Phalaris Arundinacea Research Articles

Effects of soil fertility on early development of wetland vegetation from soil seed bank: Focusing on biomass production and plant species diversity

To examine the effects of soil fertility on biomass production, plant species diversity, and early vegetation development, we performed a mesocosm experiment using soil seed bank under three soil fertility levels (ombrotrophic, mesotrophic, and eutrophic). Biomass production linearly increased (P < 0.01), whereas plant species diversity significantly decreased (P < 0.001) as soil fertility increased. Soil fertility seemed to play a role as an environmental sieve in early vegetation development, in turn, lead the patterns of biomass production and plant species diversity. Several Poaceae species which are forming tall and dense canopy, such as Phalaris arundinacea, Miscanthus sacchariflorus, and Zizania latifolia, showed higher importance values under fertilized condition, whereas relatively small macrophytes of Eleocharis acicularis, Carex dickinsii, and Isachne globosa mainly survived under ombrotrophic condition. Although plant species richness decreased as soil fertility increased, the percentages of perennials and exotics increased rather than annuals and natives. Predominance of perennials and exotics under eutrophic condition in early vegetation development seemed to lead a continuous decrease in plant species diversity as a result of competitive effect. A significant negative relationship between plant species diversity and biomass production (P < 0.0001) was obtained when all experimental plots are included in correlation analysis.

Factors affecting soil seed banks of riparian communities in an agricultural ecosystem: potential for conservation of native plant diversity

AbstractQuestionsDo agricultural land use and nitrogen (N) enrichment have negative effects on riparian soil seed banks? What is the potential of the soil seed bank for the conservation and restoration of native riparian plant diversity? Are non‐native dominant grass species affected by agriculture and do they affect species richness?LocationSouth Nation River watershed (an agricultural watershed), Ontario, Canada.MethodsWe examined the riparian above‐ground vegetation at 24 sites located across a large (~4000 km2) North American watershed and identified the corresponding soil seed bank composition from soil cores using the seedling emergence method. The above‐ground vegetation and soil seed bank species compositions were compared in terms of species richness, percentage of non‐native species and a floristic quality index. Factors affecting these descriptors of plants communities (concentration of in‐stream nitrate and percentages of surrounding natural habitat and annual crop land) were assessed. The effects of agriculture on two dominant non‐native grasses species and their effects on species richness were also assessed.ResultsIn total, 274 plant taxa were identified, including 181 taxa in the soil seed bank and 231 taxa in the vegetation. Overall species richness was high in both the soil seed bank and above‐ground vegetation and was unaffected by measures of agricultural intensity (surrounding annual crop land and N enrichment). Above‐ground vegetation species richness was strongly negatively affected by the widespread and dominant non‐native grasses, Phalaris arundinacea and Bromus inermis, whereas soil seed bank species richness was unaffected. The community compositions of both the soil seed bank and vegetation were negatively affected by the loss of natural habitat and by N enrichment. In fact, an increase in the percentage of non‐native species and a decrease in floristic quality were observed along a gradient of agricultural intensity.ConclusionsSpecies richness of the soil seed bank demonstrated resilience to invasions by P. arundinacea and B. inermis, and the soil seed bank showed good potential for conservation of taxonomic diversity. However, the loss of natural habitat and N enrichment had negative effects on the soil seed bank community composition that may lead to an eventual decline in above‐ground species richness.

Effects of citric acid and the siderophore desferrioxamine B (DFO-B) on the mobility of germanium and rare earth elements in soil and uptake in Phalaris arundinacea

ABSTRACTEffects of citric acid and desferrioxamine B (DFO-B) on the availability of Ge and selected rare earth elements (REEs) (La, Nd, Gd, Er) to Phalaris arundinacea were investigated. A soil dissolution experiment was conducted to elucidate the effect of citric acid and DFO-B at different concentrations (1 and 10 mmol L−1 citric acid) on the release of Ge and REEs from soil. In a greenhouse, plants of P. arundinacea were cultivated on soil and on sand cultures to investigate the effects of citric acid and DFO-B on the uptake of Ge and REEs by the plants. Addition of 10 mmol L−1 citric acid significantly enhanced desorption of Ge and REEs from soil and uptake into soil-grown plants. Applying DFO-B enhanced the dissolution and the uptake of REEs, while no effect on Ge was observed. In sand cultures, the presence of citric acid and DFO-B significantly decreased the uptake of Ge and REEs, indicating a discrimination of the formed complexes during uptake. This study clearly indicates that citric acid and the microbial siderophore DFO-B may enhance phytoextraction of Ge and REEs due to the formation of soluble complexes that increase the migration of elements in the rhizosphere.

