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Potamogeton a sort - complex regular group which is very hardly described. This group studied much researcher. At old university worked: ZH.Zhiliber who has described 6 kinds; S.B.Jundzil, has described 10 kinds; J. Jundzil, has described 9 kinds the First special research sorts Potamogeton has made J.F.Volfgang 72 figures the Most well-known researcher sorts Potamogeton Are found it is V.Galinis. Herbarium were kept in Vilnius pedagogical university and in Botanical institute. In Vilnius pedagogical university found 511 herbarium sheets. It is found 21 kind. On the data herbarium Vitautas Galinis 10 cards spread of the fields in territory of Lithuania are made.

Aquatic macrophytes are important components in structuring aquatic communities because they provide physical and biological functions that contribute to the stability of the ecosystem. Macrophytes provide the basis for the aquatic food-web and also provide habitat and refugia for aquatic fauna. In systems that lack macrophytes, anthropogenic re-establishment may be a feasible management approach to improve aquatic ecosystems. Understanding environmental factors that regulate colonization, dispersal, and persistence of aquatic macrophytes is pertinent to re-establishment efforts. The purpose of this study is to test hypotheses regarding success of macrophyte re-establishment efforts in Little Bear Creek Reservoir, Alabama using different macrophyte species, water depths, plant patch size and protection against herbivores at planting sites. In addition, a deductive GIS model is used to predict suitable areas to focus re-establishment efforts. Knowledge generated from hypothesis testing and application of GIS modeling provides novel information and tools for managing aquatic ecosystems.

The impact of carp on a rhizomatous macrophyte was examined in two consecutive years using three outdoor aquaculture ponds with naturally established beds of Potamogeton tricarinatus. Each pond was divided with wire fencing to form a carp (500 kg ha-1) and control treatment. After 6 weeks, plant biomass had declined to the same extent in the carp and control treatments, indicating that direct physical disturbance by carp was not reducing the biomass of P. tricarinatus. In a second experiment, carp were added to two of the same ponds when plants were regenerating after a 9-11 month drying period. After 8 weeks, P. tricarinatus biomass in the carp treatments was between one half and one tenth of the biomass in the control treatments and one control treatment supported more Najas tenuifolia than the paired carp treatment. The lower biomass of Potamogeton in the carp treatments was a result of fewer shoots and less growth per shoot. Rhizomes had been undermined in the carp treatment with less than 1% of plants growing from rhizome compared to 36% in the control treatment. Accumulation of sediment into traps was significantly higher in the carp treatments (2.5 to 77.5 times more than the control). On average, carp resuspended 662 kg dry sediment ha-1 for each 100 kg ha-1 of carp or 6.6 times their wet weight biomass in dry sediments each day. Some implications of high sediment resuspension are discussed. The research demonstrates that well anchored macrophyte species can show tolerance to the physical disturbance associated with carp benthic feeding, however, these same species are vulnerable during regenerating and recruitment stages. It is suggested that anchorage is the most important factor for determining plant tolerance to carp. The implications for aquatic plant and riverine management are discussed, including the importance of excluding carp from newly flooded wetlands and the role of carp in determining alternative stable states.

