Inaugural-Dissertation--Universität Zürich, 1982. / Vita. "Erscheint als Band 77 der Serie 'Dissertationes botanicae' im Verlag von J. Cramer, Vaduz"--T.p. verso. Includes bibliographical references (p. [2]-[10] (2nd group)).

Research Doctorate - Doctor of Philosophy (PhD) / The Hunter Estuary Wetlands (NSW, Australia) are important locally, nationally and internationally. They contain significant breeding and nursery grounds for commercial fisheries and are essential shorebird foraging and roost sites. Originally a mosaic of fresh- and salt-marsh, these wetlands have become degraded due to the erection of flood mitigation structures. Reintroduction of a more natural tidal regime is proposed, which is expected to decrease freshwater macrophytes and increase saltmarsh distribution. An a priori approach was undertaken to assess the relative salinity tolerance of three macrophytes, prior to restoration commencing. Study species included a glycophyte, Phragmites australis (Cav) Trin. ex Steudel, and two closely related estuarine saltmarsh species, the invasive exotic Juncus acutus L. and native Juncus kraussii Hochst.. Short- and long-term effects of salinity at key life stages were assessed for each species. For P. australis, the reliability of physiological and morphological responses to salinity stress was assessed under both laboratory and field conditions as potential indicators for future monitoring of initial restoration progress. Competitive/facilitative interactions between the two Juncus species under various salinity regimes were also examined. Results showed salinity affected viability of P. australis but not Juncus species seeds. Irrespective of species, cooler temperatures enhanced germination capabilities under saline conditions. Juncus species displayed superior germination capabilities ≤ 10 ppt salinity; however, unexpectedly, above 10 ppt germination of P. australis was higher. All three species are highly salt tolerant, although salt adaptation mechanisms were found to differ among species. P. australis excluded sodium (Na+) where possible, only accumulating Na+ to toxic levels beyond particular salinity concentrations (~ 20 ppt) and temporal duration (four months). Juncus spp. accumulated Na+ in both root and shoot tissue without noticeable damage. Overtime, J. acutus regulated Na+ uptake at exposure concentrations above 5 ppt salinity, while J. kraussii did not commence regulation until concentrations exceed 10 ppt. A 50% reduction in photosynthesis, biomass, height and density of P. australis was apparent at 20 ppt salinity and mortality at 30 ppt. In P. australis, although height and density were indicative of salinity stress under laboratory conditions, only density showed potential as an indicator of reduced vigour under field scenarios, providing a valuable potential tool to track initial expected restoration trajectories. Although affected, neither Juncus species experienced a 50% reduction in measured endpoints at 40 ppt salinity. However, biomass allocation was asymmetrical. Under stressful conditions, J. acutus maintained shoot increase at the expense of root development. Conversely, as salinity rose J. kraussii preserved root development rather than shoot growth. J. acutus was facilitated by the presence of J. kraussii under freshwater conditions, but suffered a competitive response at 10 ppt salinity. Juncus kraussii was detrimentally affected by being grown with J. acutus at 5 ppt, but unaffected under non-saline and 10 ppt salinity conditions. All three species possess overlapping salinity tolerances. Creating conditions that favour a particular species is perhaps not realistic, given the limited resources of many restoration initiatives. Flooding duration, depth and waterlogging may modify these results. However, the most plausible scenario is that P. australis will continue to dominate marshes after tidal reinstatement. With time, where soil salinity rises above 30 ppt, distribution of Juncus species will increase. The relative salinity tolerances of J. acutus and J. kraussii are analogous. Under mild salinity regimes J. acutus is likely to out-compete J. kraussii. Juncus kraussii is expected to be restricted to areas of high salinity stress.

