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1.
李晓红  晏再生  江和龙 《湖泊科学》2016,28(5):1023-1030
沉水植物对维持湖泊生态系统平衡有重要作用,广泛应用在水体和沉积物污染修复领域.利用电场强化沉水植物修复过程是一种新的植物修复强化方法.本文研究了不同电压强度作用下沉水植物苦草的生长和生理响应,以期为应用电场强化沉水植物修复过程提供依据.结果表明:0.2~1.0 V电压可以促进苦草生长,而1.5~3.0 V电压则会抑制其生长.其中,0.5 V电压对苦草生长的促进效果最明显,生物量、平均株高、平均叶长、根尖数、新芽数和总叶绿素含量都比对照组显著增加;而3.0 V电压处理组的苦草在实验结束时出现萎蔫和凋亡,与对照组相比,叶绿素含量显著降低,丙二醛含量则极显著增加,表明苦草生长受到严重胁迫.系统上覆水的温度在不同处理组之间没有显著变化,上覆水的p H值在电压为1.0、1.5和3.0 V时显著下降,最终接近中性,上覆水的溶解氧浓度只在3.0 V电压处理组时表现显著下降;沉积物表层5 cm处的氧化还原电位随着电压增大显著下降,最终对苦草的生长形成胁迫.因此,本实验的结论是:0.2~1.0 V电压有助于沉水植物苦草的生长和强化植物修复过程,而1.5~3.0 V电压会破坏苦草组织,同时导致苦草生境变差,不利于沉水植物苦草的生长.  相似文献   

2.
水深是影响浅水湖泊沉水植物生长的主要因素之一.莲座型苦草(Vallisneria natans)和冠层型穗花狐尾藻(Myriophyllum spicatum)是我国长江中下游浅水湖泊中常见的沉水植物种类,二者在形态特征上具有较大的差异.在自然水体中,水深变化对这两种植物的生长以及竞争格局的影响还有待研究.本文设计了3个水深梯度(水深0.5、1.5、2.5 m),探讨混栽条件下苦草和穗花狐尾藻生长和竞争格局对水深变化的响应.结果显示在实验系统内,中水深(1.5 m)处理组对两种植物的生长均最有利,表现为两种植物的相对生长率和生物量均最高.低水深(0.5 m)处理组苦草的生物量和相对生长率均显著低于高水深(2.5 m)处理组;穗花狐尾藻则相反,高水深对其生长的抑制作用更大.2种沉水植物在高水深胁迫时均表现出地上部分(叶长或茎长)增加,地下部分(根长)减少的形态响应特征.此外,随着水深由高到低,苦草与穗花狐尾藻生物量之比逐渐减小,表明苦草在两种植物中的竞争优势逐渐降低.研究表明湖泊水深变化不仅能够影响沉水植物的丰度,同时还可能会影响沉水植物的群落结构,而在我国浅水湖泊的生态修复实践中,在通过水位调控恢复沉水植物时,调控范围应考虑目标植物(如苦草)的光合特征.  相似文献   

3.
郭洪涛  曹特  倪乐意 《湖泊科学》2008,20(2):221-227
本实验分别选用武汉东湖中营养和富营养湖区的湖水和底泥,并在水柱中添加氮或磷以设置高营养、中营养、中营养添加磷、中营养添加氮等四种营养环境.测定这四种营养条件下栽培苦草(Vallisneria natans)的生长和生化指标变化,探讨不同营养环境对苦草生长的影响机制.实验结果表明,苦草的生物量、叶数和新芽数等生长指标在中营养环境最高,中营养环境添加磷次之,中营养环境添加氮较低,在高营养环境最低;苦草可溶性糖和游离氨基酸含量在高营养环境中最高,在中营养环境、中营养环境添加磷和中营养环境添加氮等处理间没有明显差异.结果分析表明,高营养环境影响苦草的碳氮代谢水平并抑制苦草生长,这可能是由于苦草过量富集高营养环境中的氮素造成的;中营养环境中氮的升高会在一定程度上抑制苦草的生长,而磷的升高对苦草生长没有明显抑制作用.  相似文献   

