Department of Environmental Science, Aarhus University, Roskilde, Denmark.
Department of Biology, University of Copenhagen, Copenhagen Ø, Denmark.
Sci Rep. 2021 Jan 12;11(1):742. doi: 10.1038/s41598-020-80732-0.
Wood ash is alkaline and contains base-cations. Application of wood ash to forests therefore counteracts soil acidification and recycle nutrients removed during harvest. Wood ash application to soil leads to strong vertical gradients in physicochemical parameters. Consequently, we designed an experimental system where small-scale vertical changes in soil properties and prokaryotic community structure could be followed after wood ash application. A mixed fly and bottom ash was applied in dosages of 3 and 9 t ha to the surface of soil mesocosms, simulating a typical coniferous podzol. Soil pH, exchangeable cations and 16S prokaryotic community was subsequently assessed at small depth intervals to 5 cm depth at regular intervals for one year. Wood ash significantly changed the prokaryotic community in the top of the soil column. Also, the largest increases in pH and concentrations of exchangeable cations was found here. The relative abundance of prokaryotic groups directionally changed, suggesting that wood ash favors copiotrophic prokaryotes at the expense of oligotrophic and acidophilic taxa. The effect of wood ash were negligible both in terms of pH- and biological changes in lower soil layers. Consequently, by micro-vertical profiling we showed that wood ash causes a steep gradient of abiotic factors driving biotic changes but only in the top-most soil layers.
草木灰呈碱性，含有碱基阳离子。因此，将草木灰施用于森林可以中和土壤酸化并回收在收获过程中去除的养分。草木灰施用于土壤会导致理化参数的强烈垂直梯度。因此，我们设计了一个实验系统，在该系统中可以在施用草木灰后跟踪土壤性质和原核生物群落结构的小规模垂直变化。将混合的飞灰和底灰以 3 和 9 t ha 的剂量施用于土壤中观模型的表面，模拟典型的针叶灰壤。随后在一年的时间内定期在小深度间隔到 5 cm 深度处评估土壤 pH 值、可交换阳离子和 16S 原核生物群落。草木灰显著改变了土壤柱顶部的原核生物群落。此外，这里还发现 pH 值和可交换阳离子浓度的最大增加。原核生物群的相对丰度定向变化，表明草木灰有利于富营养原核生物，而不利于贫营养和嗜酸分类群。就较低土壤层中的 pH 和生物变化而言，草木灰的影响可以忽略不计。因此，通过微观垂直剖析，我们表明草木灰会导致生物变化的非生物因素的陡峭梯度，但仅在最上层土壤中。
