Fine roots play a crucial role in the biogeochemical cycles of terrestrial ecosystems. Patterns of fine roots biomass formation for broad geographical areas are still unclear. We use published estimates of characteristics of European pine and spruce stands to determine their productivity and calculate the needle biomass. Then, the relationship between the fine-root:needle biomass ratio of European pine and spruce forests and the stand quality index, which is a proxy of soil fertility, was determined. We show that a rise in soil fertility is accompanied by a decrease in this ratio. Moving from the northern edge of the boreal zone southwards, with the related rise in air and soil temperatures, we see a decline in the mass ratio of fine roots and needle. The change in the fine-root:needle biomass ratio is controlled by the change in specific water uptake by roots, which is related to the osmotic pressure of the solution in the absorbing root's central vascular cylinder. The fine-root:needle ratio does not vary among stands of the same age if the stand quality index and the geographical latitude (a proxy of air and soil temperatures) are constant. These findings may be useful for further in-depth analysis of forest ecosystem functioning in Europe.

中文翻译：

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欧洲针叶林细根生物量形成的地点特异性模式


细根在陆地生态系统的生物地球化学循环中起着至关重要的作用。广泛地理区域的细根生物量形成模式仍不清楚。我们使用已发表的欧洲松树和云杉林分特征估计值来确定它们的生产力并计算针叶生物量。然后，确定了欧洲松树和云杉林的细根针生物量比与林分质量指数之间的关系，该指数是土壤肥力的代表。我们表明，土壤肥力的提高伴随着该比率的降低。从北方带的北部边缘向南移动，随着空气和土壤温度的升高，我们看到细根和针叶的质量比下降。细根：针生物量比的变化受根比吸水量的变化控制，这与吸收根中央维管筒中溶液的渗透压有关。如果林分质量指数和地理纬度（空气和土壤温度的代表）保持不变，则同一年龄的林分之间的细根针比不会发生变化。这些发现可能有助于进一步深入分析欧洲森林生态系统的功能。