摘要
【目的】探讨马尾松与油茶树种单一和混合细根分解特征及养分动态,揭示二者间相互作用机制,为马尾松人工林的复合经营与高效培育提供理论参考。【方法】在马尾松飞播林下收集马尾松和油茶树种的细根,采用原位分解袋法,测定1年内马尾松和油茶细根分解干质量剩余率变化及碳(C)、氮(N)、磷(P)、钾(K)、钙(Ca)和镁(Mg)元素动态,分析其细根分解的混合效应。【结果】马尾松细根初始C、Ca含量及C∶N、C∶P、N∶P均显著高于油茶(P<0.05,下同),而N、P、K和Mg含量显著低于油茶。细根分解过程可分为快速和缓慢分解2个阶段,养分元素C、P、K和Mg总体上为净释放,Ca为富集,N在油茶细根中为净释放,在马尾松细根中为富集。在1年的分解期内,马尾松细根养分释放速率排序依次为K>C>Mg>P,油茶细根养分释放速率排序依次为K>Mg>P>C,油茶细根的N、P、K和Mg元素释放速率显著高于马尾松细根,Ca富集量低于马尾松细根。马尾松与油茶细根混合处理在分解前期(0~3个月)抑制细根的分解,后期(9~12个月)促进分解,其对养分元素的影响较为复杂,混合处理显著抑制了细根N、K元素的释放,在分解前期抑制Ca的积累,分解6~9个月促进Ca积累,而对C、P和Mg的释放既有促进也有抑制作用。细根分解速率与温度、湿度分别呈显著正相关和负相关。【结论】马尾松与油茶混交对其凋落物细根分解及养分释放均起到不同作用,细根混合处理在分解后期显著促进细根分解,混合效应显著抑制细根N元素的释放。因此,在生产实践中还应考虑混交树种的经济效益、凋落物混合效应等选择混交树种。
【Objective】To explore decomposition characteristics and nutrient dynamics of single and mixed fine roots of Pinus massoniana Lamb.and Camellia oleifera Abel.,and to reveal the interaction mechanism between them,so as to provide theoretical reference for the compound management and efficient cultivation of P.massoniana plantation.【Method】Fine roots of P.massoniana and C.oleifera in aerially seeded P.massoniana forest were collected.The change of dry mass residual rate of P.massoniana and C.oleifera and the dynamics of carbon(C),nitrogen(N),phosphorus(P),patassium(K),calcium(Ca)and magnesium(Mg)elements in one year were measured by in situ decomposition bag method,and the mixed effect of fine root decomposition was analyzed.【Result】The initial C content,Ca content,C∶N,C∶P and N∶P of fine roots of P.massoniana were significantly higher than those of C.oleifera(P<0.05,the same below),while the contents of N,P,K and Mg were significantly lower than those of C.oleifera.There were two stages in fine roots decomposition process:fast decomposition and slow decomposition.The elements C,P,K and Mg in fine roots showed net release overall,while Ca showed enrichment;N in C.oleifera showed net release,and P.massoniana enrichment.During the one-year decomposition,the nutrient release rates of P.massoniana fine roots was K>C>Mg>P,and the nutrient release rate of C.oleifera fine roots was K>Mg>P>C.The release rate of N,P,K and Mg in C.oleifera fine roots was significantly higher than that of P.massoniana fine roots,while the Ca enrichment was lower in C.oleifera fine roots than that in P.massoniana fine roots.The mixed treatment of P.massoniana and C.oleifera fine roots inhibited fine roots decomposition in the early stage of decomposition(0-3 months),and promoted decomposition in the later stage(9-12 months),showing a complex impact on nutrient elements.The mixed treatment significantly inhibited the release of N and K elements in fine roots,inhibited the accumulation of Ca in the early stage of decomposition,promoted Ca accumulation in the 6-9 months,and both promoted and inhibited the release of C,P and Mg.The fine roots decomposition rate was significantly positively and negatively correlated with temperature and humidity,respectively.【Conclusion】The mixing of P.massoniana and C.oleifera has different effects on the decomposition of fine roots and nutrient release of litters.The mixing of fine roots of both species significantly promotes fine roots decomposition in the late decomposition period,and the mixing effects significantly inhibits the release of N element in fine roots.Therefore,the economic benefits of mixed tree species and the mixing effects of litters should be considered in the production.
作者
谢娜
郭其强
袁刚毅
张亚琴
桂琴
罗丝琼
丁贵杰
XIE Na;GUO Qi-qiang;YUAN Gang-yi;ZHANG Ya-qin;GUI Qin;LUO Si-qiong;DING Gui-jie(College of Forestry/Institute for Forest Resources&Environment of Guizhou,Guizhou University,Guiyang,Guizhou 550025,China)
出处
《南方农业学报》
CAS
CSCD
北大核心
2023年第1期190-199,共10页
Journal of Southern Agriculture
基金
国家重点研发计划项目(2017YFD0600302)
贵州省科技厅平台人才项目([2018]5261)。
关键词
细根分解
养分释放
混合分解
马尾松
油茶
fine roots decomposition
nutrient release
mixed decomposition
Pinus massoniana Lamb.
Camellia oleifera Abel.
