Effects Of Lianas On Tree Growth And Community Structure In Guanshan Forest Monitoring Plot

The overwhelming increase of lianas have hindered the forest regeneration during the implement of closing hills for afforestation policy.Therefore,lianas diversity,effects of lianas on trees and communities were studied in Jiangxi Guanshan Evergreen Broad-Leaved Forest Monitoring Plot(GSP,12 hm~2).The results were as follows:(1)A total of 5,940 liana individuals(including genets under 1.3m)with a diameter?0.5 cm at breast height were recorded in the plot,representing 82 species,47 genera,and 28families.Lianas infested host trees by four climbing categories(stem twining,root climbing,curling,hook climbing),among which the twiners and the hook climbers dominated.(2)Lianas showed preferences to certain tree species.3,318 trees(DBH?1 cm)were infested by lianas in total,among which trees Alniphyllum fortunei and Cunninghamia lanceolate et al were overrepresented by lianas Uncariar hynchophylla et al.Lianas Lonicera hypoglauca and Coptosapelta diffusa climbed trees such as Vaccinium mandarinorum,Rhododendron latoucheae et al significantly more than other trees.Moreover,trees with large diameters were more easily infested by lianas and the percentage was nearly 40.0%.(3)Lianas suppressed tree growth.The current annual radical growth and basal area growth of C.lanceolate infested by lianas dropped by 28.5%and 39.9%and A.fortune dropped by 11.4%and 15.8%respectively in recent 10 years.(4)The increasing lianas altered community structure.With the increase of the relative density of lianas,the community tree abundance,basal area and tree volume decreased signficantly.Lianas reduced the species diversity of trees but increased that of the shurbs.Our results showed that lianas were abundant in subtropical forest.Lianas'preference to trees and their deterious effects on tree growth would alter the community species composition and community structure.Therefore,we suggested appropriate lianas cutting is necessary for these heavily infested forests in forest management and protection under the closing hills for afforestation policy.Our research not only established a basis for long-term monitoring of lianas in subtropical forest but also provided references for the further researches on lianas ecology and forest management and protection.