Land Surface-Atmosphere Interactions, Technical University of Munich, 85354 Freising, Germany.
Geopedology and Landscape Development, Brandenburg University of Technology, 03046 Cottbus, Germany.
Sci Total Environ. 2020 May 15;717:137189. doi: 10.1016/j.scitotenv.2020.137189. Epub 2020 Feb 7.
Deciphering the drivers of tree growth is a central aim of dendroecology. In this context, soil conditions may play a crucial role, since they determine the availability of water and nutrients for trees. Yet, effects of systematically differing soil conditions on tree growth render a marginally studied topic. In this context, relict charcoal hearths (RCH) - a widespread legacy of anthropogenic charcoal production - render a valuable 'natural' experiment to study possible effects of artificially altered soil conditions on tree growth. We hypothesize, that the differing physico-chemical properties of RCH result in differing wood properties if compared to trees growing on unmodified soils. To test this hypothesis, we analyzed tree-growth, wood density, and wood elemental concentrations of Scots pine as well as physico-chemical soil properties. We applied a classic control-treatment design to compare RCH with unmodified soils. Our analyses identified significantly lower above-ground wood production but systematically higher wood elemental concentrations in RCH-trees compared to control trees. Since we could not identify treatment-specific growth patterns, we hypothesize the observed lower above-ground productivity of Scots pine to indicate an increased root-shoot ratio to compensate for a potentially lower plant water availability on RCH-sites. The observed higher wood elemental concentrations likely reflect higher soil elemental concentrations of Fe, Ca, K, and Mn in RCH soils. In conclusion, our study highlights diverse effects of RCH on tree growth and wood properties and strengthens the value of dendro-chemistry to use the tree-ring archive as proxy for soil conditions within a dendro-ecological context.
解析树木生长的驱动因素是树木生态学的一个核心目标。在这方面，土壤条件可能起着至关重要的作用，因为它们决定了树木获取水分和养分的能力。然而，系统的土壤条件差异对树木生长的影响是一个研究甚少的课题。在这种情况下，遗留的木炭炉（RCH）——人为生产木炭的广泛遗留物——为研究人为改变的土壤条件对树木生长的可能影响提供了一个有价值的“自然”实验。我们假设，与生长在未改性土壤上的树木相比，RCH 的不同理化性质会导致不同的木材性质。为了验证这一假设，我们分析了欧洲赤松的树木生长、木材密度和木材元素浓度以及土壤理化性质。我们采用了经典的对照处理设计，将 RCH 与未改性土壤进行了比较。我们的分析表明，与对照树相比，RCH 树上的地上部木材产量明显较低，但木材元素浓度系统较高。由于我们无法确定特定处理的生长模式，我们假设观察到的欧洲赤松地上部生产力较低表明根冠比增加，以补偿 RCH 地点潜在的植物水分可用性降低。观察到的较高的木材元素浓度可能反映了 RCH 土壤中 Fe、Ca、K 和 Mn 等土壤元素浓度的升高。总之，我们的研究强调了 RCH 对树木生长和木材性质的多种影响，并加强了使用树木化学作为树木生态学背景下土壤条件替代物的树轮档案的价值。
