996 resultados para Zizania latifolia


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九寨沟湖泊湿地在维持九寨沟的生态平衡中起着重要的作用,在旅游产业的发展下,湿地生态系统及生物多样性面临着较大的威胁。尽管九寨沟湿地具有重要的生态价值,但目前对其研究尚比较薄弱。湿地植物群落和植物地理研究可以为湿地资源的可持续利用和监测保护提供科学依据。作者从2004年8月到2007年11月对九寨沟湿地的植物物种组成、地理分布、优势植物群落的结构、生长动态、湿地土壤种子库进行了调查研究。主要结果如下: 1. 九寨沟湿地物种组成、地理分布特点及湿地植物群落特点 九寨沟湿地共有苔藓植物8科13属16种,维管植物为48科107属199种。九寨沟湿地植物的地理成份较为丰富,维管植物在科级水平上有7种地理分布型(变型),在属级水平上有13种地理分布型(变型), 在种级水平上共有29种地理分布型(变型)。九寨沟湿地植物以温带成份和我国特有成份为主,同时兼有热带、亚热带成份和环极—高山成份。九寨沟湿地植物的分布表现出明显的垂直地带性和水平地带性。湿地植物群落可划分21个群落类型,不同植物群落类型的物种多样性及物种组成存在较大的差异。九寨沟湿地植物的物种多样性和群落多样性以及较高的生产力特征,是维持其湿地生态景观多样性和稳定性的基础。 2. 土壤、水环境、海拔等对湿地植物的分布及生物多样性的影响 九寨沟湿地土壤、水等环境因子存在较大的差异。帕米尔苔草和宽叶香蒲等群落的凋落物较多,土壤有机碳、土壤总磷较高,可能是九寨沟湿地的重要土壤碳库。 九寨沟湿地植物沿水环境梯度的分布规律表现为:沉水植物(轮藻—篦齿眼子菜,水苦荬,杉叶藻)——挺水植物(水木贼,芦苇,宽叶香蒲)——湿生草本(苔草、节节草、披散木贼)——湿生灌木(柳灌丛,小檗灌丛)等。海拔也影响湿地植物的物种组成。 水深对物种多样性有影响,水深与物种丰富度负相关。随着水深的增加,水木贼、芦苇、杉叶藻、宽叶香蒲等群落的物种多样性下降;在长期淹水和季节性淹水的地方,水木贼群落物种多样性存在显著差异。土壤总氮与水木贼群落物种丰富度正相关。 3. 土壤营养元素、水环境对植物生长的影响 水深影响湿地植物生物量的分配。芦苇无性系分株在47 cm水深的环境中单株平均生物量最大;在干滩地中(地面水深0 cm),叶生物量百分比最大,而茎生物量百分比最小,茎的生物量百分比和生长速率随水深的增加而增加;在较干的滩地生境中,开花率、花序的生物量百分比明显大于水较深的生境。 水深与水木贼地上生物量负相关,但水木贼地上生物量在长期淹水和季节性淹水的地方没有显著的差异。在水浅的地方,杉叶藻、水木贼、芦苇等植物群落中,其他伴生物种的生物量占样方总生物量的百分比较大。 土壤有机碳、土壤总氮、土壤总磷等对湿地植物生物量的影响比较大:宽叶香蒲地上生物量与土壤总磷正相关;水木贼地上生物量与土壤总氮正相关;杉叶藻地上生物量与土壤有机碳正相关。 水深、土壤营养成分对湿地植物高度、密度等有影响。水木贼的平均高度在季节性淹水的地方比长期淹水的地方低,平均密度在长期淹水的地方比季节性淹水的地方低;除了5月份,其他观察月份水木贼的密度都与水深负相关,同时与土壤有机碳正相关。另外,芦苇密度与土壤有机碳含量正相关,宽叶香蒲密度与水深负相关,帕米尔苔草高度与土壤有机碳负相关。 4. 优势植物群落的动态变化 在优势植物群落中,优势种的高度、密度、盖度、生物量等在群落中占绝对优势。除五花海,水木贼群落的物种组成、高度、生物量在两年间没有显著的变化。芦苇群落的物种丰富度在近两年有所增加。 湿地植物生长表现为明显的季节动态,生长的峰值大多在7月-8月。优势植物群落的物候与水文周期有关。湿地植物群落的物种组成和密度,可以作为对湿地监测和保护的生物指示。 5. 九寨沟湿地土壤种子库特征及其在湿地生物多样性恢复中的作用 水深和现存植被物种丰富度可以解释湿地土壤种子库的变化。水深可以解释表层物种丰富度45%的变化。现存植被物种丰富度可以分别解释10 cm土层、2-5 cm土层及5-10 cm土层土壤种子库45%、48%和25%的变化。 湿地土壤种子库的密度为0-15945粒m-2, 种子库中共发现23个物种。现存植被优势物种和种子库优势物种不同。各层土壤种子库密度和物种丰富度并不存在显著的差异,但第二层土壤种子库密度最大。海拔、现存植被优势种盖度、土壤总磷、土壤总氮、土壤有机碳对湿地土壤种子库的密度和垂直结构没有影响。土壤种子库物种丰富度小于地上植被物种丰富度。湿地土壤种子库与地上植被的相关性不大。在浅水区域,湿地土壤种子库在湿地植被恢复中有一定作用。但在深水区域,保护现存植被更重要。 The lakeshore wetlands are valuable ecological units of the Jiuzhaigou lakes. Pressure for travel industry development pose a continuing and severe threat to the biodiversity-support function of the wetland system. Despite the ecological importance of wetlands in Jiuzhaigou, they are so far poorly studied. Both general plant communties and biogeographical studies are needed in order to attain basis for sustainable use the wetland resources and adequate protection of these areas. The present study was undertaken to examine aquatic plants distribution and the species compositon, structure and growth dynamics of their communities with variations of environmental factors along altitudes, water depth and soil properities gradients in Jiuzhaigou. Analysis of field survey data collected during August 2004 and November 2007 in lakeshore wetlands in Jiuzhaigou National Nature Reserve, Sichuan, China. The results were as following: (i) Species composition and biogeography in wetland vegetation 8 families, 13 genus, 16 species of moss and 48 families, 107 genus and 199 species of vascular plants in Jiuzhaigou wetlands were found. The floristic compositions were