林业有害植物金钟藤新枝在海南的月生长动态

Monthly growth dynamics of new shoots of an invasive forest plant,Merremia boisiana,in Hainan Province,China

【背景】近20多年来,金钟藤在海南和广东异常快速生长,对生物多样性和林业生产破坏严重。观测金钟藤的月生长动态,了解其在海南的生长量,能够为金钟藤的合理防治提供参考。【方法】采用定点定时观测法,对海南3个市县3种不同生境的金钟藤新枝的月生长量进行测定。【结果】金钟藤在海南全年可生长,一新枝月平均生长134 cm,全年累计平均生长1607 cm。金钟藤全年有2个生长高峰期,分别在4月和9月,其中4月平均生长206 cm,9月187 cm。金钟藤在11月生长量最小,平均生长86 cm。金钟藤在1—9月生长较快,一新枝累计平均生长1326 cm,占全年生长量的82.5%;在10月至12月生长缓慢,一新枝累计平均生长281 cm,占全年生长量的17.5%。不同生境之间的金钟藤生长有极显著差异,月平均生长量从高到低顺序为定安188 cm〉白沙131 cm〉五指山83 cm。金钟藤种子在3—7月均可萌发,花果期在4—7月。在海南月平均温度17~28℃、月平均降雨量28~396 mm的自然环境范围内,金钟藤的生长量与温度和降雨量没有显著相关性。【结论与意义】金钟藤在海南光照充足的生境里快速生长扩散,月平均生长量高达188 cm,其生长与生境、海拔和植被密切相关。

【Background】In the recent two decades,Merremia boisiana grows rapidly and abnormally,causes death to trees and destroys biodiversity and forestry production severely in Hainan and Guangdong of China. To determine the level of invasiveness of M.boisiana in Hainan,monthly growth of the weed was measured to provide a baseline for the development of reasonable control.【Method】Monthly growth of M. boisiana was measured using a fixed point observation method over a one-year period in three study sites of three cities / counties of Hainan. 【Result】M. boisiana could grow all year round in Hainan. Monthly growth of a new shoot averaged 134 cm and yearly growth,1607 cm. M. boisiana’s growth peaked in April（ mean of 206 cm） and September（ 187 cm）.The slowest growth of M. boisiana occurred in November with a mean of 86 cm. A new shoot of M. boisiana could grow by 1326 cm from January to September,representing 82. 5% of the yearly growth,while October to December represented only 17. 5% of the yearly growth or 281 cm. There were significant differences in growth among the three habitats,with values of 188 cm in Dingan,131 cm in Baisha,and 83 cm in Wuzhishan. The seeds of M. boisiana could germinate from March to July and the periods of flowering and fruiting occurred from April to July. In those sites,mean monthly temperatures varied between 17 and 28 ℃ with mean monthly rainfall of 28 ~ 396 mm. There was no significant correlation between growth of M. boisiana and temperature or rainfall.【Conclusion and significance】M. boisiana grows and spreads rapidly and in great abundance in open habitat in Hainan. Monthly average growth can reach up to 188 cm and can be affected by habitat,altitude and existing vegetation.