Soil respiration is the second largest flux of carbon between terrestrial ecosystems and the atmosphere and it is substantially sensitive to climate change. Monitoring CO₂ efflux and its upscaling from field measurements to the ecosystem level is a complex task, due to the high spatial and temporal variability of the fluxes. Human intervention, e.g. through forest harvest, may change both CO₂ efflux and its spatial heterogeneity. The objective of our study was to quantify spatial heterogeneity of soil CO₂ efflux within and among plots distributed within a topographically variable sessile oak forest stand before and after harvesting. Forest floor CO₂ efflux, soil temperature and soil water content were measured monthly in a sessile oak forest during two growing seasons: one before and one after harvesting. Stand structure characteristics (gap fraction, leaf area index, tree number and size) and the amount of understory also were determined. Relationships between individual variables and spatial heterogeneity were analyzed. The small-scale spatial heterogeneity (expresses as the coefficient of variation) of forest floor CO₂ efflux and soil water content (SWC) in the undisturbed forest was low, at maximum 0.22 and 0.13, respectively. Studied variables had no effect on spatial heterogeneity of forest floor CO₂ efflux except for the amount of understorey vegetation which positively correlated with forest floor CO₂ efflux. Although the studied forest was situated in topographically variable terrain, we observed that inter-plot heterogeneity of forest floor CO₂ efflux was lower than that within plots. Stand harvest increased the intra-plot heterogeneity of forest floor CO₂ efflux but did not affect the inter-plot heterogeneity. This leads to the conclusion that the number of positions within an individual plot should increase after harvest but the number of plots may remain unchanged to determine adequately ecosystem forest floor CO₂ efflux.

土壤呼吸是陆地生态系统和大气之间的第二大碳通量，它对气候变化非常敏感。由于通量的高时空变化性，监测CO ₂外排及其从实地测量到生态系统水平的放大是一项复杂的任务。人为干预（例如通过森林砍伐）可能会改变CO ₂外排及其空间异质性。我们研究的目的是量化在收获前后，地形变化的无柄橡树林林中分布的样地内和样地内土壤CO ₂流出的空间异质性。森林地板CO ₂在两个生长季节中，在无梗栎林中每月测量一次外排，土壤温度和土壤含水量：一个在收获前和一个在收获后。还确定了林分结构特征（间隙分数，叶面积指数，树数和大小）和林下的数量。分析了个体变量与空间异质性之间的关系。未扰动森林的林地CO ₂流出量和土壤水分（SWC）的小尺度空间异质性（表示为变异系数）较低，分别最高为0.22和0.13。研究变量对林下CO ₂流出量的空间异质性没有影响，除了与林下CO ₂正相关的下层植被数量外排。尽管所研究的森林位于地形变化的地形中，但我们观察到，林地CO ₂流出量的地块间非均质性低于地块内。林分采伐增加了林地CO ₂流出量的田间异质性，但不影响田间异质性。这得出的结论是，在收获后，单个样地中的位置数量应增加，但样地数量可以保持不变以确定足够的生态系统林地CO ₂外排量。