4.
王瑞  何亮  张萌  曹特  张霄林  刘颖  倪乐意  葛刚 《湖泊科学》2021,33(5):1315-1333
由于人类生产生活对众多淡水水体的扰动、污染,我国苦草属(Vallisneria)植物的种群规模出现了严重的退化.明确苦草属植物萌发和生长的影响因素,阐明苦草属植物退化的原因,是保护和恢复该属植物亟需解决的科学问题.通过对已发表的文献进行收集和分析,总结了影响苦草属植物萌发和生长的主要因素,并通过挖掘文献中的数据,对重要环境因子与苦草属植物萌发和生长参数的关系进行了分析.结果表明:(1)涉及苦草(V.natans(Lour.) Hara)的研究较多,而涉及刺苦草(V.spinulosa Yan)和密刺苦草(V.denseserrulata Makino)的研究较少;(2)苦草属植物种子的萌发受到温度、光照强度、水深、掩埋深度、基质情况和储存方式等因素的影响;(3)苦草属植物生长受到光照强度、水深、水体营养水平、底泥营养水平、底泥有机质和动物牧食等因素的影响;(4)其他条件适宜时,苦草和刺苦草种子在20~30℃都保持较高的萌发率(均值 50%);(5)苦草种子萌发率随着掩埋深度的增加而快速下降;(6)苦草的相对生长率随光照强度的增加而升高,随水深增加而下降;(7)苦草的相对生长率随着氨氮浓度增加而下降;(8)水体和底泥中高含量的总氮和总磷对苦草属植物生长的抑制作用主要是通过促进浮游植物和附着藻生长导致的遮光,而不是直接毒害作用.未来需要进一步加强苦草属植物萌发、生长参数与环境因子关系的定量研究,更好地服务于该属植物的保护和恢复.  相似文献   

5.
模拟湖泊系统构建了"沉积物-水-苦草(Vallisneria natans)"系统,应用磷脂脂肪酸(PLFAs)法测定在沉水植物苦草不同生长时期沉积物表层微生物群落结构的变化,探讨沉水植物对沉积物中的微生物群落结构的影响.结果表明,从苦草生长初期到旺盛期再到衰亡期,沉积物中有机质含量先下降后上升;总磷、有机磷、无机磷分别下降了8.97%、7.81%、10.28%;沉积物微生物的活性与总磷呈极显著负相关,在苦草生长初期和旺盛期,实验组的沉积物微生物活性大于对照组,而在衰亡期对照组的沉积物微生物活性略高于实验组;不同时期沉积物中微生物群落结构发生了明显变化,组成结构差异显著,微生物组成中细菌占主要成分(占微生物总量的76%~84%);细菌中革兰氏阳性菌占主要优势,且革兰氏阳性菌百分含量随苦草生长呈上升趋势,革兰氏阴性菌呈下降趋势;真菌的百分含量呈上升趋势.  相似文献   

6.
湖泊富营养化是世界面临的重大环境问题,磷在沉积物-水界面的循环在富营养化过程中起关键作用,因此,研究沉水植物对沉积物-水界面磷循环的作用及其机理具重要的理论和实践意义.本实验通过在水泥池中(4.0 m×7.0 m×1.5 m)种植苦草(Vallisneria natans),并采用定期更换原位上覆水的方式模拟自然状态下的水体交换,研究了沉水植物苦草从定植到生长末期沉积物中不同形态磷含量的变化,以期揭示期间苦草对沉积物中磷赋存形态的影响.结果表明,本实验条件下苦草经历了两个生长阶段,在约1个月的快速生长期内能显著降低沉积物中的总磷(TP)含量,TP含量降低了78.79 mg/kg,其中有机磷(Org-P)含量降低49.99 mg/kg,对TP降低的贡献度为62.67%,而钙结合态磷(Ca-P)比对照组减少2.20%,因此,苦草可能主要通过促进Org-P的矿化向水柱和间隙水中释放磷的方式降低沉积物中TP含量,其次苦草可促进Ca-P的分解;此外,苦草为满足植株生长,所吸收的沉积物铁结合态磷(Fe-P)和铝结合态磷(Al-P)分别为2.99和4.10 mg/kg,但苦草对沉积物中闭蓄态磷(Oc-P)含量没有显著影响.在缓慢生长阶段,苦草促进有机物的沉降以及Fe-P和Oc-P的形成,Fe-P和Oc-P含量分别增加14.82和101.53 mg/kg.苦草对Al-P的形成也略有促进作用,其含量升高7.39%.研究结果表明,苦草在不同生长阶段对沉积物中磷形态的转化以及各形态磷的迁移方向具有不同的影响.在快速生长期苦草转化吸收高活性磷,将其固定到植株体内;缓慢生长阶段则促进水体中的磷转化成沉积物中难分解态的磷,对磷的沉降表现出积极促进作用.  相似文献   