abundunt. Ten geographical distribution types at family level, 13 geographical distributions types at generic level and 29 geographical distribution types at specific level in vascular plants were found. Most species in Jiuzhaigou wetlands are temperate elements and Chinese endemic elements, with a few of tropical and subtropical and some circumarctic elements. And the plant distributions show clear vertical and horizontal patterns. There were 21 major wetland plant community types. Species composition and species richness in different plant communities are different. The species diversity and plant community diversity and their high biomass are the basis for the diversity and stability of wetland landscapes in Jiuzhaigou. (ii) Water depth, soil nutrients and altitudes influence on the species diversity and plant distribution. Total phosphorous and organic cabon in soil were higher in C. pamiernensis and T. latifolia communities, where are important cabon reservoirs in Jiuzhaigou wetlands. Along gradients of water depth, among populations of the dominant plant species present: submerged macrophytes (Chara vulgaris, Potagemonton pectinatus, Veronica anagalis-aquatica,Hippuris vulgaris), emergent macrophytes (Equisetum fluviatile, Phragamites australis, Typha latifolia), helophytes (Carex pamirensis )and shrubs (Salix sp., Berberis sp. ). Altitudes influence on the assemblage of plant communities. Water depth negatively correlated with species richness. Specie richness showed differences between permanently flooded sites and seasonally flooded sites in E. fluvatile communities. And total nitrogen in soil was negatively correlated with species richness in E. fluviatile communities. Altitudes show no significant influence on species richness, but in fact, through our analyses, they do have influence on the assemblage of wetland plants. (iii) Water depth, soil nutrients influence on the plant growth Water depth influences the biomass allocation in Phragmities australis. The average aboveground biomass of a single ramet (4.2 g) was the largest in the habitat with water level 47 cm above the soil surface. At the habitat with water level under soil surface 15 cm (-15 cm), the leaf biomass percentage (of the total ramet biomass) was the largest (46.1%), and the height and percentage of ramose ramets ( with branches on stem )(of the total ramets in a plot) were found obviously different. The deeper in water, the larger the biomass percentage and growth rate of stems were. The flowering rate and biomass of panicles were greater in shallow water than those in deep water. Water depth negatively correlated with aboveground biomass of E. fluviatile. However, above-ground biomass of E. fluviatile showed no significant difference between permanently flooded sites and seasonally flooded sites. But in shallow water, more biomasses of accompanying species were found in dominant plant communities such as H. vulgaris communities, E. fluviatile communities and P. australis communities. Water depth, soil nutrients influence on shoot density and shoot length of wetland plants. The shoot density of E. fluviatile was correlated to water depth