摘要
为研究人工恢复“黑土滩”(“Black soil land”,BSL)后土壤团聚体粒级组成和稳定性特征,以青藏高原东北缘祁连山西段疏勒河源多年冻土区BSL和4龄人工建植草地(Artificially planted grassland,APG)为研究对象,基于干筛和湿筛法分析0~20 cm层其变化特征。结果表明:BSL和APG干团聚体均以>3 mm粒级为主,湿筛以微团聚体(<0.25 mm)占比最高。建植后大团聚体(>0.25 mm)含量增加,微团聚体显著减少,且团聚体几何平均直径、重量平均直径和抗蚀性因子更高,破坏率更低,表明人工建植能显著提高团聚体稳定性。随土壤深度增加,APG和BSL干团聚体稳定性增加,而湿筛稳定性降低,说明0~10 cm团聚体受机械破碎强烈,10~20 cm遇水易破碎。逐步回归表明砂粒降低、氧化还原电位和有机质增加是团聚体稳定性增加的主要因素。因此,多年冻土区人工建植能改善退化草地浅层土壤结构并提高其稳定性。
To study the characteristics of particle size composition and stability of soil aggregates after artificial restoration of the“black soil land”(BSL),in this study,the BSL and the four-year-old artificially planted grassland(APG)in the permafrost regions of the Shule River headwaters in the western part of the Qilian Mountains on the northeastern margin of the QTP were selected as the study object.The characteristic changes of particle size composition and stability of soil aggregates at the layer of 0~20 cm were analyzed by using dry and wet sieving methods.The results showed that the dry sieving soil aggregates at the BSL and APG were predominated by>3 mm particle size,while the wet sieving aggregates had the largest proportion of micro-aggregates(<0.25 mm).Artificial planting increased large aggregate(>0.25 mm)contents but significantly decreased micro-aggregate contents,and the geometric mean diameter,mean weight diameter,and erosion resistance factors of aggregates in the APG were significantly higher,while the percentage of aggregate destruction was lower,indicating that artificial planting significantly improved soil aggregates stability.With increasing soil depth,the stability of dry aggregates at the BSL and APG tended to increase,yet the stability of wet sieving aggregates significantly decreased,suggesting that the soil aggregates were strongly broken by mechanical action at the 0~10 cm layer,but the aggregates were easily dispersed by water at the layer of 10~20 cm.Stepwise regression analyses showed that a decrease in sand content and increases in redox potential and soil organic matter were the main reasons for the increase in soil aggregates stability.Thus,artificial planting in permafrost regions can improve the structure and stability of shallow soils in degraded grassland.
作者
贾映兰
魏培洁
吴明辉
赵建中
高雅月
陈生云
JIA Ying-lan;WEI Pei-jie;WU Ming-hui;ZHAO Jian-zhong;GAO Ya-yue;CHEN Sheng-yun(Cryosphere and Eco-Environment Research Station of Shule River Headwaters,State Key Laboratory of Cryospheric Science,Northwest Institute of Eco-Environment and Resources,Chinese Academy of Sciences,Lanzhou,Gansu Province 730000,China;School of Geographical Sciences,Academy of Plateau Science and Sustainability,Qinghai Normal University,Xining,Qinghai Province 810008,China;University of Chinese Academy of Sciences,Beijing 100049,China;Qinghai Agri-animal Husbandry Vocational College,Xining,Qinghai Province 812100,China;Long-term National Scientific Research Base of the Qilian Mountain National Park,Xining,Qinghai Province 810000,China)
出处
《草地学报》
CAS
CSCD
北大核心
2022年第8期1934-1943,共10页
Acta Agrestia Sinica
基金
国家自然科学基金项目(41871064)
青海省重点研发与转化计划项目(2020-SF-146)
关键词
“黑土滩”
人工建植
土壤团聚体
粒级组成
稳定性
“Black soil land”
Artificial planting
Soil aggregate
Particle size composition
Stability
