Typha Domingensis Research Articles

Phenolic content and growth of wetland macrophytes: Is the allocation to secondary compounds driven by nutrient availability?

This study compares soluble phenolics and lignin content in two wetland macrophytes with contrasting life strategies grown under a varying nutrient supply in the field and in a greenhouse experiment. The differences are explained in terms of the protein competition model (PCM) hypothesis relating changes in secondary metabolites to changing nutrient limitation. The two study species, Eleocharis cellulosa (EC) and Typha domingensis (TD), are both widespread in tropical and subtropical freshwater and brackish marshes of the New World, and are often found in P-limited rather than N-limited conditions. TD is a fast-growing competitor with large nutrient requirements. EC is a stress tolerator, quite well adapted to growth in nutrient-limiting environments. In both species, the concentration of phenolics was negatively correlated with increasing growth (due to increasing nutrient levels). This is in agreement with the PCM hypothesis, which predicts an increase in phenolic synthesis when protein synthesis (and consequently growth) is low due to limited resource availability. An interesting difference was found in the correlation between tissue nutrients and phenolics. TD from both the field and the greenhouse showed a negative correlation between tissue P and phenolics, while EC displayed a significant negative correlation between tissue N and phenolics. EC is adapted to low P, and increased tissue P content represents luxury consumption (uptake of P for storage) which is not reflected in increased growth and thus is not correlated with phenolics. These are the first steps in elucidating the relationship among nutrient availability, growth and phenolic content in two important primary producers of tropical and subtropical marshes.

The concentrations of five heavy metals in components of an economically important urban coastal wetland in Ghana: public health and phytoremediation implications.

Sakumo II is an urban wetland and a receptacle for domestic and industrial wastes from two cities in Ghana. It however supports viable populations of fish and crabs, is cultivated for food crops and grazed by farm animals. Components of the wetland can therefore accumulate pollutants, but the public health and phytoremediation implications of this are yet to be evaluated. We analysed Cd, As, Hg, Cu and Pb in the lagoon water, sediment, green algae, eight species of aquatic macrophytes, seven species of arthropods and one species of fish. The concentrations of Pb were generally below detection limit whilst Cu was detected only in the lagoon water and Pheropsophus vertialis. Cadmium ranged from 21 ± 4ppb in algae to 69 ± 12ppb in Typha domingensis and was generally higher than As and Hg. The highest concentration of As was 11.7 ± 2.1ppb in Pistia stratiotes whilst Hg was highest in lagoon water (4 ± 2ppb). The Cd concentrations generally, and Hg concentrations in macrophytes, were higher than US EPA guidelines indicating the wetland's resources were unsafe for regular consumption. Among the emergent aquatic macrophytes, T. domingensis, Ludwigia sp. and Paspalum vaginatum, respectively, had the highest accumulation capacity for Cd, As and Hg, but the floating aquatic plant P. stratiotes appeared to be a better accumulator of Cd and As.

Potential of two populations of Amblyseius swirskii (Acari: Phytoseiidae) for the control of Bemisia tabaci biotype B (Hemiptera: Aleyrodidae) in Brazil.

Predatory mites of the family Phytoseiidae are commercialized in European and North American countries for the control of whiteflies (Insecta: Aleyrodidae). Amblyseius swirskii Athias-Henriot (Acari: Phytoseiidae) is one of the predators used for that purpose. This predator is not found in Brazil and in many other countries, but its introduction could promote biological control of Bemisia tabaci (Gennadius) biotype B (silverleaf whitefly) in those countries. The aim of this study was to compare two populations of A. swirskii as predators of eggs of B. tabaci of two different ages, as well as the acceptance of those populations for other food types [eggs of Tetranychus urticae Koch; larvae and protonymphs of Aleuroglyphus ovatus (Troupeau) (Astigmatina: Acaridae) and cattail pollen (Typha domingensis Persoon)]. One of the populations of A. swirskii was collected in the Republic of Benin, in tropical Africa, and the other was commercially available in The Netherlands. The comparison was done to evaluate the population with better potential for practical use, and to determine food types that could be used for mass rearing the predator. Experiments were conducted at 28 ± 1 °C, 80 ± 10 % relative humidity and 12 h photophase. Both populations were able to oviposit when fed eggs of B. tabaci, but the Netherlands population showed higher oviposition rate (2.3 and 1.6 times higher on young and older eggs, respectively). Higher predation rates were observed for eggs up to 24 h of age in comparison with older eggs. Aleuroglyphus ovatus proved to be a promising prey for possible mass rearing of this predator in Brazil, where that astigmatic mite is found naturally when pollen was used as food, no significant difference was observed for oviposition rate between populations. The results suggested a higher potential of the Netherlands population of A. swirskii for the control of B. tabaci biotype B in this country for augmentative biological control, with the possible use of A. ovatus as food for the mass production and pollen of T. domingensis as a food supplement for this predator in practical field releases.

