摘要
以空间代替时间的方法,通过对宁夏中北部荒漠草原不同沙漠化阶段草地土壤养分与植被生产力的研究,探讨土壤养分和植被根冠比对草地沙漠化的响应特征,以期为干旱与半干旱地区荒漠草原的生态恢复与重建提供科学依据。结果表明:随着荒漠草原沙漠化程度的增加,植被地上、地下生物量呈现减小的趋势,但是轻度沙漠化阶段植被地上、地下生物量均大于潜在沙漠化阶段。植物根冠比随着草地沙漠化程度加剧而减小,而重度沙漠化阶段植物根冠比比中度沙漠化阶段增加了36%;随着草地沙漠化程度的加剧,土壤有机碳、全磷、全氮、速效钾和速效氮含量均呈降低趋势;在草地沙漠化过程中,土壤养分的积累减弱导致土壤肥力降低,草地生产力下降。
The changes of soil nutrients and plant biomass were analyzed by spatial method instead of time method in different desertification stages in order to discuss the response of soil nutrient and root-shoot ratio to desertification in the north-central Ningxia, China. The results showed that decreased from light desertification stage to very severe desertification stage with the development of grassland desertification, while aboveground and belowground biomass in light desertification stage was higher than in potential desertification stage. The change trend of root-shoot ratio gradually declined with the development of grass-land desertification, while the root-shoot ratio in severe desertification stage increased by 36% compared to moderate desertification stage. The organic carbon, total nitrogen, total phosphorus, available nitrogen and available potassium of soil decreased from potential desertification stage to very severe desertification stage; while soil available phosphorus decreased from potential desertification stage to moderate desertification stage, and increased at severe desertification stage, then decreased at very severe desertification stage. Compared with moderate desertification stage, the soil available phosphorus of severe desertification stage increased by 4%, but there was no significant difference between moderate desertification and severe desertification stage. There was significantly positive correlation between total phosphorus and aboveground biomass, belowground biomass, root-shoot ratio. The desertification reduced soil fertility and caused grassland productivity decline.
出处
《草地学报》
CAS
CSCD
北大核心
2015年第3期463-468,共6页
Acta Agrestia Sinica
基金
国家自然科学基金(31260125)(41390463)
科技基础性工作专项(2014FY210100)资助
关键词
荒漠草原
沙漠化
土壤养分
根冠比
Desert steppe
Desertification
Soil Nutrient
Root-shoot ratio