7.
沉水植物恢复是富营养化湖泊生态系统重建的关键措施.沉水植物的生长受到很多因素的影响.本文通过考察生长和生理生态指标研究了硅酸盐矿物麦饭石对苦草生长的影响,为其进一步应用于水生生态修复提供理论依据.结果表明,麦饭石可以显著促进苦草的生长.添加了麦饭石处理组的苦草的生物量、株高、叶数、根长等生长指标明显高于对照组.且改性麦饭石组优于麦饭石原石组.1 cm麦饭石处理组的苦草在生长旺盛期时,其光和色素、根系活力和过氧化氢酶酶活等生理生态指标的活力均较对照组有一定程度的提高,而丙二醛含量有所降低.检测结果发现麦饭石中含有丰富的植物生长所需的常量和微量元素,可见麦饭石可进一步应用于富营养化湖泊的生态修复中.  相似文献   

8.
沉水植物和螺类都是水生生态系统的重要组成部分,两者的牧食关系也是水生食物网中重要的一环,而不同的基质类型可能会影响两者的生长和改变沉水植物对螺类牧食的防御策略.以耳萝卜螺(Radix auricularia)和苦草(Vallisneria spiralis)为对象,研究基质类型、螺类牧食对沉水植物的生长及防御策略的影响,以及基质类型及沉水植物对螺类生长和生理特征的影响.研究发现,螺类牧食和基质类型对苦草生长和元素特征具有显著的影响,存在螺类牧食时,泥沙基质和沙基质苦草的相对生长速率显著降低,泥沙、沙和泥基质苦草地上生物量分别减少了67.74%、58.58%和17.84%,根冠比分别升高了177.51%、217.23%和1.44%;且泥沙基质中苦草的叶片数显著低于无牧食组.不同基质类型下,牧食对苦草总碳含量无显著影响,但泥和泥沙组中,螺类牧食使苦草的总氮含量均显著降低,碳氮比均显著升高;沙基质下,螺类牧食使苦草总酚含量显著降低.基质类型对螺类的形态特征(除壳宽外)、生长及元素含量均无显著影响.总体来看,基质类型对耳萝卜螺牧食和苦草防御策略具有一定程度的影响,但对螺类的生长及元素特征基本无影响.本研究可以为牧食理论的研究提供基础数据支持,也可为沉水植被恢复、水生生态系统稳定提供参考,但基质类型对螺草牧食关系的长期影响,仍需进一步深入研究.  相似文献   

9.
采用沉水植物苦草(V.natans)和黑藻(H.verticillata)作为研究对象,在其旺盛生长期测定群落内外上覆水及沉积物各形态磷的含量,以探究不同根系特点的沉水植物对沉积物中各形态磷垂直分布的影响.结果表明:实验进行30 d后苦草和黑藻组沉积物总磷(TP)、无机磷(IP)和氢氧化钠提取磷(NaOH-P)含量在垂直方向均呈现不同程度的降低.苦草和黑藻组沉积物TP的含量在4.5 cm深度处降低幅度最大,较对照组分别下降了58.91和36.46 mg/kg;IP含量分别在沉积物6.0和3.0 cm深度处降低幅度最大,较对照组分别降低了85.41和57.41 mg/kg.总体来看,沉水植物苦草对沉积物各形态磷含量降低的影响大于黑藻.  相似文献   

