近自然恢复湿地植被演替与营养盐去除的相互作用研究
发布时间：2018-08-13 18:45
【摘要】：湿地退化将严重影响湿地生态功能的实现,是目前人类面临的重要生态环境问题之一,湿地生态恢复可以改善退化的湿地生态系统,恢复生态系统功能。本文通过对七星湖近自然恢复湿地的长期野外监测,研究了近自然恢复湿地植物群落演替特征,探讨了湿地典型水生植物与淹没水深、营养盐水平时空变化的响应特征,并研究了湿地植被演替过程中植物总生物量、植被面积、覆盖率、植物群落多样性指数变化对近自然恢复湿地营养盐去除的影响。研究结果表明:(1)近自然恢复湿地多年运行以来,植物物种丰度以及群落多样性在整体上有所下降,但在湿地出口区域均有所上升。近自然恢复湿地在高污染进水负荷的条件下植被群落有向简单结构发展的趋势,当环境条件适宜时,湿地植被格局向多元化发展。(2)水深对近自然恢复湿地内水生植物分布有重要影响,湿地典型水生植物通过自我调整,表现出了沿水深的不同分布特征。在恢复湿地建设完成后,湿地水生植被经过6年的自然演替,植物适应水深表现为:漂浮植物≈浮叶植物沉水植物挺水植物。近自然湿地各植物群落逐渐向自身适宜的水深区域发展,生长在同一水深区域的不同植物群落间产生了剧烈的竞争而导致群落演替。(3)近自然恢复湿地营养盐水平对水生植物分布影响作用显著,湿地水生植物对营养盐水平有不同的响应特征。芦苇和香蒲群落对污染物耐受程度较高,芦苇和香蒲能在湿地各单元内均长势良好,高浓度的氮磷不利于荷花、芡实和沉水植物的生长。近自然恢复湿地沉水植物对营养盐的耐受能力表现为:菹草金鱼藻=狐尾藻轮叶黑藻。菱角喜好生长在高营养盐的区域,荇菜在水质良好的湿地出口区域中长势最好。(4)植物群落对水体温度、pH和溶解氧有着显著的影响。水体温度在夏季与植被面积、覆盖率和植被生物量显著负相关。pH与植被面积、生物量和物种丰富度正相关,与植被覆盖率负相关。水体溶解氧在夏季和秋季与植被面积、覆盖率和生物量负相关,在春季和冬季正相关,溶解氧含量随着物种丰富度升高而上升。植物多样性指数变化与水温、pH和溶解氧无明显趋势。(5)近自然恢复湿地植被演替影响了湿地氮磷去除效率。湿地多年运行以来,整体氮磷去除率均保持较高水平,各湿地单元氮磷去除率随着植被分布变化显示了不同变化特征。在七星湖湿地植被演替过程中,湿地氮磷去除效果与湿地植物生物量和植被面积显著正相关;随着植被覆盖率的上升,湿地氮磷去除率先升高后下降,75%~80%的植被覆盖率最有利于湿地氮磷去除;湿地植物物种丰富度与氮磷去除均呈现显著正相关关系;湿地植物群落多样性指数H和优势度指数D与氮去除率相关性较差,而与溶解态磷去除率呈现显著正相关;均匀度指数J与湿地磷去除率与相关性较差,与湿地氮去除率呈显著负相关。近自然恢复湿地在长期运行过程中,湿地水生植物群落结构和功能发生了巨大的变化。本文研究了近自然恢复湿地典型水生植物群落对营养盐和水位的响应机制,探讨了近自然恢复湿地植被演替与营养盐去除相互作用关系,为近自然恢复湿地植被适应性格局构建和湿地生态修复工程提供理论依据和技术支持。
[Abstract]:Wetland degradation will seriously affect the realization of wetland ecological function, which is one of the important ecological environment problems facing mankind. Wetland ecological restoration can improve degraded wetland ecosystem and restore ecosystem function. In this paper, the near-natural restoration wetland flora was studied by long-term field monitoring of Qixing Lake near-natural restoration wetland. The response characteristics of typical aquatic plants and submerged water depth and nutrient saline in wetland were discussed. The effects of total plant biomass, vegetation area, coverage and plant community diversity index on nutrient removal in near-natural restoration wetland during vegetation succession were studied. However, plant species richness and community diversity have declined on the whole since the restoration of wetlands operated for many years, but increased in the outlet area of wetlands. (2) Water depth has an important influence on the distribution of aquatic plants in near-natural restoration wetlands. Typical aquatic plants in wetlands show different distribution characteristics along the water depth through self-adjustment. After six years of natural succession of aquatic vegetation in the restoration wetlands, plants adapt to the water depth as follows: floating plants floating leaf plants submerged in water The plant communities in the near-natural wetland gradually develop to their own suitable water depth region, and there is fierce competition among different plant communities growing in the same water depth region, resulting in community succession. (3) The level of nutrient saline in the near-natural restoration wetland has a significant effect on the distribution of aquatic plants, and the aquatic plants in the wetland have a significant effect on nutrient saline water. Phragmites australis and cattail communities have higher tolerance to pollutants. Phragmites australis and cattail can grow well in each unit of the wetland. High concentration of nitrogen and phosphorus is not conducive to the growth of lotus, seed and submerged plants. Leaf black algae. Water chestnut prefers to grow in areas with high nutrients. The growth of sauerkraut is best in areas with good water quality. 4. Plant communities have significant effects on water temperature, pH and dissolved oxygen. Water temperature is negatively correlated with vegetation area, coverage and biomass in summer. pH is negatively correlated with vegetation area, biomass and species abundance. Dissolved oxygen in water was negatively correlated with vegetation area, coverage and biomass in summer and autumn, positively correlated with spring and winter, and dissolved oxygen content increased with the increase of species richness. Nitrogen and phosphorus removal efficiency of wetland is affected by succession. Overall nitrogen and phosphorus removal rate of wetland has maintained a high level since years of operation. The nitrogen and phosphorus removal rate of each wetland unit shows different characteristics with the change of vegetation distribution. With the increase of vegetation coverage, the removal rate of nitrogen and phosphorus in wetland increased first and then decreased, and 75%~80% vegetation coverage was the most favorable for nitrogen and phosphorus removal in wetland. There was a significant positive correlation with the removal rate of dissolved phosphorus, a poor correlation between the evenness index J and the removal rate of wetland phosphorus, and a significant negative correlation with the removal rate of wetland nitrogen. The response mechanism of aquatic plant community to nutrients and water level was discussed, and the interaction between vegetation succession and nutrient removal in near-natural restoration wetlands was discussed.