Differential expression of the chemosensory transcriptome in two populations of the stemborer Sesamia nonagrioides

Among the proposed mechanisms of local adaptation to different ecological environments, transcriptional changes may play an important role. In this study, we investigated whether such variability occurred within the chemosensory organs of a herbivorous insect, for which chemosensation guides most of its host preferences. A European and an African population of the noctuid Sesamia nonagrioides that display significant differences in their ecological preferences were collected on Zea mays and Typha domingensis, respectively. RNAseq were used between the two populations for digital expression profiling of chemosensory organs from larval antennae and palps. Preliminary data on adult female antennae and ovipositors were also collected. We found 6,550 differentially expressed transcripts in larval antennae and palps. Gene ontology enrichment analyses suggested that transcriptional activity was overrepresented in the French population and that virus and defense activities were overrepresented in the Kenyan population. In addition, we found differential expression of a variety of cytochrome P450s, which may be linked to the different host-plant diets. Looking at olfactory genes, we observed differential expression of numerous candidate odorant-binding proteins, chemosensory proteins, and one olfactory receptor, suggesting that differences in olfactory sensitivity participate in insect adaptation.

Fungal contributions to carbon flow and nutrient cycling during decomposition of standing Typha domingensis leaves in a subtropical freshwater marsh

Summary Despite the well‐known occurrence of ‘standing‐dead’ emergent plant litter in freshwater marshes, the role of fungi in its decomposition is poorly known. Here, we quantified the growth and biomass dynamics of fungi associated with standing‐dead Typha domingensis leaves, estimated the contribution of fungi to carbon flow during decomposition and assessed their contribution to nutrient (nitrogen and phosphorus) cycling. In a subtropical freshwater marsh, standing leaves of T. domingensis were sampled in August while living (green) and then monthly during leaf senescence and standing‐dead decomposition for 1 year. Leaf samples were analysed for mass loss, fungal biomass (ergosterol), rates of fungal production (14C‐acetate incorporation) and microbial respiration (CO2 evolution), and for litter chitin (glucosamine), carbon, N and P concentrations. Losses in T. domingensis leaf carbon (37%) occurred during senescence and standing decomposition. During this time, increases in ergosterol and chitin concentrations were observed in the standing litter, indicating the rapid colonisation of decaying Typha leaves by fungi. Estimated fungal biomass (from ergosterol) reached a maximum of 37 mg C g−1 detrital C. Over the entire study period, estimated cumulative fungal production in standing Typha litter was 39 mg C g−1 initial detrital C, indicating that 11% of leaf C was converted to fungal C. The corresponding estimate of cumulative microbial respiration was 136 mg C g−1 initial detrital C, indicating that 37% of Typha leaf litter C was mineralised by microorganisms (bacteria and fungi) during decomposition. Fungi also immobilised up to c.27% and c.55% of the total detrital N and P, respectively. Fungi play an important role in the cycling of C and nutrients in freshwater marshes, and this should be integrated into current models that describe major biogeochemical pathways.