Submitted by dayse paz (daysepaz@hotmail.com) on 2016-04-06T11:50:24Z No. of bitstreams: 1 Disserta_o_Cristiane_Carvalho.pdf: 1091025 bytes, checksum: 71418d6d8927740542513191376e2254 (MD5) / Approved for entry into archive by cleuza maria medina dos santos (cleuzamai@yahoo.com.br) on 2016-05-09T14:26:19Z (GMT) No. of bitstreams: 1 Disserta_o_Cristiane_Carvalho.pdf: 1091025 bytes, checksum: 71418d6d8927740542513191376e2254 (MD5) / Made available in DSpace on 2016-05-09T14:26:19Z (GMT). No. of bitstreams: 1 Disserta_o_Cristiane_Carvalho.pdf: 1091025 bytes, checksum: 71418d6d8927740542513191376e2254 (MD5) Previous issue date: 2013 / Em lagos as macrófitas aquáticas são importantes fontes de matéria orgânica detrital, aumentam a complexidade do hábitat proporcionando vários nichos ecológicos a uma diversidade de espécies animais. Durante do processo de decomposição, a colonização dos detritos passa por uma sucessão ecológica entre fungos, bactérias e invertebrados, sendo seu papel fundamental para promover a circulação dos nutrientes. Assim, essa dissertação objetivou: (1) analisar os coeficientes de decomposição e a composição química dos detritos de duas macrófitas, a fim de verificar os efeitos dessas características sobre a biomassa fúngica e invertebrados; (2) analisar se o local de incubação das bolsas dos detritos influencia o recurso de hábitat e sobreposição espacial, interferindo na estrutura funcional da comunidade colonizadora. Para tanto foram realizados dois experimentos. Para o experimento 1 (setembro à dezembro de 2011), incubamos 24 bolsas de Potamogeton pectinatus e 24 de Chara zeylanica e retiradas em 1, 7, 20, 40, 60 e 80 dias. O material foi lavado, seco e triturado para análises químicas e determinação dos coeficientes de decomposição. A biomassa fúngica foi avaliada através do conteúdo de ergosterol. Para o experimento 2 (janeiro de 2012), foram incubadas 60 bolsas aleatoriamente divididas em 4 tratamentos, onde 15 bolsas contendo detritos de P. pectinatus foram incubadas em meio ao próprio estande (PP); 15 bolsas no estande de C. zeylanica (PC); 15 bolsas com detritos de C. zeylanica (CC) incubadas em meio ao seu estande e 15 no estande de P. pectinatus (CP), sendo retiradas em 5, 10 e 20 dias. Em ambos os estudos, os invertebrados foram classificados em grupos tróficos funcionais e determinadas a riqueza e abundância. As características químicas explicaram 59% da variação na abundância de invertebrados. A biomassa fúngica nos detritos não diferiu. A maior abundância e riqueza de invertebrados ocorreram nos detritos de P. pectinatus para o experimento 1 e nos detritos incubados em meio ao seu próprio estande (experimento 2). Houve diferença na perda de massa entre os tratamentos e entre detritos. A maior abundância na composição funcional foi de coletores - catadores e predadores, em ambos os estudos. Houve menor sobreposição espacial entre os grupos tróficos nos tratamentos em relação a PP. Nosso estudo demonstrou que os as características químicas e os coeficientes de decomposição interferem na colonização de invertebrados, relacionado ao tempo de incubação dos detritos. Além disso, o local de incubação afetou os coeficientes de decomposição e a estruturação da comunidade de invertebrados, relacionado à disponibilidade de hábitat oferecido pelos tratamentos. / In lakes the macrophytes are important sources of detrital organic matter, increase the complexity of providing various habitat niches to a variety of animal species. During the colonization process of decomposition of the waste undergoes an ecological succession among fungi, bacteria and invertebrates, and its key role in promoting the circulation of nutrients. Thus, this thesis aimed to: (1) analyze the decomposition rates and chemical composition of the detritus of two macrophytes in order to verify the effects of these characteristics on the fungal biomass and invertebrates, (2) examine if the site of the bags of incubation detritus influences the use and habitat overlap of space, affecting the functional structure of the settler community. Therefore, we performed two experiments. For experiment 1 (September to December, 2011), incubated 24 bags of Potamogeton pectinatus and 24 Chara zeylanica and withdrawn at 1, 7, 20, 40, 60 and 80 days. The material was washed, dried and ground for chemical analyzes and determination of the coefficients of decomposition. The fungal biomass was evaluated through the content of ergosterol. For experiment 2 (January, 2012), 60 bags were incubated randomly assigned to 4 treatments, where 15 bags of debris containing P. pectinatus were incubated in medium to own booth (PP); 15 scholarships in booth C. zeylanica (PC), 15 bags of detritus C. zeylanica (CC) incubated in the midst of its stand and 15 at the P. pectinatus (CP) and taken in 5, 10 and 20 days. In both studies, the invertebrates were classified into functional trophic groups and certain richness and abundance. The chemical characteristics explained 59% of variation in abundance of invertebrates. The fungal biomass in waste did not differ. The greatest abundance and diversity of invertebrates occurred in the debris of P. pectinatus for experiment 1 and incubated debris amidst its own booth (experiment 2). Was no difference in weight loss between treatments and among detritus. The highest abundance was in the functional composition of collectors - scavengers and predators, in both studies. There was a lower spatial overlap between trophic groups in treatments against PP. Our study demonstrated that the chemical characteristics and the coefficients of decomposition interfere with colonization of invertebrates, related to incubation time of detritus. Furthermore, the location of incubation affected the decomposition rates and invertebrate community structure, related to the availability of habitat offered by the treatments.

