豚草入侵对韶关地区植物群落多样性的影响

2007年7月和9月采用同一样地两次重复随机样点法,对位于粤北的韶关学院西南区豚草（Ambrosia artemisiifolia Linn.）入侵林地进行植物群落结构和多样性的调查研究,并采用成对法T检验对7月、9月样地两个时间段内植物群落的个体数和豚草数进行差异显著性检验.研究结果表明：7月豚草入侵地植物群落是以豚草为优势类群的单调群落,物种分布不均匀,多样性指数低;9月豚草数量减少,群落结构由单一的一年生草本植物为优势的群落过渡到以多年生草本植物为优势的群落,群落多样性指数增加,两个时间段内植物群落之间存在显著性差异（P=0.01〈0.05,df=14）（P=0.047〈0.05,df=14）,表明豚草的生长抑制了其他植物的生长,使植物群落物种多样性降低.

Effect of invaded ragweed on plant diversity in the Shaoguan

This paper investigated the effect of invaded ragweed on plant community structure and diversity in the grove,using twice duplicate random sampling method in the same sample plot,in the Shaoguan.The results showed that： the structure of plant community was monotonic herbosa,the ragweed was prevalent.the abundance of species was low,and the species was maldistribute.With the decrease of ragweed,the prevalent species transferred from therophyte to perennial herb,and the shrub appeared.And with the decrease of ragweed,the community diversity index increased,uniformity index and dominance index decreased.This showed that the ragweed was the key species on invaded land,and its growth inhibited others weeds,and it degraded the plant community diversity.and it effected the local plant diversity greatly