| 摘要: |
| 在气候变化和人类活动的影响下，鄱阳湖水文节律发生变化，表现为枯水位降低、枯水期的延长，此外，相继出现了2020年的洪水和2022、2023年的持续干旱等事件。这种变化对洲滩植物的生长和繁殖产生了深刻的影响。本研究以鄱阳湖洲滩优势植物灰化薹草(Carex cinerascens)为研究对象，设置提前退水30天、提前退水15天、正常退水、推迟退水15天、推迟退水30天五个退水时间梯度，观测灰化薹草生长和繁殖过程的变化。结果表明：（1）不同退水时间灰化薹草达到的最大株高存在显著差异（p<0.05）。相对正常退水，提前退水灰化薹草株高显著增加，而推迟退水则显著降低；此外，退水时间改变对地上生物量的影响因季节而异，秋季地上生物量随退水时间推迟显著降低（p<0.05），而春季则无显著性影响；随着退水时间推迟，春季和秋季的地下生物量均降低，从而导致春、秋季生物量分配的差异。（2）不同退水时间对薹草秋草生长阶段的无性繁殖存在显著影响，提前退水显著的增加了灰化薹草的分蘖数、间隔子的数量和长度，推迟退水则抑制了植物分蘖，此外，随着退水时间推迟，间隔子的数量和长度显著降低（p<0.05）；提前退水和推迟退水均影响春季开花株数和花穗数量，然而，相对于推迟退水, 提前退水对其影响相对较小。研究结果为变化水情下湿地优势植物的保护和管理提供了理论基础。 |
| 关键词: 退水时间 灰化薹草 生长 繁殖 鄱阳湖湿地 |
| DOI： |
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| 基金项目:国家重点基础研究发展计划（973计划）,国家自然科学基金项目（面上项目，重点项目，重大项目） |
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| Effects of different water level recession trimming on the growth and reproduction of Carex cinerascens |
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YANG WENJUAN1, XIA SHAOXIA2, YU XIUBO2
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1.Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences (CAS);2.Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences (CAS),
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| Abstract: |
| Climate change and human activities have altered the hydrological patterns of Poyang Lake, leading to lower dry season water levels and extended dry periods. Additionally, extreme events such as the floods of 2020 and the prolonged droughts of 2022 and 2023 have occurred. These changes have significantly impacted the growth and reproduction of floodplain plants. This study investigated the dominant floodplain plant, Carex cinerascens, examining five water level recession scenarios: 30 days earlier, 15 days earlier, normal, 15 days later, and 30 days later. The study observed the plant’s growth and reproductive responses. The results showed: (1) Water recession timing significantly affected the maximum height of Carex cinerascens (p＜0.05). Earlier recession increased plant height, while later recession reduced it. The impact on aboveground biomass varied seasonally; in autumn, delayed recession significantly decreased aboveground biomass (p＜0.05), while in spring, there was no significant effect. Both spring and autumn underground biomass decreased with delayed recession, affecting biomass distribution between seasons. (2) Water level recession timing also significantly influenced vegetative reproduction in the autumn growth stage. Earlier recession increased the number of tillers and the quantity and length of spacers, while delayed recession inhibited tillering and reduced spacers’ quantity and length (p＜0.05). Both earlier and delayed recession affected the number of flowering stems and inflorescences in spring, but the impact was smaller with earlier recession compared to delayed recession. These findings provide a theoretical basis for the conservation and management of dominant wetland plants under changing hydrological conditions. |
| Key words: Water level recession timing Carex cinerascens Growth Reproduction Poyang Lake Wetland |
