scholarly journals Predicting the effects of reservoir impoundment on phytoplankton and shoreline vegetation communities using the space-time substitution method

2021 ◽  
Author(s):  
Guoxin Xu ◽  
Zhengkui Ge ◽  
Qi Wang ◽  
Baozhu Pan ◽  
Ming Li
Keyword(s):  
Cynodon Dactylon ◽  
Space Time ◽  
Alternanthera Philoxeroides ◽  
Total Biomass ◽  
Ecological Compensation ◽  
Substitution Method ◽  
Polygonum Hydropiper ◽  
Vegetation Communities ◽  
Reservoir Impoundment ◽  
Time Substitution

Abstract The prediction of the influence of reservoir impoundment on water quality and phytoplankton community is the basis of ecological compensation or restoration. The aim of the current study was to predict the effects of reservoir impoundment on phytoplankton and shoreline vegetation communities using the space-time substitution method. The Huangjinxia Reservoir under construction on the Han River was selected as the research object. The space-time substitution method indicated that the average values of the total phosphorus (TP) and ammonia (NH4+-N) increased from 0.049 and 0.279 mg L−1 to 0.139 and 1.132 mg L−1, respectively, after reservoir impoundment. The percentage of diatom biomass exceeded 95% before the reservoir impoundment. However, it was gradually decreased to 75% after the reservoir impoundment. Meanwhile, the biomass of Chlorophyta, Cryptophyta and Pyrrophyta increased significantly, accounting for 32, 20 and 13% of the total biomass, respectively, after reservoir impoundment. Cynodon dactylon (65.3%), Polygonum hydropiper (51.7%) and Aster subulatus (50.3%) were the dominant shoreline vegetation before the reservoir impoundment, whereas after the reservoir impoundment, the dominant species shifted to Alternanthera philoxeroides (62.3%), Lobelia chinensis (55.7%) and C. dactylon (53.9%). Our results suggested that the percentage of bloom-forming phytoplankton would gradually increase after the reservoir impoundment. In addition, A. philoxeroides, C. dactylon and L. chinensis would be the plants suitable for living in the shoreline of reservoirs in this area.

scholarly journals Estimation of plant productivity and nutrient extraction capacity along the length of horizontal subsurface flow constructed wetland treating swine wastewater

2018 ◽  
Vol 13 (3) ◽  
pp. 1 ◽  
Author(s):  
Renata Gaudereto Andries ◽  
Antonio Teixeira de Matos ◽  
Wallisson Da Silva Freitas
Keyword(s):  
Plant Species ◽  
Dry Matter ◽  
Cynodon Dactylon ◽  
Subsurface Flow ◽  
Plant Productivity ◽  
Swine Wastewater ◽  
Alternanthera Philoxeroides ◽  
Dry Matter Yield ◽  
Extraction Capacity ◽  
Nutrient Extraction

The plant productivity and extraction capacity of nutrients present in swine wastewater (SWW) were quantified over 60 days in three horizontal subsurface flow constructed wetlands (HSSF-CW) grown with three different plant species (Typha latifolia, Alternanthera philoxeroides and Cynodon dactylon). The results show the decay of the dry matter yield (DMY) and the nutrient extraction capacity (NEC) by the plants throughout the system, which gave rise to the equations that relate these parameters to the hydraulic retention time (HRT) for each species. When possible, general equations that are independent of the plant species were also evaluated. The best model fit for the dry matter yield and N-total, N-ammoniacal, N-nitrate and P extraction by plants as a function of HRT was the decreasing potential and for K extraction was the linear regression. The coefficients of determination of equations for the species Alternanthera philoxeroides and Cynodon dactylon were, for the most part, higher than 0.8. On the other hand, the general equations presented coefficient of determination greater than 90% in all cases.

scholarly journals Evaluation of Different Weed Management Practices on Growth Variables and Yield of Wheat Varieties

2020 ◽  
pp. 7-30
Author(s):  
Md. Golam Mostafa ◽  
Syed Arvin Hassan ◽  
Md. Ehsanul Haq ◽  
Md. Ahasan Habib ◽  
Kaniz Fatema ◽  
...  
Keyword(s):  
Grain Yield ◽  
Weed Management ◽  
Management Practices ◽  
Cynodon Dactylon ◽  
Chenopodium Album ◽  
Cyperus Rotundus ◽  
Alternanthera Philoxeroides ◽  
Weed Species ◽  
Wheat Varieties ◽  
Hand Weeding

