Globally, the conversion of primary forests to plantations and agricultural landscapes is a common land use change. Kauri (Agathis australis) is one of the most heavily impacted indigenous tree species of New Zealand with <1% of primary forest remaining as fragments adjacent to pastoral farming and exotic forest plantations. By contrasting two forest systems, we investigated if the fragmentation of kauri forests and introduction of pine plantations (Pinus radiata) are significantly impacting the diversity and composition of soil microbial communities across Waipoua kauri forest, New Zealand. Using next generation based 16S rRNA and ITS gene region sequencing, we identified that fungal and bacterial community composition significantly differed between kauri and pine forest soils. However, fungal communities displayed the largest differences in diversity and composition. This research revealed significant shifts in the soil microbial communities surrounding remnant kauri fragments, including the loss of microbial taxa with functions in disease suppression and plant health. Kauri dieback disease, caused by Phytophthora agathidicida, currently threatens the kauri forest ecosystem. Results from this research highlight the need for further investigations into how changes to soil microbial diversity surrounding remnant kauri fragments impact tree health and disease expression.

中文翻译：

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邻近森林系统中的土壤微生物多样性-将原生的老生长贝壳杉（Agathis australis）森林与异国情调的松树（Pinus radiata）人工林形成对比。

在全球范围内，原始森林向人工林和农业景观的转化是常见的土地利用变化。贝壳杉（Agathis australis）是新西兰受灾最严重的本地树种之一，其中不到1％的原始森林作为碎片保留在牧场和外来人工林附近。通过对比两种森林系统，我们调查了贝壳杉林的破碎化和松树人工林（松辐射）的引入是否显着影响了新西兰怀普阿贝壳杉林中土壤微生物群落的多样性和组成。使用基于下一代的16S rRNA和ITS基因区域测序，我们确定了贝壳杉和松林土壤之间的真菌和细菌群落组成显着不同。然而，真菌群落在多样性和组成上表现出最大的差异。这项研究表明，残留贝壳杉碎片周围的土壤微生物群落发生了重大变化，包括丧失了具有抑制病害和植物健康作用的微生物分类群。由疫霉疫霉（Phytophthora agathidicida）引起的贝壳杉枯死病目前威胁着贝壳杉森林生态系统。这项研究的结果表明，有必要进一步调查残留贝壳杉碎片周围土壤微生物多样性的变化如何影响树木的健康和疾病表达。由疫霉疫霉（Phytophthora agathidicida）引起，目前威胁贝壳杉森林生态系统。这项研究的结果表明，有必要进一步调查残留贝壳杉碎片周围土壤微生物多样性的变化如何影响树木的健康和疾病表达。由疫霉疫霉（Phytophthora agathidicida）引起，目前威胁贝壳杉森林生态系统。这项研究的结果表明，有必要进一步调查残留贝壳杉碎片周围土壤微生物多样性的变化如何影响树木的健康和疾病表达。