Research Doctorate - Doctor of Philosophy (PhD) / The Hunter Estuary Wetlands (NSW, Australia) are important locally, nationally and internationally. They contain significant breeding and nursery grounds for commercial fisheries and are essential shorebird foraging and roost sites. Originally a mosaic of fresh- and salt-marsh, these wetlands have become degraded due to the erection of flood mitigation structures. Reintroduction of a more natural tidal regime is proposed, which is expected to decrease freshwater macrophytes and increase saltmarsh distribution. An a priori approach was undertaken to assess the relative salinity tolerance of three macrophytes, prior to restoration commencing. Study species included a glycophyte, Phragmites australis (Cav) Trin. ex Steudel, and two closely related estuarine saltmarsh species, the invasive exotic Juncus acutus L. and native Juncus kraussii Hochst.. Short- and long-term effects of salinity at key life stages were assessed for each species. For P. australis, the reliability of physiological and morphological responses to salinity stress was assessed under both laboratory and field conditions as potential indicators for future monitoring of initial restoration progress. Competitive/facilitative interactions between the two Juncus species under various salinity regimes were also examined. Results showed salinity affected viability of P. australis but not Juncus species seeds. Irrespective of species, cooler temperatures enhanced germination capabilities under saline conditions. Juncus species displayed superior germination capabilities ≤ 10 ppt salinity; however, unexpectedly, above 10 ppt germination of P. australis was higher. All three species are highly salt tolerant, although salt adaptation mechanisms were found to differ among species. P. australis excluded sodium (Na+) where possible, only accumulating Na+ to toxic levels beyond particular salinity concentrations (~ 20 ppt) and temporal duration (four months). Juncus spp. accumulated Na+ in both root and shoot tissue without noticeable damage. Overtime, J. acutus regulated Na+ uptake at exposure concentrations above 5 ppt salinity, while J. kraussii did not commence regulation until concentrations exceed 10 ppt. A 50% reduction in photosynthesis, biomass, height and density of P. australis was apparent at 20 ppt salinity and mortality at 30 ppt. In P. australis, although height and density were indicative of salinity stress under laboratory conditions, only density showed potential as an indicator of reduced vigour under field scenarios, providing a valuable potential tool to track initial expected restoration trajectories. Although affected, neither Juncus species experienced a 50% reduction in measured endpoints at 40 ppt salinity. However, biomass allocation was asymmetrical. Under stressful conditions, J. acutus maintained shoot increase at the expense of root development. Conversely, as salinity rose J. kraussii preserved root development rather than shoot growth. J. acutus was facilitated by the presence of J. kraussii under freshwater conditions, but suffered a competitive response at 10 ppt salinity. Juncus kraussii was detrimentally affected by being grown with J. acutus at 5 ppt, but unaffected under non-saline and 10 ppt salinity conditions. All three species possess overlapping salinity tolerances. Creating conditions that favour a particular species is perhaps not realistic, given the limited resources of many restoration initiatives. Flooding duration, depth and waterlogging may modify these results. However, the most plausible scenario is that P. australis will continue to dominate marshes after tidal reinstatement. With time, where soil salinity rises above 30 ppt, distribution of Juncus species will increase. The relative salinity tolerances of J. acutus and J. kraussii are analogous. Under mild salinity regimes J. acutus is likely to out-compete J. kraussii. Juncus kraussii is expected to be restricted to areas of high salinity stress.

Thesis (M.S.)--West Virginia University, 2005. / Title from document title page. Document formatted into pages; contains ix, 106 p. : ill. (some col.), map (part col.). Includes abstract. Includes bibliographical references.

Thesis (Ph.D.)--University of Central Florida, 2009. / Adviser: Pedro F. Quintana-Ascencio. Includes bibliographical references.

