摘要
Windmill 群岛的苔藓植被可划分为以下几种群落:1.南极紫萼藓(Grimmia antarctici)群落;2.南极紫萼藓-角齿藓(Ceratodon purpureus)群落;3.拟三列真藓(Bryum pseudo-triquetrum)群落;4.南极紫萼藓-拟三列真藓群落;5.角齿藓群落;6.角齿藓-南极紫萼藓群落;7.角齿藓-拟三列真藓群落。群落1、3、4、7趋向喜湿,群落5、6多分布于较干旱的生境,群落2的分布介于干-湿两者之间的生境。Windmill 群岛无冰盖地区苔藓群落的分布取决于由地形而引起的水分供应的状况。根据 Windmill 群岛稳定的苔藓群落种类、颜色和苔藓丘的部位,在群落的垂直结构上,可划分2—3层;从群落的水平结构看,形成了重复出现的镶嵌体。从该地区苔藓群落的其它特点看,如苔藓植物呈垫状密集生长,无性繁殖(尽管在各个种中都发现了精子器或颈卵器),苔藓丘顶部地衣、海藻的附生,同一种苔藓由于生境和群落小生境不同引起的色泽变化等,都与南极湿度的有效性、光的强度、风向和温度有关。
The moss vegetation of the Windmill Islands can be classified into the following seven communities:1.Grimmia antarctici community;2.G.antarctici-Ceratodon purpureus comm- unity;3.Bryum pseudotriquetrum community;4.G.antarctici-B,pseudotriquetrum community; 5.Ceratodon purpureus community;6.C.purpureus-G,antarctici community;7.C.purpureus- B.pseudotriquetrum community.Communities 1,3,4 and 7 occur in wet habitats while com- munities 5 and 6 are found in,rather dry habitats,community 2 distributes between dry and wet habitats.Microtopography governs the distribution of water supply and therefore comm- unity types. Stable moss communities usually form moss hummocks and hollows.Species composition, colour and height of the hummocks determines the vertical structure of the moss community layers with 2-3 strata being discernible and level structure forming mosaic. Other phytocoenological characteristics of the moss communities,such as the dense moss cushions,asexual reproduction (although antheridia or archegonia have been found in each of the species),abundance of epiphytic algae and lichens growing on the surface of moss hum- mocks,the colour change of some species in different habitats,appear related to moisture availability,light intensity,wind exposure and temperature.
关键词
苔藓植物
植物群落
南极
苔藓丘
Antarctica
Ice-free areas
Moss hummock
Moss hollow
