Typha Latifolia Research Articles

Interspecific competition and their impacts on the growth of macrophytes and pollutants removal within constructed wetland microcosms treating domestic wastewater

Eight free water surface constructed wetland microcosm (CWM) units are designed with single as well as mixed planting of Pistia stratiotes, Phragmites karka, and Typha latifolia with control to assess their competitive value (CV), relative growth rates (RGR), and pollutants removal efficiency. Further, the total dry biomass production and other growth parameters such as number of macrophytes, above-ground biomass, below-ground biomass, and root length were also measured to understand the dominant characteristics of the macrophytes. The CWM units with species mixture out-performed species monocultures. Removal of BOD, TP, SRP, NH4 +-N, NO3 −-N, and NO2 −-N by mixed planting of P. stratiotes and P. karka was higher at most of the time. Typha latifolia was the superior competitor against both P. stratiotes and P. karka due to its aggressive characteristics that inhibits the growth of neighboring macrophytes. However, P. karka was the superior competitor against P. stratiotes. The RGR of T. latifolia in all experimental units was almost two times more than that of P. karka. Novelty Statement The CWM units with species mixture out-performed species monocultures. CWMs with more than one macrophytic species are less vulnerable to seasonal fluctuations and more effective in contaminants removal as compared to single macrophyte wetlands. Removal of BOD, TP, SRP, NH4 +-N, NO3 −-N, and NO2 −-N by mixed planting of P. stratiotes and P. karka was higher at most of the time. The CWMs with P. stratiotes and P. karka are superior choice due to their higher wastewater nutrients removal capacity. The application of these three macrophytes in mixed cultures in free water surface constructed wetland is rare. The results are useful in designing large-scale multi-species wetlands which are less susceptible to seasonal variation and more effective in pollutants removal than single-species wetlands.

COMPETITIVENESS-BASED DEVELOPMENT STRATEGY FOR PURUN (TYPHA LATIFOLIA) CRAFTSMEN IN HAUR GADING SUB-DISTRICT, AMUNTAI, HULU SUNGAI UTARA DISTRICT DURING COVID-19 PANDEMIC PERIOD

Weaving purun (Typha latifolia) has been a hereditary culture for generations of women for approximately 500 years ago, including the people of Haur Gading District. Initially, purun (Typha latifolia) products were limited to household utensils, so that they developed into crafts and weaving activities became people's livelihoods. The research objective is to analyze the purun (Typha latifolia) product development strategy based on internal and external factors so that craftsmen can adjust to all conditions and business climate conditions, for example a decrease in economic activity as a result of activity restrictions during the Covid-19 pandemic period. This research uses qualitative research methods through Focus Group Discussion (FGD) and quantitative analysis using SWOT analysis. Based on primary data sources obtained through Focus Group Discussion (FGD) and questionnaires with 35 respondents through random sampling techniques in the assessment of SWOT analysis. Based on the results of the SWOT analysis, it is in Quadrant III, namely that the purun handicraft business has a large market opportunity. There are internal weaknesses in purun craftsmen which become an obstacle. The development strategy is WO (Weakness Opportunity), which is a strategy to improve internal weaknesses and strengthen opportunities to gain a bigger market share. This is supported by the results of the FGD stating that purun (Typha latifolia) craftsmen need (1) funding assistance in the production process (2) purun craftsmen need training to produce innovative products so that they can compete in the national market. The opportunity for purun (Typha latifolia) craftsmen is that the results of purun weaving are very attractive to the lower and upper middle levels. The results of this weaving are an effort to support the go - green movement. Weaving purun (Typha latifolia) is one of the local wisdoms so it needs to be preserved.

