摘要
森林植被生长普遍受土壤磷素养分限制。研究不同种植密度人工林土壤磷素组分特征与磷转化功能微生物群落结构的关系,可为选择合适的人工林经营措施提供理论依据。以广西南宁市横县镇龙林场长期定位试验样地的4种密度(低密度(2500株·hm^(-2))、中密度(3300株·hm^(-2))、中高密度(4500株·hm^(-2))和高密度(6000株·hm^(-2)))马尾松林为对象,利用HiSeq2500高通量测序方法分析土壤磷转化功能微生物和细菌的群落结构变化,结合针叶和土壤的生态化学计量学探讨不同种植密度对马尾松林土壤磷转化功能微生物群落结构的影响。结果表明:土壤有机碳和针叶P含量在中密度林较高,而土壤碳氮比值、硝态氮、交换性钙含量、6种土壤磷组分和两种土壤磷酸酶以及针叶C∶P值和N∶P值则相反,说明中密度马尾松林的磷素限制程度比其他种植密度低。土壤磷转化功能微生物和细菌群落结构在不同密度林间存在显著差异,但两者的Shannon多样性指数则不存在显著差异。另外,土壤磷转化功能微生物中占优势的慢生根瘤菌属的相对丰度在中密度林中最小。冗余分析(RDA)发现,土壤磷转化功能微生物和细菌群落结构在不同密度林分之间的显著差异也受到土壤因子的影响,说明土壤磷转化功能微生物和细菌群落组成的差异是林分密度和土壤因子共同作用的结果,但林分密度的影响更大。上述结果表明,中密度马尾松人工林受磷素养分胁迫较小,是一种比较合适的马尾松人工林营林措施。
Forest growth is commonly limited by soil phosphorus(P) availability.Understanding the relationships between soil P availability and the community structure of soil phoD-harboring microorganisms and bacteria in different stand densities of Pinus massoniana plantations would provide a theoretical basis for selecting an appropriate management strategy.We analyzed the community structures of soil phoD-harboring microorganisms and bacteria under four density stands of Pinus massoniana: low density(2500 trees·hm^(-2)),medium density(3300 trees·hm^(-2)),medium-high density(4500 trees·hm^(-2)),and high density(6000 trees·hm^(-2))stands.We used the HiSeq 2500 high-throughput sequencing method to analyze soil microbial community.In addition,the effects of stand density on the community structures of microorganisms were analyzed from an ecological stoichiometry perspective.The results showed that the concentrations of soil organic C and needle leaf P were the highest in the medium-density stands.Soil C ∶ N ratios,nitrate concentration,exchangeable calcium concentration,six P fractions(CaClP,citrate-P,HCl-P,total available P,enzyme-P,and microbial biomass P),acid and alkaline phosphomonoesterase activity,and needle leaf C ∶ P and N ∶ P ratios were the lowest in the medium-density stands.The community structure of soil phoD-harboring microorganisms and bacteria were significantly different among the four density stands.The Shannon diversity of the microbes was not significantly different among the stands.The relative abundance of the dominant genus Bradyrhizobium was the lowest in the medium-density stand.Results of redundancy analysis highlighted the role of soil pH and nutrients in driving variations in the community structures of soil phoD-harboring microorganisms and bacteria among different density stands,indicating that the differences in community structures of soil phoD-harboring microorganisms and bacteria were driven by stand density and soil factors,with greater contribution from stand density.These results suggest that medium-density Pinus massoniana plantation is least limited by P availability,and thus is a suitable plantation density.
作者
潘复静
陈英倩
梁月明
马姜明
杨章旗
颜培栋
零天旺
李明金
PAN Fu-jing;CHEN Ying-qian;LIANG Yue-ming;MA Jiang-ming;YANG Zhang-qi;YAN Pei-dong;LING Tian-wang;LI Mingjin(College of Environmental and Engineerings Guangxi Key Laboratory of Environmental Pollution Control Theory and Technology for Science and Education Combined with Science and Technology Innovation Base,Guilin University of Technology,Guilin 541000,Guangxi,China;Key Laboratory of Karst Dynamics,Ministry of Natural and Resources&Guangxi Zhuangzu Autonomy Region,Institute of Karst Geology,Chinese Academy of Geological Sciences,Guilin 541000,Guangxi,China;Key Laboratory of Ecology of Rare and Endangered Species and Environmental Protection,Ministry of Education,Guilin 541000,Guangxi,China;Guangxi Forestry Research Institute,Nanning 530000,China;Zhenlong Forest Farm of Hengxian County,Nanning 530000,China)
出处
《生态学杂志》
CAS
CSCD
北大核心
2021年第5期1233-1243,共11页
Chinese Journal of Ecology
基金
广西创新驱动发展专项课题(桂科AA17204087—7)
国家自然科学基金项目(31800441和41907208)
广西自然科学基金项目(2018GXNSFBA138012和2017GXNSFAA198241)资助。
关键词
马尾松
密度
针叶
土壤磷组分
磷转化功能微生物
Pinus massoniana
density
needle leaf
soil P fraction
phoD-harboring microorganisms
