Short-term microbial responses to soluble inorganic P input in a tropical lowland rain forest in Amazonia  

作　　者：Yuri W.L.DE SOUSA Erika BUSCARDO Carlos A.N.QUESADA Henrique E.M.NASCIMENTO Laszlo NAGY 

机构地区：[1]National Research Institute for Amazonia,Manaus 69067-375(Brazil) [2]Department of Forestry,University of Brasilia,Brasilia 70910-900(Brazil) [3]Centre for Functional Ecology,University of Coimbra,Coimbra 3000-456(Portugal) [4]Department of Animal Biology,University of Campinas,Campinas 13083-862(Brazil)

出　　处：《Pedosphere》2021年第6期964-972,共9页土壤圈（英文版）

基　　金：a M.Sc.grant from the Brazilian Coordination for the Improvement of Higher Education Personnel(CAPES);a post-doctoral grant from the Portuguese Foundation for Science and Technology(No.SFRH/BPD/77795/2011)。

摘　　要：In non-flooded lowland rain forests with low soil phosphorus(P)in parts of Amazonia,P cycling largely occurs via leaf litter recycling by arbuscular mycorrhizal(AM)fungal symbionts.Occasional high input of P into these ecosystems occurs during drought years with increased litterfall.As the length and frequency of drought events are projected to increase in the region,a single-dose nutrient addition experiment was carried out to test how this would impact P cycling.An application rate of 4 kg P ha^(-1) was used,which corresponds to twice the amount of litter-derived P in an average year.It was hypothesized that i)the added mineral P would be immobilized by soil microorganisms,leading to measurable increase in soil microbial biomass carbon(C)and P and ii)AM colonization rate would be reduced by the pulse in mineral P available for plant uptake.The results did not support either of our hypotheses.The addition of P did not have an effect on AM root colonization,nor was P immobilized by soil microbiota during the experimental period.The lack of a difference between the control and treatment at our study site could be attributed to the relatively low one-off dose of P applied that did not change either the colonization rate of roots by AM fungi or the amount of soil available labile P.To obtain a mechanistic understanding of the availability,capture,and use of P by plant-symbiont associations in tropical rain forest ecosystems,further integrated studies of the soil-plant system combining long-term nutrient manipulations,modeling,and experimental approaches are required.

关 键 词：Amazon basin arbuscular mycorrhizal fungi nutrient addition phosphorus cycling soil microbial biomass 

分 类 号：S714.3[农业科学—林学]