Clonal growth and ramet performance in the woodland herb, Asarum canadense
Clonal growth and ramet performance in the woodland herb, Asarum canadense
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DOI：
10.2307/2960609
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发表时间：
1997-12-01
影响因子：
5.5
通讯作者：
Damman, H
中科院分区：
文献类型：
--
作者：
Cain, ML;Damman, H
1对加拿大细辛在演替早期和演替后期林下的重复样地进行了长达7年的繁殖和营养扩散模式的研究。2记录了样地中加拿大细辛分株的空间位置、大小、种群表现和克隆片段同一性，以及苗木残留物的位置和命运。我们还收集了有关克隆生长模式的详细形态数据。3最近萌发的植株和克隆产生的更大的子株具有同等的存活率。大小对根茎产量的影响也不大。在基因相同的分株中，开花的分株比不开花的分株大。当有生境的影响时，分株在演替后期的森林中表现最好。4有性繁殖和无性繁殖都不会降低分株的未来表现。与其他分株的连接对存活或根茎生产几乎没有影响，但往往与开花的可能性增加有关。具有较多分株的无性系表现优于较小的无性系，并分散了遗传死亡的风险。5在强光、演替早期的森林中，根茎长度较短，但其他克隆生长参数在不同生境之间没有差异。经经验校准的模拟和扩散模型表明，生境间根茎长度的差异不足以影响无性系的长期扩展。6比较了若干物种通过克隆生长或种子传播长期传播的扩散系数。扩散模型的结果表明，植物可以通过克隆生长和种子扩散，尽管A、Canadense的值分别为14年和8895 cm(2年-1年)。7加拿大细辛似乎处于异常强烈的苗木存活选择之下。正如对其他一些克隆植物物种所观察到的那样，无论是有性繁殖还是无性繁殖，都几乎没有成本。
1 We report the results from a 7-year study on the patterns of reproduction and vegetative spread of Asarum canadense, conducted in replicate plots located in the understorey of early and late successional forest.2 We recorded the spatial location, size, demographic performance and clonal fragment identity of all A. canadense ramets in our plots, as well as the position and fate of seedling recuits. We also collected detailed morphological data on patterns of clonal growth.3 Recently germinated plants and the much larger, clonally produced daughter ramets had equal survivorship. Size also had little impact on rhizome production. Within sets of genetically identical ramets, flowering ramets were larger than non-flowering ramets. When there was an effect of habitat, ramets performed best in late successional forest.4 Neither sexual nor asexual reproduction decreased the future performance of a ramet. Having connections to other ramets had little effect on survivorship or rhizome production, but often was associated with an increased probability of flowering. Clones with more ramets outperformed smaller clones and spread the risk of genet mortality.5 Rhizome lengths were shorter in the high light, early successional forest, but no other clonal growth parameters differed between habitats. Empirically calibrated simulation and diffusion models indicated that the between-habitat differences in rhizome length were not great enough to affect the long-term expansion of clones.6 Diffusion coefficients for the long-term spread by clonal growth or seed dispersal were compared for a number of species. Diffusion model results indicated that plants can disperse as far by clonal growth as they do by seed, although the values for A, canadense were 14 and 8895 cm(2) year(-1), respectively.7 Asarum canadense appears to be under unusually strong selection for seedling survival. As has been observed for some other clonal plant species, few costs were found for either sexual or asexual reproduction.