土壤养分限制控制着退化农业生态系统中微生物食物网衍生生态功能的营养级联效应。

Soil nutrient limitation controls trophic cascade effects of micro-food web-derived ecological functions in degraded agroecosystems.

作者信息

Xu Haobo, He Xinxing, Chen Juan, Huang Xiaozhou, Chen Yazhen, Xu Yichen, Xiao Yu, Liu Tao, He Hanjie, Wang Yingping, Yang Xiaodong, Shi Leilei, Zhang Hongzhi, Yan Wende

机构信息

College of Life and Environmental Sciences, Central South University of Forestry & Technology, Changsha 410004, China; National Engineering Laboratory for Applied Technology of Forestry & Ecology in South China, Changsha 410004, China; Yuelushan Laboratory, Central South University of Forestry & Technology, Changsha 410004, China.

出版信息

J Adv Res. 2025 Jan 12. doi: 10.1016/j.jare.2025.01.018.

DOI:10.1016/j.jare.2025.01.018

PMID:39809362

Abstract

INTRODUCTION

Soil nutrient supply drives the ecological functions of soil micro-food webs through bottom-up and top-down mechanisms in degraded agroecosystems. Nutrient limitation responds sensitively to variations in degraded agroecosystems through restoration practices, such as legume intercropping.

OBJECTIVES

This study examined the effects of legume intercropping on trophic cascade dynamics through resource supply in degraded purple soil ecosystems.

METHODS

A field experiment was conducted with three plantation types: Camellia oleifera monoculture (CK), C. oleifera-Arachis hypogaea (peanut) intercropping (CP), and C. oleifera-Senna tora intercropping (CS). Using soil nutrient limitation as a premise, modified by legume intercropping, we assessed the biodiversity of soil biotic taxa, analysed their community composition, and applied partial least squares path modelling (PLS-PM) to link trophic cascade with ecological functions.

RESULTS

Legume intercropping altered the abundance of biotic taxa, leading to changes in biotic diversity and microbial life strategies. The PLS-PM results indicated that legume intercropping enhanced bacterial diversity by aggravating soil P limitation, which subsequently increased protist consumer diversity and omnivore-predator nematode abundance through a bottom-up effect. Omnivore-predator nematodes and protist consumers indirectly influenced soil P metabolism, down-regulated through bacteria in the top-down effect. We observed high consistency between the untargeted metabolomic analysis and soil nutrient limitations. These findings indicate that soil micro-food web structure and function responded sensitively to legume intercropping in degraded ecosystems.

CONCLUSION

The results highlight the role of soil nutrient limitation in shaping micro-food webs and suggest that soil P limitation controls the down-regulation of soil P-related ecological functions through bottom-up and top-down effects.

摘要

引言

在退化的农业生态系统中，土壤养分供应通过自下而上和自上而下的机制驱动土壤微型食物网的生态功能。通过诸如豆科作物间作等恢复措施，养分限制对退化农业生态系统的变化反应敏感。

目的

本研究通过退化紫色土壤生态系统中的资源供应，研究了豆科作物间作对营养级联动态的影响。

方法

进行了一项田间试验，设置了三种种植类型：油茶单作（CK）、油茶-花生间作（CP）和油茶-决明间作（CS）。以土壤养分限制为前提，通过豆科作物间作进行改良，我们评估了土壤生物分类群的生物多样性，分析了它们的群落组成，并应用偏最小二乘路径模型（PLS-PM）将营养级联与生态功能联系起来。

结果

豆科作物间作改变了生物分类群的丰度，导致生物多样性和微生物生活策略发生变化。PLS-PM结果表明，豆科作物间作通过加剧土壤磷限制提高了细菌多样性，随后通过自下而上的效应增加了原生生物消费者多样性和杂食性捕食线虫的丰度。杂食性捕食线虫和原生生物消费者通过自上而下的效应通过细菌间接影响土壤磷代谢，使其下调。我们观察到非靶向代谢组学分析与土壤养分限制之间具有高度一致性。这些发现表明，在退化生态系统中，土壤微型食物网的结构和功能对豆科作物间作反应敏感。