A field experiment was conducted in medium fertile soil at Sher-e-Bangla Agricultural University, Dhaka, Bangladesh during November 2017 to April 2018 in Rabi season with a view to evaluate the performance of wheat varieties under different weed control methods. The experiment was carried out with three varieties i.e. BARI Gom-28, BARI Gom-29 and BARI Gom-30 in the main plot and five weed management methods viz. control (no weeding), two hand weeding at 20 and 40 DAS, Panida 33EC (Pendimethalin) @ 2000 ml ha-1 at 5 DAS pre-emergence, Afinity 50.75WP (Isoproturon) 1500 g ha-1 at 25 DAS as post-emergence herbicide and Panida 33EC (Pendimethalin) @ 2000 ml ha-1 at 5 DAS + Afinity 50.75WP (Isoproturon)1500 g ha-1 at 25 DAS in the sub plot in split plot design. Nine different major weed species were found in the field such as Cynodon dactylon, Cyperus rotundus, Echinochloa colonum, Eleusine indica, Chenopodium album, Alternanthera philoxeroides, Brassica kaber, Leliotropium indicum, Vicia sativa. Results reveled that BARI Gom-30 contributed the highest grain yield 3.01 tha-1. Pre-emergence application of Panida 33EC controlled weeds significantly which showed highest growth followed by yield achieved in wheat. BARI Gom-30 in combination with Panida 33EC produced the highest grain yield 3.52 tha-1 while the lowest grain yield 2.09 t ha-1 was obtained from BARI Gom-28 with no weeding treatment. Results reveled that Panida 33EC (pre-emergence) was found more effective to controlling weeds in wheat. Results of the study finally reveled that Panida 33EC might be considered as a feasible option for combating weed and ensuring higher yield in wheat cultivation.

Effects of N:P Ratio and Nutrient Level on the Competition between Invasive Alternanthera philoxeroides and Native Oenanthe javanica

2012 ◽  
Vol 534 ◽  
pp. 337-342 ◽  
Author(s):  
Rui Ying Chang ◽  
Ren Qing Wang ◽  
Yi Ran Zhang ◽  
Jian Liu
Keyword(s):  
N:P Ratio ◽  
Nutrient Supply ◽  
Physiological Traits ◽  
Alternanthera Philoxeroides ◽  
Nutrient Level ◽  
Total Biomass ◽  
High Nutrient ◽  
Morphological And Physiological Traits ◽  
Oenanthe Javanica ◽  
High Nutrient Supply

This study examined the effects of N:P ratio and nutrient level on the competition between invasive Alternanthera philoxeroides and native Oenanthe javanica in terms of morphological and physiological traits and the relative dominance index (RDI). In the experiment, A. philoxeroides was grown in mixture with O. javanica at three N:P supply ratios (1,10,100) combined with three levels of nutrient supply. The results suggested that the morphological and physiological traits of invasive and native species were both significantly affected by N:P ratio and nutrient supply level. The total biomass of both species was maximal under the treatment of lowest N:P ratio and highest nutrient supply, and A. philoxeroides had higher total biomass than O. javanica in every treatment. A. philoxeroides had higher plasticity than O. javanica on total biomass, R/S, SLA, which had sensitive response to the changing nutrient conditions. Meanwhile, the RDI of A. philoxeroides under high nutrient supply was higher than that under low nutrient supply, which showed that high nutrient supply could promote the invasion of A. philoxeroides while P-limitation (high N:P ratio) may prevent the successful invasion of A. philoxeroides under the lower nutrient supply.

The Seed Bank Response of Five Pioneer Plants to Flooding – A Implication for Riverbank Vegetation Restoration

2014 ◽  
Vol 692 ◽  
pp. 65-69 ◽  
Author(s):  
Ji Wang ◽  
Fang Qing Chen ◽  
Lin Xiang ◽  
Meng Ya Geng
Keyword(s):  
Seed Germination ◽  
Seed Bank ◽  
Cynodon Dactylon ◽  
Alternanthera Philoxeroides ◽  
Setaria Viridis ◽  
Amorpha Fruticosa ◽  
Pioneer Plants ◽  
Xanthium Sibiricum ◽  
Flooding Time ◽  
Riverbank Vegetation

Abstract. The seed bank response of five pioneer plants, including Cynodon dactylon, Setaria viridis, Amorpha fruticosa, Alternanthera Philoxeroides and Xanthium sibiricum, to flooding were tested through simulating the flooding experiments. The flooding treatments included 30d, 60d, 90d and the control. All of the treated seeds were germinated under an appropriate germinate condition. The results showed that seed germination rate and germination index of Amorpha fruticosa and Xanthium sibiricum increased with the increasing flooding time meanwhile that of Setaria viridis and Alternanthera Philoxeroides decreased, and Cynodon dactylon germination decreased firstly and then increased with the increasing flooding time. The results suggested that flooding influenced significantly seed germination, and implicated that Amorpha fruticosa, Cynodon dactylon and Amorpha fruticosa were appropriate species for the construction of artificial seed bank to restore riverbank vegetation in the Three Gorges reservoir area.