in all growth months. Annual average density was significantly lower at permanently flooded sites than at seasonally flooded sites. But the annual average shoot length was significantly lower at seasonally flooded sites than at permanently flooded sites. (iv) Growth dynamics of dominant communities in Jiuzhaigou wetland The shoot length and shoot density, coverage and biomass of domiant species were dominated in plant communities. The species composition increased in P. australis communities in recent two years. The species richness in E. fluviatile communities showed no difference between 2005 and 2007. The above-ground biomass and shoot density in Five-flower Lake from July 2005 to July 2007 were significantly different, while in other sites, the differences were not significant. Shoot height, shoot density and above-ground biomass showed significant seasonal changes in all sites. Growth dynamics correlated with the cycle of water levels in lakes. Most plants growth parameters peaked at July or August. The biomass of T. latifolia peaked in August. But the shoot length of T. latifolia in deeper water peaked in July. The shoot length of E. fluviatile increased significantly from May to August except in seasonally flooded sites in Arrow-bamboo Lake. The species composition of communities and shoot density can be used as bioindicators in Jiuzhaigou wetland. (v) Soil seed bank in Jiuzhaigou wetland and its role in vegetation restoration Seed density in all soil layer samples was negatively correlated to water depth. Water depth can explain 45% variance of species richness in surface layer in sediment. Species richness in extant vegetation can explain 45%, 48%, 25% variance of species richness in total 10 cm and in 2-5 cm and 5-10 cm layer sediment respectively. Mean seed densities in wetlands ranged from 0 to 15945 m–2. A total of 23 species germinated in seed bank. The dominant species in seed bank and extant vegetation showed great difference. The total number of species and seedlings that germinated in different layers was not significantly different. But the second layer had the greatest seed density. In shallow water, seed bank can contribute to vegetation restoration, while in deeper water, protection of extant vegetation may be a better strategy.

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The results of the examination showed that some wetland plants' leaves and stems above the surface of water have little ability to supply water body with oxygen through roots of themselves while they are photosynthesizing. These plants are calamus(Acorus calamus), cattail(Typha angustifolia), wild rice stem(Zizania caduciflora), Cyoerus alternifokius, and water hyacinth(Eichhornia crassipes). It means that there is no relationship between these plants' photosynthesis and the breath of root cells. But duckweed(Lemna minor) has a small to raise DO 0.44mg·L -1 in average, while it is photosynthesizing during the examination. Reed(Phragmitas communis) may have a little the to provide oxygen for water body through root of itself while it is photosynthesizing. It raised DO 0.30mg·L -1 in average during the examination.

