Abstract: The vegetation of Songhua-Nenjiang Plains is composed of four contiguous Mongolian,Northeastern,Dahuricia and North China floras.The 10 Ulmus woodland sample sites and 40 sample squares boast 89 plant species of 26 families:of which 6 are of the plant growth form,4 of root growth form,6 of life form,4 of water ecological type,13 of areal plant type, and 6 of forage value type.Among the 89 species,Compositae species tops all the others,amounting to 22.5%,Gramineae and Leguminosae occupy 15.7% and 12.4% respectively.Of the plant growth form,the branched type tops all the others,reaching 39%,while the arect type and the tfted type account for 21% and 16% respectively.As for the root growth form,the taproot type reaches the majority to 66%,and the rhizome and the brush root type reaches the majority to 66%,and the rhizome and the brush root types make up 17% and 16% respectively.Among the life form plants,the hemicryptophyte amounts to 43% of the total,the geophyte and the therophyte each makes up 15%,and the hemicrypto-geophyte takes up 12%.The mesophyte species makes up 63%,and the mesoxerophyte species 19%,of the total water ecological plants.The areal types consist of 30% Mongolian-Northeastern-Dahuricia-North China type,and 16% Mongolian areal type.Within the forage value type,medium and low quality forage species make up 46%,while high and fine quality forage species only accounts for 31%.The climate of the Ulmus woodland of the Songhua-Nenjiang Plains is typically that of temperate hemicryptophyte with mesophitic habitat conditions.The areal plant structure in the plains is complicated and its plant species’ forage value is outstanding.

Key words: Grassland science, Ulmus woodland, Growth form, Life form, Ecological type, Areal type, Forage value type, Spectrum of structure type

摘要： 松嫩平原植被是蒙古、东北、兴安和华北4个植物区系成分相接触的区域,在全区所设的10个榆树疏林调查样地40个样方中,共有89种植物,隶属于26个科,6个株生长型,4个根生长型,6个生活型,4个水分生态类型,13个分布区型和6个饲用价值类型。其中,菊科种类最多,占22.5%;禾本科和豆科分别占15.7%和12.4%。株生长型结构以分枝型种类最多,占39%;直立型和丛生型分别为21%和16%。根生长型结构以直根型的种类最多,占66%;根茎型和刷状根型分别为17%和16%。生活型结构以地面芽植物最多,占43%;地下芽植物和一年生植物次之,各占15%;地面 地下芽植物占12%。水分生态类型结构以中生型种类最多,占63%;中旱生型次之,占19%。分布区型结构以蒙古 东北 兴安 华北分布区型的种类最多,占30%;蒙古分布区型次之,占16%。饲用价值类型以中、低等质量的种类最多,占46%;优、良牧草种类占31%。松嫩平原榆树疏林具有典型的温带地面芽植物气候、中生生境条件、植物分布区型结构复杂、饲用价值较高的特征。

关键词: 草原学, 榆树疏林, 生长型, 生活型, 生态类型, 分布区型, 饲用价值类型, 结构型谱