M.Sc. / Please refer to full text to view abstract

A study of macroinvertebrate colonization and assemblages, including secondary productivity of the familiar bluet damselfly or Enallagma civile Hagen (Odonata: Coenagrionidae), associated with the aquatic macrophytes Heteranthera dubia (Jacq.) MacMill. (water stargrass) and Potamogeton nodosus Poir. (American pondweed) was conducted at the Dallas Floodway Extension Trinity River Project (DFE) Lower Chain of Wetlands (LCOW), Dallas, TX, from September 2010 through November 2011. Macroinvertebrate abundance, taxa richness, Simpson's index of diversity, and Simpson's evenness from the two macrophytes and from three different wetland cells of varying construction completion dates, water sources, and native aquatic vegetation establishment were analyzed along with basic water quality metrics (temperature °C, pH, dissolved oxygen mg/L, and conductivity µs/cm). E. civile nymphs were separated into five developmental classes for secondary productivity estimations between macrophytes and wetland cell types. Mean annual secondary productivity in the DFE LCOW among two macrophytes of E. civile was 1392.90 ash-free dry weight mg/m²/yr, standing stock biomass was 136.77 AFDW mg/m2/yr, cohort production / biomass (P/B) ratio was calculated to be 4.30 / yr and the annual production / biomass (P/B) ratio was 10.18 /yr.

<p>Metal contaminated stormwater, i.e. surface runoff in urban areas, can be treated in percolation systems, ponds, or wetlands to prevent the release of metals into receiving waters. Plants in such systems can, for example, attenuate water flow, bind sediment, and directly accumulate metals. By these actions plants affect metal mobility. This study aimed to examine the accumulation of Zn, Cu, Cd, and Pb in roots and shoots of plant species common in stormwater areas. Furthermore, submersed plants were used to examine the fate of metals: uptake, translocation, and leakage. Factors known to influence metal accumulation, such as metal ion competition, water salinity, and temperature, were also examined. The following plant species were collected in the field: terrestrial plants – <i>Impatiens parviflora</i>, <i>Filipendula ulmaria</i>, and <i>Urtica dioica</i>; emergent plants –<i> Alisma-plantago aquatica</i>, <i>Juncus effusus</i>, <i>Lythrum salicaria</i>, <i>Sagittaria sagittifolia</i>, and <i>Phalaris arundinacea</i>; free-floating plants – <i>Lemna gibba</i> and <i>Lemna minor</i>; and submersed plants – <i>Elodea canadensis</i> and <i>Potamogeton natans</i>. Furthermore, the two submersed plants, <i>E. canadensis</i> and <i>P. natans</i>, were used in climate chamber experiments to study the fate of the metals in the plant–water system.</p><p>Emergent and terrestrial plant species accumulated high concentrations of metals in their roots under natural conditions but much less so in their shoots, and the accumulation increased further with increased external concentration. The submersed and free-floating species accumulated high levels of metals in both their roots and shoots. Metals accumulated in the shoots of <i>E. canadensis</i> and <i>P. natans</i> derived mostly from direct metal uptake from the water column.</p><p>The accumulation of Zn, Cu, Cd, and Pb in submersed species was in general high, the highest concentrations being measured in the roots, followed by the leaves and stems, <i>E. canadensis</i> having higher accumulation capacity than <i>P. natans</i>. In <i>E. canadensis</i> the Cd uptake was passive, and the accumulation in dead plants exceeded the of living with time. The capacity to quickly accumulate Cd in the apoplast decreased with successive treatments. Some of the Cd accumulated was readily available for leakage. In <i>P. natans,</i> the presence of mixtures of metal ions, common in stormwater, did not alter the accumulation of the individual metals compared to when presented separately. It is therefore, proposed that the site of uptake is specific for each metal ion. In addition cell wall-bound fraction increased with increasing external concentration. Further, decreasing the temperature from 20ºC to 5ºC and increasing the salinity from 0‰ to 5‰ S reduced Zn and Cd uptake by a factor of two.</p><p>In <i>P. natans</i> the metals were not translocated within the plant, while in<i> E. canadensis </i>Cd moved between roots and shoots. Thus,<i> E. canadensis</i> as opposed to <i>P. natans</i> may increase the dispersion of metals from sediment via acropetal translocation. The low basipetal translocation implies that neither <i>E. canadensis</i> nor <i>P. natans</i> will directly mediate the immobilisation of metal to the sediment via translocation.</p><p>To conclude, emergent and terrestrial plant species seem to enhance metal stabilization in the soil/sediment. The submersed plants, when present, slightly increase the retention of metals via shoot accumulation.</p>

