典型冷暖季沉水植物凋落物分解特性及沉积物微生物群落变化

Abstract

PDF HTML阅读 XML下载 导出引用 引用提醒 典型冷暖季沉水植物凋落物分解特性及沉积物微生物群落变化 DOI: 10.5846/stxb202106281715 作者: 作者单位: 作者简介: 通讯作者: 中图分类号: 基金项目: 国家水体污染控制与治理科技重大专项（2018ZX07110003）；国家自然科学基金项目（31670467） Decomposition characteristics of typical warm season and cold season submerged plant litters and change of microbial community in sediment Author: Affiliation: Fund Project: National Major Science and Technology Program-“Water Body Pollution Control and Remediation” (2018ZX07110003), National Natural Science Foundation of China (31670467) 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:为研究湿地沉水植物腐败分解对水体的污染状况，选择典型沉水植物金鱼藻（暖季植物）和菹草（冷季植物）进行了为期60 d的凋落物分解实验。结果表明金鱼藻和菹草凋落物分解规律相似，0-15 d快速分解，15-60 d缓慢分解，60 d凋落物失重率分别达到60.43%和66.72%。菹草的有机物释放量明显高于金鱼藻，N和P释放量相反，分解释放的N主要是NH+4-N和有机氮。三维荧光光谱（EEMs）结合平行因子分析法解析出一种类色氨酸物质C2和3种类腐殖质物质C1、C3、C4，易降解的类色氨酸有机物先增加后减少，难降解的类富里酸和类腐殖酸有机物逐渐增加。EEMs和四种组分的最大荧光强度百分比表明，溶解性有机物（DOM）在0-15 d以易降解有机物为主，15-60 d以难降解有机物为主。两种植物凋落物分解释放的DOM含量及特性不同，整体上呈低腐殖化特征，可能是水中难降解DOM的一个重要来源。植物凋落物的分解促进了沉积物中微生物的丰富度，降低了微生物的多样性；参与分解的主要微生物包括4 d时的Pseudomonas属（26%-35%）、15 d和30 d时的Malikia属（>8%）和Bacillus属（2.6%-9%），分解难降解有机物的微生物逐渐增加，如Flavobacterium属；沉积物中微生物群落结构的变化受营养物质可利用性变化的影响。分析发现植物凋落物分解对水质的影响具有阶段性，0-15 d，N和P释放量增加暂时导致了水质恶化；15-60 d，N和P释放量降低，难降解有机物含量逐渐增加，可能会加剧水体甚至是沉积物的腐殖化程度。因此，在植物衰亡期应及时打捞或者做好植物平衡收割管理，避免因植物大量腐败导致水质恶化。 Abstract:In order to study the pollution of submerged plant litter decomposition in wetland, a 60-days litter decomposition experiment was carried out with typical submerged plants, including Ceratophyllum demersum L. (warm season plant) and Potamogeton crispus L. (cold season plant). The results showed that decomposition process of both plant litters was similar, a fast decomposition from 0 to 15 d followed by slow decomposition from 15 to 60 d. The mass loss of plant litters on 60 d reached 60.43% and 66.72%, respectively. More organic matters were obviously released from Potamogeton crispus L. than those from Ceratophyllum demersum L., while nitrogen and phosphorus release was the opposite. The nitrogen released was mainly ammonia nitrogen and organic nitrogen. Excitation emission matrix parallel factor analysis identified four kinds of fluorescence components:tryptophan-like C2, and three kinds of humus-like C1, C3, C4. The easily biodegradable tryptophan-like organic matters increased first and then decreased, while the difficult biodegradable fulvic acid-like and humic acid-like organic matters increased gradually. Three-dimensional fluorescence spectra and the maximum fluorescence intensity percentages of the four components showed that dissolved organic matter (DOM) was dominated by easily degradable organic compounds during 0-15 d and by refractory organic compounds during 15-60 d. The contents and characteristics of DOM released during the decomposition of plant litters were different, showing a low humification feature on the whole, which may be an important endogenous source of difficult biodegradable DOM in water. The decomposition of plant litters improved the microbial richness and decreased the microbial diversity in sediments. The main microorganisms included Pseudomonas (26%-35%) at 4 d, Malikia (>8%) and Bacillus (2.6%-9%) at 15 d and 30 d for decomposition, while the microorganisms that decomposed the refractory organic matter increased gradually, such as Flavobacterium. Changes in microbial community structure in sediments were influenced by changes in the availability of nutrients. The results showed that the effects of plant litter decomposition on water quality were phased. The release nitrogen and phosphorus increased during 0-15 d, which led to the deterioration of water quality temporarily; during 15-60 d, nitrogen and phosphorus release decreased, while refractory organic matter content increased gradually, which may exacerbate the humification degree of water and even sediment. Therefore, in the decay period of plant litters, it is necessary to salvage plant litters in time or manage plant harvesting rationally to avoid the deterioration of water quality caused by plant litter decay. 参考文献 相似文献 引证文献