Monthly Water Balance of an Iconic Coastal Desert Wetland Under Reduced Flows and Increased Salinities; Implications for Management

The Cienega de Santa Clara is a brackish coastal wetland located in the Colorado River Delta Biosphere Reserve. It plays vital ecological roles that support endangered-migratory species and flora. Its main water supply comes from irrigation return flows from the United States with salinity levels (2–3 g L−1) that promote the growth of Typha domingensis. This study conducted a water-mass balance during one year of reduced water volumes and high salinity levels caused by a trial run of the Yuma Desalting Plant. The analysis projected the effects that could be expected from the plant with permanent operation conditions. During the test run, inflows varied from 0.62 to 5 m3s−1, supplying the wetland with 127.20 hm3 of water at 2–5 g L−1. Forty-five percent of this volume exited as runoff, while 52 % exited by evapotranspiration. Water depth varied from 0.10–2.1 m at different time responses; also, during the summer water salinity levels increased above the tolerance limit for the vegetation, reducing its area by 20 %. Vegetation area returned when normal flows were resumed in the fall. The results indicate that permanent operation of the plant would reduce the vegetated area in the wetland due to reduced flows and increased salinities.

Influence of Typha domingensis in the removal of high P concentrations from water

A greenhouse experiment was conducted to evaluate the removal of high P concentration from water by vegetated and unvegetated wetlands. Reactors containing 4kg of sediment and two plants of Typha domingensis (vegetated treatments) and reactors containing only sediment (unvegetated treatments) were arranged. Reactors were dosed with 100 and 500mgL−1 of P-PO4. The studied concentrations tried to simulate an accidental dump. Controls without P addition were also disposed. Water samples were collected periodically and analyzed for phosphorus. Sediment (0–3 (surface), 3–7 (medium) and 7–10cm (deep)) and plant samples (roots, rhizomes, submerged leaves and aerial leaves) were collected at the beginning and at end of the experiment and were analyzed for total phosphorus. P fractionation was performed in the surface sediment layer. Relative growth rate (RGR) was calculated in each treatment considering initial and final plant height. P was efficiently removed from water in both, vegetated and unvegetated treatments. However, the major P removal was achieved in vegetated treatments. T. domingensis has a high capacity to tolerate and accumulate high P concentrations, especially in leaves, causing P accumulation in sediment to be significantly low in vegetated treatments. P accumulation was produced in the surface sediment layer (0–3cm) in all treatments, mainly retained as iron-bound P. Present results point the large removal capacity of phosphate of systems planted with T. domingensis. Therefore T. domingensis is suitable for phytoremediation practice, being capable to tolerate high P concentration.

Aridland constructed treatment wetlands I: Macrophyte productivity, community composition, and nitrogen uptake

Urbanized areas increasingly rely on constructed treatment wetlands (CTW) for cost effective and environmentally-based wastewater treatment. Constructed treatment wetlands are particularly attractive treatment options in arid urban environments where water reuse is important for dealing with scarce water resources. Emergent macrophytes play an important role in nutrient removal, particularly nitrogen (N) removal, in CTW. However, the role of plant community composition in nutrient removal is less clear. Numerous studies have shown that macrophyte species differentially affect N uptake processes (e.g., direct plant uptake, coupled nitrification–denitrification, soil accretion). However, many of these studies have been based on small-scale experiments and have been carried out in mesic environments, which means that their findings are difficult to extrapolate to aridland CTW systems. Our study sought to examine the relationships among emergent macrophyte productivity, plant community composition, and N uptake [by both the plants and the entire ecosystem] at a 42ha CTW in arid Phoenix, Arizona, USA. We quantified above- and belowground biomass bimonthly and foliar N content annually for four species groups (Typha latifolia+Typha domingensis, Schoenoplectus californicus+Schoenoplectus tabernaemontani, Schoenoplectus acutus, and Schoenoplectus americanus) from July 2011 to September 2013. We quantified dissolved inorganic N fluxes into and out of the system and compared plant N removal to total system fluxes. Additionally, we estimated monotypic N content for each to compare the system’s current community composition and plant N removal to hypothetical scenarios in which the system was dominated by only one species.Peak aboveground biomass ranged from 1586±179 (SE) to 2666±164 (SE) gdwm−2 of which Typha spp. accounted for an increasing portion (>66%). We observed widespread ‘thatching’ – the toppling of large stands of macrophytes – that was likely related to a decline in peak biomass from July 2011 to July 2012. The foliar N content was similar among the species groups and N content for all species combined, at peak biomass, was 31±8Ngm−2. This measured foliar N content was higher than our estimates of the foliar N content in hypothetical monotypic stands, suggesting that the system’s actual community composition performed better, in terms of direct plant N uptake, than if the system had been planted with only one species group. Overall, direct plant N uptake accounted for 7% of inorganic N inputs and 19% of whole-system inorganic N removal. Our findings suggest that managers and designers should consider diverse plant communities rather than monotypic stands when designing, constructing, and managing CWT wetland systems. Future research is needed to elucidate those management strategies that might best promote or preserve diverse plant communities in these systems in a cost effective manner.

