不同生长年限黄芪田间杂草群落结构特征

杂草是抑制药用植物生长发育,影响其产量和质量的主要生物因子.黄芪为多年生药用植物,在其生长过程中田间杂草群落结构不断发生变化.通过田间调查统计发现整个黄芪田中杂草有66种,分属24科59属.其中以菊科和豆科杂草种类最多,分别有10种.优势种有冰草、狗尾草、虫实、田旋花、苦荬菜等.不同生长年限黄芪田中杂草群落结构不同,一...

Weed community structure in fields of Astragalus membranaceus of different ages

Weeds are the main biological factors that inhibit the growth， development， yield， and quality of medicinal plants. Astragalus membranaceus is a perennial medicinal plant， and the structure of the weed community structure in fields of this species evolves continuously during its growth. We conducted field surveys and found 66 species of weeds belonging to 24 families and 59 genera in A. membranaceus fields. Members of the Compositae and Leguminosae were the most abundant， with 10 species in each family. The dominant weed species were Agropyron cristatum， Setaria viridis， Corispermum mongolicum， Convolvulus arvensis， and Ixeris polycephala. The weed community structure differed among fields of A. membranaceus plants of different ages. In fields of annual A. membranaceus， the weed community had low values for richness， the Shannon-Wiener index， and the Pielou index （32， 1.71， 0.49）， a high value of Simpson’s index （0.372）， and large biomass. In a field of 10-year-old A. membranaceus， the weed community had high values of the Shannon-Wiener index （3.14） and Pielou index （0.82）， a low value of Simpson’s index （0.068）， and the community structure tended to be stable. The weed community structure was similar among fields of similarly aged A. membranaceus plants， especially 3-to 5-year-old plants Sorenson’s index （0.828）. With increasing age of A. membranaceus plants， the dominant species in the weed community changed from annual seed plants to perennial small herbs to perennial large herbs/small shrubs， and the main species of community-building plants changed from C. mongolicum to A. cristatum to Achnatherum inebrians and Artemisia frigida. We detected two main modes of weed propagation in A. membranaceus fields： The guerrilla warfare mode of seed propagation exemplified by C. mongolicum； And the base area mode of rhizome propagation exemplified by A. cristatum.