Wetland restoration by natural succession in abandoned pastures with a degraded soil seed bank

AbstractNatural restoration of historical wetland plant communities in fallow fields with a degraded seed bank has been assumed to be possible only if source populations of the target species are present adjacent to the abandoned fields and a high density of suitable microsites is available. However, few studies have monitored both factors simultaneously and verified this assumption. We hypothesized that plant communities that are similar to historical wetlands, including back marshes, back swamps, and bogs, will reestablish in abandoned pasturelands in cases when (1) gaps for new recruitment emerge, followed by the decline of pastures; and (2) seeds with longevity are supplied from the surrounding remnant plant communities of wetlands. We conducted a survey of vegetation and microsites in pastures, abandoned pastures, and reference wetlands followed by structural equation modeling to verify our hypothesis for the natural restoration of Phragmites australis–Phalaris arundinacea and Alnus japonica–Spiraea salicifolia communities. These communities represent historical back marshes and back swamps along a river. However, our hypothesis was not verified for the natural restoration of Vaccinium oxycoccos–Sphagnum spp. communities, which represent plant communities in historical bogs grown on acidic peat that are maintained by rainfall and fog. Our findings partly support our hypothesis that decline in pastures creates gaps and that cumulative seed dispersal from nearby remnant wetlands allows the original wetland plant communities to regenerate. Further case studies are needed to determine how the natural restoration of bog plant communities occurs.

The treatment of wastewater containing pharmaceuticals in microcosm constructed wetlands: the occurrence of integrons (int1\u20132) and associated resistance genes (sul1\u20133, qacE\u03941)

The aim of this study was to analyze the occurrence of sulfonamide resistance genes (sul1–3) and other genetic elements as antiseptic resistance gene (qacEΔ1) and class 1 and class 2 integrons (int1–2) in the upper layer of substrate and in the effluent of microcosm constructed wetlands (CWs) treating artificial wastewater containing diclofenac and sulfamethoxazole (SMX), which is a sulfonamide antibiotic. The bacteria in the substrate and in the effluents were equipped with the sul1–2, int1, and qacEΔ1 resistance determinants, which were introduced into the CW system during inoculation with activated sludge and with the soil attached to the rhizosphere of potted seedlings of Phalaris arundinacea ‘Picta’ roots (int1). By comparing the occurrence of the resistance determinants in the upper substrate layer and the effluent, it can be stated that they neither were lost nor emerged along the flow path. The implications of the presence of antibiotic resistance genes in the effluent may entail a risk of antibiotic resistance being spread in the receiving environment. Additionally, transformation products of SMX were determined. According to the obtained results, four (potential) SMX transformation products were identified. Two major metabolites of SMX, 2,3,5-trihydroxy-SMX and 3,5-dihydroxy-SMX, indicated that SMX may be partly oxidized during the treatment. The remaining two SMX transformation products (hydroxy-glutathionyl-SMX and glutathionyl-SMX) are conjugates with glutathione, which suggests the ability of CW bacterial community to degrade SMX and resist antimicrobial stress.

Proposal of new convenient extractant for assessing phytoavailability of heavy metals in contaminated sandy soil.