High sulfate concentrations maintain low methane emissions at a constructed fen over the first seven years of ecosystem development

Wetlands comprise a large expanse of the pre-disturbance landscape in the Athabasca Oil Sands Region (AOSR) and have become a focus of reclamation in recent years. An important aspect of wetland reclamation is understanding the biogeochemical functioning and carbon exchange, including methane (CH4) emissions, in the developing ecosystem. This study investigates the drivers of CH4 emissions over the first seven years of ecosystem development at a constructed fen in the AOSR and looks towards future CH4 emissions from this site. Specifically, the objectives were to: 1) investigate the environmental controls on CH4 emissions measured using manual static chambers between 2013 and 2019 and 2) investigate the relationship between water table depth, sulfate (SO42−) concentrations and CH4 emissions during the 2019 growing season. Methane emissions remained low throughout the majority of the measurement period; however, in later years, a small but significant increase became apparent. High levels of SO42− are likely the cause of the low CH4 emissions, despite the high-water tables and dominance of vegetation with aerenchyma such as Carex aquatilis and Typha latifolia in later years. Although low CH4 emissions may be beneficial from a climate warming perspective, the results also suggest that this constructed peatland is not functioning similarly to regional reference fens. Future climate scenarios across Western Boreal Canada could lead to higher air temperatures and changing precipitation patterns, influencing the direction of future CH4 emissions from this site. However, given the likelihood of this site maintaining extremely high SO42− concentrations over the next decade, it is expected that CH4 emissions will remain low.

Preparation and Characterization of Cellulose Nanocrystals from Typha sp. as a Reinforcing Agent

ABSTRACT In this study, Typha latifolia (Typha sp.) was investigated as a new raw material for the isolation of cellulose nanocrystals (CNCs) for future application in geopolymer cement. Cellulose was extracted from the stem fibers by carrying out alkali and bleaching treatments. CNCs were then isolated from the extracted cellulose using the acid hydrolysis method. The chemical composition of cellulose, hemicellulose, and lignin was 60.9%, 7.0%, and 5.7%, respectively. Transmission electron microscopy showed a reduction in particle size due to the loss of the amorphous portion of the Typha sp. fiber. Thermogravimetric analysis showed that CNCs in the acid hydrolysis treatment have good thermal stability at 240 °C which is higher than raw ones. Based on the characteristics of a Typha sp. CNCs, it can be concluded that CNCs have the potential to be used as a reinforcement in geopolymer cement.

Performance of constructed wetland for selenium, nutrient and heavy metals removal from mine effluents

Passive biological treatment using constructed wetlands has been employed as a cost-effective and environmentally friendly alternative for mine effluents treatment in Canada. The current work aimed to assess the performance of a laboratory-scale constructed wetland for the removal of selenium, nutrients and heavy metals. This work achieved a maximum selenium removal rate of 54.13% corresponding to the highest hydraulic residence time (almost 47 days). Typha Latifolia was efficient for selenium assimilation and removal from mine effluent. 4.4% of Se mass was accumulated in the under and aboveground biomass while 32.2% was volatilized. Levels <1.69 mg of selenate, <1.69 mg of selenite, <3.39 mg of selenomethionine and <3.39 mg of unknown selenium species were distributed in the underground biomass while levels <0.75 mg of selenate, <0.75 mg of selenite, <1.51 mg of selenomethionine and <1.51 mg of unknown selenium species were found in T. Latifolia leaves. Ammonia removal was mainly based on a nitrification process confirmed by the decrease of ammonia (>96%) and nitrite in association with the increase of nitrate concentrations in the outlet compared to the inlet. The concentrations of other nitrogen compounds mainly thiocyanate and cyanate have significantly decreased from initial average values of 163 and 22.7 mg.L−1 in the influent to 1.5 and 0.3 mg.L−1 final concentrations, respectively. Orthophosphate concentrations were also efficiently decreased from an influent average value of 21.5 ± 3.3 mg.L−1 to an effluent concentration of 9.1 ± 4.4 mg.L−1. Understanding the selenium and nutrient removal mechanisms will allow treatment performance enhancement and the development of large-scale constructed wetlands for sophisticated mine effluent treatment.