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Elemental (TOC, TN, C/N) and stable carbon isotopic (delta(13)C) compositions and n-alkane (nC(16-38)) concentrations were measured for Spartina alterniflora, a C-4 marsh grass, Typha latifolia, a C-3 marsh grass, and three sediment cores collected from middle and upper estuarine sites from the Plum Island salt marshes. Our results indicated that the organic matter preserved in the sediments was highly affected by the marsh plants that dominated the sampling sites. delta(13)C values of organic matter preserved in the upper fresh water site sediment were more negative (-23.0+/-0.3) as affected by the C-3 plants than the values of organic matter preserved in the sediments of middle (-18.9+/-0.8) and mud flat sites (-19.4+/-0.1) as influenced mainly by the C4 marsh plants. The distribution of n-alkanes measured in all sediments showed similar patterns as those determined in the marsh grasses S. alterniflora and T. latifolia, and nC(21) to nC(33) long-chain n-alkanes were the major compounds determined in all sediment samples. The strong odd-to-even carbon numbered n-alkane predominance was found in all three sediments and nC(29) was the most abundant homologue in all samples measured. Both delta(13)C compositions of organic matter and n-alkane distributions in these sediments indicate that the marsh plants could contribute significant amount of organic matter preserved in Plum Island salt marsh sediments. This suggests that salt marshes play an important role in the cycling of nutrients and organic carbon in the estuary and adjacent coastal waters. (C) 2003 Elsevier Ltd. All rights reserved.

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Thirty-nine species of marine algae collected from the coast of China were screened for their antitumor activities, and eight species Leathesia difformes, Polysiphonia urcedata, Scytosiphon lomentarius, Gloiopeliis furcata, Punctaria latifolia, Symphyocladia latiuscula, Rhodomela confervoides and Ulva pertusa showed potent cytotoxic activities. Three, Rhodomela confervoides, Scytosiphon lomentarius and Gloiopeliis furcata, were used for further investigation. More than 30 compounds were isolated and purified, and 14 bromophenols, 1 steroid and 1 carotene were identified by advanced spectroscopic methods including IR, MS, and NMR techniques. Amongst the 16 identified compounds, 7 showed vigorously selective activities against KB, Bel7402 and A549 cancer cells, and 6 bromophenols were new compounds.

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Os citros podem ser infectados por várias espécies de viróides, dentre elas destaca-se o Citrus exocotis viróide, CEVd como o agente causal da exocorte dos citros. Esta doença está presente em praticamente todos as regiões citrícolas do mundo, associada aos sintomas de descamação em porta-enxertos como o limão ´Cravo' (Citrus limonia Osbeck) e o Poncirus trifoliata e ao nanismo de plantas neles estabelecidas. Na América Latina a lima ácida ´Tahiti' (C. latifolia Tan) é também descrita como suscetível à exocorte.

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Nitrate from agricultural runoff are a significant cause of algal blooms in estuarine ecosystems such as the Chesapeake Bay. These blooms block sunlight vital to submerged aquatic vegetation, leading to hypoxic areas. Natural and constructed wetlands have been shown to reduce the amount of nitrate flowing into adjacent bodies of water. We tested three wetland plant species native to Maryland, Typha latifolia (cattail), Panicum virgatum (switchgrass), and Schoenoplectus validus (soft-stem bulrush), in wetland microcosms to determine the effect of species combination and organic amendment on nitrate removal. In the first phase of our study, we found that microcosms containing sawdust exhibited significantly greater nitrate removal than microcosms amended with glucose or hay at a low nitrate loading rate. In the second phase of our study, we confirmed that combining these plants removed nitrate, although no one combination was significantly better. Furthermore, the above-ground biomass of microcosms containing switchgrass had a significantly greater percentage of carbon than microcosms without switchgrass, which can be studied for potential biofuel use. Based on our data, future environmental groups can make a more informed decision when choosing biofuel-capable plant species for artificial wetlands native to the Chesapeake Bay Watershed.

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Loidi (Lazaroa 4:74. 1983) corrigió en contra del CNF el nombre de la asociación "Chenopodio-Oxalidetum violaceae Br-Rl. 1967", basándose en la determinacion errónea de la especie de Oxalis presente en la comunidad, ya que se trata de Oxalis latifolia Kunth y no de O. violacea L., según experiencia directa y referencias anteriores (cf. LAINZ, Collect. Bot. Barcelona 5 (3): 684, y DÍAZ GONZÁLEZ. Rev. Fac. Cienc. Oviedo, 15 (2): 482). Subsiguientemente, propuso el nombre Oxalidi latifoliae-Veronicetum persicae Br-Rl. 1967 corr. Loidi.

