入侵植物薇甘菊新枝在海南的月生长动态

Monthly growth dynamics of the shoots of invasive plant Mikania micrantha in Hainan

【背景】薇甘菊是入侵性和危害性极强的外来入侵植物,对生物多样性和农林业生产造成严重影响。观测薇甘菊新枝的月生长动态,了解薇甘菊快速生长扩散的原因,能够为薇甘菊的合理防治提供参考。【方法】采用定点定时观测法,历时2年对海南7个市县薇甘菊新枝的月生长量进行测定。【结果】薇甘菊在海南全年可生长,一新枝月平均生长66 cm,全年累计平均生长795 cm。薇甘菊生长高峰期在6月和8月,其中6月平均生长120 cm,8月平均生长106 cm。薇甘菊最小生长量在1月和12月,平均生长量均为21 cm。薇甘菊在6—10月生长较快,一新枝累计平均生长489 cm,占全年生长量的61.5%;在4—5月和11月生长次之,一新枝累计平均生长196 cm,占全年生长量的24.7%;在1—3月和12月生长缓慢,一新枝累计平均生长110 cm,占全年生长量的13.8%。薇甘菊的花果期在10月至次年3月,一些种群在1—3月再次开花或在3—5月开花。薇甘菊的生长量与温度呈极显著正相关,相关系数为0.91;与降雨量呈显著正相关,相关系数0.56。【结论与意义】薇甘菊是多分枝植物,一新枝年生长量可达795 cm,能迅速生长形成种群。温度是薇甘菊生长的主要因素,降雨在一定程度促进了薇甘菊的生长。

【Background】Mikania micrantha is an invasive alien plant with high invasiveness and perniciousness and severe impact on biodiversity and agriculture and forestry. To determine the level of invasiveness of M. micrantha in Hainan,monthly growth of the weed was measured to provide a baseline for the development of reasonable control. 【Method】Monthly growth of M. micrantha was measured using a fixed point observation method over a 2-year period in 7 cities / counties of Hainan. 【Result】M. micrantha could grow all the year round in Hainan. The average monthly growth of a shoot was 66 cm with an annual growth of 795 cm. M. micrantha grew the most in June（ mean of 120 cm） and August（ mean of 106 cm） and the least in January and December（ mean of 21 cm）.The fastest period of growth was from June to October with a mean of 489 cm or 61.5% of its yearly growth. Growth in April,May and November represented 24.7% of yearly growth（ 196 cm） and January to March and December,13.8% of the yearly growth（ or110 cm）. Flowering and fruiting occurred between October and March. Some populations flowered again from January to March while others from March to May. There was a highly significant positive correlation between growth of M. micrantha and temperature（ R =0.91,p〈0.01） and a significant positive correlation between growth of M. micrantha and rainfall（ R = 0.56,p〈0.05）. 【Conclusion and significance】M. micrantha is a multi-branched plant and growth of a shoot reaches 795 cm yearly. Its growth allows it to establish populations rapidly. Both temperature and rainfall can affect M. micrantha growth.