地被物处理及补苗对华南退化荒坡乡土树种定居的影响

The Influences of Ground Cover and Recruitment Methods on Seedling Establishment of Castanea henryi and Psychotria rubra on A Degraded Hilly Land in South China

为了人工辅助华南地区退化荒坡的早期恢复,合理利用地表覆被物及补苗方式加速乡土种在退化荒坡的定居进程,本研究采用3×2析因设计和随机区组设计,系统研究了荒坡地表植被和凋落物去除、播种和幼苗移栽对乡土树种锥栗(Castanea henryi)和九节(Psychotria rubra)幼苗定居的影响。研究结果表明,补苗方式(P=0.013)、物种和补苗方式的交互作用(P=0.029)以及物种和林下植被和凋落物管理间的交互作用(P=0.013)均显著影响了幼苗的生物量积累。具体表现为:退化荒坡地表植被和凋落物的去除显著促进了九节幼苗的生物量累积,其中实生苗由1.31 g增加至8.44 g,移栽苗由6.75 g增加至13.54 g。地表植被和凋落物的去除导致锥栗和九节实生苗和移栽苗的生物量均由叶向根和茎部分转移,其中锥栗转移了9%,九节转移了5%。幼苗通过增加根茎重比,强化生物体对水分和养分的吸收运输,从而适应地表植被和凋落物去除。移栽幼苗的方式可显著提高九节幼苗定居的成功率并促进幼苗生物量的积累。因此,在华南地区退化荒坡的植被恢复过程中,可通过移栽幼苗的补苗方式并辅以地表植被和凋落物去除的管理,来促进乡土树种九节的定居;就锥栗而言,可采取人工播种的方式来辅助乡土树种的引入和幼苗定居。

In order to assist the early restoration of degraded hilly land in South China and appropriately use the ground covers and recruitment methods to accelerate the establishment of native trees on degraded land,this study adopted3×2factorial design and randomized block design to systematically discussed the influences of ground cover,seeding and transplanting methods on the establishment of native tree Castanea henry and Psychotria rubra in degraded hilly land.The results showed that,the recruitment ways(P=0.0130),interaction between species and recruitment methods(P=0.0287),and interaction between species and the management of ground covers(P=0.0134)significantly affect the biomass accumulation of seedlings.The specific performances were as followings:the removal of ground cover significantly accelerated the biomass accumulation of P.rubra seedlings.The average biomass of germinated seedlings changed from1.31g to8.44g,and the values was6.75g to13.54g for transplanted seedlings.The removal of understory vegetation and litters resulted in the leaf biomass of C.henryi and P.rubra transformed to their stems and roots(9%for C.henryi and5%for P.rubra).The seedlings enhanced their absorption and transportation of water and nutrients in order to adapt to the effects of the removal of understory vegetation and litters.Direct seeding and transplanting manners did not influence the establishment of C.henryi seedlings,but seedling transplantation significantly improved the establishment success and biomass accumulation of P.rubra seedlings.In conclusion,we could accelerate the establishment of P.rubra through the removal of understory vegetation and litters and select seedling transplantation method during the restoration of degraded hilly land in subtropical China.For C.henryi,we can adopt artificial seeding method to assist the species introduction and seedling establishment.