Positive interspecific interactions in resource capture and soil property modification benefit the establishment of mixed plantations, contingent on environmental conditions. However, primary species frequently reject companion tree species frequently arises in forest management practices. To understand this contradiction, we investigated the effects of five planting patterns involving two local companion tree species ( and ) and on the soil nitrogen (N) and phosphorus (P) content, enzyme activities, net N mineralization rates, microbial composition, fungal functional groups, and the AMO gene abundance under both shade and full light conditions using a pot experiment. Under the full light condition, altered soil properties were predominantly influenced by interspecific interaction compared to intraspecific interactions, leading to an overall enhancement in nutrient availability and enzymatic activities. Under the shade condition, mixing with similarly facilitated increased NH-N content, ammonification rate, and urease activity. However, significantly decreased ammonia monooxygenase and its encoding gene, as evidence by the unbalanced ratio of net ammonification to net nitrification (2.2-fold) under the shade condition, resulting in high NH-N/NO-N ratios. Additionally, the shade condition induced soil microbial communities in the mixture to resemble those of monocultured dominant species (). Our findings also indicated that specific plant-fungal associations in companion species were disrupted when intercropped with . Therefore, this study highlights how the performance of companion species, linked to soil NH-N/NO-N ratios and plant-fungal associations, leads to their suppression by under shade conditions.

中文翻译：

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土壤铵硝比和营养共生体的变化增强了毛竹对阴凉处异质竞争者的抑制


资源捕获和土壤性质改变方面积极的种间相互作用有利于混合种植园的建立，具体取决于环境条件。然而，主要树种经常排斥森林管理实践中经常出现的伴生树种。为了理解这一矛盾，我们研究了涉及两种当地伴生树种（和）的五种种植模式对土壤氮（N）和磷（P）含量、酶活性、净氮矿化率、微生物组成、真菌功能的影响。组，以及使用盆栽实验在遮荫和全光照条件下的 AMO 基因丰度。在全光照条件下，与种内相互作用相比，改变的土壤性质主要受到种间相互作用的影响，从而导致养分利用率和酶活性的全面增强。在遮荫条件下，与类似物混合有利于增加NH-N含量、氨化速率和脲酶活性。然而，氨单加氧酶及其编码基因显着下降，表现为遮荫条件下净氨化作用与净硝化作用比例不平衡（2.2倍），导致较高的NH-N/NO-N比值。此外，遮荫条件导致混合物中的土壤微生物群落类似于单一栽培的优势物种（）。我们的研究结果还表明，当间作时，伴生物种中特定的植物-真菌关联被破坏。因此，本研究强调了与土壤 NH-N/NO-N 比率和植物-真菌关联相关的伴生物种的表现如何导致它们在遮荫条件下受到抑制。