Efficiency of Cyperus alternifolius, Typha latifolia, and Juncus inflexus in the removal of nitrate from surface water

Abstract Nitrate is one of the most toxic and pathogenic substances in drinking water. Nitrate levels have increased significantly in groundwater and surface water because of the high usage of nitrogenous fertilizers, which have lethal effects on human health. Therefore, the removal of this toxic material from surface water is absolutely essential. The goal of this paper is to evaluate the efficiency of three aquatic plant species, called Cyperus alternifolius, Typha latifolia, and Juncus inflexus, in the removal of nitrate from surface water. This experiment has been carried out in the laboratory scale using a hydroponics method. To do this, the water samples containing nitrate were collected and evaluated before and after the treatment to see the effects of these three plants on both the nitrate removal and the pH variation of water. The results show that all the plants can remove excessive levels of nitrate from the surface water. The comparison of the results has revealed that T. latifolia plant has higher ability to remove nitrate from water than C. alternifolius and J. inflexus. It was observed that the nitrate removal efficiency of T. latifolia was 95%, J. inflexus was 85%, and C. alternifolius was 70% after 10 days. Moreover, it was observed that the pH values of the treated water have been affected by these plants. The results of this study can be employed for further improvement of surface water quality, thereby lowering water purification time and costs as well as decreasing the nitrate-related diseases significantly.

Phytoremediation: A Novel Strategy for the Removal of Heavy Metals from the Offshore of Lake Hawassa using Typha Latifolia L

ABSTRACT Aquatic macrophytes absorb a number of pollutants from where they are growing and thus, they can be used as a tool for the removal of pollutants from the aquatic ecosystem. Therefore, the aim of this study was to evaluate heavy metals (Hg, Cr, Zn, Cd, and Pb) removal efficiency of Typha latifolia L. from the offshore of Hawassa Lake, Ethiopia. Based on the potential exposure of the lake to different sources of pollutants, six sampling sites were selected, and then T. latifolia and composite plant samples were collected from each sampling site and transported to Addis Ababa Environmental Protection Agency (EPA) laboratory for analysis. The results showed that significantly (P < .05) higher heavy metal concentration was recorded in T. latifolia than in composite plant samples, particularly samples collected from S2, S4, and S5. Moreover, significantly (P < .05) higher heavy metal concentration was found in the root parts of the T, latifolia than its shoot. The concentration of heavy metals recorded in this study has slightly exceeded the level set by the WHO guideline. In addition, medium to very high correlations were recorded for some heavy metal pairs as well as with some physicochemical parameters (e.g. pairs of Zn/Pb, Cd/Pb, EC, and pH with most heavy metals).In conclusion, T. latifolia have shown promising potential for the removal of Zn, Pb and Cd, while composite macrophytes samples for Hg and Cr. The shoot part of T. latifolia has a relatively better capacity to remove Cr, while the root is for Hg, Zn, Cd and Pb. These results indicated the suitability of the plant for phytoremediation, and the usefulness of the technique as an option for improving the water quality of the lake by removing those heavy metals from the lake offshore.

Selenium speciation and bioavailability from mine discharge to the environment: a field study in Northern Quebec, Canada.

The speciation, behaviour, and bioavailability of released selenium (Se) from mine effluent discharge to sediments and plants were assessed. Discharged mine effluent containing 65±0.9 μg/L of total Se subsequently contaminated the exposed sediment with an average total Se concentration of 321 mg/kg as well as exposed Typha latifolia plants where 534 and 92 mg/kg were found in roots and leaves, respectively. The strategy of T. latifolia in Se phytoremediation consisted of a phytostabilization and accumulation of Se predominantly in roots. Se plant root uptake was promoted by synergistic effects of Cu, Pb, Zn, and Cd while Co, Fe, Mn, Ni, Na, K, and Mg had antagonistic effects. Se plant uptake was also governed by sediment characteristics mainly pH, total Se, and iron concentration. Se speciation results demonstrated that the most accumulated Se species by T. latifolia roots were selenite and selenomethionine with average concentrations of 2.68 and 2.04 mg/kg respectively while other Se species were the most translocated (average translocation factor of 1.89). Se speciation in roots was positively correlated with sediment pH, organic matter, electrical conductivity, and iron concentration. This study confirms deploying corrective measures for mine effluent treatment before discharge in a sediment-plant environment to protect living organisms from toxic effects. T. latifolia is recommended as a Se-hyperaccumulator to be used for mine soil phytoremediation in cold regions in Canada.

