Dried cattail and bulrush plant pieces in mesh bags were incubated in the constructed wetland treating Pope & Talbot pulp mill effluent. Two ponds planted with each species and two depth ranges in each pond were chosen, to determine decomposition rates. Bags were withdrawn and analyzed at five time points for the cattail and three for the bulrush. Also a laboratory study was conducted, where ground cattail and bulrush material was incubated aerobically and anaerobically. Both species and control were sampled at five time points. The remaining dry mass and the contents of hemicellulose, cellulose, lignin, and silica was examined. Decomposition rates were determined by fitting the data to the single exponential model with the intercept fixed in 1 (100%). An asymptotic model was used to obtain better fit. The sum of squared errors (SSE) was used as a measure of fit. In the field study the ANOVA revealed no change in decomposition with depth. Neither was there a difference between cattail and bulrush ponds. During the first two days only the cell compounds are drastically reduced. Cellulose and hemicellulose start to decline later. Lignin increased slightly during the first half of the experiment. Decay rates from the single exponential model with the intercept fixed were higher than the ones listed for wetlands by Webster & Benfield (1986). The asymptotic model indicates, that there is a fraction, which does not decompose significantly during the time frame of the experiment. It predicts 36% cattail and 53% bulrush material to be left after one year of decomposition. All samples in the laboratory incubation showed strong leaching during the first day (26.5% for cattail, 23% for bulrush). After this the t-test (95% confidence) showed a significant decay coefficient only for the aerobic cattail samples the model with the best fit. These same samples had an increased cell component, and a very small particle size at the last sampling time (120 days). Neither bulrush nor the anaerobic cattail incubations showed the same effect. Cattail and bulrush plants in the field were labeled to observe the senescence. Their height and in the case of cattail the amount of green and dry leaves was recorded monthly. Plants were harvested once a month until February, and the fiber composition was measured. Cattail was completely dry in January, while bulrush still showed green spots in February. Cattail entered the aquatic system mainly by dropping pieces of leaf tips, less by breaking off and losing the outside leaves. In February the average height of cattail plants was 64.7% of the maximum average height in August. Bulrush plants shortened to 84.1% of the maximum average height from September. Most of the bulrush plants died through nutria, a rodent, which is chopping off the plants. Less material was lost by dropping small pieces off the plant tips. / Graduation date: 1994

Au XIX ème siècle, la construction d'un réseau de digues autour du delta du Rhône a conduit à l'établissement de nouveaux milieux colonisés par de nouvelles espèces végétales et animales. Ces nouveaux milieux caractérisés, entre autre, par des marais temporaires ont vite été utilisés comme pâturage par le bétail et les chevaux durant la période estivale. Le Scirpe maritime (Scirpus maritimus L.) présent dans ces terres fertiles est alors devenu une des espèces végétales les plus appétantes pour ces herbivores qui en consomment les parties aériennes. Au début des années 80, les Oies cendrées (Anser anser anser) ont commencé à s'installer en quartier d'hivernage dans ces marais temporaires et leur ef'fectif' n'a cessé d'augmenter pour atteindre 1300 individus au cours de l'hiver 1999/2000. En se nourrissant des tubercules de Scirpe maritime, les oies occasionnent des déconnexions physiologiques dans les chaînes rhizomateuses que forment les parties souterraines de Scirpus maritimus. De telles déconnexions peuvent perturber l'allocation des ressources, le mode de reproduction et par conséquent la dynamique des scirpaies. Nous avons déterminé les tailles optimales de quadrat et de carotte pour échantillonner les parties aérienne et souterraine de Scirpus maritimus. Par la suite, nous avons élaboré des relations allométriques sur Scirpus maritimus. Un total de 115, 120 et 60 tiges a été échantillonné en 2002 et 2003 dans un marais brouté et pâturé par les oies et le bétail et en 2003 dans un marais non fréquenté par ces herbivores, respectivement. Ces relations nous ont permis d'estimer la biomasse aérienne du Scirpe maritime dans chacun de ces marais. Nous avons également déterminé la relation entre les biomasses aérienne et souterraine, Nous avons utilisé les précédentes données de biomasses et de densités (aériennes et souterraines) pour discerner si les plants de Scirpe allouaient différemment leurs ressources dépendamment que ceux-ci sont broutés et pâturés par les deux herbivores. Des données sur la salinité de l'eau, la durée de submersion et la densité d'oies en alimentation ont également été intégrées dans les analyses. Les quadrats de 15 x 15 cm et les carottes de 15 x 15 x 15 cm se sont avérés être les tailles optimales pour échantillonner les parties aérienne et souterraine. La hauteur et le diamètre ont expliqué plus de 95% de la variation de la biomasse des tiges mais les modèles allométriques différaient entre les années et entre les marais. Malgré une sous-estimation des relations allométriques sur la biomasse obtenue par l'échantillonnage destructif, les résultats sont encourageants dans le sens où ils nous permettent de voir qu'il est possible d'estimer de manière non destructive les biomasses aérienne et souterraine dans des milieux perturbés; la biomasse de tubercules et la biomasse souterraine totale ayant été prédites avec justesse par la biomasse aérienne. Même si la biomasse souterraine est deux fois plus importante dans le marais brouté, il semble que les oies et le bétail n'aient pas eu un impact important sur la structure et la dynamique des scirpaies étudiées. Il est possible que les ef'fets des herbivores aient été tamponnés par l'étroit niveau d'intégration physiologique des genets de scirpe. ______________________________________________________________________________ MOTS-CLÉS DE L’AUTEUR : Relations allométriques, Échantillonnage non destructif, Scirpus Maritimus, Herbivorie, Allocation des ressources, Plante clonalc, Biomasse, Scirpe maritime, Marais.