The aim of the study was to compare the usefulness of 1M HCl with aqua regia, EDTA, and CaCl2 for the extraction of phytoavailable forms of Cu, Ni, and Zn on coarse-textured soils contaminated with these metals. Two microplot experiments were used for the studies. Reed canary grass (Phalaris arundinacea), maize (Zea mays), willow (Salix viminalis), spartina (Spartina pectinata), and miscanthus (Miscanthus × giganteus) were used as test plants. They were grown on soil artificially spiked with Cu, Ni, and Zn. The experimental design included a control and three increasing doses of metals. Microplots (1m2×1m deep) were filled with sandy soil (clay-6%, pH 5.5, Corg-0.8%). Metals in the form of sulfates were dissolved in water and applied to the plot using a hand liquid sprayer. During the harvest, samples were collected from aboveground parts, roots, and the soil and then tested for their Cu, Zn, and Ni contents. The metal content of the soil was determined using four tested extractants. It was found that Cu and Ni were accumulated in roots in bigger amounts than Zn. The usefulness of the extractants was evaluated based on the correlation between the content of metals in the soil and the plant (n=32). This study demonstrated that 1M HCl, aqua regia, and EDTA were more efficient or equally useful for the assessment of the phytoavailability of Cu, Ni, and Zn as CaCl2. Due to the ease of performing determinations and their low cost, 1M HCl can be recommended to assess the excess of Cu, Ni, and Zn in the coarse-textured soils.

Photo-protective mechanisms in reed canary grass to alleviate photo-inhibition of PSII on the Qinghai-Tibet Plateau

Due to its characteristic of high biomass yield potential, there is considerable interest in cultivating Phalaris arundinacea L. cv. ‘chuancaoyin No.3' (reed canary grass) on the Qinghai-Tibet Plateau where there is an abundance of alpine steppe meadow and a potential large market for animal husbandry. In this study, we 1) investigate whether reed canary grass exhibits superior productive capacity to Elymus nutans ‘Aba' (E. nutans), ordinary common pasture, during the long warm days of summer at high-altitude; and 2) compare the cold tolerance between reed canary grass and E. nutans, including photosynthesis, photo-inhibition, and photo-protection. The results suggest that reed canary grass exhibits higher photosynthetic capacity compared to E. nutans at latitudes of the cool temperate zone. Meanwhile, cold-induced photo-inhibition and photo-damage at high altitudes in reed canary grass were due to both stomatal and non-stomatal limitation, and the enhancement in photo-respiration, thermal dissipation, and Mehler reaction are important processes to minimize the negative effects of high elevation and a cold environment.

Position of tillers in a clone determines their ontogeny: example of the clonal grass Phalaris arundinacea

For practical reasons, all ramets of a clonal plant are considered to be independent individuals in demographical studies, but there are reports that ramet ontogeny is affected by their position in a clone. This means that ramets growing from buds located in certain parts of the rhizome system differ in size and probability of flowering from ramets emerging from buds at various positions. We studied the growth characteristics and ontogeny of tillers (ramets) of a rhizomatous grass in relation to their position in a clone and examined whether it is affected by the disturbance regime. We assessed the position of tillers in a clone, the developmental stage of their apical meristem and growth characteristics in mown and unmown stands of the rhizomatous grass Phalaris arundinacea at two sites, one representing optimal (lowland) and the other suboptimal (highland) environmental conditions. We found that tiller characteristics and the probability of a tiller to start flowering are related to the tiller position in a clone. Tiller differences were preserved even in suboptimal environmental conditions but disappeared after mowing, which equalized size and ontogeny. Our results imply that ramets of clonal plants are not independent demographical units, thus their position in a clone should be taken into account.

Non-enhanced phytoextraction of cadmium, zinc, and lead by high-yielding crops.

Heavy metal soil contamination from mining and smelting has been reported in several regions around the world, and phytoextraction, using plants to accumulate risk elements in aboveground harvestable organs, is a useful method of substantially reducing this contamination. In our 3-year experiment, we tested the hypothesis that phytoextraction can be successful in local soil conditions without external fertilizer input. The phytoextraction efficiency of 15 high-yielding crop species was assessed in a field experiment performed at the Litavka River alluvium in the Příbram region of Czechia. This area is heavily polluted by Cd, Zn, and Pb from smelter installations which also polluted the river water and flood sediments. Heavy metal concentrations were analyzed in the herbaceous plants' aboveground and belowground biomass and in woody plants' leaves and branches. The highest Cd and Zn mean concentrations in the aboveground biomass were recorded in Salix x fragilis L. (10.14 and 343mgkg-1 in twigs and 16.74 and 1188mgkg-1 in leaves, respectively). The heavy metal content in woody plants was significantly higher in leaves than in twigs. In addition, Malva verticillata L. had the highest Cd, Pb, and Zn concentrations in herbaceous species (6.26, 12.44, and 207mgkg-1, respectively). The calculated heavy metal removal capacities in this study proved high phytoextraction efficiency in woody species; especially for Salix × fragilis L. In other tested plants, Sorghum bicolor L., Helianthus tuberosus L., Miscanthus sinensis Andersson, and Phalaris arundinacea L. species are also recommended for phytoextraction.