Carbon Dioxide and Methane Fluxes from a Tropical Freshwater Wetland Under Natural and Rice Paddy Conditions: Implications for Climate Change Mitigation

We investigated the impact of converting a natural tropical freshwater wetland in Uganda into a rice paddy wetland on climate change mitigation, by comparing carbon dioxide (CO2) and methane (CH4) fluxes from the natural section (under different vegetation communities dominated by Cyperus papyrus, Typha latifolia and Phragmites mauritianus) and from a rice paddy section, during the dry and wet seasons. CO2 fluxes (mg C m− 2 h− 1) from the rice paddy section during the dry and wet seasons were 1045.4 ± 46.6 (mean ± SE) and 804.4 ± 50.2 respectively, significantly higher (p < 0.05) than those obtained from all the three vegetation communities of the natural section. However, CH4 fluxes (mg C m− 2 h− 1) from the rice paddy section during the dry and wet seasons were 2.1 ± 0.4 and 5.1 ± 0.5 respectively, significantly lower (p < 0.05) than those observed from all the vegetation communities of the natural section. Considering total carbon emission, it was observed that whereas conversion of natural tropical freshwater wetlands into rice paddies may limit CH4 emission, it compromises climate change mitigation efforts by increasing total carbon emission, that could make rice paddy wetlands net carbon sources. Fluxes of CO2 and CH4 from the wetland were mainly influenced by water level. Further, we estimated that rice paddy wetlands currently emit only 0.72 and 0.14 % of the total annual CO2 and CH4 respectively, emitted from Uganda’s wetland soils due to their low spatial coverage. However, we predict that future emission of both gases from Uganda’s wetlands will mainly originate from rice paddy wetlands due to their rapid expansion rate.

Nutrient recovery from the digestate obtained by rumen fluid enhanced anaerobic co-digestion of sewage sludge and cattail: Precipitation by MgCl2 and ion exchange using zeolite

The aim of this study was to recover nutrients (NPK and other) from the liquid fraction of digestate obtained by rumen fluid enhanced anaerobic co-digestion of sewage sludge and cattail (Typha latifolia grass). Firstly, anaerobic digestion (AD) studies were performed to examine the biogas potential of selected substrates. The liquid fraction of digestate was then used in nutrient recovery experiments. Four methods were applied to recover nutrients: i) conventional struvite precipitation by MgCl2, ii) simultaneous precipitation and ion exchange by Na-zeolite, and iii) two-step recovery using precipitation, followed by ion exchange with powdered or iv) granulated Na-zeolite. The products of nutrient recovery were characterised using different chemical methods and the cress seed germination test was performed to evaluate their fertility potential.The results show that co-digestion of sewage sludge with cattail enhanced biogas production by almost 50 vol%. The addition of rumen fluid positively contributed to the degradation of lignocellulosic materials and to biogas production. In all of the recovery methods tested, phosphorus was successfully recovered with efficiency of more than 99 wt%. Nitrogen recovery was less efficient than phosphorus recovery, 85–92 wt%. Simultaneous precipitation and ion exchange lowered nitrogen recovery efficiency compared to classical struvite precipitation, while sequential precipitation and ion exchange resulted in improvement. The most efficient method was two-step recovery using granulated zeolite. The precipitates consisted of different Mg and K-phosphates in quite irregular shapes. The struvite and K-struvite were detected in low quantities. The precipitates contained more than 25 wt% of macronutrients (NPK), exhibited effective utilization of nutrients by plants, and showed good fertility potential. Precipitate mixed with powdered Na-zeolite promises to be interesting for further agricultural use, as zeolite offers several potential improvements for soil. Both zeolites exhibited good performance in the recovery of K+ ions.

Boron Bioaccumulation by the Dominant Macrophytes Grown in Various Discharge Water Environments.

Turkey has the largest boron (B) reserves in the world (> 70 %). Therefore, the land and water resources in Turkey contaminated with high concentration of B Pollution due to mining and industrial operations. This study investigates the accumulation of B in aquatic macrophytes soil and water in the both mining and municipal waste water discharges. For this purpose, soil, plant and water samples were collected from the streams at the areas of mining and municipal waste water discharge sites and analyzed for B using ICP-MS. Results show that the Xanthium strumarium, Eupatorium cannabinum, Lythrum salicaria, Tamarix tetrandra, Typha latifolia, and Salix sp. hyperaccumulate B. These hyperaccumulator plants have a great capacity to accumulate and transport B to plant parts from the soil and water. Therefore, these plants can be useful for decontaminating or rehabilitation of soils and waters polluted with B.

