Buhk Constanze, Kämmer Marcel, Beierkuhnlein Carl, Jentsch Anke, Kreyling Jürgen, Jungkunst Hermann F
Institute of Environmental Sciences, Geoecology University of Koblenz-Landau Landau Germany.
Biogeography University of Bayreuth Bayreuth Germany.
Ecol Evol. 2016 Oct 21;6(22):8276-8290. doi: 10.1002/ece3.2472. eCollection 2016 Nov.
Climate projections propose that drought stress will become challenging for establishing trees. The magnitude of stress is dependent on tree species, provenance, and most likely also highly influenced by soil quality. European Beech () is of major ecological and economical importance in Central European forests. The species has an especially wide physiological and ecological amplitude enabling growth under various soil conditions within its distribution area in Central Europe. We studied the effects of extreme drought on beech saplings (second year) of four climatically distinct provenances growing on different soils (sandy loam and loamy sand) in a full factorial pot experiment. Foliar δC, δN, C, and N as well as above- and belowground growth parameters served as measures for stress level and plant growth. Low-quality soil enhanced the effect of drought compared with qualitatively better soil for the above- and belowground growth parameters, but foliar δC values revealed that plant stress was still remarkable in loamy soil. For beeches of one provenance, negative sandy soil effects were clearly smaller than for the others, whereas for another provenance drought effects in sandy soil were sometimes fatal. Foliar δN was correlated with plant size during the experiment. Plasticity of beech provenances in their reaction to drought versus control conditions varied clearly. Although a general trend of declining growth under control or drought conditions in sandy soil was found compared to loamy soil, the magnitude of the effect of soil quality was highly provenance specific. Provenances seemed to show adaptations not only to drought but also to soil quality. Accordingly, scientists should integrate information about climatic pre-adaptation and soil quality within the home range of populations for species distribution modeling and foresters should evaluate soil quality and climatic parameters when choosing donor populations for reforestation projects.
气候预测表明，干旱胁迫将对树木的定植构成挑战。胁迫的程度取决于树种、种源，很可能还受到土壤质量的强烈影响。欧洲山毛榉（）在中欧森林中具有重要的生态和经济意义。该物种具有特别广泛的生理和生态幅度，能够在中欧分布区内的各种土壤条件下生长。我们在一项全因子盆栽试验中，研究了极端干旱对生长在不同土壤（砂壤土和壤质砂土）上的四个气候差异明显的种源的山毛榉幼树（第二年）的影响。叶片的δC、δN、C和N以及地上和地下生长参数作为胁迫水平和植物生长的指标。与质量较好的土壤相比，低质量土壤增强了干旱对地上和地下生长参数的影响，但叶片δC值表明，壤质土壤中的植物胁迫仍然很显著。对于一个种源的山毛榉，砂土的负面影响明显小于其他种源，而对于另一个种源，砂土中的干旱影响有时是致命的。在试验期间，叶片δN与植株大小相关。山毛榉种源对干旱与对照条件的反应可塑性差异明显。尽管与壤质土壤相比，在对照或干旱条件下，砂土中的生长普遍呈下降趋势，但土壤质量影响的程度因种源而异。种源似乎不仅表现出对干旱的适应性，还表现出对土壤质量的适应性。因此，科学家在进行物种分布建模时，应整合种群原生范围内气候预适应和土壤质量的信息，而林业工作者在为造林项目选择供体种群时，应评估土壤质量和气候参数。
