不同生境准噶尔无叶豆群落特征及物种多样性研究

Community Characteristics and Species Diversity of Eremosparton songoricum under Different Habitats

采用样带调查方法对古尔班通古特沙漠南缘的3种典型生境(沙垄顶部、人工沙障和积沙平缓处)的准噶尔无叶豆(Eremosparton songoricum)群落特征和物种多样性进行调查。结果表明,准噶尔无叶豆群落中包含19个物种,隶属于11科18属,单种科、单种属多,区系优势现象明显;依据Dufrene和Legendre的计算方法将准噶尔无叶豆群落划分为3个群丛:准噶尔无叶豆+白茎绢蒿+角果藜群丛、囊果薹草+准噶尔无叶豆+黑沙蒿群丛和准噶尔无叶豆+艾比湖沙拐枣+蛇麻黄群丛;植物区系种类以北温带广布成分占优势,主要特点为:具有典型的旱生植物分布特征;植物组成主要为适沙和耐旱的种类,结构、层次单调;准噶尔无叶豆群落多样性指数和丰富度指数均表现为积沙平缓处最高,沙垄顶部次之,人工沙障处最低,优势度指数则表现为相反的趋势。物种的丰富度指数、多样性指数与群落的结构以及立地环境条件等有密切的关系,结构复杂的群落较其他群落的多样性指数高,但由于人工沙障的特殊生境所形成的准噶尔无叶豆单优群落物种多样性指数则较低。

As a kind of rare species, Eremosparton songoricum is mainly patched distributed in Gurbantunggut Desert,Xinjiang,China.To analyze the community characteristic and species diversity of E.songoricum,the method of transect sampling survey was adopted in three typical habitats (top of the dune,artificial sand-protecting barrier,smooth sandy area) at the south edge of the desert.The results showed that the community of E.songoricum was consisted of 19 species,which belonged to 11 families and 18 genera.The species mainly concentrated on monotypic family and genus.The dominant phenomenon of the flora was obvious.According to the research method suggested by Dufrene and Legendre,we classified the community of E.songoricum into three ecological associations: E.songoricum+Seriphidium terrae-albae+Ceratocarpus arenarius association. E.songoricum+Artemisia ordosica+Carex physodes association and E.songoricum+Calligonum ebinuricum+Ephedra distachya .For phytogeographical elements,the north temperate elements had a dominant position.The main characteristics were as follows:it had a typical distribution feature of arid plant,plants were mainly consisted of sand-adaptable and drought-tolerant species,which had less structures and layers The diversity index and richness index of the E.songoricum community in smooth sandy area were the highest,followed by the top of the dune,and the artificial sand-protecting barrier,and the dominance index showed the opposite trend.There existed a close relationship among species richness index,diversity index,community structure and environmental conditions of the habitats.Complex communities had a higher diversity index than other communities.However,the species diversity index of E.songoricum was lower because of the special habitat of artificial sand-protecting barrier.