Evaluation of Antioxidant, Analgesic and Cytotoxic Activities of Typha angustata L. Root

Ethanolic extract of the root of Typha angustata was evaluated for antioxidant, analgesic and cytotoxic activities. T. angustata extract exhibited DPPH free radical scavenging activity with IC50 value of 124.96 ± 0.93 ?g/ml. The total phenolic and tannin content were found to be 596.73 ± 1 mg GAE/100 g and 319.68 ± 64 mg GAE/100 g of dried plant material, respectively. Analgesic activity was determined using acetic acid induced writhing inhibition in mice model. The root extract, at doses of 250 mg/kg and 500 mg/kg body weight, showed inhibition of writhing reflex by 33.55% (p < 0.01) and 56.78% (p<0.001), respectively. Cytotoxicity of the extract was measured by brine shrimp lethality bioassay where the LC50 against brine shrimp nauplii was found to be 41.54?g/ml.Dhaka Univ. J. Pharm. Sci. 14(1): 55-59, 2015 (June)

Stable isotope compositions of aquatic flora as indicators of wetland eutrophication

Abstract Carbon and nitrogen stable isotopes (δ13C and δ15N) have been used as indicators for environmental changes in aquatic ecosystems. In this study, δ13C and δ15N values of select flora taxa were evaluated as indicators of human-induced eutrophication in an Everglades wetland which has been impaired by the source and quality of inflow and the alteration of hydrological pattern. Results showed that δ13C of cattail (Typha domingensis Pers.) increased with the decrease in total phosphorus (TP) concentration. Limited data for sawgrass (Cladium jamaicenses Crantz) collected at three study sites along the nutrient gradient also show a similar change in δ13C. However, δ13C of periphyton and bladderwort (Utricularia sp.) decreased with the decrease in TP concentration. The elevated δ13C values of emergent vascular plants (cattail and sawgrass) were likely the results of decreases in stomatal conductance, carboxylation and 13C fractionation under nutrient stress. This is supported by corresponding decreases in photosynthetic rate of cattail along the decreasing nutrient gradient. In contrast, δ15N values of all flora taxa increased with the increase in TP concentration. Findings from this study indicate that δ13C of emergent plants is a sensitive indicator for nutrient stress while δ15N of major flora species may serve as a robust indicator for wetland eutrophication.

Gas chromatography mass spectrometry based profiling of alkyl coumarates and ferulates in two species of cattail (Typha domingensis P., and Typha latifolia L.)

Several long-chain n-alkyl coumarates and ferulates were identified in cattails (Typha domingensis and Typha latifolia) from the Florida Everglades. Characterization of these compounds was achieved based on the interpretation of mass spectra obtained by GCMS as their trimethylsilyl ether derivatives, comparison with published mass spectra and available standards. Both n-alkyl p-coumarates and n-alkyl ferulates were identified in roots and leaves of both Typha species, featuring unique distribution patterns and differences between leaf and root biomass. For both Typha species, roots have higher concentrations and a much greater diversity of n-alkyl p-coumarates and ferulates but with different side chain carbon numbers ranging from C14 to C28. Typha domingensis leaves only contained n-alkyl ferulates with traces of n-alkyl p-coumarates, while both types of compounds were present in Typha latifolia leaf material. These chemicals were not found in the other dominant wetland vegetation, which suggests their potential for application as phytochemical tracers of fresh cattail-derived organic matter in the Everglades ecosystem.