Dissertação(mestrado) - Universidade Federal do Rio Grande, Programa de Pós–Graduação em Oceanografia Biológica, Instituto de Oceanografia, 2011. / Submitted by Cristiane Gomides (cristiane_gomides@hotmail.com) on 2013-12-16T13:10:23Z No. of bitstreams: 1 rubens.pdf: 37071078 bytes, checksum: e7a36c0d198f25aa295e0031caf953d7 (MD5) / Approved for entry into archive by Sabrina Andrade (sabrinabeatriz@ibest.com.br) on 2013-12-18T18:04:16Z (GMT) No. of bitstreams: 1 rubens.pdf: 37071078 bytes, checksum: e7a36c0d198f25aa295e0031caf953d7 (MD5) / Made available in DSpace on 2013-12-18T18:04:16Z (GMT). No. of bitstreams: 1 rubens.pdf: 37071078 bytes, checksum: e7a36c0d198f25aa295e0031caf953d7 (MD5) Previous issue date: 2011 / No estuário da Lagoa dos Patos são escassos os trabalhos sobre a comunidade fúngica. O objetivo deste estudo foi determinar a ocorrência de leveduras em duas áreas de marismas e os fatores abióticos que afetam sua distribuição espacial e temporal. O estudo foi realizado durante o inverno (Agosto) de 2009 e o verão (Fevereiro) de 2010 em duas enseadas rasas no estuário da Lagoa dos Patos, com diferentes níveis de eutrofização. As amostras foram coletadas em marismas dominadas por duas espécies macrófitas emersas: Juncus kraussii e Scirpus olneyi. Nos locais de coleta foram analisados os parâmetros abióticos e coletadas amostras de sedimento, água intersticial e de vegetação. Foi realizado o isolamento das leveduras do sedimento através de diluição em meio de cultivo. A identificação dos isolados foi feita através da análise de caracteres morfológicos e testes fenotípicos de metabolismo através do Sistema Vitek II. Foram isoladas 73 leveduras classificadas em 09 gêneros, com predominância de Ascomycotas. Entretanto, 10 destes isolados de leveduras não identificados e 02 isolados leveduriformes foram identificados como microalgas do gênero Prototheca. Dentre os gêneros de leveduras encontrados, houve uma predominância de leveduras do gênero Candida (n=20), seguidos por Rhodotorula (n=14), Yarrowia (n=07), Cryptococcus (n=06), Clavispora (n=04), Issatchenkia (n=03), Pichia (n=03), Torulaspora (n=03) e Kluyveromyces (n=01). O maior número de leveduras foi isolado em temperatura mais alta, no ambiente menos eutrofizado, em condições com maiores concentrações de nutrientes dissolvidos e no sedimento dominado por detrito de J. kraussii. / In the Patos Lagoon estuary few studies have been conducted on the fungal community. The aim of this study was to determine the occurrence of yeasts and the environments factors that affect their spatial and temporal distribution. The study was conducted during the winter (August) of 2009 and summer (February) 0f 2010 in two shallow bays of the Patos Lagoon estuary with different eutrophication level. The samples were collected in salt marsh areas dominated by two emerged macrophytes species: Juncus kraussii and Scirpus olneyi. Abiotic parameters were analyzed in the field and sediment samples, interstitial water and vegetation were collected. Yeasts were isolated from the sediment by dilution using the culture medium method. The identification of isolates was performed according to morphological characteristics and through metabolic tests using the Vitek II system. Seventy and three yeasts were isolated and classified in 09 genera with the predominance of Ascomycota. However, 10 of these isolated yeasts were unidentified and 02 yeast-like organisms, were identified as microalgae of the genera Prototheca. Among the identified genera of yeasts, there was a predominance of the genera Candida (n=20), followed by Rhodotorula (n=14), Yarrowia (n=07), Cryptococcus (n=06), Clavispora (n=04), Issatchenkia (n=03), Pichia (n=03), Torulaspora (n=03) e Kluyveromyces (n=01). Highest number of isolates was found in higher temperature, less polluted environment, in water with higher dissolved nutrient concentrations and in sediment dominated by detritus of Juncus kraussii. Key-words:

