally as a result of seasonal shifts in environmental conditions and vegetation. Biological factors (e.g. plant and microbial biomass) were important determinants of the spatial pattern of SR in July, when the strongest spatial heterogeneity was observed.

中文翻译：

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草甸草原土壤呼吸空间变异性的时间变化：非生物和生物因素的作用

摘要 土壤呼吸 (SR) 的空间模式如何以及为什么会随着时间的推移而出现、变化或持续，以及是什么使 SR 的空间模式与环境变量相互依赖或不相互依赖，我们知之甚少。我们的目标是量化以羊草为主的草地的 SR 空间模式的时间变化，并探索潜在的生态机制。我们在 5 月、7 月（由于土壤含水量和温度的明显时间波动导致 SR 被测量两次）和 9 月的 75 个采样点同时测量了 SR 以及一系列其他地上和地下特性。5 月未检测到 SR 的空间结构。9月份SR的空间依赖程度低于7月17日和7月23日，而 9 月 SR 的自相关范围（7.2 m）高于 7 月 17 日（1.7 m）和 7 月 23 日（3.8 m）。5月份土壤理化性质（土壤有机碳含量、有机碳：全氮比和土壤pH值）解释了SR，此时土壤pH值是影响最大的因素。7 月 17 日，土壤水分含量、容重、地上生物量、土壤真菌：细菌生物量比和 C 获得酶活性的组合解释了 SR。土壤温度、容重、土壤电导率和地上生物量解释了 7 月 23 日 SR 空间变异的 53%。9 月 SR 主要受土壤温度（正向）控制。这些结果表明，SR 的空间模式在四个观测中变化显着，并且由于环境条件和植被的季节性变化而在时间上发生变化。生物因素（如植物和微生物生物量）是 7 月份 SR 空间格局的重要决定因素，此时空间异质性最强。