10.
顾燕飞  王俊  王洁  方根生  韩璐 《湖泊科学》2017,29(3):654-661
苦草(Vallisneria natans)为我国常见的沉水植物之一,目前对水生态修复工程后苦草种群生长策略尚缺乏深入了解.以水生态修复工程1年后的苦草种群为研究对象,探讨水深对苦草叶片、匍匐茎、块茎等形态特征和苦草株数、匍匐茎数以及生物量等种群参数的影响,并分析水深胁迫下苦草的生长策略.结果表明,随着水深增加,尽管苦草单位面积株数和单位面积匍匐茎数均显著降低,但叶片长度、叶片宽度、叶片厚度、叶面积、匍匐茎长度、匍匐茎粗和块茎粗随水深显著增加,因而,苦草地上生物量也显著增加.其中,叶片长度和叶面积变异较大,对水深变化敏感,而叶片宽度、叶片厚度、匍匐茎长度、匍匐茎粗和块茎粗变异不大,对水深变化敏感程度低.在低光照胁迫下,苦草在亲株生长和子株输出之间存在权衡,一方面通过增加叶片投资保障亲株的资源利用效率,一方面通过降低亲株密度保障子株生长发育,从而实现种群空间生态位扩展和持续更新.在水生态修复工程中,考虑苦草的种群更新能力和施工的可操作性,在透明度为1.0~1.5m的条件下,苦草的适宜种植水深为0.5~1.0 m.  相似文献   

11.
Experiments were conducted to investigate the growth and morphology of the submersed macrophyte Vallisneria natans in relation to seven substrate types. The study also aims to evaluate the influence of the grain size of the aquatic substrate on the submersed macrophyte. The results show that growth, morphology and biomass accumulation of V. natans were significantly affected by the physical properties of the growth substrate. Compared with V. natans grown in pebble and gravel substrates, V. natans grown in silt and clay substrates had greater height, more ramets and leaves, as well as greater biomass accumulation. No significant differences in biomass allocation patterns were found among the different experimental treatments. The total porosity and dry bulk density of the growth substrate strongly influence plant traits. Substantial positive correlations were observed between total porosity and height and total biomass. Also, negative correlations were observed between dry bulk density and height, number of ramets, total biomass and lacunal volume. These results indicate that at high concentrations of water-column nutrients, V. natans responds to different physical properties of the growth substrate by changing growth and biomass accumulation strategies, rather than by changing biomass allocation patterns. Compared with V. natans grown in substrates with larger grain sizes, V. natans appeared well-adapted to substrates with smaller grain sizes. Thus, the physical properties of the growth substrate could be important in determining submersed macrophyte colonization and distribution in shallow eutrophic lakes. This information may be useful in managing shallow eutrophic lakes wherein rooted submersed macrophytes are declining.  相似文献   

12.
湖泊水深是影响沉水植物生长、繁殖与分布的重要环境因子,水深增加改变了水下光照、风浪和底泥特性等,因而可能导致沉水植物的生理生化指标发生相应变化.本研究通过对云南洱海沉水植物苦草(Vallisneria natans)随水深分布的情况进行调查,并分析了定植于不同水深的苦草叶片碳(C)、氮(N)和磷(P)含量及其比率,以阐明水深变化对苦草叶片生态化学计量学的影响.结果表明洱海苦草定植的水深范围为0.5~5.6 m,在1.5~2.4 m处达到最大频度,在2.5~3.4 m处达到最大相对生物量,这表明苦草在洱海中的最适生长深度在1.5~3.4 m范围内;苦草叶片C、N和P含量平均值分别为356.10、26.13和3.54 mg/g,C:N、C:P和N:P的平均值分别为14.38、113.46和7.85;苦草叶片C含量、C:N和C:P均随水深增加而降低,N和P含量则随水深增加而升高,N:P在0.5~1.4 m较高,其余水深梯度之间则没有显著差异.总体上,苦草叶片C、N、P含量及其化学计量特征显著地受到了湖泊水深的影响.另外,本研究还发现水深的增加使得苦草叶片N、P含量发生聚敛,这导致其N、P之间的耦合性变弱.  相似文献   

