Influence of land cover changes on the physical and chemical properties of alpine meadow soil

来源 :科学通报 | 被引量 : 0次 | 上传用户:yyyypolo
下载到本地 , 更方便阅读
声明 : 本文档内容版权归属内容提供方 , 如果您对本文有版权争议 , 可与客服联系进行内容授权或下架
论文部分内容阅读
Taking the alpine cold meadow grassland in the southeastern part of the Qinghai-Tibetan Plateau as an example, this research deals with the characteristics of alpine meadow soil property changes, including soil nutrients, soil physical properties and soil moisture content under different land coverage conditions. With the degradation of grassland vegetation and the decline of vegetation coverage, soil compactness reduces, gravel content increases and bulk density increases. The originally dense root-system layer is gradually denuded, making the soil coarse and gravel. The change of the organic matter contents with the vegetation coverage change in the surface soil layer (0-20 cm) has shown an obvious cubic polynomial curve process. The organic matter contents increase rapidly when land coverage is above 60%, contrarily decreases on a large scale when land coverage is below 30%. Between 30%-60% of land coverage the organic matter contents remain stable. The total N and organic matter contents in soil have shown quite similar change regularity. Following this the mathematic equations are derived to describe such change processes. Moisture content in soil changes sharply with the vegetation coverage change. Soil moisture content change with the vegetation coverage change has shown a quadratic parabola process. Results have shown that organic matter content and the total N content of the alpine meadow soil decrease by 14890 kg/hm2 and 5505 kg/hm2 respectively as the vegetation coverage reduces from 90% to less than 30%. The heavy changes of soil physical and chemical properties with grassland degradation have made the recovery of alpine meadow ecological system impossible. The protection of alpine meadow vegetation is of vital importance to the maintenance of the regional soil environment and the regional ecological system.
其他文献
对在不同切削条件下木材切削加工过程木工刀具磨损的多组试验数据,采用PLSR方法,根据变量重要性指标分析和因子载荷分析,从7个变量及其组合中筛选出了5个用于建模的自变量,以刀具
以胶合板为研究对象,通过改变温度、相对湿度以及空气交换率与负荷因子之比3种环境因素,探究一种快速检测的方法,分析各环境因素对胶合板VOC释放的影响以及胶合板VOC释放规律。
以PE基木塑复合材料的动态弹性模量预测模型为研究对象,利用无损检测的方法对PE基木塑复合材料的动态弹性模量进行检测。将制备方式与实验结果分别利用回归预测模型与灰色理论
将FeSO4-THPS结合鞣法与Cr鞣法和Fe(Ⅱ)鞣法进行对比,考察了它们鞣制绵羊皮后革坯的状态,测定和评估了复鞣加脂后成革的物理力学性能及感官特征,并对坯革的耐热老化性进行了
陕北某页岩气田压裂返排液处理后的出水用于回注和配制压裂液。针对该处理系统局部结垢严重的问题,对垢样采用扫描电镜/能谱和化学法进行了微观扫描和组成分析,判定结垢物的主
The indirect influence of heavy metal contamination of soil on nutrient availability, an important aspect of soil quality, may need to be taken into considerati
Objective To estimate the benefits of reductions in underweight and Vitamin A deficiency forchild survival in China that might be expected as a result of loweri
为了进一步办好《临床与实验病理学杂志》,总结该刊十多年的办刊经验,认真分析自身特点和发展潜力。认为地方性学术期刊要想在学术期刊界占领一席之地并持续健康地发展,准确
Soil erosion on sloping field has led to a lot of environmental problems. In order to reveal the seriousnessof the damage of soil erosion on sloping fields 137C
A novel coronavirus has been identified as the causative agent of the severe acute respiratory syndrome (SARS). For all the SARS-CoV associated proteins derivat