Part of a cutover bog in Pokesudie Island, New Brunswick, Canada was contaminated with seawater and was still largely devoid of vegetation 5 years after the event and was consequently chosen for study. The study area consisted of rectangular fields with cambered surface that sloped down (2%) to the drainage ditches on both sides. Across this slope zones were created: Up-, Mid- and Low- areas on either side of the centerline of fields. Two field experiments were conducted to determine abiotic stresses to plant re-establishment in terms of hydrology and peat characteristics along this cambered surface. The general objective was to identify microsites or zones that could be suitable to the introduction of wetland halophytes <em>Juncus balticus</em> Willd. and <em>Spartina pectinata</em> Link obtained from nearby salt marshes. <br /><br /> In the first experiment, cylindrical <em>J. balticus</em> sods were transplanted into the Up- and Low- areas, at 1, 3, 5, 10 and 20 d of incubation (in May 2005) with measurements made on the Outer and Inner annular sod sections, replicated over 4 blocks. Moisture (% dry weight basis (dwb)) reached maximum values 1 day after transplantation, 84±0. 05 for Outer and 103±0. 07 for Inner sod section. Salinity (dS m^-1) in sods due to ingress of sodium (Na⁺ ) and chloride (Cl^-) reached values of the surrounding peat 3 days after transplantation, 3. 52±1. 06 for Inner sod section and 4. 11±0. 99 for Outer sod section in Up-areas, and 1. 76±0. 24 for Inner sod section and 2. 57±0. 28 for Outer sod section in Low-areas. Maximum decrease in pH was at 5 days after transplantation, in Outer sod section in the Up-areas (from 5. 89 to 4. 88±0. 14) which was much higher than the pH range of 3-4 of the surrounding peat. This was due to the buffering capacity of calcium (Ca²⁺) and magnesium (Mg²⁺) in sods which did not change in concentration after 20 days of incubation. Therefore, Inner sod sections were less affected by the surrounding peat compared to the Outer sod sections, suggesting that a larger sod volume may alleviate stressful conditions for a longer time at transplantation and consequently allow greater time for adaptation. <br /><br /> In the second experiment, <em>J. balticus</em> and <em>S. pectinata</em> were transplanted on the 3 Locations Up-, Mid- and Low- areas, replicated over 10 blocks; and peat characteristics were measured at Depths 0-5, 5-10, 10-15 and 15-20 cm 5 times during the study period May-August 2005. Survival of <em>J. balticus</em> was poorest (27. 5±8. 3 %) in the Low-areas compared to 68. 5±8. 9 % in the Up- and 58. 5±8. 7% in the Mid- areas. <em>S. pectinata</em> survival was very good at all Locations (89±5. 3, 91. 6±3. 1 and 84. 2±4. 4 for Up-, Mid- and Low- areas, respectively) having better adaptation to early season waterlogged conditions. Waterlogged conditions resulted from a perched water table during the early part of the growing season (May-June) and were alleviated only upon the complete thaw of the frozen peat layer on 8 July. Thereafter, important changes in hydrology and peat characteristics occurred: water table depths decreased from -8. 5±1. 7 and -1. 6±1. 2 cm on 26 May, to -51. 5±2. 5 and -40. 7±2. 4 cm by 9 August in Up- and Low-areas, respectively; redox potentials at 12 cm depth increased from 26 June (190. 9±8, 175±10. 8 and 109. 2±29. 4 mV) to 9 August (282. 8±8, 302. 8±14. 3 and 312. 3±29. 6 mV) in the Up-, Mid- and Low-areas, respectively which showed that anaerobic conditions were maintained throughout the study period; decreased moisture content from 1256. 8±61. 9, 1667. 4±126. 3 and 1728. 6±153 on 30 May, to 851. 7±21. 2, 874. 6±47 and 1008. 2±57. 5 % dwb on 25 July) which caused increased dry bulk density (from 0. 07±0. 002, 0. 06±0. 003 and 0. 07±0. 01 to 0. 09±0. 003, 0. 09±0. 005 and 0. 08±0. 004) in the Up-, Mid- and Low-areas, respectively; and increased electrical conductivity (salinity) especially on the 0-5cm surface (from 1. 9±0. 13, 1. 8±0. 31 and 1. 5±0. 29 to 18±1. 9, 17. 5±1. 1 and 12. 2±1 dS m^-1) which also caused decreased pH (from 3. 