CAJ | 학술논문

金钟藤在海南和广州的爆发成灾严重威胁着当地的森林生态系统.不同林型被金钟藤入侵的程度不一样,干扰严重、透光度较高的次生林容易被入侵,而自然林则不易被入侵.本研究比较金钟藤幼苗在海南五指山干扰林及自然林下土壤上生长的差别,以说明是否土壤性状的差别可部分解释金钟藤入侵性的差别.于2011年11月在五指山自然林和干扰林山坡分别取土及表层凋落物,带回实验室放入花盆中.一半的花盆中加入活性炭以检验凋落物可能释放的化感物质对金钟藤幼苗生长的影响.金钟藤种子经萌发后种入花盆中.在14.72%的透光度及排除地上部分天敌的条件下,于2011年11月至2012年7在大棚内种植8个月后收获、烘干并称重.结果表明:自然林土壤的全氮、全磷、有效氮含量高于干扰林土壤,而有效磷含量低于干扰林土壤,说明土壤资源并不是在干扰林下更高.在自然林土壤生长的金钟藤幼苗地下、地上部分生物量分别为1.496±0.14 g、3.22±0.31 g,比在干扰林土壤生长的生物量略大(1.129±0.135 g、2.93±0.357 g),但两者的差异并不显著(地下:t=1.881, P=0.072.地上:t=0.662, P=0.539);添加活性炭以吸附凋落物化感物质并不显著改变金钟藤地下、地上部分生物量.本实验说明,在一定的光照及排除地上部分天敌的条件下,仅是自然林下的土壤本身并不能抵抗金钟藤的入侵.然而,在野外观察到金钟藤种子可以在自然林下萌发但幼苗却难以存活,说明其他因素造成了金钟藤幼苗的死亡.未来研究这些因素对于保护生物多样性、维护森林生态系统健康具有重要意义.
금종등재해남화엄주적폭발성재엄중위협착당지적삼림생태계통.불동림형피금종등입침적정도불일양,간우엄중、투광도교고적차생림용역피입침,이자연림칙불역피입침.본연구비교금종등유묘재해남오지산간우림급자연림하토양상생장적차별,이설명시부토양성상적차별가부분해석금종등입침성적차별.우2011년11월재오지산자연림화간우림산파분별취토급표층조락물,대회실험실방입화분중.일반적화분중가입활성탄이검험조락물가능석방적화감물질대금종등유묘생장적영향.금종등충자경맹발후충입화분중.재14.72%적투광도급배제지상부분천활적조건하,우2011년11월지2012년7재대붕내충식8개월후수획、홍간병칭중.결과표명:자연림토양적전담、전린、유효담함량고우간우림토양,이유효린함량저우간우림토양,설명토양자원병불시재간우림하경고.재자연림토양생장적금종등유묘지하、지상부분생물량분별위1.496±0.14 g、3.22±0.31 g,비재간우림토양생장적생물량략대(1.129±0.135 g、2.93±0.357 g),단량자적차이병불현저(지하:t=1.881, P=0.072.지상:t=0.662, P=0.539);첨가활성탄이흡부조락물화감물질병불현저개변금종등지하、지상부분생물량.본실험설명,재일정적광조급배제지상부분천활적조건하,부시자연림하적토양본신병불능저항금종등적입침.연이,재야외관찰도금종등충자가이재자연림하맹발단유묘각난이존활,설명기타인소조성료금종등유묘적사망.미래연구저사인소대우보호생물다양성、유호삼림생태계통건강구유중요의의.
The invasion and explosion of Merremia boisiana in Hainan and Guangzhou significantly threaten forest ecosystems. Different forest types show the varieties in the degree of invasion by M. boisiana, in which severely disturbed secondary forests with high light levels at the ground are more prone to invasion, as compared to natural forests. This study compared the growth of M. boisiana seedlings on soils of disturbed and natural forests in Wuzhi Mountain of Hainan, so as to elucidate if differences in soil properties might partly explain this pattern. Soil samples of disturbed and natural forests and the litter on their surface in Wuzhi Mountain were collected and then placed into pots after taking back to the laboratory. Half of the pots were added with activated carbon to examine the influence of allelopathic substances potentially released from litter on the seedling growth of M. boisiana. Seeds of M. boisiana were germinated and then planted into the pots. Under a light penetration ratio of 14.72%, the seedlings of M. boisiana were allowed to grow without aboveground natural enemies from November 2011 to July 2012. After that, the seedlings were harvested, dried and weighed. The results showed that the contents of soil total nitrogen, total phosphorus, and available nitrogen in the natural forest were higher than those in the disturbed forest, whereas the opposite trend was observed in the soil available phosphorus content, indicating that soil resources were not higher under the disturbed forest. The belowground biomass and aboveground biomass of M. boisiana seedlings grown on soils of the natural forest were 1.496±0.14 g and 3.22±0.31 g, respectively, which were slightly higher than those of seedlings grown on soils of the disturbed forest (1.129±0.135 g and 2.93±0.357 g, respectively). But the values of biomass of M. boisiana seedlings grown on soils of these two forest types did not differ significantly (belowground biomass: t = 1.881, P= 0.072; aboveground biomass: t = 0.662, P= 0.539). The activated carbon addition did not significantly change the belowground and aboveground biomass of M. boisiana seedlings. These findings suggest that soils of natural forests alone cannot resist the invasion of M. boisiana under a specific light level and exclusion of aboveground natural enemies. However, it was observed that seeds of M. boisiana could germinate but seedlings could not survive in the natural forest understory, indicating that some other factors caused the death of M. boisiana seedlings. Future studies to examine the factors contributing to the resistance of natural forests to M. boisiana invasion would be important for protection of biodiversity and maintenance of forest health.