Abstract. Inclination and spatial variability in soil and litter properties influence soil greenhouse gas (GHG) fluxes, and thus on-going climate change, but their relationship in forest ecosystems is poorly understood. To elucidate this, we explored the effect of inclination, distance to a stream, soil moisture, soil temperature, and other soil and litter properties on soil-atmosphere fluxes of carbon dioxide (CO₂), methane (CH₄), and nitrous oxide (N₂O) with automated static chambers in a temperate upland forest in Eastern Austria. We hypothesised that soil CO₂ emissions and CH₄ uptake are higher in sloped locations with lower soil moisture content, whereas soil N₂O emissions are higher in flat, wetter locations. During the measurement period, soil CO₂ emissions were significantly higher on flat locations (p < 0.05), and increased with increasing soil temperature (p < 0.001) and decreasing soil moisture (p < 0.001). The soil acted as a CH₄ sink, and CH₄ uptake was not significantly related to inclination. However, CH₄ uptake was significantly higher at locations furthest away from the stream compared to at the stream (p < 0.001), and positively related to litter weight and soil C content (p < 0.01). N₂O fluxes were significantly higher on flat locations and further away from the stream (p < 0.05), and increased with increasing soil moisture (p < 0.001), soil temperature (p < 0.001) and litter depth (p < 0.05). Overall, this study underlines the importance of inclination and the resulting soil and litter properties in predicting GHG fluxes from forest soils and therefore their potential source-sink balance.

中文翻译：

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倾斜控制温带高地森林土壤中的 CO2 和 N2O 通量，但不控制 CH4 吸收

摘要。土壤和凋落物特性的倾斜度和空间变异性会影响土壤温室气体 (GHG) 通量，从而影响持续的气候变化，但人们对它们在森林生态系统中的关系知之甚少。为了阐明这一点，我们探讨了倾斜度、与溪流的距离、土壤湿度、土壤温度以及其他土壤和枯枝落叶特性对二氧化碳 (CO 2 )、甲烷 (CH 4 ) 和一氧化二氮的土壤-_大气通量_的影响(N ₂ O) 和自动静态室，位于奥地利东部的温带高地森林中。我们假设土壤 CO ₂排放量和 CH ₄吸收量在土壤水分含量较低的倾斜位置较高，而土壤 N ₂O 排放量在平坦、潮湿的地方更高。在测量期间，平坦位置的土壤CO ₂排放量显着增加( p < 0.05)，并且随着土壤温度的升高( p < 0.001) 和土壤湿度的降低( p < 0.001)而增加。土壤充当 CH ₄汇，CH ₄吸收与倾斜度无显着关系。然而，与溪流相比，距离溪流最远的位置的CH _{4吸收显着更高 (} p < 0.001)，并且与凋落物重量和土壤碳含量呈正相关 ( p < 0.01)。氮气₂O 通量在平坦位置和远离溪流的地方显着更高 ( p < 0.05)，并且随着土壤湿度 ( p < 0.001)、土壤温度 ( p < 0.001) 和凋落物深度 ( p < 0.05)的增加而增加。总的来说，这项研究强调了倾斜度和由此产生的土壤和枯枝落叶特性在预测森林土壤的温室气体通量及其潜在的源汇平衡方面的重要性。