5±0. 04, 3. 5±0. 08 and 3. 6±0. 01 to 2. 85±0. 04, 2. 85±0. 01 and 2. 9±0. 03) in the Up-, Mid- and Low-areas, respectively. Therefore, spring flooding followed by high surface salinity in summer precludes plant establishment by seeding and explains the current lack of spontaneous revegetation. Waterlogged conditions were of greater magnitude and duration at lower elevation areas unfavourable to <em>J. balticus</em> survival but salinity levels were high in the Up- and Mid-areas. <br /><br /> In the subsequent part of the second experiment, plants of <em>J. balticus</em> and <em>S. pectinata</em> grown in the study area and those collected from marshes were divided into above- and below- ground parts and accumulation of salt ions in plant tissues were determined to understand the species' salt-tolerance mechanism, as well as the accumulation of potentially toxic levels of iron (Fe) and manganese (Mn). Both plant species had similar accumulations (mmol kg^-1 dry wt,) of Na⁺ (474. 3±41 and 468. 3±31. 7, respectively) and Cl^- (314. 9±21. 9 and 310. 5±27. 5, respectively) in the above-ground parts but differed in how they managed Na⁺. <em>J. balticus</em> accumulated more Na⁺ in below-ground parts (659. 3±88. 7) and had limited transport to the above-ground parts, while <em>S. pectinata</em> accumulated and excreted Na⁺ in the above-ground parts and had less accumulation in the below-ground parts (397. 4±25. 1). <em>S. pectinata</em> maintained (313. 1±23. 8 in marsh <em>vs. </em> 292. 4±26. 2 in bog) and <em>J. balticus</em> increased (84. 2±1. 2 in marsh <em>vs. </em> 531. 2±38. 6 in bog) K⁺-selectivity in the shoots, a key requirement for survival in saline conditions. Compared with their respective marsh plants, <em>S. pectinata</em> had more salinity-tolerance than <em>J. balticus</em> primarily through its maintenance of Ca²⁺ (21. 5±1. 7 in marsh <em>vs. </em> 35. 6±3. 8 in bog) compared to a decrease in <em>J. balticus</em> (144. 7±12. 5 in marsh <em>vs. </em> 41±3. 7 in bog). Furthermore, Fe and Mn uptake in both species decreased but reached critical Fe-deficiency levels (1. 1±0. 1 mmol kg^-1 dry wt,) only in <em>S. pectinata</em> grown in drier areas. <br /><br /> It is concluded that local conditions of waterlogging (especially in lower elevation areas) and high salinity and low pH (notably in the upper elevation areas) were favourable to the survival of <em>S. pectinata</em> in all areas and <em>J. balticus</em> only in upper elevation areas. Sod transplanting may alleviate the acidity problem and depending on sod volume may delay the effects of harsh conditions of the cutover bog. However, long-term survival and growth of both species in drier areas may be constrained by deficiency in calcium in <em>J. balticus</em> and iron in <em>S. pectinata</em>.

Part of a cutover bog in Pokesudie Island, New Brunswick, Canada was contaminated with seawater and was still largely devoid of vegetation 5 years after the event and was consequently chosen for study. The study area consisted of rectangular fields with cambered surface that sloped down (2%) to the drainage ditches on both sides. Across this slope zones were created: Up-, Mid- and Low- areas on either side of the centerline of fields. Two field experiments were conducted to determine abiotic stresses to plant re-establishment in terms of hydrology and peat characteristics along this cambered surface. The general objective was to identify microsites or zones that could be suitable to the introduction of wetland halophytes <em>Juncus balticus</em> Willd. and <em>Spartina pectinata</em> Link obtained from nearby salt marshes. <br /><br /> In the first experiment, cylindrical <em>J. balticus</em> sods were transplanted into the Up- and Low- areas, at 1, 3, 5, 10 and 20 d of incubation (in May 2005) with measurements made on the Outer and Inner annular sod sections, replicated over 4 blocks. Moisture (% dry weight basis (dwb)) reached maximum values 1 day after transplantation, 84±0. 05 for Outer and 103±0. 