Differences in Breeding Bird Assemblages Related to Reed Canary Grass Cover and Forest Structure on the Upper Mississippi River

Abstract Floodplain forest of the Upper Mississippi River provides habitat for an abundant and diverse breeding bird community. However, reed canary grass Phalaris arundinacea invasion is a serious threat to the future condition of this forest. Reed canary grass is a well-known aggressive invader of wetland systems in the northern tier states of the conterminous United States. Aided by altered flow regimes and nutrient inputs from agriculture, reed canary grass has formed dense stands in canopy gaps and forest edges, retarding tree regeneration. We sampled vegetation and breeding birds in Upper Mississippi River floodplain forest edge and interior areas to 1) measure reed canary grass cover and 2) evaluate whether the breeding bird assemblage responded to differences in reed canary grass cover. Reed canary grass was found far into forest interiors, and its cover was similar between interior and edge sites. Bird assemblages differed between areas with more or less reed canary grass cover (&amp;gt;53% cover breakpoint). Common yellowthroat Geothlypis trichas, black-capped chickadee Parus atricapillus, and rose-breasted grosbeak Pheucticus ludovicianus were more common and American redstart Setophaga ruticilla, great crested flycatcher Myiarchus crinitus, and Baltimore oriole Icterus galbula were less common in sites with more reed canary grass cover. Bird diversity and abundance were similar between sites with different reed canary grass cover. A stronger divergence in bird assemblages was associated with ground cover &amp;lt;15%, resulting from prolonged spring flooding. These sites hosted more prothonotary warbler Protonotaria citrea, but they had reduced bird abundance and diversity compared to other sites. Our results indicate that frequently flooded sites may be important for prothonotary warblers and that bird assemblages shift in response to reed canary grass invasion.

Lignin and Etherified Ferulates Affect Digestibility and Structural Composition of Three Temperate Perennial Grasses

Breeding grasses for increased digestibility increases their value and profitability in ruminant livestock production systems. Digestibility can be improved in grasses by either increasing the concentration of soluble and readily fermentable carbohydrates or by altering the plant cell wall to create faster and more ready access to carbohydrates by rumen microbes. Two mechanisms to accomplish the latter are to decrease lignin concentration or to decrease the frequency of lignin‐ferulate covalent bonds. The purpose of this study was to quantify the relative impact of these two mechanisms on in vitro neutral detergent fiber digestibility for three forage grasses: orchardgrass (Dactylis glomerata L.), reed canarygrass (Phalaris arundinacea L.), and smooth bromegrass (Bromus inermis Leyss.). The selection scheme was designed to create divergence and independence between Klason lignin and etherified ferulates. This was successful only in reed canarygrass, due to the strong positive genetic correlation between the two traits in the other two grasses. Repeatability of Klason lignin concentration was very low, which probably contributed to our inability to create the desired spectrum of multitrait differentiation. Future studies should be refocused on the use of acid detergent lignin, which has shown a history of high repeatability and heritability. Repeatability of etherified ferulates was high for all three species, indicating that further genetic gains could be realized by selection for reduced etherified ferulate cross‐linking within the cell walls of these grasses.

Structural features of Phalaris arundinacea in the Jianghan Floodplain of the Yangtze River, China

We examined reed canary grass, Phalaris arundinacea, under shallowly flooded conditions along the Jianghan Floodplain of the Yangtze River to determine structural traits with an emphasis on histochemistry of cell walls in endodermal, exodermal, and epidermal layers and to determine if these traits are consistent with those of other wetland plants of the Floodplain. Roots have an endodermis with Casparian bands, suberin lamellae, and secondarily lignified walls. Outside schizo-lysigenous aerenchyma of the cortex, a biseriate exodermis has Casparian bands and suberin lamellae and lignified walls, and often an internal suberized layer is present. Rhizomes have a thick cuticle, lignified peripheral mechanical ring with an exodermis, large cortical cavities, an endodermis delimiting a central cylinder and sclerenchyma ring, and pith cavities. Culms with leaf sheaths have a thick cuticle and an exodermis in a narrower peripheral mechanical ring, small cortical cavities, a central cylinder with a sclerenchyma ring and pith cavities, but no endodermis. Most vascular bundles are located in the central cylinder and its sclerenchyma ring. These structural features of reed canary grass are characteristic of plants adapted to the seasonal flooding of the Floodplain below the Three Gorges Reservoir Region of the Yangtze River in China.

