荒漠草原放牧遗留效应和模拟降水对土壤粒径组成及有机碳的影响
Effects of Grazing Residuals and Simulated Precipitation on Soil Particle Size and Organic Carbon in Desert Steppe
付净瑶 1王忠武1
作者信息
- 1. 内蒙古农业大学草原与资源环境学院,内蒙古 呼和浩特 010011;内蒙古农业大学草地资源教育部重点实验室,内蒙古 呼和浩特 010011
- 折叠
摘要
为研究荒漠草原土壤粒径组成及有机碳含量对不同强度放牧遗留效应和降水变化的响应,以内蒙古短花针茅荒漠草原为研究对象,在不放牧、轻度放牧、重度放牧3个不同放牧强度小区设置模拟降水试验平台并开展野外控制试验,4个降水梯度分别为减少50%自然降水、自然降水、增加50%自然降水、增加100%自然降水.于生长季8月进行土壤样品采集,测定了土壤粒径组成及土壤有机碳含量.结果表明:1)放牧遗留效应和降水变化及其交互作用均对土壤有机碳含量有显著影响(P<0.05),放牧遗留效应对土壤有机碳含量呈正向影响,而降水变化对土壤有机碳含量呈负向影响.2)放牧遗留效应和降水变化及其交互作用均对土壤黏粒、粉粒含量有显著影响(P<0.05),轻度放牧遗留效应下土壤黏粒、粉粒含量显著高于重度放牧遗留效应,增加降水和重度放牧遗留效应都会导致土壤中黏粒、粉粒含量减少.重度放牧遗留效应使土壤砂粒含量增加.3)放牧遗留效应和降水变化会直接影响土壤有机碳含量,也会通过影响土壤粒径组成间接对土壤有机碳含量造成影响.综上,轻度放牧遗留效应和适宜的降水量下短花针茅荒漠草原的土壤质地较好,有机碳含量较高,围封六年后留存的放牧效应依然对荒漠草原土壤有机碳含量及粒径组成有影响,放牧遗留效应和极端降水会导致土壤粒径组成发生改变,影响土壤有机碳的积累.
Abstract
This study investigated the long-term effects(residual effects)of grazing intensity and altered precipitation regimes on soil particle size composition and organic carbon content in a Stipa breviflora desert steppe ecosystem located in Inner Mongolia,China.A simulated precipitation experiment was established within three grazing intensities(no grazing,light grazing,and heavy grazing)alongside a field control.Four precipitation gradients were implemented:50%reduction in natural precipitation,natural precipitation level,50%increase in natural precipitation,and 100%increase in natural precipitation.Soil samples were collected in August of the growing season,and the soil particle size composition and soil organic carbon content were ana-lyzed.The results showed the following:1)Both grazing residual effect and precipitation change significantly impacted soil organic carbon content(P<0.05).The grazing residual effect positively affected on soil organic carbon content,while changes in precipitation negatively affected soil organic carbon content.2)Grazing residual effect,precipitation change,and their interaction significantly affected soil clay and silt content(P<0.05).Soils under a legacy of light grazing exhibited higher clay and silt content compared to those under heavy grazing.Furthermore,increased precipitation in conjunction with heavy grazing legacy led to a decrease in clay and silt contents,while soil sand particles content under a legacy of heavy grazing exhibited the opposite trend.3)The study suggested that grazing residual effect and precipitation changes directly influence soil organic car-bon content and indirectly affected it through alternations in soil particle size composition.In conclusion,light grazing and appropriate precipitation levels resulted in optimal soil texture and organic carbon content within the desert steppe.The findings also indicate that soil organic carbon content and particle size composition remain affected by grazing history even after six years of enclosure.The combined effects of grazing and extreme pre-cipitation events can significantly alter soil particle size composition,further impacting the accumulation of soil organic carbon.
关键词
荒漠草原/模拟降水/放牧遗留效应/土壤粒径组成/土壤有机碳含量Key words
Desert steppe/Simulated precipitation/Grazing residual effect/Soil particle size composi-tion/Soil organic carbon content引用本文复制引用
基金项目
内蒙古农业大学学科交叉基金项目(BR22-14-04)
内蒙古自治区重大科技专项(2021ZD0044)
国家自然科学基金项目(31560140)
国家自然科学基金项目(31760143)
出版年
2024
NETL
NSTL
万方数据