07 for Inner sod section. Salinity (dS m^-1) in sods due to ingress of sodium (Na⁺ ) and chloride (Cl^-) reached values of the surrounding peat 3 days after transplantation, 3. 52±1. 06 for Inner sod section and 4. 11±0. 99 for Outer sod section in Up-areas, and 1. 76±0. 24 for Inner sod section and 2. 57±0. 28 for Outer sod section in Low-areas. Maximum decrease in pH was at 5 days after transplantation, in Outer sod section in the Up-areas (from 5. 89 to 4. 88±0. 14) which was much higher than the pH range of 3-4 of the surrounding peat. This was due to the buffering capacity of calcium (Ca²⁺) and magnesium (Mg²⁺) in sods which did not change in concentration after 20 days of incubation. Therefore, Inner sod sections were less affected by the surrounding peat compared to the Outer sod sections, suggesting that a larger sod volume may alleviate stressful conditions for a longer time at transplantation and consequently allow greater time for adaptation. <br /><br /> In the second experiment, <em>J. balticus</em> and <em>S. pectinata</em> were transplanted on the 3 Locations Up-, Mid- and Low- areas, replicated over 10 blocks; and peat characteristics were measured at Depths 0-5, 5-10, 10-15 and 15-20 cm 5 times during the study period May-August 2005. Survival of <em>J. balticus</em> was poorest (27. 5±8. 3 %) in the Low-areas compared to 68. 5±8. 9 % in the Up- and 58. 5±8. 7% in the Mid- areas. <em>S. pectinata</em> survival was very good at all Locations (89±5. 3, 91. 6±3. 1 and 84. 2±4. 4 for Up-, Mid- and Low- areas, respectively) having better adaptation to early season waterlogged conditions. Waterlogged conditions resulted from a perched water table during the early part of the growing season (May-June) and were alleviated only upon the complete thaw of the frozen peat layer on 8 July. Thereafter, important changes in hydrology and peat characteristics occurred: water table depths decreased from -8. 5±1. 7 and -1. 6±1. 2 cm on 26 May, to -51. 5±2. 5 and -40. 7±2. 4 cm by 9 August in Up- and Low-areas, respectively; redox potentials at 12 cm depth increased from 26 June (190. 9±8, 175±10. 8 and 109. 2±29. 4 mV) to 9 August (282. 8±8, 302. 8±14. 3 and 312. 3±29. 6 mV) in the Up-, Mid- and Low-areas, respectively which showed that anaerobic conditions were maintained throughout the study period; decreased moisture content from 1256. 8±61. 9, 1667. 4±126. 3 and 1728. 6±153 on 30 May, to 851. 7±21. 2, 874. 6±47 and 1008. 2±57. 5 % dwb on 25 July) which caused increased dry bulk density (from 0. 07±0. 002, 0. 06±0. 003 and 0. 07±0. 01 to 0. 09±0. 003, 0. 09±0. 005 and 0. 08±0. 004) in the Up-, Mid- and Low-areas, respectively; and increased electrical conductivity (salinity) especially on the 0-5cm surface (from 1. 9±0. 13, 1. 8±0. 31 and 1. 5±0. 29 to 18±1. 9, 17. 5±1. 1 and 12. 2±1 dS m^-1) which also caused decreased pH (from 3. 5±0. 04, 3. 5±0. 08 and 3. 6±0. 01 to 2. 85±0. 04, 2. 85±0. 01 and 2. 9±0. 03) in the Up-, Mid- and Low-areas, respectively. Therefore, spring flooding followed by high surface salinity in summer precludes plant establishment by seeding and explains the current lack of spontaneous revegetation. Waterlogged conditions were of greater magnitude and duration at lower elevation areas unfavourable to <em>J. balticus</em> survival but salinity levels were high in the Up- and Mid-areas. <br /><br /> In the subsequent part of the second experiment, plants of <em>J. balticus</em> and <em>S. pectinata</em> grown in the study area and those collected from marshes were divided into above- and below- ground parts and accumulation of salt ions in plant tissues were determined to understand the species' salt-tolerance mechanism, as well as the accumulation of potentially toxic levels of iron (Fe) and manganese (Mn). Both plant species had similar accumulations (mmol kg^-1 dry wt,) of Na⁺ (474. 3±41 and 468. 3±31. 7, respectively) and Cl^- (314. 9±21. 9 and 310. 5±27. 5, respectively) in the above-ground parts but differed in how they managed Na⁺. <em>J. balticus</em> accumulated more Na⁺ in below-ground parts (659. 