应用PCA及MST研究浙中麦田杂草生态学相似关系

Using Principal Components Analysis and Minimal Spanning Tree to Study Weed Ecological Similarity in Wheat Fields in Middle

应用七级目测法对浙江金华地区１６个麦田样点中随机取样的１６０个样方的杂草进行了优势度等级调查，将所得数据转换成重要值；以杂草在１６个样点中的重要值为运算指标，应用主成分分析和图论聚类中的最小生成树法，对２２种杂草的生态学相似性进行了比较．结果表明，２２种杂草中，野燕麦Ａｖｅｎａｆａｔｕａ与猪殃殃Ｇａｌｉｕｍａｐａｒｉｎｅｖａｒ．ｔｅｎｅｒｕｍ、波斯婆婆纳Ｖｅｒｏｎｉｃａｐｅｒｓｉｃａ、卷耳Ｃｅｒａｓｔｉｕｍｖｉｓｃｏｓｕｍ、艾蒿Ａｒｔｅｍｉｓｉａａｒｇｙｉ及荠菜Ｃａｐｓｅｌａｂｕｒｓａ－ｐａｓｔｏｒｉｓ等杂草的生态学相似性较大，而看麦娘与雀舌草Ｓｔｅｌａｒｉａａｌｓｉｎｅ、牛繁缕Ｍａｌａｃｈｉｕｍａｑｕａｔｉｃｕｍ、水苦荬Ｖｅｒｏｎｉｃａｕｎｄｕｌａ－ｔａ则与棒头草Ｐｏｌｙｐｏｇｏｎｆｕｇａｘ、稻槎菜Ｌａｐｓａｎａａｐｏｇｏｎｏｉｄｅｓ、一年蓬Ｅｒｉｇｅｒｏｎａｎｎｕｕｓ及罔草Ｂｅｃｋｍａｎｎｉａｓｙｚｉｇａｃｈｎｅ等杂草的生态特性比较相近．文章指出，除草剂长期单一使用导致农田杂草种群迅速更迭的原因涉及到两方面因素：杂草对除草剂的敏感性差异以及不同杂草间的生态学特性的差异，因此，深入研究农田杂草种群，比较它?

In the wheat fields of middle Zhejiang Province,160 random sampling fields of 16 sites on different ecological conditions were surveyed in detail with seven scales by visualization of weed dominance to wheat to obtain the weed important value. The principal components analysis and the method of minimal spanning tree were used to reveal the ecological similarity of 22 main weeds in wheat fields. The results showed that the ecological similarity among Avena fatua,Galium aparine var. tenerum,Veronica persica, Cerastium viscosum, Artemisia argyi and Capsella bura pastoris is high,while Alopecurus aequalis, Stellaria alsine, Malachium aquaticum, Veronica undulata, Polypogon fugax and Lapsana apogonoides have the similar ecological demands. The fast shift of weed populations under succesive application of a certain herbicide in a long period of time results from two factors: the different sensitivity of various weeds to the herbicides applied and the different ecological demands of weeds in crop fields, which makes it important to study the ecological difference among various weeds in crop fields.