三种增温情景对入侵植物空心莲子草形态可塑性的影响

Abstract

PDF HTML阅读 XML下载 导出引用 引用提醒 三种增温情景对入侵植物空心莲子草形态可塑性的影响 DOI: 10.5846/stxb201306101575 作者: 作者单位: 成都理工大学,成都理工大学,成都理工大学,成都理工大学 作者简介: 通讯作者: 中图分类号: 基金项目: Three warming scenarios differentially affect themorphological plasticity of an invasive herb Alternanthera philoxeroides Author: Affiliation: Chengdu University of Technology,Chengdu University of Technology,Chengdu University of Technology,Chengdu University of Technology Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:虽然国内外已对克隆植物的表型可塑性开展了大量研究，但是气候变暖对克隆植物，尤其是入侵性克隆植物形态可塑性的影响及其可能的生态学意义研究仍然有限。通过设置白天增温、夜间增温和全天增温3种方式，通过切断或不切断匍匐茎处理，探讨入侵植物空心莲子草（Alternanthera philoxeroides）形态特征对不同气候变暖情景的响应。研究发现：夜间增温2 ℃条件下，切断匍匐茎连接显著降低空心莲子草匍匐茎总长度和平均分株长度;白天增温和全天增温2 ℃对匍匐茎切断和连接组的空心莲子草的匍匐茎总长和平均分株长影响不显著;3种增温方式对空心莲子草的分蘖数均无显著影响。这些结果表明：空心莲子草对增温具有较高的耐受性，并对不同增温方式采取不同的响应策略;夜间增温可能通过光合补偿效应增加其匍匐茎的长度和平均分株长从而促进其水平方向的扩展以占据更加有利的生境，增强其入侵能力;白天和全天增温对整个克隆片段匍匐茎形态几乎无影响。 Abstract:Phenotypic plasticity may be one of the crucial factors determining the success of plant invasions in diverse habitats, particularly for those very noxious species with low genetic diversity such as Alternanthera philoxeroides in China. Although phenotypic responses of clonal plants to different light intensities, soil water or soil nutrient availabilities have been extensively studied in the past decades, little is known about how climate warming affects morphological plasticity of plants, particularly invasive plant species. Climate warming is among the serious threats to biodiversity and ecosystem functions, thereby raising concerns over its ecological consequences. Increasing evidence suggests that climate warming is asymmetric and the magnitude of nighttime minimum air temperature may increase greater than that of daytime maximum air temperature. Recent studies have shown that climate warming is likely to have significant effects on plant photosynthesis and respiration. Consequently, it is necessary to understand how terrestrial plants respond to differential warming scenarios, which can help us better predict their response under these conditions. We conducted a simulated warming experiment at Chengdu in which the invasive clonal herb Alternanthera philoxeroides was subjected to each of the eight combinations consisting of serving stolons (i.e. serving and intact stolons) and simulated warming (i.e. day-warming, night-warming, daily warming, and control treatment). This experiment lasted three months. At the end of the experiment the morphological traits of all experimental materials were determined. Overall warming treatment increased air temperature by about 2 ℃, and the warming magnitude was variable depending on specific weather conditions. Our central object was to test how A. philoxeroides plants responded to different warming treatments morphologically. Across all three warming treatments, physically severed connection significantly suppressed the growth of A. philoxeroides fragments primarily through reducing the total stolon length and average stolon length per ramet. In contrast, simulated warming per se did not exhibit significant effects on these indices mentioned above. When the three warming treatments were considered separately, they had contrasting consequences for the morphological traits of A. philoxeroides. Specifically, day-warming and daily-warming did not confer significant impacts on both severed and connected fragments in terms of total stolon length and average stolon length; night warming significantly elongated the total stolon length and average ramet length of A. philoxeroides with connected stolons, but did not affect those of A. philoxeroides with connected stolons; all the three warming scenarios did not affect ramet numbers of both fragments. These findings are relatively preliminary, but they have some potential implications. First, our results suggest that A. philoxeroides fragments may have strong tolerance to the 2 ℃ warming and differentially respond to these projected warming scenarios. Second, for A. philoxeroides fragments commonly growing in disturbed habitats, night-warming may facilitate their growth and clonal integration through photosynthetic overcompensation, thereby enhancing their invasion by rapidly spatial expanding along the horizontal direction and occupying favorable habitats. Third, day-warming and daily warming may have no obvious impacts on the morphological characteristics of those fragments of A. philoxeroides. Finally, modeling plant responses to climate warming should consider warming timing. Additionally, these findings also provide an initial indication that more efforts should be paid to uncover response patterns of plants to different warming scenarios and how these responses influence community composition and structure, and ecosystem functions. 参考文献 相似文献 引证文献