Metal contaminated stormwater, i.e. surface runoff in urban areas, can be treated in percolation systems, ponds, or wetlands to prevent the release of metals into receiving waters. Plants in such systems can, for example, attenuate water flow, bind sediment, and directly accumulate metals. By these actions plants affect metal mobility. This study aimed to examine the accumulation of Zn, Cu, Cd, and Pb in roots and shoots of plant species common in stormwater areas. Furthermore, submersed plants were used to examine the fate of metals: uptake, translocation, and leakage. Factors known to influence metal accumulation, such as metal ion competition, water salinity, and temperature, were also examined. The following plant species were collected in the field: terrestrial plants – Impatiens parviflora, Filipendula ulmaria, and Urtica dioica; emergent plants – Alisma-plantago aquatica, Juncus effusus, Lythrum salicaria, Sagittaria sagittifolia, and Phalaris arundinacea; free-floating plants – Lemna gibba and Lemna minor; and submersed plants – Elodea canadensis and Potamogeton natans. Furthermore, the two submersed plants, E. canadensis and P. natans, were used in climate chamber experiments to study the fate of the metals in the plant–water system. Emergent and terrestrial plant species accumulated high concentrations of metals in their roots under natural conditions but much less so in their shoots, and the accumulation increased further with increased external concentration. The submersed and free-floating species accumulated high levels of metals in both their roots and shoots. Metals accumulated in the shoots of E. canadensis and P. natans derived mostly from direct metal uptake from the water column. The accumulation of Zn, Cu, Cd, and Pb in submersed species was in general high, the highest concentrations being measured in the roots, followed by the leaves and stems, E. canadensis having higher accumulation capacity than P. natans. In E. canadensis the Cd uptake was passive, and the accumulation in dead plants exceeded the of living with time. The capacity to quickly accumulate Cd in the apoplast decreased with successive treatments. Some of the Cd accumulated was readily available for leakage. In P. natans, the presence of mixtures of metal ions, common in stormwater, did not alter the accumulation of the individual metals compared to when presented separately. It is therefore, proposed that the site of uptake is specific for each metal ion. In addition cell wall-bound fraction increased with increasing external concentration. Further, decreasing the temperature from 20ºC to 5ºC and increasing the salinity from 0‰ to 5‰ S reduced Zn and Cd uptake by a factor of two. In P. natans the metals were not translocated within the plant, while in E. canadensis Cd moved between roots and shoots. Thus, E. canadensis as opposed to P. natans may increase the dispersion of metals from sediment via acropetal translocation. The low basipetal translocation implies that neither E. canadensis nor P. natans will directly mediate the immobilisation of metal to the sediment via translocation. To conclude, emergent and terrestrial plant species seem to enhance metal stabilization in the soil/sediment. The submersed plants, when present, slightly increase the retention of metals via shoot accumulation.

1. Aquatic macrophytes generally dominate energy and nutrient transfers in wetland ecosystems. They provide a diverse habitat for other organisms but each species or life-form, has a different role in determining ecosystem structure and function. A multidisciplinary research project on the Pongolo River Floodplain, Zululand, South Africa, provided a good opportunity to study the role of a submerged species, Potamogeton crispus L. in a wetland ecosystem. 2. The role of a plant species in ecosystem structure and functioning is contingent primarily upon its adaptations to the interactive biotic and abiotic components of the multifactorial environment. This role is manifest in the contribution the species makes both to the sum total of transfers of resources within the ecosystem and to the nature of the physical and chemical environment. These contributions can be to both the conservative energy-matter transfers of the ecosystem and to the information network which regulates ecosystem functioning. 3. This study set out, using Tete pan as the main field site, to: i) Characterise the major physical, chemical and biotic variables of the floodplain ecosystem which are most likely to affect the acquisition of resources by P. crispus. ii) Determine the way the species influences the environment. iii) Assess the species adaptations to environmental characteristics. iv) Assess transfers of resources from P. crispus to other ecosystem components, the factors affecting them and the contributions they make to ecosystem structure and functioning. v) Outline the implications of the findings for management of the ecosystem which is threatened by the construction of an upstream dam. Annual flooding of the Pongolo river and resultant poor light climate and fluctuating water levels create an unfavourable habitat for submerged plant growth in Tete pan during summer. During autumn through spring, however, stable water levels and good light penetration are favourable for plant growth. The duration of favourable and unfavourable periods varies annually, and on a longer time scale periodic droughts cause the pan to dry up completely. Nutrient concentrations and salinity of the water were favourable for freshwater plant growth during the study. 