Soil nutrient content and stoichiometric characteristics of Dendrocalamus brandisii forests in different planting patterns

<bold>Objective</bold> To investigate the effects of different planting patterns of <italic>Dendrocalamus brandisii</italic> on soil nutrient content and stoichiometric characteristics，and to provide a scientific basis for the sustainable management of <italic>D. brandisii</italic> forests. <bold>Method</bold> Four planting patterns were selected in Mengjiao，a village in Cangyuan County，Yunnan Province，for analysis：<italic>D. brandisii</italic> × <italic>Camellia sinensis</italic>（ZC），<italic>D. brandisii</italic> × <italic>Betula alnoides</italic>（ZX），<italic>D. brandisii</italic> × <italic>Juglans regia</italic>（ZH），and <italic>D. brandisii</italic> pure forest（CK）.Soil samples from the 0-20 cm layer were collected to determine soil organic carbon（SOC），total nitrogen（TN），total phosphorus（TP），and other nutrient indicators.Soil nutrient content，stoichiometric characteristics，and their correlations were analyzed，and a principal component analysis（PCA was conducted to evaluate the comprehensive soil fertility of different planting patterns. <bold>Result</bold> （1）Soil total nutrient content responded differently to planting patterns.SOC was significantly higher in ZC than in other patterns（<italic>P</italic>&lt;0.05），while no significant differences were observed among the other three patterns（<italic>P</italic>&gt;0.05）.TN varied significantly across patterns（<italic>P</italic>&lt;0.05）.TP was significantly higher in CK and ZC than in ZX and ZH（<italic>P</italic>&lt;0.05）.Total potassium（TK）was the highest in CK，significantly exceeding other patterns（<italic>P</italic>&lt;0.05），with no significant differences among ZC，ZX，and ZH（<italic>P</italic>&gt;0.05）.Soil available nutrients showed less sensitivity to planting patterns：available nitrogen（AN）was significantly higher in ZC than in others（<italic>P</italic>&lt;0.05），while available phosphorus（AP）was the highest in ZH（<italic>P</italic>&lt;0.05）.Available potassium（AK）was the highest in CK，significantly surpassing ZX and ZH（<italic>P</italic>&lt;0.05）.（2）Soil stoichiometric ratios exhibited varied responses.C∶N，C∶P，and P∶K ratios showed no significant differences among patterns（<italic>P</italic>&gt;0.05）.C∶K，N∶P，and N∶K ratios were the highest in ZC.Specifically，C∶K in ZC was significantly higher than in CK（<italic>P</italic>&lt;0.05） but not significantly different from ZX and ZH（<italic>P</italic>&gt;0.05）.N∶P and N∶K in ZC were significantly higher than in all other patterns（<italic>P</italic>&lt;0.05）.（3）Correlation analysis revealed strong relationships between soil nutrients and stoichiometric ratios.SOC was positively correlated with C∶P，C∶K，N∶P，and N∶K（<italic>P</italic>&lt;0.01）.TN showed positive correlations with N∶P，N∶K（<italic>P</italic>&lt;0.01），and C∶K，P∶K（<italic>P</italic>&lt;0.05）.AN was positively correlated with N∶P，N∶K，and P∶K（<italic>P</italic>&lt;0.01） and with C∶K（<italic>P</italic>&lt;0.05）.TP was positively correlated with P∶K（<italic>P</italic>&lt;0.05）.TK was negatively correlated with C∶K and P∶K（<italic>P</italic>&lt;0.01） and with N∶K（<italic>P</italic>&lt;0.05）.AP and AK showed no significant correlations with stoichiometric ratios.（4）Principal component analysis indicated the comprehensive soil fertility ranking as：ZC&gt;CK&gt;ZX&gt;ZH. <bold>Conclusion</bold> In summary，different mixed tree species create varying microenvironments within the forest，resulting in differences in soil nutrient profiles.The ZC pattern demonstrates the best overall soil fertility among the planting strategies studied.