陆生生境中喜旱莲子草的生长模式  

Growth pattern of alligator weed(Alternanthera philoxeroides) in terres-trial habitats

作　　者：贾昕[1,2] 傅东静[1,2] 潘晓云[1] 李博[1] 陈家宽[1] 

机构地区：[1]生物多样性和生态工程教育部重点实验室,复旦大学生物多样性科学研究所,上海200433 [2]西北大学生命科学学院

出　　处：《生物多样性》2007年第3期241-246,共6页Biodiversity Science

基　　金：国家自然科学基金(30400052)

摘　　要：喜旱莲子草(Alternanthera philoxeroides)原产南美洲,后被引入到北美洲、大洋洲、东南亚和中国等地,成为一个世界性的外来入侵种。对喜旱莲子草陆生种群的有效控制一直是一个难题。本文中通过种植实验建立了陆生生境中喜旱莲子草主枝长、生物量、叶面积和斑块面积等的生长模型。结果表明:(1)喜旱莲子草的主枝长、生物量、叶面积和斑块面积等均表现为指数式生长,其日增长率(%)分别为4.28、11.27、11.59和8.67。(2)喜旱莲子草的地上重(x)-地下根茎重(y)的异速生长指数b约为3/4(0<b<1),即随着植株的生长其根冠比下降;主枝长-总重、主枝长-叶面积的异速生长指数b约为2(b>1),即总重和叶面积相对于主枝长呈二次幂增长,由此可进一步推出总重和叶面积与斑块面积成正比;生物量-叶面积的异速生长指数b约为1,为等速生长(b=1),即单位生物量所支持的叶面积不随植株大小的变化而变化(冠层恒定性)。其叶面积比为88.24cm2/g,比叶面积为287.97cm2/g。通过本研究期望对喜旱莲子草陆生局域斑块的生长进行预测,同时为进一步建立其控制模型提供基础数据,为制定经济有效的控制对策提供科学依据。Alligator weed （Alternantheraphiloxeroides） is a notorious invasive alien species worldwide. How to limit its population expansion in terrestrial habitats has long been an intractable problem. To predict growth of alligator weed in local patches, a field planting experiment was performed. Using harvesting data, we established growth models of different growth variables; meanwhile, the allometric relationships of these variables were determined. The growth models of main stern length, biomass, leaf area and patch area all in- creased in an exponential pattern with growth period, and the daily growth rates （%） of main stern length, total biomass, leaf area and patch area were 4.28, 11.27, 11.59 and 8.67, respectively. The result of allometric analysis showed that it was significantly correlated between all the growth variables. The allometric exponent b of shoot mass （x） vs. root mass （y） indicated that the root/shoot ratio decreased with the growth of the plant. From the allometric exponent b of main stern length vs. total biomass and of main stern length vs. leaf area, we could deduce that the total biomass and leaf area increased quadratic relative to main stern length, and increased proportionally to patch area. As for variables of biomass vs. leaf area, an isometric relationship was found, i.e. the canopy size kept relatively constant when plant size increased. Based on the relation between leaf area and biomass, leaf area ratio （LAR） and specific leaf area （SLA） of the alligator weed in terrestrial habitat were calculated, being 88.24 cm^2/g and 287.97 cm^2/g, respectively. These results provide basic data for future growth modeling further to effective and economical control.

关 键 词：Alternanthera philoxeroides 生物入侵 外来入侵种 异速生长分析 指数生长模型 

分 类 号：Q948[生物学—植物学]