Institute of Dendrology, Polish Academy of Sciences, Kórnik, Poland.
Department of General Botany, Institute of Experimental Biology, Faculty of Biology, Adam Mickiewicz University, Poznań, Poland.
Glob Chang Biol. 2021 Aug;27(16):3859-3869. doi: 10.1111/gcb.15668. Epub 2021 May 18.
Harsh environmental conditions affect both leaf structure and root traits. However, shoot growth in high-latitude systems is predominately under photoperiod control while root growth may occur for as long as thermal conditions are favorable. The different sensitivities of these organs may alter functional relationships above- and belowground along environmental gradients. We examined the relationship between absorptive root and foliar traits of Scots pine trees growing in situ along a temperate-boreal transect and in trees grown in a long-term common garden at a temperate latitude. We related changes in foliar nitrogen, phosphorus, specific leaf area, needle mass and C signatures to geographic trends in absorptive root biomass to better understand patterns of altered tree nutrition and water balance. Increased allocation to absorptive fine roots was associated with greater uptake of soil nutrients and subsequently higher needle nutrient contents in the northern provenances compared with more southern provenances when grown together in a common garden setting. In contrast, the leaf δ C in northern and southern provenances were similar within the common garden suggesting that higher absorptive root biomass fractions could not adequately increase water supply in warmer climates. These results highlight the importance of allocation within the fine-root system and its impacts on needle nutrition while also suggesting increasing stomatal limitation of photosynthesis in the context of anticipated climatic changes.
恶劣的环境条件会影响叶片结构和根系特征。然而，高纬度系统中的地上部生长主要受光周期控制，而只要热条件有利，根部就可能生长。这些器官的不同敏感性可能会改变环境梯度上、下地上部的功能关系。我们研究了在温带-北方的一个梯度上生长的现场生长的苏格兰松树木的吸收根和叶片特征之间的关系，以及在温带纬度的一个长期共同花园中生长的树木之间的关系。我们将叶片氮、磷、比叶面积、针叶质量和碳特征的变化与吸收性根生物量的地理趋势联系起来，以更好地了解改变的树木营养和水分平衡的模式。与在共同花园中一起生长的较南部种源相比，在北部种源中，增加对吸收性细根的分配与土壤养分的更大吸收以及随后更高的针叶养分含量有关。相比之下，共同花园中北部和南部种源的叶片δ C 相似，这表明在温暖的气候下，更高的吸收性细根生物量分数不能充分增加供水。这些结果强调了细根系统内分配的重要性及其对针叶养分的影响，同时也表明在预期的气候变化背景下，光合作用的气孔限制增加。
