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草业学报 ›› 2020, Vol. 29 ›› Issue (3): 38-48.DOI: 10.11686/cyxb2019277

• 研究论文 • 上一篇    下一篇

气候变暖和物种多样性交互效应对空心莲子草入侵的影响

吴昊1,2,*, 张辰1, 代文魁2,3   

  1. 1.信阳师范学院生命科学学院,河南 信阳 464000;
    2.中国科学院武汉植物园,湖北 武汉 430074;
    3.广东省生物资源应用研究所,广东 广州 510260
  • 收稿日期:2019-05-28 出版日期:2020-03-20 发布日期:2020-03-20
  • 通讯作者: *E-mail: wuhao86868686@163.com
  • 作者简介:吴昊(1986-),男,河南光山人,讲师,博士。E-mail: wuhao86868686@163.com
  • 基金资助:
    信阳师范学院“南湖学者奖励计划”青年项目(2018B051)和国家自然科学基金青年项目(31800460)资助

Interactive effects of climate warming and species diversity on the invasiveness of the alien weed Alternanthera philoxeroides

WU Hao1,2,*, ZHANG Chen1, DAI Wen-kui2,3   

  1. 1.College of Life Sciences, Xinyang Normal University, Xinyang 464000, China;
    2.Wuhan Botanical Garden, Chinese Academy of Sciences, Wuhan 430074, China;
    3.Guangdong Institute of Applied Biological Resources, Guangzhou 510260, China
  • Received:2019-05-28 Online:2020-03-20 Published:2020-03-20

摘要: 全球变暖加剧了生物入侵进程,而物种多样性对于入侵物种通常具有阻抗作用,探讨二者交互效应对生物入侵的影响有助于预测入侵态势及制定有效的防治措施。通过在我国N 21°-37°设置59个调查样地,探讨外来入侵植物空心莲子草群落物种多样性与其入侵态势之间的关系;并采用人工构建群落的方式,设置不同温度、物种多样性组合两种因子,研究增温及本土植物多样性对空心莲子草入侵的影响。结果表明:1)样地群落的Shannon-Wiener多样性指数介于0~2.434,空心莲子草入侵盖度(P<0.001)、分枝数(P=0.022)随多样性上升而显著降低,纬度以及纬度×物种多样性交互效应对其入侵态势没有产生显著影响;2)增温导致构建群落中空心莲子草的高度(P=0.004)、最大茎长(P=0.002)以及马唐、苦苣菜和牛筋草3种本土植物的高度(P=0.038)均显著下降,物种多样性上升导致空心莲子草高度、无性分株数、分枝数和最大茎长均显著下降(P<0.001),增温×物种多样性交互效应导致空心莲子草分枝数在“入侵单种”处理中显著升高(P=0.035),而增温×物种属性交互效应显著降低了构建群落中苦苣菜的最大茎长(P<0.001);3)增温并未显著影响空心莲子草及本土植物生物量,物种多样性增加显著削弱了空心莲子草的生物量(P<0.001),但显著提高了其根冠比(P=0.014),即空心莲子草以相对储存更多地下资源的方式应对种间竞争。综上可知,较高水平的物种多样性有助于抵制空心莲子草的入侵,但增温可能会削弱本土物种的抗性;气候变暖背景下应更加重视保护本土植物多样性,以遏制空心莲子草入侵蔓延。

关键词: 生物入侵, 空心莲子草, 增温, 纬度梯度, 物种多样性

Abstract: Global warming has, in many cases, accelerated the spread of introduced invasive plant species, while the species diversity can produce bio-resistance to the invasive species. Exploring the effects of climate warming-biodiversity interactions on biological invasions is beneficial for predicting invasion outcomes and formulating effective bio-control measures. Here, 59 sampling plots were selected across a geographic range from 21° N to 37° N in China, the objective was to study the relationships between species diversity and invasiveness of the alien weed Alternanthera philoxeroides in field community. Temperature and species diversity data were examined in artificial community, to examine the effects of increased temperature and native plant species diversity on A. philoxeroides invasion. It was found that: 1) Values of Shannon-Wiener diversity index within A. philoxeroides communities ranged from 0-2.434, and the coverage and branches of A. philoxeroides both significantly decreased as species diversity increased, while the latitude and latitude×species diversity interaction did not significantly affect the invasiveness. 2) Increased temperature was associated with a significant reduction of both height and maximum stem length of A. philoxeroides, as well as the heights of resident plants Digitaria sanguinalis, Sonchus oleraceus and Eleusine indica. Increased species diversity significantly reduced the height, numbers of clonal ramets and maximum stem length of A. philoxeroides, thus weakened its invasiveness. An interaction between latitude and species diversity significantly increased A. philoxeroides branches when growing in the monoculture, and a species-specific interaction with latitude significantly shortened the maximum stem length of S. oleraceus in the artificial community. 3) Increased temperature had no significant effect on either A. philoxeroides or native plant species biomass. A. philoxeroides biomass decreased with increased species diversity, but its root/stem ratio increased, indicating that A. philoxeroides allocated relatively more resources to underground storage in response to the interspecies competition. In conclusion, these results indicate that a higher biodiversity is helpful for reducing A. philoxeroides invasiveness, but increased temperature may weaken the competitive resistance of resident plants. Thus, protection of native plant species diversity should receive more attentions to counteract the potential facilitating effects of global warming on the spread of A. philoxeroides.

Key words: biological invasions, Alternanthera philoxeroides, warming, latitudinal gradient, species diversity