外来种喜旱莲子草的克隆生长特性

通过对外来种喜旱莲子草（Alternanthera philoxeroides（Mart．）Griseb）生长指标的测定和分析，研究了它的克隆生长规律，并探讨丁它的觅食行为．在一个生长季节内，喜旱莲子草生物量增加了近30倍，一级葡萄茎分株数增加了近50倍，最长的一级葡萄茎长度增长了近40倍，一级葡萄茎总长度增长了近13倍；一、二、三级葡萄茎上的总分株数增加了近130倍，3个级别匍匍苇总长度增长了近28倍．通过各级葡萄茎个数，葡萄茎总长度和葡萄茎总分株数比较发现，二级葡萄茎比一、二级葡萄苇生长的都要快，而一级葡萄茎的间隔物平均长度远远大于二级和三级葡萄茎．克隆植物的觅食行为与它的克隆生长紧密相连，从觅食行为来看，喜旱莲子草克隆构型随生长季节的变化说明了它对生长季节具有很强的适应性．这种快速克隆生长的特性和对生长季节的适应性有利于喜旱莲子成功入侵新的生境。

Clonal Growth of the Invasive Species Alternanthera philoxeroides (Mart.) Griseb

Alternanthera philoxeroides(Mart.) Griseb(Amaranthaceae) is an invasive species in China.A study regarding to its clonal growth characteristics was presented here.Also,we discussed its foraging behaviour associated with its clonal growth.The measured growth parameters were biomass,total length of each creeping stem,ramet numbers of each creeping stem,average spacer length of each creeping stem,the length of the longest primary creeping stem.During its one-year growing season,there were about 30 times increase in its biomass,50 times increase in the ramet numbers of its primary creeping stems,40 times in the length of its longest creeping stem and about 13 times increase in the total length of the whole creeping stems.The total ramet numbers of all creeping stems increased by about 130 times and the total length of all these creeping stems by about 28 times.With the comparison among the number of creeping stems,the total length and ramet numbers of each creeping stem,we found that the secondary creeping stems grew more rapid than the primary and the third ones.Moreover,the average spacer length of the primary creeping stems was longer than those of the secondary and the third creeping stems.Foraging behaviour in clonal plants is tightly associated with its clonal growth,as far as foraging behaviour is concerned,clonal architecture of Alternanthera philoxeroides changed by its growing seasons showed that it has great adaptation to growing seasons.This rapid clonal growth characteristics and great adaptation to growing seasons could be benefit to its successful invasion.