ABSTRACT

Stumping is an effective forest management practice for reducing the incidence of Armillaria root-rot in regenerating trees, but its impact on the soil bacterial community has not been ascertained. This study investigated the long-term impact of stumping and tree species composition in a 48-year-old trial at Skimikin, British Columbia, on the relative abundance, diversity and taxonomic composition of bacterial communities by sequencing the v4 region of 16S rRNA gene using the Illumina Miseq platform. A total of 108 samples were collected from the forest floor (fermented (F) and humus (H) layers) and mineral soil (A (0–10 cm) and B (10–20 cm) horizons) of 36 plots (half each stumped or unstumped) that were planted with pure stands and admixtures of Douglas-fir, western redcedar and paper birch. Bacterial α-diversity in the B horizon declined with stumping whereas β-diversity was affected both by tree species and stumping treatments, with fir and birch supporting distinct bacterial communities. All horizons of stumped plots of birch and its admixtures were significantly enriched with potential plant growth-promoting bacteria. In conclusion, stumping along with planting birch alone or in admixture with other species promotes a bacterial microbiome that appears beneficial in the suppression of root disease.

中文翻译：

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去除树桩和树种成分可促进细菌微生物组，这可能有利于抑制根部疾病

摘要

树桩是一种有效的森林管理措施，可减少再生树木中蜜环菌根腐病的发生，但尚未确定其对土壤细菌群落的影响。这项研究在不列颠哥伦比亚省Skimikin进行了一项48年的试验，研究了树桩和树木种类组成对细菌群落的相对丰度，多样性和分类学组成的长期影响，方法是使用16S rRNA基因的v4区域进行测序。 Illumina Miseq平台。从36个样地（每个半样）的森林地表（发酵（F）和腐殖质（H）层）和矿质土壤（A（0-10厘米）和B（10-20厘米）层）中总共采集了108个样本。树桩或树桩），种有纯林分和道格拉斯冷杉，西部雪松和桦木的混合物。残端，B层细菌的α多样性下降，而树种和残端处理都影响β多样性，其中冷杉和桦树支持不同的细菌群落。桦树及其混交物的残缺地块的所有视野都明显富集了潜在的促进植物生长的细菌。总之，树桩与单独种植桦树或与其他物种混合种植会促进细菌微生物组的生长，这似乎对抑制根部疾病有益。