Plant Secondary Metabolites in Alfalfa, Birdsfoot Trefoil, Reed Canarygrass, and Tall Fescue Unaffected by Two Different Nitrogen Sources

Plant secondary metabolites (PSM) may increase the sustainability of agriculture systems by reducing inputs, as PSM protect plants against herbivores and pathogens, act as pesticides, insecticides, and anthelmintics while also attracting pollinators and seed dispersers. Therefore, it is important to understand what affects PSM fluctuation in plant tissues. Limited research has investigated how different nitrogen (N) sources affect PSM concentration in alfalfa (Medicago sativa L., Alf), birdsfoot trefoil (Lotus corniculatus L., BFT), reed canarygrass (Phalaris arundinacea L., RCG), and endophyte‐infected tall fescue (Festuca arundinacea Schreb., E+TF). We investigated how fecal manure (feces) and synthetic N fertilizer (urea, 46% H2NCONH2) influence N concentrations and the PSM ergovaline, gramine, saponins, and extractable condensed tannins (CT) in E+TF, RCG, Alf, and BFT, respectively. Ergovaline, saponins, and CT were not affected by fertilization. Gramine tended (P = 0.06) to be greater in control plots than in fertilized plots. Total N in E+TF and RCG was greater (P &lt; 0.05) and tended to be greater for Alf (P = 0.08) in synthetically fertilized plots than in unfertilized plots. Seasonal variation in PSM and N was significant (P &lt; 0.003) across all species and was species specific. Total N in E+TF was greatest in June (41.4 g kg−1), while ergovaline contents were at the lowest values recorded (117.2 μg kg−1), with subsequent increases to the greatest ergovaline values observed in July (680.0 μg kg−1). Our results reveal the variability in PSM production by plants and highlight the complexities of predicting fluctuations of PSM in forages. As environments where plants grow vary through space and time, we recommend studies on a case‐by‐case basis, depending on land management objectives.

Water use efficiency and shoot biomass production under water limitation is negatively correlated to the discrimination against 13C in the C3 grasses Dactylis glomerata, Festuca arundinacea and Phalaris arundinacea

Climate change impacts rainfall patterns which may lead to drought stress in rain-fed agricultural systems. Crops with higher drought tolerance are required on marginal land with low precipitation or on soils with low water retention used for biomass production. It is essential to obtain plant breeding tools, which can identify genotypes with improved drought tolerance and water use efficiency (WUE). In C3 plant species, the variation in discrimination against 13C (Δ13C) during photosynthesis has been shown to be a potential indicator for WUE, where discrimination against 13C and WUE were negatively correlated. The aim of this study was to determine the variation in the discrimination against 13C between species and cultivars of three perennial C3 grasses (Dactylis glomerata (cocksfoot), Festuca arundinacea (tall fescue) and Phalaris arundinacea (reed canary grass)) and test the relationships between discrimination against 13C, season-long water use WUEB, shoot and root biomass production in plants grown under well-watered and water-limited conditions. The grasses were grown in the greenhouse and exposed to two irrigation regimes, which corresponded to 25% and 60% water holding capacity, respectively. We found negative relationships between discrimination against 13C and WUEB and between discrimination against 13C and shoot biomass production, under both the well-watered and water-limited growth conditions (p < 0.001). Discrimination against 13C decreased in response to water limitation (p < 0.001). We found interspecific differences in the discrimination against 13C, WUEB, and shoot biomass production, where the cocksfoot cultivars showed lowest and the reed canary grass cultivars highest values of discrimination against 13C. Cocksfoot cultivars also showed highest WUEB, shoot biomass production and potential tolerance to water limitation. We conclude that discrimination against 13C appears to be a useful indicator, when selecting C3 grass crops for biomass production under drought conditions.

