树木向根排泄物分配碳:对碳预算,土壤封存和干旱应对的影响
Melanie Brunn1,2, Carsten W Mueller3,4, Nikhil R Chari5
1IES, Institute for Environmental Sciences, University of Kaiserslautern-Landau (RPTU), Fortstraße 7, 76829 Landau, Germany.
Tree physiology
|March 4, 2025
概括
根碳排泄对于生态系统至关重要. 干旱可以增加排泄率,但不能增加总碳输入,影响土壤碳动态和森林弹性.
科学领域:
- * 土壤科学和微生物生态学
- * 植物生理学和生态系统动力学
- * 生物地质化学循环
背景情况:
- * 根碳 (C) 排泄对于营养循环,分解和生态系统功能至关重要.
- * 在变化的水资源供应条件下,对根排液的C分配有有限的定量理解.
- * 根排泄物显著影响土壤有机物质的形成和生态系统的弹性.
研究的目的:
- * 审查和综合森林生态系统中排泄物C流的重要性.
- * 量化质量特异性排泄率 (SER),总排泄率 (TER) 和根排泄分数 (REF).
- * 检查干旱对根排水的影响,并确定研究重点.
主要方法:
- *文献综述和现有关于根排泄的研究的综合.
- *从已公布的数据中对SER,TER和REF进行定量总结.
- *对干旱对排泄率和C分配的影响分析.
主要成果:
- *平均SER<1毫克C干根-1天-1,TER 3.8毫克C年-1,REF 1-17%的净初级生产.
- * 干旱通常会增加SER和REF (1.2到11倍),但TER保持不变,表明稳定的绝对C输入.
- *受排泄物影响的土壤量在热带森林中最大,在北极森林中最小.
结论:
- * 根排泄是一种重要的C流,干旱会改变其动态,但不一定是土壤总输入量.
- * 时空变化和生物群对干旱的特定反应需要进一步的标准化研究.
- *了解排泄对于预测生态系统C动态,土壤形成和气候变化适应至关重要.
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