English

Wastewater from leather processing industries is very complex and leads to water pollution if discharged untreated, especially due to its high organic loading and chromium content. In this study, the phytoremediation efficiency of selected wetland plant species in subsurface flow (SSF) constructed wetlands receiving tannery wastewater was investigated. Four pilot units were vegetated with Cyprus alternifolius, Typha domingensis, Parawaldeckia karaka and Borassus aethiopum and a fifth unit was left as unvegetated (control). The treatment performance of the systems for total Cr, chemical oxygen demand (COD), biochemical oxygen demand (BOD) and nitrogen under a 5 day hydraulic retention time were analyzed based on HACH manual. The Cr in the plant tissue was analyzed through oven dried milled, weighed, digested and analyzed using atomic absorption spectrophotometer (AAS.) The wastewater analysis showed that Cr in the effluent was reduced up to 99.3% for an inlet average Cr loading rate of 40 mg/L, COD was reduced up to 80% for an inlet organic loading varying between 2202 and 8100 mg/L and BOD5 was reduced up to 77% for an inlet organic loading varying between 650 and 1950 mg/L. NO3 and NH3-N removal achieved 57 and 82%, respectively. Roots accumulate significantly higher Cr in all plant species when compared with shoots. B. aethiopium and P. karaka shows higher Cr translocation factor than the others. Constructed wetlands are cost effective and environmentally friendly treatment methods in tropical climate hence can be used as an alternative treatment method in developing countries.   Key words: Species in subsurface flow (SSF) constructed wetland, tannery wastewater, chromium uptake, chromium translocation, bioaccumulation factor.

Use of an abandoned gravel-pit in inland Spain as a stopover site for the Aquatic Warbler Acrocephalus paludicola

Stopover sites are of vital importance for migrating birds, especially long-distance migrant species. This study describes a wetland in NW Spain, as a particular habitat used by the Aquatic Warbler, one of the most threatened passeriformes in Europe, during postnuptial migration. It is a recently abandoned gravel-pit with an artificial water regime, a large area of standing water and a mosaic of vegetation predominated by a rush-meadow of Juncus effusus and a cattail community of Typha domingensis, a priori very favourable conditions for the Aquatic Warbler. The Acrola index value for this locality is very high, and together with some of the results including mean stopover period, fattening rate, interannual site fidelity and calculated potential flight distances, indicates that the mosaic of plant communities offers good conditions as a refuelling site for the Aquatic Warbler. Nevertheless, in only 3 years a process of homogenization has been observed in the vegetation, where rush-meadow cover has decreased noticeably and cattail and willow cover have increased. This process caused a decrease in the Acrola index throughout 2008–2010, as well as a significant decrease in the importance of this wetland with regard to others in Spain. Significant differences were found in body condition between the two age groups: adults are heavier and obtain more body fat, which provides them with greater potential flight autonomy. Although gravel pits can act as alternative wetlands, rapid changes in plant communities succession requires more active management than in the case of natural wetlands.

Adsorption of Basic Dye, Methylene Blue by a Novel Activated Carbon Prepared from Typha Angustata (L.)

This paper presents the feasibility of removal of basic dye methylene blue from aqueous solutions by using a low cost AC-MnO2-NC. Batch adsorption experiments were carried out as a function of pH, contact time, initial concentration of the adsorbate, adsorbent dosage and temperature. Langmuir, Freundlich and Tempkin isotherms were also studied. Pseudo first order, Pseudo second order, intra-particle diffusion model and Elovich kinetic models were studied. Thermodynamic parameters such as ∆H ∆S ∆G also calculated. Adsorbent used in this study were characterized by FT-IR, XRD and SEM analysis.

