中国西南地区植被恢复对土壤化学计量特征的影响——基于Meta分析

Effect of vegetation restoration on soil stoichiometry characteristics in southwestern China based on meta-analysis

明确植被恢复对生态系统修复及土壤质量改善的作用,可为评价植被恢复综合效益提供数据支撑.为系统分析西南地区土壤养分及生态化学计量比对植被恢复的响应特征,搜集到47篇相关文献,提取729组有效数据进行Meta分析.结果表明:(1)乔木、灌木和草本3种植被恢复模式均可显著提高土壤有机碳(SOC)、全氮(TN)含量及土壤碳氮比(C:N),灌木恢复后土壤养分含量的综合效应值最高;(2)植被恢复1-5年和6-10年均可显著提高SOC、TN、土壤全磷(TP)含量,植被恢复大于10年时土壤C:N、碳磷比(C:P)也显著提高(P<0.05);(3)不同年降水量地区植被恢复后SOC、TN、TP含量均显著增加(P<0.05),综合效应值随年降水量的增加先增大后减小,年降水量大于1200 mm时土壤C:N、C:P显著提高(P<0.05);(4)与微碱性土壤相比,酸性土壤在植被恢复后质量改善更显著,SOC、TN、TP含量及C:N均显著提高(P<0.05);(5)土壤含水量较少(<28%)的地区,植被恢复后土壤碳、氮、磷养分含量明显增加;土壤含水量较多(>28%)的地区,植被恢复可以显著提高土壤C:N、C:P;(6)土壤含水量对植被恢复后TP、C:N、C:P、N:P变化的贡献率较高.综上,西南地区植被恢复可显著改善土壤质量,优化土壤生态化学计量指标;在实践中可采用乔灌草相结合的恢复模式,因地制宜选择适生植被,重点考虑恢复地区的水分条件,在提高植被覆盖度的同时,增强水土保持能力,为地表植物和土壤微生物提供适宜的生存环境,以促进土壤资源的可持续利用与保护.

Determining the effects of vegetation restoration on ecosystem restoration and soil-quality improvement is necessary for evaluating its benefits.To systematically analyze the effects of vegetation restoration on soil nutrients and eco-stoichiometric statistics in Southwestern China,we collected 47 relevant articles and extracted 729 sets of data for meta-analysis.The results indicated that:(1)All three 3 vegetation restoration patterns,including forest,shrub,and grass,could significantly increase soil organic carbon(SOC)and total nitrogen(TN)content and soil C:N ratios.The combined effect size of the soil nutrient content was highest after shrub restoration.(2)Vegetation restoration for 1-10 years significantly increased SOC,TN,and total phosphorus(TP)contents.The soil C:N and C:P ratios also improved significantly when the vegetation period was>10 years(P<0.05).(3)In regions with different annual precipitation,vegetation restoration significantly improved SOC,TN,and TP contents(P<0.05).With an increase in annual precipitation,the combined effect size first increased and then decreased.In regions with annual precipitation>1200 mm,soil C:N and C:P ratios improved(P<0.05).(4)Compared with slightly alkaline soil,the quality of acidic soil improved significantly after vegetation restoration.In addition,the SOC,TN,TP,and C:N ratios increased significantly in the acidic soil.(5)After vegetation restoration,the contents of soil carbon,nitrogen,and phosphorus nutrients improved significantly in regions with lower soil water content(<28%),whereas the ratios of soil C:N and C:P significantly increased in regions with higher soil water content(>28%).(6)Soil water content had a higher contribution rate to variations in TP,C:N,C:P,and N:P after vegetation restoration.Therefore,in southwestern China,vegetation restoration can significantly improve the soil quality and optimize the soil eco-stoichiometric index.A combination of trees,shrubs,and herbs can be used as the recovery pattern,and select suitable vegetation considering local conditions and prioritize water conditions in the recovery regions.While improving vegetation coverage,the capacity to maintain water and soil should be enhanced,and the conditions of soil moisture and air should be improved.It is also necessary to provide an appropriate living environment for the ground flora and soil microorganisms to promote the sustainable utilization and protection of soil resources.