【学位授予单位】：华北电力大学(北京)
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：X171.4
[Abstract]:Wetland degradation will seriously affect the realization of wetland ecological function, which is one of the important ecological environment problems facing mankind. Wetland ecological restoration can improve degraded wetland ecosystem and restore ecosystem function. In this paper, the near-natural restoration wetland flora was studied by long-term field monitoring of Qixing Lake near-natural restoration wetland. The response characteristics of typical aquatic plants and submerged water depth and nutrient saline in wetland were discussed. The effects of total plant biomass, vegetation area, coverage and plant community diversity index on nutrient removal in near-natural restoration wetland during vegetation succession were studied. However, plant species richness and community diversity have declined on the whole since the restoration of wetlands operated for many years, but increased in the outlet area of wetlands. (2) Water depth has an important influence on the distribution of aquatic plants in near-natural restoration wetlands. Typical aquatic plants in wetlands show different distribution characteristics along the water depth through self-adjustment. After six years of natural succession of aquatic vegetation in the restoration wetlands, plants adapt to the water depth as follows: floating plants floating leaf plants submerged in water The plant communities in the near-natural wetland gradually develop to their own suitable water depth region, and there is fierce competition among different plant communities growing in the same water depth region, resulting in community succession. (3) The level of nutrient saline in the near-natural restoration wetland has a significant effect on the distribution of aquatic plants, and the aquatic plants in the wetland have a significant effect on nutrient saline water. Phragmites australis and cattail communities have higher tolerance to pollutants. Phragmites australis and cattail can grow well in each unit of the wetland. High concentration of nitrogen and phosphorus is not conducive to the growth of lotus, seed and submerged plants. Leaf black algae. Water chestnut prefers to grow in areas with high nutrients. The growth of sauerkraut is best in areas with good water quality. 4. Plant communities have significant effects on water temperature, pH and dissolved oxygen. Water temperature is negatively correlated with vegetation area, coverage and biomass in summer. pH is negatively correlated with vegetation area, biomass and species abundance. Dissolved oxygen in water was negatively correlated with vegetation area, coverage and biomass in summer and autumn, positively correlated with spring and winter, and dissolved oxygen content increased with the increase of species richness. Nitrogen and phosphorus removal efficiency of wetland is affected by succession. Overall nitrogen and phosphorus removal rate of wetland has maintained a high level since years of operation. The nitrogen and phosphorus removal rate of each wetland unit shows different characteristics with the change of vegetation distribution. With the increase of vegetation coverage, the removal rate of nitrogen and phosphorus in wetland increased first and then decreased, and 75%~80% vegetation coverage was the most favorable for nitrogen and phosphorus removal in wetland. There was a significant positive correlation with the removal rate of dissolved phosphorus, a poor correlation between the evenness index J and the removal rate of wetland phosphorus, and a significant negative correlation with the removal rate of wetland nitrogen. The response mechanism of aquatic plant community to nutrients and water level was discussed, and the interaction between vegetation succession and nutrient removal in near-natural restoration wetlands was discussed.
【学位授予单位】：华北电力大学(北京)
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：X171.4
【参考文献】
相关期刊论文 前10条
1 周s，
本文编号：2181855
本文链接：https://www.wllwen.com/shengtaihuanjingbaohulunwen/2181855.html