Germanium and rare earth elements in topsoil and soil-grown plants on different land use types in the mining area of Freiberg (Germany)

The total concentrations and chemical fractionation of Germanium (Ge) and selected rare earth elements (REEs) in top soils and soil-grown plants of different land use types (moist grassland, mesic grassland, arable land) were investigated in the post-mining area of Freiberg (Saxony, Germany). The study area covers approximately 1000km2 in the south of Central Saxony, and 138 samples from 46 sampling sites were examined. Ge and REEs in soils were partitioned by a sequential extraction procedure into mobile/exchangeable (Fraction 1), acid soluble (Fraction 2), bound to organic matter (Fraction 3), amorphous Fe/Mn-oxyhydroxides (Fraction 4), crystalline Fe/Mn-oxides (Fraction 5) and residual fractions (Fraction 6). Total concentrations of Ge and REEs in soil varied considerably ranging from 1.0μgg−1 to 4.3μgg−1 for Ge (mean 1.9μgg−1) and 97μgg−1 to 402μgg−1 (mean 168μgg−1) for total REE contents, accounting for 17% and 14% to the investigated light REEs La and Nd, respectively and 2.8% and 1.5% to the investigated heavy REEs Gd and Er, respectively. Elements in potentially plant available fractions represented 8% of total Ge and 30% of total REEs, respectively. Soils on moist grasslands characterized as acidic fluvisols and gleysols with high organic matter content contained significantly higher total concentrations of Ge and REEs and higher concentrations of Ge and REEs in the potentially plant available Fractions 1–3 compared to soils of mesic grassland and arable land. Grass species accumulated significantly higher concentrations of Ge than herb species. Highest concentrations of Ge were measured in plant species growing on moist grassland (Phalaris arundinacea: 449ngg−1), while there were no significant differences with regard to the concentrations of REEs in plants among the different land use types. The results of this study indicate that moist grasslands may act as sinks for Ge and REEs. In these soils high amounts of soil organic matter and low pH may foster the retention of labile forms, increasing the pool of Ge and REEs accessible for phytoextraction. However, the species-specific processes involved during the uptake of REEs need to be understood in order to optimize phytomining techniques.

Biofuel pellets made at low moisture content – Influence of water in the binding mechanism of densified biomass

In order to find the optimum moisture content for strength and density for pellets produced in a laboratory single pellet press, three different materials were prepared, birch (Betula pendula), spruce (Picea abies) and reed canary grass (Phalaris arundinacea). Pellets were produced at different process settings. Density and strength of the produced pellets were analyzed. Both pressure and temperature had a positive effect on pellet density and strength, while raw material moisture content was the dominant factor for pellet density and compression strength.For all raw materials, a maximum moisture content for pellet density and strength could be found. For birch at all compression pressures, maximum pellet density and maximum strength coincided at 6.1% moisture content. For reed canary grass, optimal pellet density occurred at 5.2% moisture content, the maximum pellet strength was at 8.5% moisture content for compression pressure of 300 MPa and 400 MPa. For spruce, maximum pellet density was found at 5.1% moisture content, and maximum pellet strength at 8.3% moisture content for compression pressure of 300 MPa and 400 MPa and at 10.7% for 200 MPa. When the process temperature was increased to 80 °C, the optimal moisture content for pellet strength shifted to a lower value. The moisture content for monolayer coverage was 6.2%, 7.7%, 7.5% for birch, RCG and spruce, respectively. Optimal moisture content coincided with monolayer coverage at room temperature when the compaction pressure was sufficient high, in the case of spruce and RCG, the pressure should be above 300 MPa.

Plant species diversity reduces N2O but not CH4 emissions from constructed wetlands under high nitrogen levels.

