| 氮添加和地下水位交互作用对通江湖泊湿生植物陌上菅生长的影响 |
| |
| 引用本文： | 远勇帅,皇甫超河.氮添加和地下水位交互作用对通江湖泊湿生植物陌上菅生长的影响[J].环境科学研究,2020,33(12):2838-2847. |
| |
| 作者姓名： | 远勇帅 皇甫超河 |
| |
| 作者单位： | 安徽大学资源与环境工程学院, 安徽 合肥 230601 |
| |
| 基金项目： | 国家重点研发计划项目（No.2016YFC1202200） |
| |
| 摘 要： | 研究地下水位变化和氮沉降对植物功能性状的影响，有助于揭示植物对环境变化的响应和适应规律.采用原位试验的方法，选择不同地下水位梯度〔低水位（-75 cm）、中水位（-69 cm）、高水位（-39 cm）〕和氮添加〔缺氮处理（430 g/m2）、空白对照（0 g/m2）、低氮（4.32 g/m2）、中氮（8.64 g/m2）、高氮（17.28 g/m2）〕（其中缺氮处理添加量以碳元素含量计，其余处理以氮元素含量计），研究升金湖消落带湿地物种丰富度、陌上菅（Carex thunbergii）地上生物量和根系形态学指标对地下水位和氮添加的响应.结果表明:①双因素方差分析显示，地下水位主要影响物种丰富度、陌上菅地上生物量和根系形态学指标；氮添加主要影响土壤养分含量和陌上菅比根长、根比表面积及根组织密度；地下水位和氮添加的交互作用对陌上菅比根长和根平均直径影响显著（P < 0.05）；相对而言，水位对陌上菅的影响大于氮添加.②地下水位对陌上菅地上生物量和根系形态学指标有显著影响.地下水位升高会降低陌上菅地上生物量、根系比根长和根组织密度，同时增加其根平均直径和根比表面积，且不同处理间差异显著（P < 0.05）.在空白对照处理下，相比于低水位，高水位下陌上菅地上生物量、比根长和根组织密度分别降低了97.6%、46.1%、86.1%，根平均直径和根比表面积分别增加了326.1%、198.5%.③氮添加主要影响陌上菅根系形态学指标.随着施氮水平的增加，陌上菅比根长和根比表面积呈现先减后增的趋势，根组织密度呈现先增后减的趋势.在高水位条件下，相比于空白对照，低氮处理下陌上菅比根长和根比表面积分别减少了36.1%、41.8%，陌上菅根组织密度增加了182.4%，且差异显著（P < 0.05）.研究显示，地下水位升高与氮添加对陌上菅地上生物量和陌上菅比根长的影响呈相互抵消的态势，这体现了土壤水分增加对陌上菅生长的胁迫作用；水位升高和氮添加对根比表面积和根组织密度的影响表现为协同效应，揭示了在水位胁迫条件下陌上菅对养分获取策略的变化.
|
| 关 键 词： | 氮添加 地下水位 地上生物量 物种丰富度 细根形态 |
| 收稿时间： | 2019/12/3 0:00:00 |
| 修稿时间： | 2020/4/6 0:00:00 |
Effects of Nitrogen Addition and Groundwater Level Interaction on Growth of the Wet Plant Carex thunbergii in Lakes Connecting the Yangtze River |
| |
| YUAN Yongshuai,HUANGFU Chaohe.Effects of Nitrogen Addition and Groundwater Level Interaction on Growth of the Wet Plant Carex thunbergii in Lakes Connecting the Yangtze River[J].Research of Environmental Sciences,2020,33(12):2838-2847. |
| |
| Authors: | YUAN Yongshuai HUANGFU Chaohe |
| |
| Affiliation: | School of Resources and Environmental Engineering, Anhui University, Hefei 230601, China |
| |
| Abstract: | Investigating the effects of groundwater level and N deposition on plant functional traits will help reveal the adaptation strategy of plants to environmental changes. In this study, an in situ experiment was designed to examine the influences of different groundwater levels (low, -75 cm; middle, -69 cm; high, -39 cm) and N additions (N reduction, 430 g C/m2, in form of sugar; ambient N, 0 g/m2; low N, 4.32 g/m2; middle N,8.64 g/m2; high N,17.28 g/m2) on the plant species richness in the littoral zones of Shengjin Lake, the above-ground biomass and root morphology of Carex thunbergii. We found that groundwater level mainly affected species richness, above-ground biomass and root morphological indicators of C. thunbergii, while N addition significantly influenced soil nutrient contents, root specific root length, specific surface area, and tissue density. Meanwhile, the interaction between groundwater level and N addition had a significant influence on the specific root length and average diameter of C. thunbergii (P<0.05), with the groundwater level dominating the variations. Compared with those under the low groundwater level, the above-ground biomass, root specific root length and tissue density decreased by 97.6%, 46.1% and 86.1% on average, respectively. But the root diameter and specific surface area of C. thunbergii increased by 326.1% and 198.5%, respectively, under high groundwater level. With increasing N addition, the specific root length and root specific surface area of C. thunbergii decreased and then increased, but root tissue density showed an opposite pattern. Compared to ambient control treatment, low level of N addition reduced the length and specific surface area of C. thunbergii roots by 36.1% and 41.8%, respectively, but increased the root tissue density by 182.4% under high groundwater level (P<0.05). The increased groundwater level and N addition could offset respective effects on aboveground biomass and specific root length of C. thunbergii, indicating an inhibition of increasing soil moisture on the growth of C. thunbergii. The N addition showed an effect on root specific surface area and tissue density, suggesting the adaptation of nutrient acquisition strategies of C. thunbergii to the water stress. |
| |
| Keywords: | nitrogen addition groundwater level aboveground biomass species richness fine root morphology |
| 本文献已被 万方数据 等数据库收录！ |
| 点击此处可从《环境科学研究》浏览原始摘要信息 |
|
点击此处可从《环境科学研究》下载全文 |
|
