摘要
为探明铁添加对不同植被类型土壤有机碳(SOC)周转的影响,以芦芽山3种植被类型(草甸、灌丛、森林)下表层(0-10 cm)和亚表层(10-20 cm)土壤为研究对象,通过室内培养实验,研究Fe(Ⅱ)对SOC矿化特征的影响,并采用一级动力学方程拟合SOC矿化过程.结果表明:(1)草甸、灌丛和森林SOC矿化的变化趋势一致,均表现为前期矿化较快,其矿化速率在开始培养时(1 d)最高,并在培养前期(1-20 d)分别显著下降了44.4%、57.0%、54.6%,后期显著减慢并趋于平稳;(2)不同植被类型下土壤理化性质存在差异,且SOC、全氮(TN)、碱解氮(AN)、有效磷(AP)和土壤含水量(SWC)均随土层深度的增加而减少;(3)各植被类型不同土层SOC累积矿化量、矿化速率和矿化效率均表现为0-10 cm>10-20 cm,且草甸和森林土壤的矿化作用高于灌丛;(4)外源加Fe(Ⅱ)抑制了土壤SOC的矿化速率,对草甸和森林的抑制作用较高(19.4%-32.6%),灌丛次之(20.2%-28.3%);此外,相对于表层土壤(16.0%-19.4%),Fe(Ⅱ)添加对亚表层土壤(24.9%-32.6%)SOC的保护作用更强;(5)一级动力学方程对SOC矿化过程的模拟结果较好,灌丛土壤的Cp/SOC值为4.86-7.87,显著低于草甸和森林(5.50-12.9),表明灌丛土壤的固碳能力最强,草甸和森林次之;加Fe(Ⅱ)后土壤Cp/SOC值显著降低,表明Fe(Ⅱ)添加有利于SOC的固存;(6)逐步回归分析表明,SOC、pH和TP是土壤有机碳矿化的主要控制因素.由此得出,植被类型是影响土壤SOC矿化的重要因素,外源加Fe(Ⅱ)可以在一定程度上促进土壤SOC的固存,这与养分可利用性和土壤性质密切相关;结果可为理解气候变化背景下铁氧化物如何驱动芦芽山不同植被下土壤SOC周转提供基础数据.(图2表6参37)
To explore the effect of iron(Fe)addition on soil organic carbon(SOC)turnover under different vegetation types,meadow,shrub,and forest samples obtained from surface soil(0–10 cm)and subsurface soil(10–20 cm)from Mount Luya in Shanxi,northern China,were incubated in the laboratory to study the effects of Fe addition on SOC mineralization characteristics.A first-order kinetic equation was used to fit the SOC mineralization process.Six main results were obtained.First,the SOC mineralization trend in meadow,shrub,and forest soils was consistent,indicating that mineralization was faster in the early stage.The SOC mineralization rate was the highest at the beginning of cultivation(1 d)and significantly decreased by 44.4%,57.0%,and 54.6%in the early stage of cultivation(1–20 days),slowed down significantly,and tended to be stable in the later stage.Second,the physicochemical properties of meadow,shrub,and forest soil were significantly different,with SOC,total nitrogen,alkaline hydrolytic nitrogen,available phosphorus,and soil water content decreasing with increasing soil depth.Third,the cumulative mineralization amount,mineralization rate,and mineralization efficiency of SOC in different soil layers of different vegetation types were greater at 0–10 cm than at 10–20 cm,with higher values in meadow and forest soils than in shrub soil.Fourth,addition of Fe(II)inhibited the SOC mineralization rate in meadow,shrub,and forest soils.The rate of inhibition in meadow and forest soils(19.4%–32.6%)was higher than that in shrub soil(20.2%–28.3%).Additionally,Fe(II)addition had a stronger protective effect on the SOC of the subsurface soil(24.9%–32.6%)than on that of the surface soil(16.0%–19.4%).Fifth,SOC mineralization in soil samples of the different vegetation types followed a first-order kinetic equation.The Cp/SOC values of shrub soil(4.86–7.87)were significantly lower than the values of meadow and forest soil(5.50–12.9),indicating that the SOC sequestration capacity was significantly weaker in meadow and forest soils than in shrub soil.The addition of Fe(II)significantly decreased the soil Cp/SOC ratio,indicating that the addition of Fe(II)promoted SOC sequestration in all vegetation types.Sixth,stepwise regression analysis showed that SOC,pH,and total phosphorus were the main driving factors affecting SOC mineralization.The collective findings indicate that vegetation type is an important factor affecting SOC mineralization and that the addition of Fe(II)promotes SOC sequestration,which is closely related to nutrient availability and soil properties.This study provides basic data on how Fe oxides drive soil SOC turnover in different vegetation types on Mount Luya in the context of climate change.
作者
曹亚鑫
程曼
文永莉
CAO Yaxin;CHENG Man;WEN Yongli(Institute of Loess Plateau,Shanxi University,Taiyuan 030006,China)
出处
《应用与环境生物学报》
CAS
CSCD
北大核心
2024年第1期18-25,共8页
Chinese Journal of Applied and Environmental Biology
基金
国家自然科学基金项目(41807025,41807072)
山西省自然科学研究面上项目(202203021211317)
山西省高等学校科技创新项目(2021L013)资助。
关键词
植被类型
土壤深度
铁
土壤有机碳
矿化
vegetation type
soil depth
iron
soil organic carbon
mineralization