Constructed wetlands (CWs) have been widely used for treating wastewater. CWs also are the sources of greenhouse gas (GHG) due to high pollutant load. It has been reported that plant species diversity can enhance nitrogen (N) removal efficiency in CWs for treating wastewater. However, the influence of plant species diversity on GHG emissions from CWs in habitats with high N levels still lack research. This study established four species richness levels (1, 2, 3, 4) and 15 species compositions by using 75 simulated vertical flow CWs microcosms to investigate the effects of plant species diversity on the GHG emissions and N removal efficiency of CWs with a high N level. Results showed plant species richness reduced nitrous oxide (N2O) emission and N (NO3--N, NH4+-N, and TIN) concentrations in wastewater, but had no effect on methane (CH4) emission. Especially, among the 15 compositions of plant species, the four-species mixture emitted the lowest N2O and had under-depletion of N (DminTIN<0). The presence of Oenanthe javanica had a significantly negative effect on the N2O emission but had no effect on N removal efficiency. The presence of Rumex japonicus significantly reduced the N (NO3--N and TIN) concentrations in wastewater but had no effect on the N2O and CH4 emissions. The N concentrations and GHG emissions in the community of R. japonicus × Phalaris arundinacea were as low as those in the four-species mixture. Assembling plant communities with relatively high species richness (four-species mixture) or particular composition (R. japonicus × P. arundinacea) could enhance the N removal efficiency and reduce the GHG emissions from CWs for treating wastewater with a high N level.

The combined effects of sediment accretion (burial) and nutrient enrichment on the growth and propagation of Phalaris arundinacea

Sediment accretion (burial) and nutrient enrichment occur concurrently in lacustrine wetlands, but the role of these two aspects of sedimentation on macrophyte performance has rarely been examined. Here, we investigated the concurrent effects of sediment accretion and nutrient enrichment on the growth and propagation of Phalaris arundinacea L. using a factorial sediment burial by nutrient addition experimental design. Regardless of burial depth, nutrient addition increased biomass accumulation, shoot mass ratio, the number of rhizomes, and the length of ramets and rhizomes. While burial had little effect on plant growth and propagation, it had an interactive effect with nutrient addition on belowground growth and ramet production. These results indicate that P. arundinacea is tolerant to burial, which allows it to grow in habitats with high sedimentation rates. However, the enhanced growth and propagation of P. arundinacea following sedimentation were primarily related to nutrient enrichment. This suggests that nutrient enrichment of sediments, which occurs in many lacustrine wetlands, increases the risk of invasion by P. arundinacea.

