Demographic consequences of greater clonal than sexual reproduction in Dicentra canadensis

Clonality is a widespread life history trait in flowering plants that may be essential for population persistence, especially in environments where sexual reproduction is unpredictable. Frequent clonal reproduction, however, could hinder sexual reproduction by spatially aggregating ramets that compete with seedlings and reduce inter-genet pollination. Nevertheless, the role of clonality in relation to variable sexual reproduction in population dynamics is often overlooked. We combined population matrix models and pollination experiments to compare the demographic contributions of clonal and sexual reproduction in three Dicentra canadensis populations, one in a well-forested landscape and two in isolated forest remnants. We constructed stage-based transition matrices from 3 years of census data to evaluate annual population growth rates, λ. We used loop analysis to evaluate the relative contribution of different reproductive pathways to λ. Despite strong temporal and spatial variation in...

克隆性（clonality）是被子植物中广泛存在的生活史性状，对于种群存续可能不可或缺，尤其在有性生殖难以预测的环境中。然而频繁的克隆繁殖可能通过空间聚集分株（ramet）、使分株与实生苗竞争并降低基株（genet）间传粉效率，从而阻碍有性生殖。尽管如此，克隆性在种群动态中与有性生殖变异相关的作用却常被忽视。本研究结合种群矩阵模型与传粉实验，对三个加拿大荷包牡丹（Dicentra canadensis）种群的克隆繁殖与有性繁殖的种群统计贡献进行比较：其中一个种群分布于完整茂密的林景中，另外两个种群位于孤立林片段内。研究基于3年的野外普查数据构建了基于阶段的转移矩阵，以评估种群年增长率λ；同时采用环分析法评估不同繁殖途径对λ的相对贡献。尽管在……中存在显著的时空变异