植物生态学报 ›› 2017, Vol. 41 ›› Issue (4): 450-460.DOI: 10.17521/cjpe.2016.0193

所属专题: 入侵生态学专辑

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闽江河口入侵种互花米草和本地种短叶茳芏的养分动态及植物化学计量内稳性特征

蒋利玲1, 曾从盛2,3, 邵钧炯4, 周旭辉1,*()   

  1. 1复旦大学教育部生物多样性与生态工程重点实验室, 生物多样性科学研究所, 上海 200433
    2福建师范大学地理科学学院, 福州 350007
    3福建师范大学亚热带湿地研究中心, 福州 350007
    4华东师范大学生态与环境科学学院, 上海 200062
  • 收稿日期:2016-06-07 接受日期:2017-01-03 出版日期:2017-04-10 发布日期:2017-05-19
  • 通讯作者: 周旭辉
  • 基金资助:
    国家大学生创新项目(201210394011)、国家自然科学基金(31370489和31100352)、上海高校特聘教授(东方学者)岗位计划和中共中央组织部青年千人计划

Plant nutrient dynamics and stoichiometric homeostasis of invasive species Spartina alterniflora and native Cyperus malaccensis var. brevifolius in the Minjiang River estuarine wetlands

Li-Ling JIANG1, Cong-Sheng ZENG2,3, Jun-Jiong SHAO4, Xu-Hui ZHOU1,*()   

  1. 1Ministry of Education Key Laboratory for Biodiversity Science and Ecological Engineering, Institute of Biodiversity Science, Fudan University, Shanghai 200433, China

    2College of Geographical Science, Fujian Normal University, Fuzhou 350007, China
    and
    3Subtropical Wetland Research Center, Fujian Normal University, Fuzhou 350007, China
    and
    4School of Ecological and Environmental Sciences, East China Normal University, Shanghai 200062, China
  • Received:2016-06-07 Accepted:2017-01-03 Online:2017-04-10 Published:2017-05-19
  • Contact: Xu-Hui ZHOU

摘要:

化学计量内稳性是维持生态系统结构、功能和稳定性的重要机制。互花米草(Spartina alterniflora)的入侵对闽江河口湿地生态系统的结构和功能产生了威胁。互花米草入侵如何影响植物化学计量内稳性特征的研究有助于深入了解湿地生态系统稳定性, 对拓展生态化学计量学的研究范围有重要意义。该文基于化学计量内稳性理论, 以互花米草单种群落、短叶茳芏(Cyperus malaccensis var. brevifolius)单种群落和互花米草-短叶茳芏混生群落为研究对象, 对土壤和植物的氮(N)、磷(P)元素进行了测定, 并计算了植物的内稳性指数(H)。结果显示: 互花米草入侵对土壤N、P含量无显著影响, 但是显著提高了土壤N:P。对生态系统而言, N的内稳性(HN, 平均值为25.31)显著高于P的内稳性(HP, 平均值为10.33)与N:P值的内稳性(HN:P, 平均值为2.50)。在器官水平上, 根的HN显著高于茎的HN, 鞘的HN:P显著高于根的HN:P, 而不同器官间的HP差异不显著。种间内稳性对比发现, 混生群落中的互花米草根的HN显著高于混生群落中的短叶茳芏根的HN, 单种群落中的互花米草茎的HN:P显著高于单种群落中的短叶茳芏茎的HN:P。此外, 入侵对植物内稳性的影响表现在混生群落中的互花米草根、叶和鞘的HN均显著高于单种群落中的互花米草根、茎和鞘的HN。以上结果表明: 养分元素、器官、植被类型和入侵等均影响植物化学计量内稳性特征, 但无论是在单种群落还是在混生群落中, 互花米草均有内稳性显著高于短叶茳芏内稳性的现象, 没有发现短叶茳芏显著高于互花米草的研究结果。因此, 互花米草较高的内稳性可能是其入侵成功的一个原因。

关键词: 生物入侵, 养分动态, 生态化学计量内稳性, 生态系统功能, 闽江河口湿地

Abstract:

Aims Stoichiometric homeostasis is an important mechanism in maintaining ecosystem structure, function, and stability. The invasion of exotic species, Spartina alterniflora, has largely threatened the structure and function of native ecosystems in the Minjiang River estuarine wetland. However, how S. alterniflora invasion affect plant stoichiometric homeostasis is largely unknown. This could enhance our understanding on wetland ecosystem stability and expand the applications of ecological stoichiometry theory.
Methods Nitrogen (N) and phosphorus (P) contents of plant organs and soils in the S. alterniflora, Cyperus malaccensis var. brevifolius, and S. alterniflora-C. malaccensis var. brevifolius mixture were measured, and the homeostatic index (H) was calculated according to the stoichiometric homeostasis theory.
Important findings Our results showed that the invasion of S. alterniflora significantly increased soil N:P ratio (p < 0.05), but did not affect soil N or P contents. The N and P contents of leaf and stem were the highest for S. alterniflora, and those of the stem were the highest for C. malaccensis var. brevifolius. At the ecosystem level, the average of homeostatic index (H) of N (HN, 25.31) was larger than those of P (HP, 10.33) and N:P (HN:P, 2.50). At the organ level, root HN was significantly larger than stem HN (p < 0.05) and sheath HN:P was greater than root HN:P (p < 0.05), while there was no significant difference for HP among root, stem, leaf, and sheath (p > 0.05). As for species, root HN of S. alterniflora was significantly larger than that of C. malaccensis var. brevifolius in the mixture community (p < 0.05). In the monoculture, stem HN:P of S. alterniflora was significantly higher than that of C. malaccensis var. brevifolius (p < 0.05). Furthermore, root HN, leaf HN and sheath HN of S. alterniflora in the mixed community was significantly larger than that of S. alterniflora in the monoculture (p < 0.05), suggesting that S. alterniflora invasions increased their stoichiometric homeostasis. Meanwhile, the stoichiometric homeostasis of invasive and native plants were influenced by multiple factors, such as nutrients, organs, vegetation, and invasion. However, larger homeostasis was found in S. alterniflora than in C. malaccensis var. brevifolius in some particular organs either in mixture or monoculture communities. Therefore, the successful invasion of S. alterniflora may result from higher homeostatic index than the native species, C. malaccensis var. brevifolius.

Key words: biological invasion, nutrient dynamics, ecological stoichiometric homeostasis, ecosystem function, Minjiang River estuary wetland