Sulfide concentration effects on Typha domingensis Pers. (cattail) and Cladium jamaicense Crantz (sawgrass) growth in Everglades marshes

Displacement of large areas of native Cladium jamaicense Crantz (sawgrass) by Typha domingensis Pers. (cattail) in the Everglades has occurred during the past several decades, and is widely attributed to phosphorus (P) enrichment. In addition, sulfide toxicity to marsh vegetation, particularly Cladium, has been cited as a possible consequence of increased loading of sulfate to the Everglades (USA) from anthropogenic sources, and a potential contributor to the shift from Cladium to Typha. We initiated a plant growth study at three “low P” sites in the Everglades with differing surface water sulfate (1–48mgL−1) and porewater sulfide (0.09–8.0mgL−1) concentrations. Leaf elongation (LE) rates of Cladium and Typha were monitored, along with surface and porewater concentrations of iron, nutrients, and inorganic sulfur species. During the course of the study, we observed no reduction in Cladium or Typha LE rates at the two sulfate-impacted locations, relative to LE at a sulfate-unimpacted site. Moreover, across all study sites, we observed a positive, instead of a negative, relationship between Cladium LE rates and porewater sulfide concentrations. This suggests overriding effects of other factors such as P availability and supply on plant growth in these low-P environments, which was supported by a positive relationship between dissolved porewater P concentrations and Cladium LE rates, and by the Typha to Cladium LE ratios.

Ecology of bacterial endophytes associated with wetland plants growing in textile effluent for pollutant-degradation and plant growth-promotion potentials

In this study, 41 culturable endophytic bacteria were isolated from the roots and shoots of three wetland plants, Typha domingensis, Pistia stratiotes and Eichhornia crassipes, and identified by 16S rRNA gene sequencing. Textile effluent-degrading and plant growth-promoting activities of these endophytes were determined. The analysis of endophytic bacterial communities indicated that plant species had a pronounced effect on endophytic bacterial association and maximum endophytes (56.5%) were associated with T. domingensis. These endophytic bacteria mainly belonged to different species of the genera Bacillus (39%), Microbacterium (12%) and Halomonas (12%). Eight of the 41 strains showing maximum efficiency of textile effluent degradation also exhibited plant growth-promoting activities such as production of indole-3-acetic acid and siderophore, presence of 1-amino-cyclopropane-1-carboxylic acid deaminase, and solubilization of inorganic phosphorous. This is the first study describing the diversity and plant-beneficial characteristics of the textile effluent-degrading endophytic bacteria associated with wetland plants. T. domingensis showed better growth in textile effluent and also hosted maximum number of endophytic bacteria in roots and shoots. The interactions between T. domingensis and its associated endophytic bacteria could be exploited to enhance the efficiency of constructed wetlands during the remediation of industrial effluent.

Macrophyte root and rhizome decay: the impact of nutrient enrichment and the use of live versus dead tissue in decomposition studies

The decomposition of roots and rhizomes of two macrophytes, Eleocharis cellulosa and Typha domingensis, was studied in oligotrophic phosphorus (P) limited marshes of northern Belize. The experiment was conducted in long-term control and P enriched plots in five limestone-based inland marshes. Decomposition of naturally senescent root and rhizome litter was studied over 9 months using litterbags. Belowground litter was acquired by growing plants in unenriched (control) or P enriched marsh soils for 5 months. Plants were then allowed to naturally senesce using a split root design, which promoted nutrient retranslocation. The resulting senescent litter had 30 % higher C:P and 40 % lower P content than living roots and rhizomes. There were no differences in C:N among treatments or senescent versus live litter. Litterbags, filled with control or enriched root and rhizome litter, were buried in the upper 10–14 cm soil in the corresponding plot of each marsh. Differences in the rate of decay between species were greatest for rhizome tissue, with Typha decaying more than twice as fast as Eleocharis. For both species, however, tissue P enrichment had no effect on coarse root and rhizome decay. Enhanced root production from P enrichment, coupled with no change in decay, should lead to enhanced accretion over time. Additional tests, using litterbags filled with living roots and rhizomes, yielded dramatically different results between treatments compared to senescent tissue. Results from senescent belowground tissue also differed from shoot decomposition. Caution should be exercised when inferring belowground decomposition from live tissue and aboveground rates of decay.

