摘要
采用野外调查方法研究了青藏高原腹地退化青藏苔草草原植物生态位的特征,结果表明:随着青藏苔草草原的退化,青藏苔草的重要值和生态位宽度逐渐降低,莎草科的高山嵩草、禾本科的紫羊茅和波伐早熟禾、豆科的黄花棘豆和多枝黄耆的生态位宽度先升高后降低,轻度和中度退化阶段时最大,杂类草西伯利亚蓼自出现后随退化程度增强,其重要值和生态位宽度逐渐增加。不同退化阶段,植物间生态位重叠度最大的物种对存在分异,在未退化、轻度、中度和重度退化阶段,青藏苔草分别与矮火绒草、紫羊茅、珠芽蓼和高山嵩草的生态位重叠度最高;中度退化时,物种间生态位重叠度最低的是兰石草和线叶龙胆,但其余各阶段多枝黄耆是生态位重叠度最低的物种之一。
A field survey was carried out to determine the plant niche characteristics of degraded Carex moorcroftii steppe in the hinterland region of Qinghai-Tibetan Plateau.The results showed that the important value and niche breadth of C.moorcroftii gradually decreased as the C.moorcroftii steppe degraded,whereas the niche breadth of Kobresia pygmaeain Cyperaceae,Festuca rubra and Poa poophagorum in Gramineae,Oxytropis ochrocephalaand Astragalus polycladus in Legume firstly increased and then decreased in the degradation process of C.moorcroftii steppe,and was maximal in lightly and moderately degraded steppe.The important value and niche breadth of Polygonum sibiricumincreased with degraded degree of C.moorcroftii steppe.The biggest niche overlap between different plants was different among C.moorcroftii steppes in different degraded degree.The niche overlap between C.moorcroftii and Leontopodinm nanum,Festuca rubra,Polygonum viviparum and K.pygmaea was the biggest in non-degraded,lightly,moderately and highly degraded degree of C.moorcroftii steppe,respectively.The niche overlap between Lancea tibetica and Gentiana farreri was the lowest in moderately degraded degree,while Astragalus polycladus had the lowest coefficient of niche overlap in non-degraded,lightly and highly degraded degree of C.moorcroftii steppe.
出处
《中国草地学报》
CSCD
北大核心
2015年第1期30-37,共8页
Chinese Journal of Grassland
基金
国家农业行业公益科技项目(201203006)
国家科技支撑计划项目(2012BAD13B00)
兰州大学中央高校基本科研业务费项目(lzujbky-2014-m01)
关键词
青藏苔草草原
重要值
生态位宽度
生态位重叠值
退化程度
Carex moorcroftii steppe
Important value
Niche breadth
Niche overlap
Degradation degree