Phytoextraction of ciprofloxacin and sulfamethoxaxole by cattail and switchgrass

Cattail (Typha latifolia L.) and switchgrass (Panicum virgatum L.) can effectively remove inorganic contaminants from soils and biosolids, but their role in the attenuation of organic contaminants, such as antimicrobials, is currently poorly understood. Uptake by plants is one of several mechanisms by which plant-assisted attenuation of antimicrobials can be achieved. The objectives of this growth room study were to evaluate the plant uptake of ciprofloxacin (CIP) and sulfamethoxazole (SMX) and examine their partitioning between plant roots and aboveground biomass (AGB). Plant uptake of the two 14C labeled antimicrobials was studied at two environmentally relevant concentrations (5 and 10 μg L−1). Plants were destructively sampled every 3–4 d during the 21-d growth period. Accumulation of CIP and SMX in both plant species was greater in the roots than in the AGB. The percentage uptake values of the two antimicrobials were significantly greater for cattail (34% for CIP, 20% for SMX) than for switchgrass (10% for both CIP and SMX). Translocation factors of the two antimicrobials were <1 for both plants, indicating slow movement of the antimicrobials from the roots to the shoots. For cattail roots, the BCF for CIP (1.58 L g−1) was significantly greater than that for SMX (0.8 L g−1). By comparison, BCFs for switchgrass roots did not differ significantly between CIP (0.88 L g−1) and SMX (1.13 L g−1). These results indicate greater potential for cattail to phytoextract CIP and SMX and significantly contribute to the attenuation of these antimicrobials in systems designed for the phytoremediation of contaminated wastewater.

The purification of wastewater on a small scale by using plants and sand filter

The canteen and laboratory of every academic organization need a lot of clean water, and it generates equivalent amount of wastewater every hour which is neither purified nor reused. Due to water scarcity, the recycling and reusing of wastewater become very essential. The present study describes the simple and cost-effective method for the design of a small-scale wastewater treatment plant for the purification of wastewater generated by household, canteen and laboratory of an academic institute. The current study explored the process of phytoremediation by Typha latifolia L. and Canna indica L. for removal of metal ions and phosphate ions from the wastewater. The partially treated water after phytoremediation was further purified by sand filtration. The various water quality parameters (pH, hardness, dissolved oxygen, chemical oxygen demand, turbidity, total dissolved solids and metal ions) of the treated and untreated water were analyzed. It was observed that there are significant reduction in hardness, turbidity and chemical oxygen demand and increase in dissolved oxygen value. The treated water can be reused for various household works and agriculture.

Phytoremediation potential of Typha latifolia and water hyacinth for removal of heavy metals from industrial wastewater

Phytoremediation potential of Typha latifolia and water hyacinth for removal of heavy metals from industrial wastewater

Environmental conditions and the performance of free water surface flow constructed wetland: a multivariate statistical approach

During the past three decades, constructed wetlands have become an integral part of the suite of technologies for removing domestic and industrial wastewater contaminants. The use of constructed wetlands has disproportionately focused on domestic and agricultural wastewaters and storm water runoff and less on oil and gas-related produced water. In this context, the cumulative effect of environmental factors on the treatment/removal efficiency of contaminants in produced water is underserved by research. Therefore, this study assessed the effect of environmental factors (temperature, dissolved oxygen, oxidation–reduction potential, and pH) on contaminant removal efficiency in free water surface flow constructed wetland (FWSFCW) using ordinary least squares regression and experimental data from a waste treatment facility in Ghana. The results showed that environmental factors did not systematically vary across the experimental group and control set-up. Generally, the environmental factors explained relatively far less of the variance in contaminant removal efficiency compared with the plant species (Typha latifolia, Ruellia simplex and Alternanthera philoxeroides). Environmental factors cumulatively explained only 1.3%, 16.4%, 22.6%, and 5.6% of the variance in removal efficiency of BOD, COD, oil and grease, and total coliform bacteria, respectively. Temperature was the most important environmental predictor of the removal of BOD and phosphorus whereas DO was most important for removing nitrates and total coliform bacteria. ORP and pH were the most important predictors of COD, and oil and grease, respectively. These findings underscore the complex relationships among environmental factors and contaminant removal efficiency and the need for contaminant management practices and remedial techniques that address these complexities.

