Vegetation community and geochemistry in the Uummannaq District, West Greenland

Beach and salt marsh vegetation of the Uummannaq District, northern West Greenland (c. 70°15' N – 72° N, 49° W – 54° W) was studied 1998 according to the Braun-Blanquet phytosociological approach. Habitat analyses included soil chemistry. Such vegetation locally occurs and is not developed over extensive areas. On gravely stony beaches a Mertensia maritima ssp. maritima community occurs, while a Honckenya peploides var. diffusa community is confined to sandy beaches. The association Honckenyo diffusae-Elymetum mollis Thannh. 1975 is confined to sandy shore walls and low dunes. All vegetation types are assigned to the alliance Honckenyo- Elymion arenariae Tx. 1966, which again is a unit of the order Honckenyo- Elymetalia arenariae Tx. 1966, which is sub ordered to the class Honckenyo-Elymetea arenariae Tx. 1966. On fine sediments along sheltered coasts salt marsh vegetation is locally developed mainly on fiord deltas and outwash plains of small rivers and streams. A distinct zonation pattern in vegetation can be observed from the lower to upper salt marsh: Puccinellietum phryganodis Hadac 1946 association, Caricetum subspathaceae Hadac 1946 association, Caricetum ursinae Hadac 1946 association (all assigned to the alliance Puccinellion phryganodis Hadac 1946) and Festuco-Caricetum glareosae Nordh. 1954 association (assigned to the alliance Armerion maritimae Br.-Bl. et de Leeuw 1936). Both alliances are units of the order Glauco- Puccinellietalia Beeftink et Westhoff in Beeftink 1965, which is assigned to the class Asteretea tripolii Westhoff et Beeftink in Beeftink 1962. TWINSPAN and CCA support the vegetation classification and the CCA with soil chemistry parameters shows that salinity (related to position above MHW) and Ncontent are strongly correlated with the floristical differentiation of the vegetation of the Honckenyo-Elymetea class. In the Asteretea tripolii class, position above MHW (negatively correlated with pH, conductivity and Clcontent) and fresh water supply are likely the main factors, which affect vegetation differentiation. A synoptic survey of vegetation types from Greenland based on published phytosociological tables is presented and distribution of the vegetation types is addressed, just as their position in a circumpolar context. Moreover a Cochlearia groenlandica-Melandrium triflorum community is described as a new vegetation type, occurring on shallow soil on cliffs influenced by salt spray.

本研究于1998年采用布劳恩-布朗奎特（Braun-Blanquet）植物社会学方法，对西格陵兰北部乌马纳克地区（约北纬70°15'至72°、西经49°至54°）的海滩与盐沼植被展开调查研究。栖息地分析涵盖土壤化学特征测定。该区域植被呈局部分布，未形成大面积连片的群落。在砾石质海滩上，分布有海勿忘草（Mertensia maritima ssp. maritima）群落；砂质海滩则以Honckenya peploides var. diffusa群落为优势类群。1975年由Thannh命名的Honckenyo diffusae-Elymetum mollis群落，仅分布于砂质岸堤与低矮沙丘。所有植被类型均隶属于1966年Tx.确立的Honckenyo-Elymion arenariae群丛联盟，该联盟又归属于1966年Tx.确立的Honckenyo-Elymetalia arenariae群丛目，而该目隶属于1966年Tx.确立的Honckenyo-Elymetea arenariae群丛纲。在受庇护海岸的细粒沉积物环境中，盐沼植被局部分布于峡湾三角洲与小型河流的冲积平原。从低潮带向高潮带可观察到清晰的植被分带现象：依次为1946年Hadac发表的Puccinellietum phryganodis群落、1946年Hadac发表的Caricetum subspathaceae群落、1946年Hadac发表的Caricetum ursinae群落（以上三者均隶属于1946年Hadac确立的Puccinellion phryganodis群丛联盟），以及1954年Nordh.发表的Festuco-Caricetum glareosae群落（隶属于1936年Br.-Bl. et de Leeuw确立的Armerion maritimae群丛联盟）。上述两个群丛联盟均归属于1965年Beeftink et Westhoff在Beeftink文献中确立的Glauco-Puccinellietalia群丛目，该目隶属于1962年Westhoff et Beeftink在Beeftink文献中确立的Asteretea tripolii群丛纲。双向指示种分析（TWINSPAN）与典范对应分析（CCA）验证了本研究的植被分类方案；结合土壤化学参数的典范对应分析显示，盐度（与平均高潮位（MHW）以上的高程呈相关关系）与土壤氮含量，是影响Honckenyo-Elymetea群丛纲植被区系分异的关键驱动因子。而在Asteretea tripolii群丛纲中，平均高潮位以上的高程（与pH值、电导率及氯含量呈负相关）与淡水补给量，是影响植被分异的主要因素。本研究还基于已发表的植物社会学数据表，对格陵兰地区的植被类型开展了概览性调查，阐述了各类植被的分布格局及其在环北极植被系统中的分类地位。此外，本研究描述了一个新的植被类型——受盐雾影响的悬崖浅土生Cochlearia groenlandica-Melandrium triflorum群落。