Submitted by dayse paz (daysepaz@hotmail.com) on 2016-04-06T14:31:14Z No. of bitstreams: 1 Disserta_o_Daiane_KAFER.pdf: 1161357 bytes, checksum: 583dfb9dd82e3830703145f214aa3bf1 (MD5) / Approved for entry into archive by cleuza maria medina dos santos (cleuzamai@yahoo.com.br) on 2016-05-10T19:58:37Z (GMT) No. of bitstreams: 1 Disserta_o_Daiane_KAFER.pdf: 1161357 bytes, checksum: 583dfb9dd82e3830703145f214aa3bf1 (MD5) / Made available in DSpace on 2016-05-10T19:58:37Z (GMT). No. of bitstreams: 1 Disserta_o_Daiane_KAFER.pdf: 1161357 bytes, checksum: 583dfb9dd82e3830703145f214aa3bf1 (MD5) Previous issue date: 2013 / Neste estudo, investigamos a composição e distribuição das macrófitas aquáticas de uma área úmida no sul do Brasil conhecida como Banhado 25 e sua relação com algumas variáveis abióticas. Para tanto foram alocadas 30 unidades amostrais permanentes de 1m2 distribuídas em duas áreas: uma com domínio de Scirpus giganteus Kunth (Área A) e outra com domínio de Cladium jamaicense Crantz (Área B) onde realizamos a identificação e estimativa da cobertura das macrófitas durante dois períodos, inverno e verão. Simultaneamente foram avaliadas características químicas do sedimento, a profundidade da água e a radiação fotossinteticamente ativa (PAR) em cada unidade amostral. Foram identificadas 66 espécies distribuídas em 27 famílias nas duas áreas estudadas durante os dois períodos amostrados. Os valores de riqueza de espécies (S), diversidade de Shannon (H’) e o equabilidade de Pielou (J’) diferiram entre as áreas amostradas, assim como a composição de espécies, apresentando maiores valores na área B. A área A apresentou uma maior dispersão multivariada quando comparada com a área B, ocorrendo uma maior variabilidade de espécies nas unidades amostrais. A ordenação das unidades amostrais da análise de correspondência canônica (CCA) evidenciou a diferença entre as duas áreas, onde a área A esteve associada a profundidade da coluna d’ água, PAR e ao teor de alumínio no sedimento enquanto que a área B esteve associada ao pH, Mg e Ca. O coeficiente de Spearman indicou correlação negativa entre a cobertura das espécies dominantes e a riqueza de espécies, assim como com a taxa de radiação fotossintéticamente ativa que chega ao substrato. Concluímos que a variação na composição e distribuição das macrófitas refletiu a heterogeneidade espacial e temporal do Banhado 25. / In this study, we have investigated the composition and distribution of macrophytes in two locations of a wetland in southern of Brazil and its relation to abiotic variables. For this purpose were allocated 30 permanent samples units of 1m² divided into two areas: one area of Scirpus giganteus Kunth (Area A) and another domain of Cladium jamaisence Crantz (Area B) where we performed the identification and estimation of coverage of macrophytes during two periods, winter and summer. Simultaneously were evaluated chemical characteristics of the sediment, water depth and photosynthetic active radiation (PAR) in each sample unit. We identified 66 species distributed in 27 families in the two areas studied during the two periods. Species richness (S) values, Shannon index (H’) and Pielou equability (J’) showing difference between the sampling sites, as well as species composition, with higher values in the area B. The area A showed a greater dispersion multivariate compared to the area B, occurring a greater variability of species in the sample units. The ordination of sample units of canonical correspondence analysis (CCA) showed the difference between the two areas, where the area A was associated to the depth of the water column, PAR and the aluminum content in the sediment while area B was associated to the other chemical sediment variables. The Spearman correlation coefficient indicated a negative correlation between the cover of the dominant species and species richness, as well as the rate of photosynthetic active radiation that reaches to the substrate. We have concluded that variation in the composition and distribution of macrophytes reflected the spatial and temporal heterogeneity of Banhado 25.

