Spatial patterns of causality in temperate silvopastoral systems:a perspective on nitrification stability in response to flooding  

作　　者：Romane Mettauer Mathieu Emily Zita Bednar-Konski Anaïs Widmer Olivier Godinot Lukas Beule Edith Le Cadre 

机构地区：[1]SAS,Institut Agro,INRAE,35000,Rennes,France [2]Institut Agro,Univ Rennes,CNRS,IRMAR,35000,Rennes,France [3]Julius Kühn Institute(JKI)-Federal Research Centre for Cultivated Plants,Institute for Ecological Chemistry,Plant Analysis and Stored Product Protection,Berlin,Germany

出　　处：《Ecological Processes》2024年第4期67-81,共15页生态过程(英文)

基　　金：financially supported by La Fondation de France(grant no.00117721/WB-2021-35937).

摘　　要：Background Extreme rainfall and flooding events are projected to increase in frequency and disturb biogeochemical cycles such as the nitrogen(N)cycle.By combining trees and grasses,silvopastoral agroforestry is expected to increase the stability of this cycle in response to flooding.However,little is known about the response of nitrification to flooding in silvopastoral systems.Aim of this study was to assess nitrification stability in response to flooding and identify the main causal relations that drive it in temperate silvopastures.Methods The nitrification stability(i.e.,resistance and resilience)was assessed in two silvopastoral systems(i.e.,hedgerows and alley cropping)at three positions relative to the trees.The resistance and resilience of nitrification potential were measured in the laboratory after four weeks of flooding stress and four weeks after the end of the stress,respectively.For the first time,we used multigroup latent structural equation modeling(ML-SEM)to explore the spatial structure of causal relations between nitrification stability and soil properties across all positions of the two silvopastoral systems.Results Tree rows of both systems favored nitrification resistance,while the mean nitrification potential under flooded conditions was on average 27%and 35%higher as compared to non-stressed soils at the two positions assessed in the grass alleys.ML-SEM revealed that the causal relations that explained these results differed between the two systems.The ML-SEM models tested were unable to explain the causal relations in the hedgerow system.However,the model that considered a covariance between soil physical properties and soil resources availability(model A)was able to explain them in the alley-cropping system.It revealed that causal relations explaining nitrification stability varied according to the position relative to the trees:in the tree rows nitrification stability was associated with higher soil organic carbon concentration and earthworm abundance;in the grass alleys it was associat

关 键 词：Nitrogen cycle Soil microorganisms AGROFORESTRY HEDGEROW Alley-cropping system Grassland Microbial resistance Microbial resilience Multigroup latent structural equation modeling Nitrogen losses mitigation 

分 类 号：S718.5[农业科学—林学] TV122[水利工程—水文学及水资源]