Performance of horizontal flow constructed wetland for secondary treatment of domestic wastewater in a remote tribal area of Central India

The purification of the primary treated domestic sewage was performed in the present study through the horizontal sub-surface flow constructed wetland (CW) of 10 × 3.5 m dimension. The study was performed using three setups of CW 1 (Unplanted CW), CW 2 (CW planted with macrophyte Typha latifolia), and CW 3 (CW planted with two species of macrophyte T. latifolia and Commelina benghalensis). The purification experiments were performed by converting one type of CW into the other form sequentially, i.e., CW 1 was built first and after the experiments, it was converted into CW 2 and then CW 3. The CW was filled with a layer of coarse and fine gravel of 70 cm depth as filter media in 1:2 ratio. Each set of wetland was operated for 3 months (12 wk) during which the treatment performance of wetlands for basic physicochemical parameters was evaluated. The CW was operated in continuous mode at an average hydraulic loading rate of 250 L h− 1 and the treated effluent was analysed twice every week at four different sampling points having hydraulic retention times (HRT) of 12, 24, 36 and 48 h for important sewage quality parameters All the three setups of CW were able to clean the primary treated sewage significantly. Among the three sets of wetlands used, CW 3 was the best performer removing 79, 77, 79, 79, and 78% of biochemical oxygen demand, chemical oxygen demand, nitrate, ammonia, and phosphate respectively in 48 h HRT. Among the three sets of wetlands, the CW 3 removed the highest percent of total coliforms, fecal coliforms, and E. coli as 64, 61 and 52% respectively.

Degradation by hydrothermal liquefaction of fluoroalkylether compounds accumulated in cattails (Typha latifolia)

Per- and polyfluorinated substances with an ether bond (ether-PFAS), such as undecafluoro-2-methyl-3-oxahexanoic acid (GenX), dodecafluoro-3 H-4,8-dioxanonanoate (ADONA) and 9-chlorohexadecafluoro-3-oxanonane-1-sulfonate (F-53B), have been widely used to replace conventional PFAS, especially perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS). The wide use of ether-PFAS will lead to inevitable release of these chemicals to the environment and cause environmental and human health risks. In this study, we first investigated plant uptake of GenX, ADONA and F-53B by cattails (Typha latifolia), then tested destruction of these chemicals by hydrothermal liquefaction (HTL). The results showed that GenX, ADONA, and F-53B could be taken up and accumulated in cattail tissues. HTL could completely degrade GenX and ADONA in aqueous solutions and in wet cattail biomass at both 250 °C and 300 °C. F-53B, however, was resistant to the thermal treatment. Increasing HTL temperature improved degradation of this chemical by HTL. F-53B in plant biomass had higher removal efficiency, which indicated positive catalytic effect from cattail biomass. With the addition of Ca(OH)2, 100% degradation of F-53B in plant tissues was observed.

Effectiveness of typha latifolia for phytoremediation of cadmium in acid mine drainage

One evidence of environmental pollution is the formation of acid mine drainage. In passive processing systems, the technique that is often used is phytoremediation because the costs incurred for this method are affordable and take advantage of natural ecosystems. In this study, the effectiveness of Typha latifoliain neutralizing acidity and removing heavy metal such as cadmium (Cd) is determined. Cadmium is one of the heavy metals that can be found in nickel, gold, and copper mining area. The acid mine drainage used in this study was artificially made with a concentration of 5and 10 mg/L with a pH of 4.pH testing was carried out using a pH meter and the accumulation concentration of Cd was analyzed using Atomic Absorption Spectrophotometer (AAS). The results revealed that Typha latifolia planted on soil without fertilizer could increase the pH of acid mine drainage containing heavy metal Cd from 4 to ± 7 within 28 days.Typha latifolia can reduce the concentration of Cd in artificial acid mine drainage with the removal efficiency of 95 - 96%. The value of the Bioconcentration Factorin Typha latifolia exposed to acid mine drainage with concentrations of Cd 5 and 10 mg/L are > 1000, which means that this plant has the potential to be a heavy metal hyperaccumulator in phytoremediation.