scholarly journals Influência da espécie vegetal cultivada nas condições redox de sistemas alagados construídos

2010 ◽  
Vol 30 (3) ◽  
pp. 518-526 ◽  
Author(s):  
Antonio T. de Matos ◽  
Wallisson da S. Freitas ◽  
Mozart da S. Brasil ◽  
Alisson C. Borges
Keyword(s):  
Cynodon Dactylon ◽  
Typha Latifolia ◽  
Alternanthera Philoxeroides

Em vista da escassez de informações sobre a influência de diferentes macrófitas nas condições ambientais de Sistemas Alagados Construídos (SACs), monitorou-se o potencial redox (Eh) da água residuária da suinocultura (ARS) em tratamento, em 5 SACs, com dimensões de 24,0 m x 1,1 m x 0,70 m. A ARS, previamente tratada em filtros, foi aplicada numa vazão de 0,8 m³ d-1, com tempo de residência aproximado de 4,8 d. Nos SAC1, SAC2 e SAC3 foram plantados, respectivamente, taboa (Typha latifolia L.), alternanthera (Alternanthera philoxeroides (Mart.) Griseb) e capim tifton-85 (Cynodon dactylon Pers.); no SAC4 foi plantado, no primeiro terço do tanque, alternanthera, no segundo terço, taboa e no terceiro terço, capim tifton-85. No SAC5, nada foi plantado. Coletaram-se amostras do afluente luente dos filtros e nos pontos de coleta posicionados a 4; 8; 12; 16; 20 e 24 m (saída) de cada SAC. Os valores de Eh nos afluentes dos SACs variaram entre -18 e -152 mV, entretanto, houve predomínio de condições anóxicas/aeróbias, geralmente a partir de 4 m nos sistemas. Os efluentes dos SACs apresentaram potencial redox que variou de 53 a 226 mV. Houve tendência de mais rápida oxigenação das águas residuárias no SAC1, cultivado com a taboa e, a partir de 12 m de percurso, a condição redox do meio foi semelhante em todos os SACs.

scholarly journals IN VITRO ACARICIDAL EFFECTS OF SOME INDIGENOUS PLANTS AGAINST BOOPHILUS MICROPLUS (ARACNIDA: IXODIDAE)

2012 ◽  
Vol 3 (2) ◽  
pp. 118-123
Author(s):  
L Nahar ◽  
Anisuzzaman . ◽  
MA Alim ◽  
MJ Karim ◽  
KI Islam ◽  
...  
Keyword(s):  
Filter Paper ◽  
Cynodon Dactylon ◽  
Ethanol Extract ◽  
Boophilus Microplus ◽  
Cattle Tick ◽  
Indigenous Plants ◽  
Polygonum Hydropiper ◽  
Plant Materials ◽  
Ethanol Extracts

In vitro efficacy of neem (Azadirachta indica), bishkatali (Polygonum hydropiper), ata (Annona retirulata), sharifa (A. squamosa) and durba ghas (Cynodon dactylon) against Boophilus microplus (tropical cattle tick) was tested during the period from July to December 2004 in the Department of Parasitology, Bangladesh Agricultural University, Mymensingh. To prepare the paste, aqueous and ethanol extracts, the leaves of neem, bishkatali, ata, sharifa and leaves along with stem of durba ghas were used. Three different types of preparation of plant materials such as paste, aqueous extracts and ethanol extracts were applied in three methods such as thin layer of paste, as spray and as impregnated filter paper (IFP). Extracts were used in 0.5%, 1 % and 2% concentrations and the percent mortality of the ticks were recorded at 12, 24 and 72 hours after treatment. Among them, ethanol extract of ata at 2% concentration showed highest efficacy (100%) followed by aqueous extract of bishkatali (93.33%) at same concentrations and ethanol extract of ata (93.33%) at 1% concentration in spray on method. Among the various methods of application "spray on" method was found to be most effective followed by paste and impregnated filter paper. On the other hand, among the preparations ethanol extract was found to be more efficacious incase of ata plant only. From the study, it is revealed that ata and bishkatali have great acaricidal value against B. microplus.

Sign in / Sign up

Export Citation Format

Share Document