不同种植模式甜龙竹林土壤养分及化学计量特征OA

[Objective]To investigate the effects of different planting patterns of Dendrocalamus brandisii on soil nutrient content and stoichiometric characteristics,and to provide a scientific basis for the sustainable management of D.brandisii forests.[Method]Four planting patterns were selected in Mengjiao,a village in Cangyuan County,Yunnan Province,for analysis:D.brandisii×Camellia sinensis(ZC),D.brandisii×Betula alnoides(ZX),D.brandisii×Juglans regia(ZH),and D.brandisii 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.[Result](1)Soil total nutrient content responded differently to planting patterns.SOC was significantly higher in ZC than in other patterns(P<0.05),while no significant differences were observed among the other three patterns(P>0.05).TN varied significantly across patterns(P<0.05).TP was significantly higher in CK and ZC than in ZX and ZH(P<0.05).Total potassium(TK)was the highest in CK,significantly exceeding other patterns(P<0.05),with no significant differences among ZC,ZX,and ZH(P>0.05).Soil available nutrients showed less sensitivity to planting patterns:available nitrogen(AN)was significantly higher in ZC than in others(P<0.05),while available phosphorus(AP)was the highest in ZH(P<0.05).Available potassium(AK)was the highest in CK,significantly surpassing ZX and ZH(P<0.05).(2)Soil stoichiometric ratios exhibited varied responses.C∶N,C∶P,and P∶K ratios showed no significant differences among patterns(P>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(P<0.05)but not significantly different from ZX and ZH(P>0.05).N∶P and N∶K in ZC were significantly higher than in all other patterns(P<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(P<0.01).TN showed positive correlations with N∶P,N∶K(P<0.01),and C∶K,P∶K(P<0.05).AN was positively correlated with N∶P,N∶K,and P∶K(P<0.01)and with C∶K(P<0.05).TP was positively correlated with P∶K(P<0.05).TK was negatively correlated with C∶K and P∶K(P<0.01)and with N∶K(P<0.05).AP and AK showed no significant correlations with stoichiometric ratios.(4)Principal component analysis indicated the comprehensive soil fertility ranking as:ZC>CK>ZX>ZH.[Conclusion]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.