植物生态学报 ›› 2025, Vol. 49 ›› Issue (12): 2069-2079.DOI: 10.17521/cjpe.2025.0014  cstr: 32100.14.cjpe.2025.0014

• 研究论文 • 上一篇    下一篇

湿地植物对土壤水分变化与凋落物覆盖的差异化响应

张旭东1,2, 刘波1,*(), 张丹2, 武海涛1, 潘媛1, 郑皓文1, 李蕊1, 严硕1, 申敏琰1, 赖明子1   

  1. 1中国科学院东北地理与农业生态研究所, 长春 130102
    2长春大学, 长春 130022
  • 收稿日期:2025-01-09 接受日期:2025-04-08 出版日期:2025-12-20 发布日期:2025-04-09
  • 通讯作者: *刘波(liubo@iga.ac.cn)
  • 基金资助:
    国家重点研发计划(2022YFF1300901);国家自然科学基金(41771108)

Differential responses of wetland plant species to water depth changes and litter cover

ZHANG Xu-Dong1,2, LIU Bo1,*(), ZHANG Dan2, WU Hai-Tao1, PAN Yuan1, ZHENG Hao-Wen1, LI Rui1, YAN Shuo1, SHEN Min-Yan1, LAI Ming-Zi1   

  1. 1Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun 130102, China
    2Changchun University, Changchun 130022, China
  • Received:2025-01-09 Accepted:2025-04-08 Online:2025-12-20 Published:2025-04-09
  • Supported by:
    National Key R&D Program of China(2022YFF1300901);National Natural Science Foundation of China(41771108)

摘要:

水深是湿地生态系统的关键环境因素, 影响植物的生长更新和分布格局。作为自然生态系统的重要组成部分, 凋落物通过消光效应、机械阻碍和化感作用等多种途径影响植物幼苗的更新。湿地生态系统由于淹水和厌氧等环境条件的影响, 凋落物积累量更大。但目前关于凋落物覆盖和水深变化交互作用对植物幼苗更新的研究鲜有报道。该研究在移动遮雨棚模拟野外环境条件, 分析了不同水深变化(湿润、水分饱和及淹水)及凋落物覆盖量(0、500、1 000、1 500 g·m-2)对稗(Echinochloa crus-galli)、无芒稗(E. crus-galli var. mitis)、鬼针草(Bidens pilosa)和泽泻(Alisma plantago-aquatica)种子萌发及出苗的影响。结果表明: 稗、无芒稗和泽泻种子萌发与出苗均受凋落物覆盖、水深变化及其交互作用的显著影响, 而鬼针草仅受凋落物覆盖的显著影响。凋落物覆盖使鬼针草萌发率和出苗率分别下降了59.4%-96.9%和94.4%-100.0%; 处于凋落物下方的鬼针草种子萌发率比处于凋落物上方的萌发率大幅降低了94%, 说明凋落物覆盖产生的消光效应是限制鬼针草种子萌发的主要原因。泽泻种子在土壤湿润条件下萌发率几乎为0, 而在水分饱和或淹水环境, 萌发率增加至30%以上, 说明充足的水分对于泽泻种子萌发至关重要; 在水分饱和或淹水处理, 泽泻种子在凋落物覆盖下有29%-60%的种子可以萌发, 但能够穿过凋落物层的种苗仅为1.5%-17%, 凋落物覆盖产生的机械阻碍作用应该是影响其种苗更新的关键因素。该研究为理解环境变化下湿地植被分布格局和演替动态提供了科学依据, 对湿地植被生态恢复和科学管理具有重要意义。

关键词: 凋落物, 水深, 湿地生态系统, 种子萌发

Abstract:

Aims Water depth is a critical environmental factor in wetland ecosystems, influencing plant growth, regeneration, and distribution patterns. As an essential component of natural ecosystems, litter affects the regeneration of plant seedlings through various mechanisms such as light attenuation, mechanical obstruction, and allelopathy. Wetland ecosystems tend to accumulate a larger amount of litter because of flooding and anaerobic conditions. However, few studies have investigated the interactive effects of litter cover and water depth on the regeneration of plant seedlings.

Methods This research simulated the field environmental conditions in mobile rain shelters to analyze the influences of water depth (wet, water-saturated, and flooded) and litter cover (0, 500, 1 000, and 1 500 g·m-2) on the seed germination rates and emergence rates of Echinochloa crus-galli, E. crus-gallivar. mitis, Bidens pilosa, and Alisma plantago-aquatica.

Important findings We found that the seed germination rates and emergence rates of E. crus-galli, E. crus-gallivar. mitis and A. plantago-aquatica were significantly affected by litter cover, water depth, and their interactions, while B. pilosa was only significantly influenced by litter cover. Litter cover decreased the germination and emergence rates of B. pilosa by 59.4% to 96.9% and 94.4% to 100.0%, respectively. The germination rate of B. pilosa seeds beneath litter was significantly reduced by 94% compared to that above litter, indicating that the shading effect resulting from litter cover was the primary cause restricting the germination of B. pilosa seeds. The germination rate of A. plantago-aquatica seeds was nearly zero under wet conditions, but increased to over 30% in water-saturated or flooded environments, suggesting that sufficient moisture is of vital importance for the germination of A. plantago-aquatica seeds. Under water-saturated or flooded conditions, 29% to 60% of the seeds of A. plantago-aquatica germinated when covered by litter. However, only 1.5% to 17% of the seedlings penetrated through the litter layer. We posit that mechanical obstruction caused by litter cover is a critical factor influencing the seedling regeneration of A. plantago-aquatica. This study can help understand the distribution patterns and succession dynamics of wetland vegetation under environmental changes and has important implications for the ecological restoration and scientific management of wetland vegetation.

Key words: litter, water depth, wetland ecosystem, seedling germination