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Die vorliegende Arbeit stellt eine umfassende taxonomische Revision der Gattung Fosterella L.B. Sm. (Bromeliaceae) dar, die alle 31 derzeit akzeptierten Arten umfasst und einen Bestimmungsschlüssel für diese beinhaltet. Die Revision beruht auf der morphologisch-anatomischen Auswertung von Herbarmaterial (über 800 Exsikkate), Lebendpflanzen (ca. 150 Akzessionen) und eigenen vergleichenden Untersuchungen im Freiland. Die Gattung Fosterella ist seit nunmehr etlichen Jahren Forschungsgegenstand einer interdisziplinären Studie, die sowohl molekulrae, als auch anatomische, morphologische und biogeographische Untersuchungen einbezieht. Unser Interesse an der Gattung Fosterella gründet sich auf ihrer enormen ökologischen und biogeographischen Vielfalt, sie gilt als hervorragendes Modellsystem für Artbildungsmechanismen in den Anden. In den letzten Jahren wurde von verschiedenen molekularen Methoden Gebrauch gemacht, um die verwandtschaftlichen Beziehungen innerhalb der Gattung zu untersuchen, so dass mittlerweile gut aufgelöste Stammbäume vorliegen. Diese molekularen Studien, überwiegend durchgeführt von Dr. Martina Rex, wurden ergänzt durch intensive Sammelaktivitäten und eingehende taxonomische Untersuchungen im Rahmen der vorliegenden Revision. Auf diese Weise konnten die morphologische Plastizität der einzelnen Arten erfasst und schließlich ein wohlfundiertes Artkonzept vorgelegt werden. Zunächst wird ein kurzer Überblick über die Familie der Bromeliaceen als auch die Gattung Fosterella gegeben, in dem jeweils Informationen zur Verbreitung, Morphologie, Physiologie, Ökologie und Phylogenie geliefert werden. Im Anschluss an einen historischen Überblick des taxonomischen Werdegangs wird die Abgrenzung der Gattung Fosterella zu den nächstverwandten Gattungen Deuterocohnia, Dyckia und Encholirium erläutert. Die morphologischen Merkmale zur Differenzierung der Arten innerhalb der Gattung werden im Hinblick auf ihre Zuverlässigkeit und ihr Gewicht diskutiert. Der Artschlüssel basiert auf Merkmalen, die leicht auszumachen und gut zu unterscheiden sind. Bei der ausführlichen Beschreibung der Arten wird auch auf ihre jeweilige Verbreitung, Ökologie, taxonomische Abgrenzung, systematische Verwandtschaft sowie die Etymologie des Namens eingegangen. Beigefügt sind jeweils Zeichnungen, ein Foto vom Holo-/Lectotypus, Fotos von Lebendpflanzen sowie eine Verbreitungskarte. Im Rahmen der taxonomischen Arbeit wurden fünf Arten zu Synonymen reduziert: Fosterella chiquitana Ibisch, R. Vásquez & E. Gross und F. latifolia Ibisch, R. Vásquez & E. Gross wurden in die Synonymie von F. penduliflora (C.H. Wright) L.B. Sm. eingezogen; F. fuentesii Ibisch, R. Vásquez & E. Gross als Synonym zu F. albicans (Griseb.) L.B. Sm. gestellt; F. elata H. Luther in die Synonymie von F. rusbyi (Mez) L.B. Sm. verwiesen und F. nowickii Ibisch, R. Vásquez & E. Gross als Synonym zu F. weddelliana (Brongn. ex Baker) L.B. Sm. gestellt. Fosterella schidosperma (Baker) L.B. Sm. var. vestita L.B. Sm. & Read wird zum Synonym von Fosterella weberbaueri (Mez) L.B. Sm. reduziert. Sechs Arten wurden neu beschrieben: Fosterella batistana Ibisch, Leme & J. Peters; F. christophii Ibisch, R. Vásquez & J. Peters; F. elviragrossiae Ibisch, R. Vásquez & J. Peters; F. kroemeri Ibisch, R. Vásquez & J. Peters; F. nicoliana J. Peters & Ibisch und F. robertreadii Ibisch & J. Peters. Das