应用生态学报2018，Vol.29Issue(4)：1098-1106,9.DOI:10.13287/j.1001-9332.201804.001
毛红椿天然种群有性繁殖适合度及其繁殖更新
Fitness of sexual reproduction of Toona ciliata var.pubescens natural populations and their sexual reproduction and regeneration
摘要
Abstract
To examine the reproduction fitness coefficients and individual-level fitness of Toona ciliata var.pubescens,their sexual reproduction and natural regeneration were investigated during 2006-2016,with four natural populations in Jiulianshan National Reserve as test objects.The results showed that there were only 2-10 trees for the natural populations of T.ciliata var.pubescens with a small initial number of fruiting plants (3-9 trees),which were from the initial fruiting plants or their first/second generation.The sexual reproduction of these isolated populations were significantly different,and their seed production capacities tended to decline over time.With the maturing of communities,soil seed banks and seed germinations were extremely poor,and the number of trees that could be growing to mature stage was nearly zero.The optimum maturity age of T.ciliata var.pubescens was about 40 a,and the fitness coefficients (2.0-2.8) rapidly increased in early development stage,but then was sharply reduced (0.3-0.5),and then gradually dropped to almost 0.There were significant differences in the fitness at individual level (0-14 tree · cm-2) among different populations,but their values were low (close to zero).Based on the existing reproduction rate,the actual values of sexual reproduction and regeneration fitness were much lower than the predicted ones.Due to the low level of genetic fitness,the sexual reproductive ability of different populations all showed decreasing trends.The natural sexual regeneration ability tended to decline,while the fitness of T.ciliata var.pubescens further decreased.All those factors suggested higher investment risks.Therefore,the systems of sexual reproduction became unbalanced and deteriorating.We proposed that more studies,including breeding mating,pollination,seed setting,and genetic diversity evaluation,are needed.Moreover,we should provide suitable forest environment through cleaning up litter in the fruiting stage and applying appropriate thinning during the transition period from seedling to young tree growth.关键词
毛红椿/天然种群/有性繁殖/适合度系数/个体繁殖适合度/更新Key words
Toona ciliata var.pubescens/natural population/sexual reproduction/fitness coefficient/individual reproductive fitness/regeneration引用本文复制引用
黄红兰,张露,贾黎明,梁跃龙,蔡军火..毛红椿天然种群有性繁殖适合度及其繁殖更新[J].应用生态学报,2018,29(4):1098-1106,9.基金项目
本文由江西省科技支撑重点项目(20151BBF60019)、国家自然科学基金项目(31360171)和教育部博士生导师基金项目(20123603110002)资助 （20151BBF60019）
This work was supported by the Major Project of Science and Technology of Jiangxi (20151BBF60019),the National Natural Science Foundation of China (31360171) and the Doctoral Fund of Ministry of Education of China (20123603110002). （20151BBF60019）
