Organic matter quality of forest floor as a driver of C and P dynamics in acacia and eucalypt plantations established on a Ferralic Arenosols, Congo  

作　　者：Lydie-Stella Koutika Lorenzo Cafiero Annamaria Bevivino Agustín Merino 

机构地区：[1]Research Centre on the Durability and the Productivity of Industrial Plantations(CRDPI),Av.Ma Loango Moe Poaty BP 1291,Pointe-Noire,Republic of the Congo [2]Department for Sustainability,Biotechnologies and Agroindustry Division,Laboratory for AgriFood Sustainability,Quality and Safety,Italian National Agency for New Technologies,Energy and Sustainable Economic Development,ENEA,Casaccia Research Centre,Via Anguillarese,301-,00123,Rome,Italy [3]Department for Sustainability,Division Resource Efficiency,Laboratory Technologies for the Reuse,Recycling,Recovery and valorisation of Waste and Materials,Italian National Agency for New Technologies,Energy and Sustainable Economic Development,ENEA,Casaccia Research Centre,00123,Rome,Italy [4]Department of Soil Science and Agricultural Chemistry,University of Santiago de Compostela,2702,Lugo,Spain

出　　处：《Forest Ecosystems》2020年第3期511-525,共15页森林生态系统（英文版）

基　　金：supported by a TWAS-ENEA Research Training Fellowship Programme in Italy。

摘　　要：Background: Land-use change and forest management may alter soil organic matter(SOM) and nutrient dynamics,due in part to alterations in litter input and quality. Acacia was introduced in eucalypt plantations established in the Congolese coastal plains to improve soil fertility and tree growth. Eucalypt trees were expected to benefit from N2 fixed by acacia. However, some indicators suggest a perturbation in SOM and P dynamics might affect the sustainability of the system in the medium and long term. In tropical environments, most of the nutrient processes are determined by the high rates of organic matter(OM) mineralization. Therefore, SOM stability might play a crucial role in regulating soil-plant processes. In spite of this, the relationship between SOM quality, C and other nutrient dynamics are not well understood. In the present study, OM quality and P forms in forest floor and soil were investigated to get more insight on the C and P dynamics useful to sustainable management of forest plantations.Methods: Thermal analysis(differential scanning calorimetry(DSC) and thermogravimetry(TGA)) and nuclear magnetic resonance(solid state13 C CPMASS and NMR and31 P-NMR) spectroscopy have been applied to partially decomposed forest floor and soils of pure acacia and eucalypt, and mixed-species acacia-eucalypt stands.Results: Thermal analysis and13 C NMR analysis revealed a more advanced stage of humification in forest floor of acacia-eucalypt stands, suggesting a greater microbial activity in its litter. SOM were related to the OM recalcitrance of the forest floor, indicating this higher microbial activity of the forest floor in this stand might be favouring the incorporation of C into the mineral soil.Conclusions: In relation with the fast mineralization in this environment, highly soluble orthophosphate was the dominant P form in both forest floor and soils. However, the mixed-species forest stands immobilized greater P in organic forms, preventing the P losses by leaching and contributing to sustain the P demand i

关 键 词：Mixed-species plantations Soil chemical stability Organic P Forest ecosystems Potential climate change mitigation 

分 类 号：S718.5[农业科学—林学]