Effects of Population Size, Forest Fragmentation, and Urbanization on Seed Production and Gene Flow in an Endangered Maple (Acer miyabei)
Effects of Population Size, Forest Fragmentation, and Urbanization on Seed Production and Gene Flow in an Endangered Maple (Acer miyabei)
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DOI：
10.1674/0003-0031-172.2.303
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发表时间：
2014-10-01
影响因子：
0.6
通讯作者：
Hiura, Tsutom
中科院分区：
文献类型：
--
作者：
Nagamitsu, Teruyoshi;Kikuchi, Satoshi;Hiura, Tsutom
森林破碎化威胁着树种的繁殖，因为树种的栖息地与城市和农村地区重叠。濒危枫树 Acer miyabei f. miyabei，就是日本北部的一个物种。我们研究了森林破碎化对种子生产和配偶多样性的影响，并评估了破碎化森林内部和之间的基因流动。我们测量了农村和城市地区 21 个零散森林中 82 棵目标树周围散布的种子的密度、活力和亲缘关系。随着目标树木的大小和每个森林中成年树木的数量减少，分散的种子密度也随之减小。随着每片森林中成年树木数量的减少，有活力的种子比例也随之减少。我们没有发现散布在每棵目标树周围的种子之间的亲缘系数有任何影响。种子成对亲缘系数对距离的回归线在森林之间比在森林内部具有更高的截距和更平缓的下降斜率，表明森林破碎化改变了基因流模式。结果表明，由于花粉限制和破碎森林中米亚贝再生种群遗传结构的变化，种子产量减少。
Forest fragmentation threatens the reproduction of tree species, for which habitats overlap with urban and rural areas. An endangered maple, Acer miyabei f. miyabei, is such a species in northern Japan. We examined the effects of forest fragmentation on seed production and mate diversity and assessed gene flow within and between fragmented forests. We measured the density, viability, and kinship of seeds dispersed around 82 target trees in 21 fragmented forests in rural and urban areas. The dispersed seed density decreased as the size of the target trees and the number of adult trees in each forest decreased. The viable seed proportion also decreased as the number of adult trees in each forest decreased. We did not find any effects on the kinship co-efficient among seeds dispersed around each target tree. The regression line of the pairwise kinship co-efficient of the seeds against the distance had a higher intercept and a more gently declining slope between the forests than within the forests, indicating forest fragmentation altered gene flow patterns. The results suggest reduced seed production due to pollen limitation and changes in the genetic structure of regenerating populations of A. miyabei in fragmented forests.