Constructed Wetland for Treating Effluent from Subtropical Aquaculture Farm

A free water surface flow constructed wetland (CW) was designed to evaluate the capacity of this biological treatment system, which receives wastewater from aquaculture and upflow anaerobic sludge blanket (UASB) reactors, to retain heavy metal. The purpose of this study was to determine the role of the sediment and the macrophytes Cyperus giganteus, Typha domingensis, Eichhornia crassipes, and Pontederia cordata in accumulating Al, Cd, Cr, Cu, Fe, Ni, Mn, Pb, and Zn, during the dry (winter) and rainy (summer) seasons. In general, the concentrations and mass loading of heavy metals in the outlet water were lower than in the inlet water. The highest removal efficiency rates of water (mainly mass removal) occurred in the dry season. In the rainy season, the probable low oxygen level in the upper layer of sediment resulted in a release of reduced metals into the water because of organic matter mineralization and an increase in depth. This, coupled with an increase in the hydraulic loading rate (HLR), affected the efficiency removal in this season. The metals were especially immobilized as a result of the sedimentation process and could be removed weakly via macrophyte uptake, with the exception of Mn. In addition to the sediment, which is the main compartment for heavy metal retention in the CW system, the macrophytes have the advantage of being harvested. Therefore, E. crassipes and T. domingensis, which are good metal accumulators, can be recommended for the removal of heavy metals from agricultural wastewaters.

Typha domingensis Pers. growth responses to leaf anatomy and photosynthesis as influenced by phosphorus

Cattail (Typha domingensis Pers.) can show intense growth depending on phosphorus (P) eutrophication. We verify how P enrichment and deficiency influence T. domingensis growth and the relationship with anatomical and physiological modifications. Vegetative T. domingensis plants were grown for 60 days in a modified nutrient solution in five P levels: 0, 0.20, 0.40, 0.60 and 0.80mM. Plant growth was evaluated at the end of the experiment. Leaf fragments were collected and fixed in F.A.A.70 and sectioned in bench-top microtome. Sections were stained with safrablau solution, mounted in slides and photographed with an optical microscope. Images were evaluated in UTHSCSA-Imagetool software which was used to measure leaf tissues. Leaf gas exchanges were evaluated 30 and 60 days after the experiment started. The data were submitted to one-way ANOVA and regression analyses or means were compared using the Scott–Knott test. Plants showed more growth in a P-rich nutrient solution. T. domingensis showed different biomass partitioning under P levels, with an increasing leaf biomass allocation for higher P levels and a lower rhizome investment. For higher P levels, plants showed increased photosynthesis, stomatal conductances and transpiratory rates. However, the highest concentration promoted a decrease in these characteristics. The leaves of T. domingensis showed larger stomata, thicker palisade parenchyma and an increased phloem proportion under higher P levels. Our results suggest that the increased growth of T. domingensis in P-rich conditions may be related to increased photosynthesis; this characteristic is limited to anatomical traits such as palisade parenchyma and stomatal modifications.

Estimating the Importance of Aquatic Primary Productivity for Phosphorus Retention in Florida Everglades Mesocosms

Constructed wetlands are being utilized to mitigate the impact that excess phosphorus in surface water has on the natural state of the Florida Everglades. This study investigates the role of aquatic metabolism in the retention of phosphorus in wetlands and how it varies with plant community. Eighteen 6-m2 mesocosms receiving inflows with relatively low phosphorus concentrations were planted with one of five wetland plant communities or left to natural colonization. In 2012, the mesocosms left to naturally colonize had significantly higher aquatic gross primary production (GPP) at 7.0 g O2 m−2 d−1 than all other communities. Mesocosms planted with Nymphaea odorata and those planted with a mix of Najas guadalupensis and Chara sp. had significantly higher GPP (5.5 and 5.9 g O2 m−2 d−1, respectively) than those with Typha domingensis, Eleocharis cellulosa, and Cladium jamaicense (1.7, 2.3, and 1.5 g O2 m−2 d−1, respectively). Rates of phosphorus cycling due to aquatic metabolism were estimated to range from 2.5 g P m−2 yr−1 in both the Cladium and Eleocharis communities to 7.7 g P m−2 yr−1in the naturally colonized mesocosms. These results provide evidence that wetland plant communities without high-biomass emergent macrophytes may perform best in the retention of phosphorus in low inflow concentration conditions.