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| 洞庭湖湿地短尖薹草种群克隆生长对泥沙淤积的适应 |
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潘柏含1, 邹雅1, 邓正苗2, 谢永宏2, 侯志勇2, 李旭2, 曾静2, 吴滔1, 谢洪涛3, 黎慧娟4
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1.湖南师范大学生命科学学院;2.中国科学院亚热带农业生态研究所，亚热带农业生态过程重点实验室，洞庭湖湿地生态系统观测研究站;3.益阳市林业局;4.湖南鑫远环境科技股份有限公司，湖南省环境保护入河湖湿地生态修复工程技术中心
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| 摘要: |
| 泥沙淤积是影响湿地植物生存和生长的重要因素。克隆植物是湿地生态系统的主要植物类型之一。在自然水文条件下，湿地克隆植物种群对不同淤积速率的响应研究相对较少。本研究以洞庭湖湿地优势克隆植物短尖薹草（Carex brevicuspis）为对象，通过连续三年的野外控制试验，研究了不同淤积速率（0、2、4、6 cm/a，分别对应对照、低、中和高淤积速率）对湿地克隆植物种群的影响。结果发现：淤积速率对短尖薹草的种群密度影响显著，淤积处理的密度显著低于对照处理。随着淤积速率的增加，密度下降，地下/地上生物量比增加，高淤积速率下种群的密度最低，地下/地上生物量比最高。与对照处理相比，泥沙淤积促进了更多的短根（< 10 cm）、长根茎（≥ 2 cm）和游击型克隆分株的形成，长根茎的长度随淤积速率的增加而增加。高淤积速率下的长根茎数量较低，但其根长最长，表明其克隆生长策略由密集型向游击型转变。由此可见，短尖薹草种群可通过对密度、生物量分配、根系长度和克隆生长策略的调节，有效地应对不同泥沙淤积速率的影响。 |
| 关键词: 淤积速率 湿地植物 种群特征 根系 克隆生长 |
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| 基金项目:国家自然科学基金区域创新联合基金项目（U21A2009），国家基础性工作调查专项（2019FY100602），湖南省教育厅科学研究项目（19B378） |
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| Clonal Growth Adaptation to Sediment Deposition of Carex brevicuspis Population in Dongting Lake Wetland |
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Pan Baihan1, Zou Ya1, Deng Zhengmiao2, Xie Yonghong2, Hou Zhiyong2, Li Xu2, Zeng Jing2, Wu Tao1, Xie Hongtao3, Li Huijuan4
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1.College of Life Sciences,Hunan Normal University,Changsha;2.Key Laboratory of Agro-ecological Processes in Subtropical Region, Dongting Lake Station for Wetland Ecosystem Research, Institute of Subtropical Agriculture, Chinese Academy of Sciences;3.Forestry bureau of Yiyang City;4.Hunan Xinyuan Environment Technology Co., Ltd.
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| Abstract: |
| Sediment deposition is an important factor affecting the survival and growth of wetland plants. Clonal plants are one of the most important plants in the wetland ecosystem. At present, there are few studies on the response of clonal plant populations to different deposition rates in wetlands under natural hydrological conditions. In this study, Carex brevicuspis, a typical clonal plant in Dongting Lake Wetland, was chosen to investigate the effects of different deposition rates (0, 2, 4, 6 cm/a, corresponding to control, low, medium, and high deposition rates, respectively) on the growth and development of clonal plant populations in wetlands by field control experiments for three consecutive years. The results showed that the sedimentation rate had a significant effect on the plant population density, and the plant population density in the sedimentation treatment was significantly lower than that in the control treatment. Plant population density decreased and the underground/aboveground biomass ratio increased with the increase in sedimentation rate, while the plant population density of high sedimentation rate was the lowest and the underground/aboveground biomass ratio was the highest in all treatments. Sediment burial promoted the formation of more short roots (< 10 cm), long rhizomes (≥ 2 cm), and spreading ramets than no burial treatments, and the length of long rhizomes increased with the deposition rate. The number of long rhizomes was lower and the length of long rhizomes was the longest in high sedimentation rate than other treatments, which indicated that the clonal growth strategy of C. brevicuspis population changed from phalanx type to guerrilla type. Therefore, at the population level, plants can effectively deal with the influence of different sediment deposition rates by regulating plant population density, biomass allocation, root length, and clonal growth strategies. |
| Key words: Sedimentation rate Wetland plants Plant population characteristics Root system Clonal growth |
