Institute of Forestry and Conservation, John H. Daniels Faculty of Architecture, Landscape, and Design, University of Toronto, Toronto, ON, Canada.
Ecol Appl. 2023 Jun;33(4):e2832. doi: 10.1002/eap.2832. Epub 2023 Mar 20.
Many invasive and some native tree species in North America exhibit strong allelopathic effects that may contribute to their local dominance. Pyrogenic carbon (PyC; including soot, charcoal, and black carbon) is produced by the incomplete combustion of organic matter and is widespread in forest soils. Many forms of PyC have sorptive properties that can reduce the bioavailability of allelochemicals. We investigated the potential for PyC produced by controlled pyrolysis of biomass ("biochar" [BC]) to reduce the allelopathic effects of black walnut (Juglans nigra) and Norway maple (Acer platanoides), a common native tree species and a widespread invasive species in North America, respectively. Seedling growth of two native tree species (Acer saccharinum [silver maple] and Betula papyrifera [paper birch]) in response to leaf-litter-incubated soils was examined; litter incubation treatments included leaves of black walnut, Norway maple, and a nonallelopathic species (Tilia americana [American basswood]) in a factorial design with varying dosages; responses to the known primary allelochemical of black walnut (juglone) were also examined. Juglone and leaf litter of both allelopathic species strongly suppressed seedling growth. BC treatments substantially mitigated these effects, consistent with the sorption of allelochemicals; in contrast no positive effects of BC were observed in leaf litter treatments involving controls or additions of nonallelopathic leaf litter. Treatments of leaf litter and juglone with BC increased the total biomass of silver maple by ~35% and in some cases more than doubled the biomass of paper birch. We conclude that BCs have the capacity to largely counteract allelopathic effects in temperate forest systems, suggesting the effects of natural PyC in determining forest community structure, and also the applied use of BC as a soil amendment to mitigate allelopathic effects of invasive tree species.
许多北美入侵和一些本地树种表现出强烈的化感作用，这可能有助于它们在当地占主导地位。热解碳（PyC；包括烟尘、木炭和黑碳）是有机物质不完全燃烧产生的，广泛存在于森林土壤中。许多形式的 PyC 具有吸附特性，可以降低化感物质的生物可利用性。我们研究了生物质热解（“生物炭”[BC]）产生的 PyC 减少黑胡桃（Juglans nigra）和挪威枫（Acer platanoides）化感作用的潜力，黑胡桃是一种常见的本地树种，挪威枫是北美广泛入侵的树种。研究了两种本地树种（糖枫[Acer saccharinum]和纸皮桦[Betula papyrifera]）对叶凋落物孵化土壤的幼苗生长的反应；叶凋落物孵化处理包括黑胡桃、挪威枫和非化感物种（美国椴木[Tilia americana]）的叶子，采用因子设计，剂量不同；还研究了黑胡桃的已知主要化感物质（胡桃醌）的反应。胡桃醌和两种化感物种的叶凋落物强烈抑制了幼苗生长。BC 处理大大减轻了这些影响，这与化感物质的吸附一致；相比之下，在涉及对照或添加非化感叶凋落物的叶凋落物处理中，没有观察到 BC 的正效应。用 BC 处理叶凋落物和胡桃醌增加了糖枫的总生物量约 35%，在某些情况下，纸皮桦的生物量增加了一倍以上。我们得出结论，BC 具有抵消温带森林系统化感作用的能力，这表明天然 PyC 在确定森林群落结构中的作用，以及 BC 作为土壤改良剂应用于减轻入侵树种的化感作用。