13.
目前对于沉水植物碳(C)、氮(N)和磷(P)化学计量学的野外研究主要集中在中营养或富营养化水体,而对于贫营养水体中沉水植物C、N和P的积累特征研究较少.基于对贫营养湖泊抚仙湖沉水植物的调查,研究抚仙湖9种常见沉水植物C、N和P化学计量学特征及其种间和种内差异.结果表明:1)抚仙湖沉水植物主要分布在湖岸浅水区域,分布水深范围为0.5~14.0 m,平均分布水深为3.6 m;2)抚仙湖沉水植物地上部分C、N和P含量平均值分别为381.89、18.59和2.13 mg/g,N∶P比平均值为9.21,且C、N和P含量之间呈显著正相关;3)抚仙湖沉水植物地上部分C、N和P含量及C∶N比和C∶P比值种间差异大于种内差异,而N∶P比种内差异大于种间差异;4)抚仙湖沉水植物C含量和N:P比平均值要大于长江中下游一些富营养化湖泊的沉水植物,抚仙湖沉水植物的生长可能潜在地受到P的限制.  相似文献   

14.
We examined the relevance of dissolved inorganic nitrogen (DIN) forms (nitrate and ammonium) in stream water as N sources for different macrophyte species. To do this, we investigated the variability and relationships between 15N natural abundance of DIN forms and of four different macrophyte species in five different streams influenced by inputs from wastewater treatment plants and over time within one of these streams. Results showed that 15N signatures were similar in species of submersed and amphibious macrophytes and in stream water DIN, whereas 15N signatures of the riparian species were not. 15N signatures of macrophytes were generally closer to 15N signatures of nitrate, regardless of the species considered. Our results showed significant relationships between 15N signatures of DIN and those of submersed Callitriche stagnalis and amphibious Veronica beccabunga and Apium nodiflorum, suggesting stream water DIN as a relevant N source for these two functional groups. Moreover, results from a mixing model suggested that stream water DIN taken up by the submersed and amphibious species was mostly in the form of nitrate. Together, these results suggest different contribution to in-stream N uptake among the spatially-segregated species of macrophytes. While submersed and amphibious species can contribute to in-stream N uptake by assimilation of DIN, macrophyte species located at stream channel edges do not seem to rely on stream water DIN as an N source. Ultimately, these results add a functional dimension to the current use of macrophytes for the restoration of stream channel morphology, indicating that they can also contribute to reduce excess DIN in streams.  相似文献   

15.
张雨  晏再生  吴慧芳  江和龙  郝征 《湖泊科学》2018,30(4):1012-1018
沉水植物是浅水湖泊生态系统的关键种群,对水环境质量及水生生态系统结构有重要影响.以东太湖大水港和湖湾区2个典型的具有不同污染程度的沉水植物苦草(Vallisneria natans)生长区域为研究对象,考察苦草对多环芳烃(PAHs)的修复效果.结果表明,经过34 d植物修复试验,重度污染的东太湖大水港沉积物中PAHs的去除率为62%,沉积物中PAHs降解速率为0.024 d-1;而中度污染的东太湖湖湾区沉积物的PAHs去除率为42%,其降解速率为0.015 d~(-1).种植苦草的沉积物中PAHs的降解速率是未种植苦草的降解速率的2~3倍.苦草对沉积物中高分子量PAHs的修复效果尤为显著.因此,苦草可以有效地用于PAHs污染沉积物的修复,尤其是在重污染和高分子量PAHs污染沉积物中,苦草的修复作用更加明显.  相似文献   

