Long period exposure to serious cadmium pollution benefits an invasive plant (Alternanthera philoxeroides) competing with its native congener (Alternanthera sessilis).
Long period exposure to serious cadmium pollution benefits an invasive plant (Alternanthera philoxeroides) competing with its native congener (Alternanthera sessilis).
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长期暴露于严重的镉污染中，有利于入侵植物（空心莲子草）与其本地同源植物（无梗空心莲子草）竞争。
DOI：
10.1016/j.scitotenv.2021.147456
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发表时间：
2021-04
影响因子：
9.8
通讯作者：
李庆军
中科院分区：
文献类型：
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作者：
王燕;熊云涛;王毅;李庆军
许多入侵植物对重金属具有很强的耐性，但它们在重金属污染区的入侵能力却知之甚少。我们进行了一个温室实验，以研究镉（0，10，30，60和100 mg kg−1）和种间竞争对入侵植物空心莲子草（Alternanthera philoxeroides）及其原生同源植物无柄莲子草（Alternanthera sessilis）繁殖能力的影响。我们还研究了本地和入侵物种的种群动态在一个模拟的现场实验。与A. philoxeroides，nativA.在混合培养条件下，无柄花是一个较强的竞争者，表现为营养生长、有性繁殖和优势地位。然而，A.喜旱植物的根质量比具有很大的可塑性，种间竞争和高镉水平对根质量比产生积极影响。这样高的根分配可能允许延迟生长的A。空心莲子草根茎作为A.空心莲子草属A.在田间试验中，小孢子在培养9个月后逐渐增加，并> 1，特别是在高镉处理下。我们的研究结果表明，A.喜旱性高度依赖于上下文和时间。在严重污染的环境中，A.种间竞争和重金属污染的协同负效应可能抑制了入侵植物的无柄化，两种竞争物种的长期共存有利于入侵植物的定殖。
Many aggressive plants possess high tolerance to heavy metals, but little is known about their invasiveness at heavy metal polluted sites. We performed a greenhouse experiment to examine the impacts of Cd (0, 10, 30, 60, and 100 mg kg−1) and inter-specific competition on the reproductive capability of an invasive plant,Alternanthera philoxeroides, and its native congener,Alternanthera sessilis. We also examined the population dynamics of both native and invasive species in a simulated field experiment. Compared withA. philoxeroides, nativeA. sessiliswas a stronger competitor as measured by vegetative growth, sexual reproduction, and dominance status in a mixed culture. However,A. philoxeroidesshowed great plasticity in root mass ratio that was positively affected by inter-specific competition and high Cd levels. Such high root allocation might allow for delayed growth ofA. philoxeroidesrhizomes as the relative cover ofA. philoxeroidestoA. sessilisin the field experiment gradually increased and > 1 after nine months culture, especially at high Cd treatment. Our results suggest that the invasiveness ofA. philoxeroidesis highly context- and time-dependent. In severely polluted environments, clonal propagation ofA. sessilisis likely inhibited by the synergistic negative effects of inter-specific competition and heavy metal pollution, and a long time co-existence of these two competing species would facilitate the colonization of invasive plant.