广州地区四季叶菜田杂草群落组成及其生态位

为明确南亚热带地区四季叶菜田杂草群落组成及其生态位，利用倒置“W”九点取样法，对广州地区4个市区16个规模化菜场杂草群落进行季节动态调查。结果表明，春季杂草群落结构以腋花蓼（Polygonum plebeium）+马齿苋（Portulaca oleracea）+光头稗（Echinochloa colonum）为主；夏季以马齿苋+碎米莎草（Cyperus iria）+凹头苋（Amaranthus lividus）为主；秋季以马齿苋+酸模叶蓼（Polygonum lapathifolium）+凹头苋为主；冬季以腋花蓼+碎米荠（Cardamine hirsuta）+酸模叶蓼为主。运用改进的Levins生态位宽度指数和Pianka生态位重叠指数对四季优势杂草生态位进行分析，结果表明，15种优势杂草生态位总宽度大部分在0.50以上，其中生态位总宽度生态位宽度大于1.00的有马齿苋（1.22）、腋花蓼（1.15）、酸模叶蓼（1.08）。夏季生态位重叠指数达到0.50的最多，秋季则最少。生态位重叠指数最大的3组杂草分别为春季的马唐（Digitaria sanguinalis）和牛筋草（Eleusine indica）（0.87），夏季的马齿苋和凹头苋（0.82）以及马齿苋和牛筋草（0.80）。

Weed Community Composition and Niches of Leaf-vegetable Plots in Guangzhou Region in Four Seasons

The seasonal dynamics of weed community in 16 large-scale vegetable plots of 4 cities and districts in Guangzhou region were surveyed by using invertedWsampling method to study weed community composition and niches of leaf-vegetable plots of south subtropical region in four seasons.The weed community was mainly consisted of(Polygonum plebeium)+(Portulaca oleracea)+(Echinochloa colonum) in spring,(Portulaca oleracea)+(Cyperus iria)+(Amaranthus lividus) in summer,Portulaca oleracea+(Polygonum lapathifolium)+(...