土壤有机碳组分对土地利用方式响应的Meta分析

Meta-analysis of soil organic carbon fraction response to land uses

增加土壤有机碳累积对于缓解全球气候变化背景下大气温室效应具有重要意义。为研究不同土地利用方式对土壤有机碳组分的影响,本研究采用整合分析方法(Meta-analysis)研究了林地、果园、天然草地、栽培草地、农田5种不同土地利用方式下0–100 cm土壤剖面总有机碳(TOC)及其活性组分的变化特征,并探讨了土壤总有机碳与活性有机碳之间的相关关系。结果表明:与农田(对照)相比,林地和栽培草地均能显著增加0–100 cm土层TOC含量(P<0.05),增幅在3.1%~26.6%和8.7%~24.7%;天然草地和果园分别对0–60、20–80 cm土层TOC含量有显著增加作用(P<0.05),增幅在6.0%~17.2%和5.6%~19.8%。活性有机碳组分对土地利用方式的响应程度在不同土层也有明显差别,土壤颗粒有机碳(POC)、土壤微生物量有机碳(MBC)在0–100 cm土层与TOC具有相似的变化趋势,而土壤易氧化有机碳(EOC)和土壤可溶性有机碳(DOC)略有不同。林地和果园均能显著提高0–80 cm土层EOC含量(P<0.05),而对80–100 cm土层EOC含量无显著影响(P>0.05);天然草地和栽培草地近乎在0–100 cm整个剖面对EOC含量均有显著增加作用(P<0.05);果园和天然草地的DOC含量在0–80 cm土层显著增加(P<0.05),林地和栽培草地则在0–60 cm土层DOC含量显著增加(P<0.05)。相关性分析显示,TOC与EOC、POC、MBC呈极显著正相关关系(P<0.01),而与DOC无明显相关关系。综上,与农田相比,林地和栽培草地具有较强的土壤固碳功能。该研究可为土壤有机碳管理提供理论参考。

Improving soil carbon sequestration is important in the mitigation of the atmospheric greenhouse effect in the context of global climate change.The effects of different land uses on soil organic carbon fractions were explored by a meta-analysis.This analysis studied the characteristics of soil total organic carbon(TOC)and active organic carbon in the 0–100 cm soil layers under five different land uses:Forestland,orchard,natural grassland,artificial grassland,and cropland.In addition,the relationship between TOC and active organic carbon in soil was explored.Compared with cropland(control),both forestland and artificial grassland significantly increased the TOC content of 0–100 cm soil layers by 3.1%~26.6%and 8.7%~24.7%,respectively(P<0.05).Natural grassland and orchard significantly increased the TOC content of 0–60 and 20–80 cm soil layers by 6.0%~17.2%and 5.6%~19.8%,respectively(P<0.05).The response of the active organic carbon fraction to land use also differed significantly in different soil layers.Particulate organic carbon(POC)and microbial biomass carbon(MBC)displayed similar trends to TOC in the 0-100 cm soil layers,while easily oxidizable carbon(EOC)and dissolved organic carbon(DOC)were slightly different.Both forestland and orchard significantly increased EOC content in the 0-80 cm soil(P<0.05),while there was no significant effect of the EOC content in the 80-100 cm soil layer(P>0.05).Natural grassland and artificial grassland increased EOC content significantly in the 0-100 cm soil layers(P<0.05).DOC content was affected by orchard and natural grassland,and was significantly higher than cropland in the 0-80 cm(P<0.05).DOC content of forestland and artificial grassland was significantly higher than cropland in the 0-60 cm soil layers(P<0.05).There were highly significant positive correlations between TOC and EOC,POC,and MBC(P<0.01),and no significant correlations with DOC(P>0.05).Overall,the effect values of soil organic carbon components in different soil depths were heterogeneous due to land uses.Among these uses,forestland and artificial grassland displayed better soil fertility and soil quality maintenance functions.The data provide a theoretical reference for management of soil carbon fraction under different land uses.