Taxon F. gracilis (Rusby) L.B. Sm. wurde neu etabliert. Um die Evolution von einzelnen morphologischen Merkmalen zu rekonstruieren, wurden die Zustände von zehn ausgewählten Merkmalen kodiert und auf einen molekularen Stammbaum kartiert. Die folgenden Merkmalszustände wurden als ursprünglich innerhalb der Gattung ermittelt: Stammlosigkeit, ganzrandige Blattspreiten, flache Rosetten mit dem Boden aufliegenden Blättern, locker beschuppte Blattunterseiten, schildförmige Haare mit gezähntem Rand, ganzrandige Pedunkel-Brakteen, rispenförmiger Blütenstand, kahle/verkahlende Blütenstandsachsen, weiße Petalen und einfach-aufrechte Narben. Rückschlüsse bezüglich der Evolution und Ausbreitung der Gattung Fosterella werden diskutiert: Die überwiegend kleinen Verbreitungsgebiete der Arten hängen offensichtlich mit ihren fragmentierten, inselartigen Habitaten (z.B. innerandine Trockentäler) zusammen. Die Tatsache, dass die Yungas-Bergregenwälder des Departamento La Paz, Bolivia, die Region mit der größten Artenvielfalt darstellen, lässt sich mit der extrem variablen Topographie und der außerordentlich hohen Vielfalt an Habitaten dieser Region erklären. Aus folgenden Gründen erscheint es sehr wahrscheinlich, dass die Gattung Fosterella ihren Ursprung im Tiefland hat: Die Mehrheit der Arten weist einen eher mesophytischen Habitus auf und ist in mehr oder weniger humiden Habitaten zu finden. Die Gattung ist durch mehrere Arten in sehr alten Habitaten des präkambrischen Schilds im Tiefland von Zentral-Südamerika vertreten. Weiterhin betreiben, soweit bekannt, alle Fosterella Arten C3 Photosynthese, während in den Gattungen der Schwestergruppe, Deuterocohnia, Dyckia and Encholirium, CAM der verbreitete Photosyntheseweg ist. In jedem Fall ist die Besiedelung der Anden und/oder Tieflandhabitate mehrfach unabhängig voneinander geschehen, vielleicht sogar in beiden Richtungen.

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The Lake Pertobe wetland system is a semi-natural wetland that has been modified primarily for recreational use. However, this lake system receives stormwater from much of the central business district of Warrnambool City (Victoria, Australia) and serves as a buffer zone between the stormwater system and the Merri River and Merri Marine Sanctuary. This work considers the impact of stormwater inputs on Lake Pertobe and the effectiveness of the lake in protecting the associated marine sanctuary. Sediment contaminants (including heavy metals and polycyclic aromatic hydrocarbons (PAHs)) and water quality parameters within the lake, groundwater and stormwater system were measured. Water quality parameters were highly variable between stormwater drains and rain events. Suspended solids rapidly settled along open drains and shortly after entering the lake. Groundwater inputs increased both salinity and dissolved nitrogen in some stormwater drains. Some evidence of bioaccumulation of metals in the food chain was identified and sediment concentrations of several PAHs were very high. The lake acted as a sink for PAHs and some metals and reductions in Escherichia coli, biological oxygen demand and total phosphorus were observed, affording some protection to the associated marine sanctuary. Nutrient retention was inadequate overall and it was identified that managing the lake primarily as a recreational facility impacted on the effectiveness of stormwater treatment in the system.