A subsurface flow constructed wetland was built at the Wastewater Treatment Plant in Muncie, Indiana, in May, 1995. In May, 1996, this wetland was divided into two equal cells and planted with Scirpus validus vahl (softstem bulrush). Samples were collected from July 30, 1996, through October 22, 1996. This study had two objectives. The first was to determine if harvesting the aboveground biomass of the Scirpus would affect the wetland's ability to remove nitrogen from the wastewater. The second objective of this study was to determine if harvesting the bulrush twice during a growing season would substantially increase the annual biomass production. Water was collected from four locations in each cell and analyzed for organic nitrogen, ammonical nitrogen, nitrate, and total nitrogen. The concentration of each nitrogen parameter was significantly reduced between the inlet and well 1 in each cell of the wetland. There were no significant reductions in nitrogen concentration in subsequent sampling locations. There were also no significant differences between the two wetland cells. / Department of Natural Resources and Environmental Management

No description available.

No description available.

Au cours des dernières décennies, une grande variété de pesticides émergents, tels que le chlorantraniliprole (CAP), ont été introduits malgré le manque de connaissance approfondie de leur risque écotoxicologique. Les marais filtrants (TW) sont des technologies écologiques et durables qui ont montré un grand potentiel d’atténuation des polluants agricoles communs, tels que les pesticides dans le ruissellement. L’objectif de cette étude était d’optimiser l’utilisation du marais filtrant sous-surfacique à écoulement horizontal (HSSF) en déterminant: a) l'effet d’un amendement de biochar au substrat et b) la performance de trois espèces de macrophytes (Phragmites australis subsp. americanus, Scirpus cyperinus et Sporobolus michauxianus) dans l'abattement du CAP du ruissellement agricole. L'efficacité d'abattement a été calculée en utilisant la méthode du bilan de masse dans des mésocosmes HSSF matures alimentés avec un ruissellement agricole synthétique contenant du CAP pendant une période d'un mois. Les mésocosmes avec l’ajout de biochar se sont avérés très efficaces dans l’abattement du CAP (90 à 99%) et ils le sont restés tout au long de la période expérimentale. Cette efficacité est probablement due à la grande capacité d’adsorption du biochar, bien que ce mécanisme n’ait pas été directement mesuré. En revanche, l'abattement du CAP dans les mésocosmes plantés sans biochar était faible et limité et il n’y avait pas de différence entre les espèces, bien qu’elles aient eu des différences dans leur biomasse aérienne et leur taux d'évapotranspiration (ET). Cependant, les traitements plantés ont agi comme zone tampon, en atténuant la masse du CAP de l'influent et en la libérant lentement dans l'effluent. Le taux d'ET de Scirpus et Phragmites était plus élevé que celui de Sporobolus, ce qui s’est traduit par un meilleur effet tampon. Cette étude suggère que l'ajout de biochar au substrat HSSF TW est prometteur pour l'atténuation du CAP dans le ruissellement agricole, mais leur efficacité à long terme reste à être étudiée. Malgré tout, les TW devraient être utilisés comme un outil complémentaire, dans le cadre d'actions plus larges visant à réduire la pression des polluants sur les écosystèmes aquatiques. / Over the past decades, a wide variety of emergent pesticides, such as chlorantraniliprole (CAP), have been introduced despite the lack of in-depth knowledge of their ecotoxicological risk. Treatment wetlands (TWs) are environmentally friendly and sustainable technologies that have shown great potential to mitigate common agricultural pollutants, such as pesticides in runoff. The objective of this study was to optimize the use of the horizontal subsurface flow treatment wetlands (HSSF TWs) by determining a) the effect of biochar amendment to the substrate and b) the performance of three species of macrophytes (Phragmites australis subsp. americanus, Scirpus cyperinus and Sporobolus michauxianus) in CAP removal from agricultural runoff. The removal efficiency was calculated using the mass balance method in mature HSSF mesocosms fed with synthetic agricultural runoff containing CAP for a period of one month. Mesocosms with the addition of biochar were very effective in removing CAP (90-99%) and remained so throughout the experimental period. This efficiency is likely due to the high adsorption capacity of biochar, although this mechanism has not been directly measured. In contrast, CAP removal in mesocosms planted without biochar was low and limited and there was no difference between species, although there were differences in their above-ground biomass and their evapotranspiration (ET) rate. However, the planted mesocosms acted as buffer zones, reducing the CAP mass of the influent and slowly releasing it into the discharge. The ET rate of S. cyperinus and P. australis was higher than that of S. michauxianus, resulting in a better buffering effect. This study suggests that adding biochar to the HSSF TW substrate is promising for CAP attenuation in agricultural runoff, but their long-term effectiveness remains to be investigated. Nevertheless, TWs should be used as a complementary tool, as part of wider actions aimed at reducing the pressure of pollutants on aquatic ecosystems.