3±88. 7) and had limited transport to the above-ground parts, while <em>S. pectinata</em> accumulated and excreted Na⁺ in the above-ground parts and had less accumulation in the below-ground parts (397. 4±25. 1). <em>S. pectinata</em> maintained (313. 1±23. 8 in marsh <em>vs. </em> 292. 4±26. 2 in bog) and <em>J. balticus</em> increased (84. 2±1. 2 in marsh <em>vs. </em> 531. 2±38. 6 in bog) K⁺-selectivity in the shoots, a key requirement for survival in saline conditions. Compared with their respective marsh plants, <em>S. pectinata</em> had more salinity-tolerance than <em>J. balticus</em> primarily through its maintenance of Ca²⁺ (21. 5±1. 7 in marsh <em>vs. </em> 35. 6±3. 8 in bog) compared to a decrease in <em>J. balticus</em> (144. 7±12. 5 in marsh <em>vs. </em> 41±3. 7 in bog). Furthermore, Fe and Mn uptake in both species decreased but reached critical Fe-deficiency levels (1. 1±0. 1 mmol kg^-1 dry wt,) only in <em>S. pectinata</em> grown in drier areas. <br /><br /> It is concluded that local conditions of waterlogging (especially in lower elevation areas) and high salinity and low pH (notably in the upper elevation areas) were favourable to the survival of <em>S. pectinata</em> in all areas and <em>J. balticus</em> only in upper elevation areas. Sod transplanting may alleviate the acidity problem and depending on sod volume may delay the effects of harsh conditions of the cutover bog. However, long-term survival and growth of both species in drier areas may be constrained by deficiency in calcium in <em>J. balticus</em> and iron in <em>S. pectinata</em>.

Este trabalho apresenta o estudo taxonômico da família Juncaceae Juss. para o Rio Grande do Sul, Brasil. A família é cosmopolita e tem 7 gêneros distribuídos no mundo. No estado, ocorrem os gêneros Juncus L. e Luzula DC. O primeiro gênero apresentou 20 espécies e o segundo, apenas 1 espécie. Foram encontradas 2 novas ocorrências para o Brasil, J. venturianus Castillón e J. ilanquihuensis Barros. Foram realizados chaves dicotômicas de identificação e descrições dos táxons, sinônimos, ilustrações e mapa de distribuição geográfica no Estado. Descreveu-se algumas considerações sobre hábitat, aspectos ecológicos, uso e importância econômica, fenologia e filogenética. / This work presents a taxonomic study of Juncaceae Juss. in the state of Rio Grande do Sul, Brazil. The family is cosmopolite and have 7 genus by the World. The State have the ocurrence the genus Juncus L. and Luzula DC. The first genus have 20 species and the second, have only 1 specie. J. venturianus Castillón and J. ilanquihuensis Barros, are citet as a news occurrences to the flora of Brazil. Analitical keys and descriptions of the taxons, synonyms, illustrations, maps of geographic distribuition are realized.

Este trabalho apresenta o estudo taxonômico da família Juncaceae Juss. para o Rio Grande do Sul, Brasil. A família é cosmopolita e tem 7 gêneros distribuídos no mundo. No estado, ocorrem os gêneros Juncus L. e Luzula DC. O primeiro gênero apresentou 20 espécies e o segundo, apenas 1 espécie. Foram encontradas 2 novas ocorrências para o Brasil, J. venturianus Castillón e J. ilanquihuensis Barros. Foram realizados chaves dicotômicas de identificação e descrições dos táxons, sinônimos, ilustrações e mapa de distribuição geográfica no Estado. Descreveu-se algumas considerações sobre hábitat, aspectos ecológicos, uso e importância econômica, fenologia e filogenética. / This work presents a taxonomic study of Juncaceae Juss. in the state of Rio Grande do Sul, Brazil. The family is cosmopolite and have 7 genus by the World. The State have the ocurrence the genus Juncus L. and Luzula DC. The first genus have 20 species and the second, have only 1 specie. J. venturianus Castillón and J. ilanquihuensis Barros, are citet as a news occurrences to the flora of Brazil. Analitical keys and descriptions of the taxons, synonyms, illustrations, maps of geographic distribuition are realized.