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A disposição no solo, qualificada ou não, provavelmente por longo tempo permanecerá como alternativa adotada por países não abastados para a destinação dos seus resíduos sólidos. Dada a escassez de recursos econômicos de tais nações, há uma demanda urgente por alternativas de baixo custo para o tratamento do efluente líquido ambientalmente altamente impactante gerado em tal processo: o lixiviado. O presente trabalho, desenvolvido em uma área do Aterro Sanitário da Extrema, Porto Alegre, vem contribuir apresentando resultados da utilização de três métodos biológicos de baixo custo aplicados consecutivamente ao tratamento de lixiviado bruto proveniente de aterro sanitário de resíduos sólidos: (1) filtro biológico anaeróbio com meio suporte de pedra britada nº 5, (2) filtro biológico aeróbio de baixa taxa com meio suporte de pedra britada nº 3 e (3) banhado construído de fluxo subsuperficial com cultivo de Typha latifolia sobre areia de elevada granulometria. O filtro anaeróbio demonstrou constituir-se em excelente alternativa de reduzido custo para o tratamento de lixiviado bruto. Utilizando-se afluente com 2690-8860 mgDBO5/L e 5345-14.670 mgDQO/L, apontou-se para um tempo de detenção hidráulica próximo a 56 dias como ótimo dos pontos de vista operacional e econômico, produzindo eficiências de remoção de DBO5 de 82,43% e de DQO de 77,70%. A pesquisa conduzida com filtro aeróbio de baixa taxa, ainda que produzindo resultados de significância limitada do ponto de vista estatístico, em função do reduzido número de repetições e utilização de apenas uma unidade experimental, apontou para um desempenho satisfatório da unidade, uma vez que, aplicado lixiviado previamente tratado anaerobicamente a 0,063 m3/(m2.d), obtiveram-se remoções de 53,17% de NTK, de 46,12% de nitrogênio (todas as formas) e de 36,01% de DBO5. A pesquisa com banhado construído de fluxo subsuperficial utilizado no polimento do lixiviado previamente tratado anaeróbia e aerobicamente produziu limitado número de resultados, sobretudo pela dificuldade de aclimatação das macrófitas utilizadas. Ainda assim, elevadas remoções de DBO5, DQO, NTK, nitrogênio (todas as formas), fósforo e cromo total foram obtidas operando-se com diluições para controle da salinidade, havendo adaptado-se as plantas a lixiviado com condutividade elétrica de 6370 µmho/cm.

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No desenvolvimento das condições ótimas para a avaliação da viabilidade, através da determinação de métodos eficientes na condução dos testes de germinação e de tetrazólio, e do vigor, através do estudo das variáveis que influenciam a realização dos testes de condutividade elétrica e de envelhecimento acelerado, foram utilizadas sementes forrageiras nativas das gramíneas Paspalum dilatatum Poir., P. lividum Trin. ex Schltdl., P. nicorae Parodi, P. notatum Flügge, P. pauciciliatum Parodi Herter, P. plicatulum Michx., P. pumilum Ness, P. regnellii Mez, P. urvillei Steud e das leguminosas Desmodium incanum DC., Trifolium riograndense Burkart, Adesmia latifolia (Spreng.) Vogel. e Desmanthus depressus Humb. & Bonpl. ex Willd. Os trabalhos foram desenvolvidos no Laboratório de Análise de Sementes do Departamento de Plantas Forrageiras e Agrometeorologia da Faculdade de Agronomia/Universidade Federal do Rio Grande do Sul. Os dados em porcentagem de germinação foram transformados em arco-seno√x/100. As médias foram comparadas pelo Teste de Tukey (P<0,05), de Dunnett (P<0,05) e análise de regressão. O delineamento experimental foi o completamente casualizado, com quatro repetições de 25 sementes cada. As condições adequadas de germinação, tipo de substrato, posição e temperatura utilizada, variaram conforme a espécie, mas de um modo geral as sementes de leguminosas mostraram bons resultados sobre substrato papel e em temperaturas alternadas. Nas gramíneas do gênero Paspalum, a condição papel, a posição sobre o substrato e as temperaturas constantes de 20 e 25°C e a alternada de 20-35°C destacaram-se das demais, para a maioria das espécies. A temperatura alta (40°C), o maior período de embebição (24 horas) e a concentração de 0,5%, de uma forma geral, apresentaram-se como as condições mais adequadas para condução do teste de tetrazólio nas espécies trabalhadas. A combinação 24 horas/25°C, para grande parte das leguminosas e gramíneas em questão, levou a uma liberação maior de lixiviados na realização do teste de condutividade elétrica. As condições de temperatura de 45°C e o período de exposição de 96 horas, de modo geral, afetaram de forma mais drástica a porcentagem média de germinação das sementes após o envelhecimento acelerado nas espécies estudadas.

