摘要
为了解黄河源地区“黑土滩”退化草地的空间分布规律和分布的关键地形特征,利用2019年黄河源区玛沁县、河南县、泽库县遥感影像解译数据,结合实地调查,分析高寒“黑土滩”型退化草地空间分布特征。结果表明:黄河源区“黑土滩”型退化草地海拔为3500~4000m,且在海拔3700~3800m时退化最严重;从坡向分析来看,“黑土滩”型退化草地主要发生于阳坡、半阳坡,从坡度分析来看,“黑土滩”型退化草地主要发生于缓坡地和滩地。聚类分析发现研究区草地类型为阳坡极度退化草地、半阳坡重度退化草地、阳坡-滩地轻度退化草地、半阳坡轻度退化草地、湿地轻度退化草地、阴坡未退化草地等6类。随着退化程度的加剧,植被盖度、地上生物量减少;同一土层的全氮、全磷、碱解氮、速效磷、有机质含量在湿地轻度退化草地和阴坡轻度退化草地中最高,阳坡极度退化草地最低,且差异显著(P<0.05);丰富度指数、多样性指数、均匀度指数以及土壤速效钾含量在重度、轻度退化草地较高,湿地轻度退化草地显著最低。阳坡极度退化草地全钾含量、鼠害破坏率和鼠洞数最高,湿地轻度退化草地全钾含量最低,与阳坡极度退化草地差异显著(P<0.05);湿地轻度退化草地和阴坡轻度退化草地均无鼠类活动。
In order to understand the regularity of spatial distribution and the key topographic features of the degraded grassland in the black soil beach,the data of remote sensing image interpretation in the year of 2019 in counties of Maqin,Henan and Zeku in the source region of the Yellow River were used and field investigation was conducted to analyze the spatial distribution characteristics of alpine de-graded grassland in black soil beach.The results showed that the degraded grassland in the black soil beach of the source region of the Yellow River was distributed at the altitude of 3500-4000 m,and themost serious degradation was at the altitude of 3700-3800 m.From the slope analysis,the de-graded grassland in black soil beach mainly occurred on the sunny and semi-sunny slopes,from the analysis of slope degree,the degraded grassland in black soil beach mainly occurred on the gentle slope and beach.After the cluster analysis,the degraded grassland could be divided into six types,namely extremely degraded grassland on the sunny slope,severely degraded grassland on the semi-sunny slope,slightly degraded grassland on the beach and sunny slope,slightly degraded grassland on the semi-sunny slope,slightly degraded grassland on the wetland,and non-degraded grassland on the shad-y slope.With the deterioration of degradation,the vegetation coverage and aboveground biomass de-creased;the contents of total nitrogen,total phosphorus,alkali-hydrolysable nitrogen,available phos-phorus and organic matter in the same soil layer of the different degradations were highest in the slightly degraded grassland on the wetland and onthe shady slope,while it was the lowest in extremely degraded grassland on the sunny slope,and the differences were significant(P<0.05).The richness index,diversity index,evenness index and soil available potassium content were higher in severely and slightly degraded grassland,howerver,it was lower in slightly degraded grassland on thewetland,and there were significant differences between slightly degraded grassland on the wetland and other types of degraded grassland(P<0.05).In the extremely degraded grassland on the sunny slope,the total potassium content and the rat damage rate were highest,the number of rat holes were the most,the total potassium content was the lowest in slightly degraded grassland on the the wetland,which was extremely different from the extremely degraded grassland on the sunny slope(P<0.05),and there was no any rodent activity on the slightly degraded grassland on the shady slope,so the characteristics of terrain characteristics was consistent with the conditions of rodents’habitat.
作者
李积兰
王苑
李希来
刘慧
王晓波
LI Jilan;WANG Yuan;LI Xilai;LIU Hui;WANG Xiaobo(College of Agriculture and Animal Husbandry,Qinghai University,Xining 810016,China;College of Eco-Environment Engineering Qinghai University,Xining 810016,China;Geospatial and Natural Resources Big Data Center of Qinghai Province,Xining 810008,China;Qinghai Natural Resources Comprehensive Investigation and Monitoring Institute,Xining 810008,China)
出处
《西北农业学报》
CAS
CSCD
北大核心
2024年第1期108-120,共13页
Acta Agriculturae Boreali-occidentalis Sinica
基金
青海省科技厅应用基础研究计划(2018-ZJ-780)
国家自然科学基金(31872999)。
关键词
黄河源区
退化草地
空间分布
植物群落
Source region of the Yellow River
Degraded grassland
Spatial distribution
Plant com-munity