16.
Ecological restoration of eutrophic lakes using aquatic macrophytes is an important and practical technology. Here, we investigated the response of phytoplankton and zooplankton to a large-scale 2015-built aquatic macrophyte enclosure (AME, 200,000 m2) screened of by a PVC net in Baima Lake, a eutrophic lake, from spring to autumn of 2019. AME significantly improved water quality by increasing water transparency, and reducing total nitrogen, total phosphorus, and chlorophyll-a content during the growing season. AME significantly decreased phytoplankton abundance and biomass and marginally increased zooplankton abundance and biomass. Phytoplankton and zooplankton communities were closely related to environmental factors, such as water temperature, conductivity, total phosphorus, chemical oxygen demand, and chlorophyll-a inside and outside the AME. The zooplankton:phytoplankton biomass ratio inside was slightly higher than outside the AME. Zooplankton and phytoplankton biomass were significantly positively correlated inside and outside the AME, as were chlorophyll-a and total phosphorus. We found phosphorus to be a key factor limiting primary productivity in Baima Lake, and that bottom-up effects were the main driver to control phytoplankton in the AME. Using aquatic macrophytes to reduce nutrient loads is an effective way to manage eutrophication in Baima Lake.  相似文献   

17.
Aquatic plants (macrophytes) can have a large effect on river hydraulics and geomorphology. Though, the extent to how plant morphological plasticity actively influences these feedbacks has received little scientific attention. The nymphaeid macrophyte species Nuphar lutea (L.) Smith is characterized by a distinct leaf duality. Floating leaves shade most of the submerged leaves thereby limiting light penetration in the water. Despite their apparent negligible photosynthetic role, submerged leaves of N. lutea remain intact during summer and contribute a significant part to the total biomass. Our results indicate that the submerged leaves are crucial in plant–flow interactions and hence in the engineering potential of the plant, i.e. the capacity to locally reduce flow velocities and to promote sedimentation, including organic matter deposition. Plant individuals growing in running river water were compared to individuals from adjacent oxbow lake water. The number and size of submerged leaves were significantly higher for river standing individuals and the accumulated sediment contained significantly more organic matter, total nitrogen and total phosphorus, and was characterized by a lower carbon/nitrogen ratio and a finer grain size. We therefore argue that the submerged N. lutea canopy in rivers has the ability to create a high‐nutrient, low hydrodynamic environment, resembling the conditions found in oxbow lakes. Copyright © 2014 John Wiley & Sons, Ltd.  相似文献   

18.
Inlay Lake is the second largest natural lake in Myanmar. Located in Shan State, in the eastern part of the country, it is a known biodiversity hotspot. The lake is negatively affected by an increasing local human population and rapid growth in both agriculture and tourism. In recent decades, several studies have listed faunistic and floristic groups in Inlay Lake, but there is still a general lack of knowledge about the aquatic macrophyte and phytoplankton community composition and abundance, and their interactions. To fill this knowledge gap, field surveys of biological and physical and chemical parameters were carried out in the period 2014–2017. They show that Inlay Lake is a shallow, clear water and calcareous lake, with nutrient concentrations indicating mesotrophic-eutrophic conditions. However, close to the shore, nutrient concentrations are generally higher, reflecting pollution from inflowing rivers, shoreline villages and floating gardens. Both the richness and abundance of aquatic macrophytes in Inlay Lake were high, with several species forming extensive stands in most of the lake over the whole survey period. Total phytoplankton and cyanobacterial biomass were low, but cyanobacteria included toxin-producing strains of Microcystis, suggesting that cyanobacterial and total phytoplankton biomass need to be kept low to avoid potentially harmful cyanobacterial blooms. Submerged macrophyte abundance and phytoplankton biomass were inversely correlated in the heavily vegetated northern lake area. Our survey suggests a great importance of the submerged macrophytes to the general water quality and the clear water state in Inlay Lake. Maintaining high macrophyte abundances should therefore be a goal in management strategies, both for Inlay Lake and other lakes in Myanmar. It is highly desirable to include macrophytes and phytoplankton in the lake monitoring in Myanmar.  相似文献   

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