Abstract

The study of all factors that contribute to the carbon balance in the biosphere is of paramount importance due to the current increase in carbon dioxide content in the atmosphere. This article presents data on the carbon dioxide exchange for the needles of common spruce (Picea abies L.) and Douglas fir (Pseudotsuga menziesii L.) in an urban environment (based on the example of Moscow). It is established that the warm spell in autumn 2018 contributed to the prolongation of the period of carbon dioxide uptake by coniferous trees. Our analysis into the effect of environmental factors on the needle photosynthetic activity has revealed that the intensity of photosynthesis depends only on the level of illumination. The midday increase in air temperature failed to affect the photosynthesis intensity, which is probably explained by the adaptation of the plants to low night and morning air temperatures. A regression analysis has shown that the dependence of CO₂ assimilation on illumination represented a logarithmic curve (with the approximation validity coefficient (R²) of 0.8). The effect of environmental conditions on conifer photosynthesis in autumn has proven to be species-specific. Common spruce was the most resistant to environmental factors: its photosynthetic activity was 1.4 times higher than that of Douglas fir. Calculations revealed that the level of CO₂ assimilation was 3.6 and 2.7 times higher than the light respiration level for common spruce and Douglas fir, respectively, which indicates a positive carbon dioxide exchange and an important role of coniferous trees in regulating the carbon balance of an urban ecosystem.

中文翻译：

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城市生态系统中木本植物的二氧化碳交换

摘要

由于当前大气中二氧化碳含量的增加，对影响生物圈碳平衡的所有因素的研究至关重要。本文介绍了常见云杉（Pice abies L.）和花旗松（Pseudotsuga menziesii）针头的二氧化碳交换数据L.）在城市环境中（以莫斯科为例）。可以确定的是，2018年秋季的温暖天气导致针叶树吸收二氧化碳的时间延长。我们对环境因素对针叶光合作用活性的影响的分析表明，光合作用的强度仅取决于光照水平。午间气温的升高未能影响光合作用强度，这可能是由于植物适应夜间和早晨的低温所致。回归分析表明，CO ₂同化对光照的依赖性表示对数曲线（具有近似有效系数（R ²）的0.8）。事实证明，环境条件对秋季针叶树光合作用的影响是特定于物种的。常见的云杉对环境因素的抵抗力最强：其光合作用活性是花旗松的1.4倍。计算表明，CO ₂ 同化水平分别比普通云杉和花旗松的光呼吸水平高3.6倍和2.7倍，这表明二氧​​化碳交换正，并且针叶树在调节针叶林碳平衡中具有重要作用。城市生态系统。