兰州地区胡麻田杂草消长动态及群落生态位研究

采用田间调查和室内测定、相对丰度和生态位计算与分析相结合的方法,对兰州地区胡麻田杂草群落进行了研究。初步明确了兰州地区胡麻田间杂草种类共有11科23种,其中主要科为:禾本科、菊科、藜科、苋科和旋花科;优势种群为:地肤、狗尾草、藜、苣荬菜、稗草和打碗花。同时明确了优势杂草的消长变化规律,即4月中旬为杂草始发期,5月中旬和6月中旬为2个出草高峰期。优势杂草生态位的研究结果表明,地肤的综合生态位宽度值最大,对胡麻的危害最大,其次为狗尾草和藜;地肤与狗尾草的时间生态位重叠值最大,与苣荬菜的水平生态位重叠值最大;而苣荬菜和藜的垂直生态位重叠值最大,它们相互之间利用资源的相似性较高。利用相对丰度和生态位宽度均能确定优势杂草的种类,反映杂草对作物危害程度的大小。

A study on weed population dynamics and niches in a flax field in the Lanzhou area

Combining field investigation and laboratory measurements,the calculation and analysis of the relative abundance and niches,of a weed community of a flax field in the Lanzhou area were studied.There were 23 species from 11 families in the flax fields.The main families were Gramineae,Compositae,Chenopodiaceae,Amaranthaceae and Convolvulaceae,and the dominant species were Kochia scoparia,Setaria viridis,Chenopodium album,Sonchus brachyotus,Echinochloa crusgalli and Calystegia hederacea.Weeds appeared in mid-A...