恒湖农场茶叶港草洲枯水期湿地植物与土壤关系及种群生态位分析

PDF HTML阅读 XML下载 导出引用 引用提醒 恒湖农场茶叶港草洲枯水期湿地植物与土壤关系及种群生态位分析 DOI: 10.5846/stxb201604050614 作者: 作者单位: 江西师范大学鄱阳湖湿地与流域研究教育部重点实验室,江西师范大学鄱阳湖湿地与流域研究教育部重点实验室,江西省科学院;江西省科学院 作者简介: 通讯作者: 中图分类号: 基金项目: 国家自然科学基金项目（81260449）；江西省教育厅2012 年度科技项目（CJJ12185）；江西省青年科学基金项目（20132BAB214022） Analysis of wetland plant-soil relationships and population niches in Chayegang marshland near Henghu farm in the Poyang Lake region during the dry season Author: Affiliation: Key Laboratory of Poyang Lake Wetland and Watershed Research,Ministry of Education,Jiangxi Normal University,Nanchang City,Key Laboratory of Poyang Lake Wetland and Watershed Research,Ministry of Education,Jiangxi Normal University,Nanchang City,Jiangxi Academy of Sciences,Nanchang City Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:湿地植物与土壤关系问题一直就是生态学研究的热点，也是湿地植物种群生态位研究的基础。基于鄱阳湖典型湿地-｜恒湖农场茶叶港草洲19个样地20种植物重要值组成的样地-｜物种矩阵，用等级聚类分析中的Ward法（离差平方和法）将研究区植物划分为灰化薹草（Carex cinerascens）群落、虉草（Phalaris arundinacea）群落及南荻（Triarrhena lutarioriparia）群落3个群落类型。通过Spearman秩相关分析检验物种多样性指数（Shannon-Wiener多样性指数H'、物种丰富度指数S和Pielou均匀度指数J）与土壤因子（土壤pH值、电导率、含水量和有机质）的相关性，结果发现研究区植物物种的Shannon-Wiener多样性指数H'、物种丰富度指数S与土壤pH值分别为显著（P < 0.05）和极显著（P < 0.01）正相关关系，而与土壤有机质分别达到显著（P < 0.05）和极显著（P < 0.01）负相关水平，Pielou均匀度指数J与土壤因子相关性不明显。利用RDA（冗余分析）排序分析研究区植物物种分布与土壤pH值、电导率、含水量、有机质的关系，结果发现土壤pH值、土壤有机质与研究区植物物种分布关系最为密切（P=0.042，0.048），可以看成是关键控制因子。基于对研究区植物物种分布影响较大的土壤pH值及有机质环境因子，将其分别划分为10个梯度等级，分析植物种群生态位。发现研究区优势种灰化薹草、虉草生态位宽度较大，蚊母草（Veronica peregrina）、荇菜（Nymphoides peltata）等生态位宽度较小，生态位重叠值整体保持在较低水平，说明物种在土壤pH值和土壤有机质两个环境梯度上生态位分化明显。 Abstract:Interactive effects exist among soil, vegetation, hydrology and climate in wetland areas, affecting the charateristics of wetland ecosystems. Wetland soil is usually a product of long-term interactions between ecological environment factors and plays a vital role in preserving the regional ecological balance. The factors that influencewetland vegetation include biological and abiological variables, which soil of abiological variable has the most profound effect on wetland plant growth. Relationships between wetland plants and soil have always been a hot topic in ecology and also form the basis for plant population niches research. Based on a sample plot-species matrix of Importance Value (IV) of 20 species at 19 sampling plots in the Chayegang marshland of the Poyang Lake region near Henghu farm, we used the Ward cluster method of hierarchical clustering to divide the plants in the study area into 3 community types-Com. Carex cinerascens, Com. Phalaris arundinacea and Com. Triarrhena lutarioriparia. Spearman rank correlations results revealed that, when considering biodiversity indices (Shannon Wiener diversity index H', species richness index S and Pielou evenness index J) and soil factors (soil pH, electrical conductivity, moisture and organic matter), there were significant positive correlations (P < 0.05) between H' and soil pH, and highly significant positive correlations (P < 0.01) between S and soil pH; However, there were significant negative correlations (P < 0.05) between H' and soil organic matter and highly significant negative correlations (P < 0.01) between S and soil organic matter. However, the Pielou evenness index J had no discernible correlation with soil factors. The relationships of plant species distribution with soil pH, electrical conductivity, moisture and organic matter were assessed using redundancy analysis (RDA); Results revealed significant relationships of plant distribution with soil pH and soil organic matter (P=0.042 and 0.048), which were regarded as the key soil factors that controlled species distribution.As soil pH and organic matter were determined to be the principal environmental factors that had a considerable influence on plant species distribution, both were divided into 10 gradient levelsto analyze the plant population niches. The results showed that the dominant species, C. cinerascens and P. arundinacea, had larger niche breadths, while Veronica peregrina, Nymphodes peltatum, and other specieshad smaller niche breadths. All plant species in the study area had relatively small niche overlaps on the whole, suggesting that the population niches had obvious differentiation in soil pH and soil organic matter gradients. 参考文献 相似文献 引证文献

Anaphylaxis in a 4-year-old male caused by contact with grasses: a case report

Background Acute urticaria is the presence of urticaria for <6 weeks, and it is the most common type of urticaria in children. Sometimes, it may be associated with anaphylaxis, a life-threatening condition. Urticaria must be differentiated from anaphylaxis because the latter may require emergency treatment. We describe a child with anaphylaxis exposed to grasses on two occasions.Case presentation We described a 4-year-old male child with anaphylaxis exposed to grasses. Patient also suffered mild neurologic/respiratory symptoms but it is unlikely that he had anaphylaxis. Skin-prick tests were positive to Cynodon dactylis, Phalaris arundinacea and Festuca elatior. Little is known about the importance of pollens as a cause of urticaria in young children.Conclusions The case reported here is particularly interesting because, to the best of our knowledge, anaphylaxis due to pollen exposure in children aged <4 years has not been reported before. We strongly encourage all physicians searching for the cause of acute urticaria (allergists, dermatologists, primary-care physicians) to consider the possibility of pollen allergy, and to screen these patients for pollen sensitization.