摘要
芒苞草(Achanthoclamys bracteata P.C.Kao)是分布于横断山区局部狭小区域的一种单型科植物,在指示植物系统进化和地理环境变迁中具有十分重要的作用和地位.对四川省道孚县鲜水河流域的两个芒苞草分布地点(麦粒山和亚卓山)进行了群落学特征和土壤学研究.芒苞草生境群落类型为温性干旱河谷灌丛和草地,上接亚高山云冷杉针叶林.麦粒山芒苞草生境为毛莲蒿-矮嵩草-芒苞草群落;而亚卓山灌丛草地类型为川滇蔷薇-毛莲蒿-西南野古草-芒苞草群落,亚卓山草地则以西南野古草、直芒草、金发藓等为优势种.物种多样性指数以灌丛最高,亚卓山草地物种多样性在中海拔处出现极小值,海拔越高,芒苞草单株重量越轻,中海拔位置处的地上地下生物量比值(2.06±0.17)最大.土壤元素含量以铝和铁最丰富,而磷和钾的含量分别为(8873.5±1463.3)mgkg-1和(431.1±180.4)mgkg-1,比该区域的平均值低.芒苞草多生长在有岩石出露的地方,在道孚县的分布区域局限在鲜水河河谷地带.芒苞草强烈的生境选择作用以及河谷地带强度较大的人为活动,是威胁芒苞草生存的主要因素.
Achanthoclamys bracteata P.C. Kao is a monotypic family species distributing in the Hengduan Mountains in Sichuan, China. This plant is significantly important for phylogenetic and phytogeographic research. According to the studies on the communities and soil of two A. bracteata habitats （Mt. Maili and Mt. Yazhuo） along Xianshui River in Daofu County, Sichuan, the vegetation of the A. bracteata habitats belongs to temperate arid-valley shrub and grassland. The shrub types in Mt. Yazhuo are mainly composed of Rosa soulieana, Artemisia vestita, Arundinella hookeri and Acanthochlamys bracteata, while the nearby meadow is dominated by Arundinella hookeri, Orthoraphium roylei, and Polytrichum commune, etc. Thg community type in Mr. Maili near Daofu Town is Artemisia vestita - Kobresia humilis - Acanthochlamys bracteata. The highest species diversity index （Shannon-Wiener index, SW index） is held by shrub community in Mt. Yazhuo. However, the SW index of the meadow is the lowest at the middle of the elevational gradient, where the ratio of aboveground to belowground biomass ofA. bracteata is highest （2.06±0.17）. The dry biomass of the individual plants decreases along the elevation. The soil is rich in aluminum and iron. However, the contents of potassium （431.1±180.4 mg kg^-1） and phosphor （8 873.5±1 463.3 mg kg^-1） are below the average of this region. A. bracteata generally grows in the vicinity of outcrops and is restricted in the valley areas, where human activities are extensive. The strong habitat selectivity of A. bracteata might be the major reason of its extinction. To effectively protect A. bracteata, the pressure of land use and exploitation of natural resot^rces need to be largely reduced. Fig 5. Tab 3. Ref24
出处
《应用与环境生物学报》
CAS
CSCD
北大核心
2009年第1期1-7,共7页
Chinese Journal of Applied and Environmental Biology
基金
四川省应用基础研究基金
中国科学院知识创新工程重大项目(No.KZCX2-XB2-02)
中国科学院知识创新工程
国家自然科学基金面上项目(No.40671181)
国家科技支撑计划课题(No.2007BAC18B04)资助~~
关键词
芒苞草
群落
土壤元素
生境
四川道孚
Achanthoclamys bracteata
Daofu County
community
soil element
habitat