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Empresa de Pesquisa Agropecuária do Rio Grande do Norte

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Foram estudados os grãos de pólen de 12 gêneros e 41 espécies de Solanaceae ocorrentes na Reserva do Parque Estadual das Fontes do Ipiranga: Acnistus arborescens (L.) Schlecht., Athenaea picta (Mart.) Sendtn., Brunfelsia latifolia Benth., Brunfelsia pauciflora (Cham. & Schlecht.) Benth., Capsicum flexuosum (L.) Sendtn., Capsicum villosum (L.) Sendtn., Cestrum amictum (L.) Schlecht., Cestrum corymbosum (L.) Schlecht., Cestrum lanceolatum (L.) Miers, Cestrum schlechtendalii (L.) G. Don, Cestrum sendtnerianum (L.) Mart. ex Sendtn., Cyphomandra diploconos Sendtn., Cyphomandra velutina Sendtn., Dyssochroma viridiflora (Sims) Ducke, Nicotiana langsdorffii (Weinm.) Roem. & Schult., Physalis peruviana L., Physalis viscosa L., Sessea brasiliensis Tol., Solandra grandiflora Sw, Solanum americanum Mill., Solanum atropurpureum Schrank., Solanum bullatum Vell., Solanum capsicoides Allion., Solanum cernuum Vell., Solanum concinnum Schott ex Sendtn., Solanum didynum Dun., Solanum diflorum Vell., Solanum excelsum St. Hil. ex Dun., Solanum granuloso-leprosum Dun., Solanum hoehnei Morton, Solanum inaequale Vell., Solanum inodornum Vell., Solanum lycocarpum St. Hil. ex Dun., Solanum mauritianum Scop., Solanum paniculatum L., Solanum rufescens Sendtn., Solanum sisymbriifolium Lam., Solanum swartzianum Roem. & Schult., Solanum vaillantii Dun., Solanum variabile Mart., Solanum viarum Dun. São apresentadas descrições para todas as espécies estudadas, ilustrações, observações e seis chaves polínicas.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Both N excess and deficiency may affect cotton yield and quality. It would therefore be useful to base the N management fertilization on the monitoring of the nutritional status. This study investigated the correlations among the following determination methods of the N nutritional status of cotton (Gossypium hirsutum L., var. Latifolia): chlorophyll readings (SPAD-502 (R), Minolta), specific-ion nitrate meter (Nitrate Meter C-141, Horiba-Cardy (R)), and laboratory analysis (conventional foliar diagnosis). Samples were taken weekly from two weeks before flowering to the fifth week after the first flower. The experiment was conducted on the Fazenda Santa Tereza, Itapeva, State of São Paulo, Brazil. The crop was fertilized with 40 kg ha(-1) N at planting and 0, 30, 60, 90, and 120 kg ha(-1) of side-dressed N. The range of leaf N contents reported as adequate for samples taken 80-90 days after plant emergence (traditional foliar diagnosis) may be used as reference from the beginning of flowering when the plant is not stressed. Specific-ion nitrate meter readings can be used as a nutritional indicator of cotton nutrition from one week after pinhead until the third week of flowering. In this case, plants are well-nourished when readings exceed 8,000 mg L(-1) NO(3)(-). The chlorophyll meter can also be used to estimate the nutritional status of cotton from the third week of flowering. In this case the readings should be above 48 in well-nourished plants.