5. Potamoget on crispus on the Pongolo r.iver floodplain is a winter producing annual which reproduces both sexually (achenes) and asexually (turions). Winter growth is initiated by turion germination each year and achenes ensure survival after drought. If floods continue into autumn young plants remain dormant until the light climate improves. Individual plants have a life span of 4 - 5 months but staggered germination of turions from April to June ensured that the population was present for up to 8 months. Pot amogeton crispus was classified as a competitiveruderal with multiple regenerative strategies. This life history enables the species to exploit the favourable period between floods and survive both summer flooding of unpredictable duration and intermittent droughts. 6. The major source of nutrfents for P. crispus is the sediment pool and plant growth brings large amounts of nitrogen and phosphorus into circulation each year. The rapid completion of the life cycle ensures that in most years Nand P released to the water during decay are taken up by other components of the ecosystem before the next summer floods. Thus, despite a potential for flushing of nutrient rich water by floods, pans such as Tete experienced a net gain in nutrients between flood periods during the study period. 7. Potamogeton crispus was the major primary producer in Tete pan during this study and although production was seasonal it was high (126 gm¯³ in comparison to other species reported in the literature. The presence of an abundant and nutritious food source in the form of P. crispus turions, attracts a large and diverse waterfowl population to the floodplain each winter. During feeding the waterfowl uproot P. crispus plants and remove almost 90% of the turions. This represents a potentially unstable grazing system as the birds utilize the "residual growth potential" of the plant population. The hypothesis was formulated that stability of the grazing system and maintenance of P. crispus reproduction may be achieved by production of small turions which are energetically unrewarding for the waterfowl but form viable propagules. Overall, transfer of nutrients and organic matter to this grazing food chain represents a small (<10 % ) proportion of P. crispus production. 9. The growth of P. crispus in Tete pan provides a large surface area for epiphyton growth which increases in density and species diversity as plants age. Experiments showed that the host plant epidermis was invaded by necrotrophic bacteria but grazing of epiphyton by snails retarded this process in young leaves. However, as leaves aged the action of the bacteria softened (conditioned) the host tissues and promoted consumption of the leaves by snails. The co-existence of epiphyton and host plant is therefore achieved through a complex set of interacting attributes of the epiphyton community, the host plant and grazing animals. Comparisons with previously published hypotheses of the macrophyte-host relationship indicated that attempts to find a single controlling factor may be misleading and that adaptation for co-existence should be sought in a number of interacting variables. 10. Since conditioning of P. crispus by epiphytes and consumption of plants by snails follows a succession which reaches a climax during host senescence, it was important to develop a method of studying decomposition which included these processes. Experiments showed that both snails and bacterial conditioning had marked effects on the rates and pathways of dry matter and nutrient transfer during decomposition and that no single technique (eg. litter bags) will permit a thorough understanding of decomposition processes. Conservative transfers of organic matter, nitrogen and phosphorus in Tete pan are dominated by the detrital food web with only a small proportion going to the grazing food chain. The consumption of P. crispus and its epiphyton by snails in winter and spring provides the major pathway of allochthonous production to the benthic detrital aggregate and detrital food web. These transfers are separated in both time and space from the allochthonous inputs of C. dacty lon detritus which occur as a result of decay in the flooded pan margins during summer. The major input of phosphorus to the pans appears to occur by deposition of silt during floods but fixation of di-nitrogen by the epiphyton and in the detrital aggregate greatly exceed flood related inputs of nitrogen. 12. The continued functioning of the detritus dominated foodweb of the floodplain pans is dependent upon a sequence of resource transfers which are dominated, during periods between floods, by P. crispus and its epiphyton. The processes which regulate these conservative transfers show characteristics typical of the information network of cybernetic ecosystem functioning and hence it was hypothesised that the Pongolo floodplain ecosystem has the potential to buffer changes in resource input which will occur now that a dam has been constructed upstream. While the hydrological regime of the Pongolo river forms the primary determinant of the floodplain ecosystem, structure and function management of the system must also account for the "managerial" role of animals and temperature which initiate and rate regulate major ecosystem processes. / Thesis (Ph.D.)-University of Natal, Pietermaritzburg, 1984.