Carbon Dioxide and Methane Fluxes from Various Vegetation Communities of a Natural Tropical Freshwater Wetland in Different Seasons

Emission of carbon dioxide (CO2) and methane (CH4) is of interest in tropical wetland studies because the high and relatively stable temperatures year-round enhance both primary productivity and organic matter decomposition. Nonetheless, there is scarcity of data on emission of these carbon-based greenhouse gases from tropical wetlands. We investigated CO2 and CH4 fluxes from a natural tropical freshwater wetland in Uganda under different dominant vegetation communities, i.e., Cyperus papyrus (Papyrus), Typha latifolia (Typha) and Phragmites mauritianus (Phragmites), during the dry and wet seasons. Gas samples were collected using static chambers and analyzed by gas chromatography. Fluxes (mg C m−2 h−1) of both CO2 and CH4 from Papyrus (732.9 ± 48.7 [mean ± standard error] and 14.1 ± 0.8, respectively) and from Typha (759.7 ± 51.4 and 13.5 ± 1.2, respectively) insignificantly varied (p > 0.05) during the dry season. However, CO2 and CH4 fluxes from both vegetation communities during this season were significantly lower and higher (p 0.05) occurred among the three vegetation communities for both CO2 and CH4 fluxes (Phragmites: 691.9 ± 55.8 and 15.6 ± 1.1, Typha: 682.0 ± 53.3 and 16.3 ± 1.2, and Papyrus: 651.2 ± 49.0 and 17.1 ± 1.7, respectively). Water level was the main driver of CO2 and CH4 fluxes from the wetland, suggesting its importance in any efforts to regulate fluxes of both gases in tropical wetlands. We estimated total annual CO2 and CH4 emissions from Uganda’s wetland soils in the ranges of 159.5 × 106–180.2 × 106 t C (tonnes of carbon) and 278.9 × 104–359.7 × 104 t C, respectively. • Vegetation community does not influence CO2 and CH4 fluxes from a tropical freshwater wetland soil under continuous flooding • High water level in a tropical freshwater wetland lowers CO2 flux but increases CH4 flux • A wetland’s role in climate change mitigation is a function of carbon sequestration and emission

Genetic Diversity and Connectivity in Plant Species Differing in Clonality and Dispersal Mechanisms in Wetland Island Habitats.

In plants, long-distance dispersal is both attenuated and directed by specific movement vectors, including animals, wind, and/or water. Hence, movement vectors partly shape metapopulation genetic patterns that are, however, also influenced by other life-history traits such as clonal growth. We studied the relationship between area, isolation, plant-species richness, reproduction, and dispersal mechanisms with genetic diversity and divergence in 4 widespread wetland plant-species in a total of 20 island-like kettle-hole habitats surrounded by an intensive agricultural landscape. Our results showed that genetic parameters reflect the reproduction strategies with the highest genetic diversity being observed in the non-clonal, outcrossing Oenanthe aquatica compared to the clonal Lycopus europaeus, Typha latifolia, and Phragmites australis. Lycopus showed a positive relationship between genetic diversity and kettle-hole area, but a negative relationship with the number of neighboring kettle holes (less isolation). Genetic diversity increased with plant-species richness in the clonal species Phragmites and Lycopus; while it decreased in the non-clonal Oenanthe. Finally, genetic divergence and, therefore, connectivity differed between alternative dispersal strategies, where wind-dispersed Typha and Phragmites had a higher gene flow between the analyzed kettle holes compared with the insect-pollinated, hydrochorous Lycopus and Oenanthe. Our study provides information on genetic patterns related to reproduction and dispersal mechanisms of 4 common wetland species contributing to the understanding of the functioning of plant metacommunities occurring in kettle holes embedded in agricultural landscapes.