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Xalapa de Enríquez, Mexico

Peralta Pelaez L.A.,Technological Institute of Veracruz | Moreno-Casasola P.,Institute of Ecology AC | Lopez Rosas H.,National Autonomous University of Mexico
Marine and Freshwater Research | Year: 2014

Coastal dunes include several habitats, including dune lakes. These habitats are valuable environmental assets. We analysed the impact of the surrounding land use on plant species composition, vegetation structure and water quality of 15 dune lakes in the coast of Veracruz in the Gulf of Mexico. The physical and chemical characteristics were determined for water during both the dry and rainy seasons, and vegetation was sampled once. Ammonium, nitrate, orthophosphate and total phosphorus varied between seasons and among lakes. Multivariate analysis revealed a gradient from lakes in a good state (water and wetland vegetation) to degraded lakes. These lakes fall into two groups: the first one has five lakes with a higher nutrient content, and surrounded by land where livestock is pastured and sugarcane is grown. The vegetation of these lakes consists of a combination of aquatic plants and flood-tolerant grasses introduced to feed cattle (Cynodon dactylon, Pennisetum purpureum, Setaria geniculata). Oligotrophic and mildly eutrophic lakes are characterised by little human activity, and aquatic species predominate (Cabomba palaeformis, Nymphaea ampla, Acrostichum aureum). Rural activities such as sugarcane cultivation and cattle rearing are likely the main factors causing changes in water enrichment and affecting the composition and structure of wetland vegetation. Management measures should be implemented to recover these areas and prevent further deterioration. © CSIRO 2014. Source


Navarro A.E.,Technological University of Mexico | Hernandez M.E.,Institute of Ecology AC | Bayona J.M.,IDAEACSIC | Morales L.,Technological University of Mexico | Ruiz P.,Institute of Ecology AC
International Journal of Environmental Analytical Chemistry | Year: 2011

The removal efficiency of selected emerging pollutants, total (TotCol) and faecal (FecCol) coliforms in surface (SF) and subsurface (SSF) flow constructed wetlands (CWs) was compared. The pilot plant (located in southeastern Mexico) consisted of eight CWs: four with SF and four with SSF. Two cells of each type were planted with Typha sp. and two were left without plant as controls. CWs were fed with water from Sordo river, which receives untreated urban sewage and industrial wastewaters. Water samples from river and outflow from each CW were collected in four sampling campaigns, they were filtered, extracted and analysed by GC/MS. Redox potential (Eh) was measured in all cells. The following pollutants were identified and quantified: Caffeine, CAF; Galaxolide, GAL; Methyl dihydrojasmonate, MDHJ; Linear alkylbenzenes, LAB; Butylated hydroxytoluene, BHT; Surfynol 104, SSURF; Alkylphenols, AP; 4-alkylphenol monoetoxylates, APE; Parsol, PAR. Typical removals of studied compounds were attained with slightly better results in SSFCW. A multiple linear regression analysis considering Eh, time, influent pollutant concentration (C 0) and the presence of plants and filtering media (Fmedia) as independent variables showed that Eh has a significant influence in the removal for almost all the studied compounds with the exception of BHT and AP. C 0 influences removal processes with the exception of coliforms. A significant influence of Fmedia in the BHT and PAR removal is observed, also positive for AP, APE, CAF, LAB and GAL in decreasing order. The effect of plants is positive for PAR (significant), GAL, CAF, BHT and MDHJ. SURF has a distinct behaviour with a negative coefficient for its C 0. For TotCol and FecCol the most significant effects are Eh and time. This may be related to the fact that predation by aerobic microbial communities may be the predominant factor in their removal and the development of these microbial communities with time. © 2011 Taylor & Francis. Source


Marin-Muniz J.L.,University of Veracruz | Hernandez M.E.,Institute of Ecology AC | Moreno-Casasola P.,Institute of Ecology AC
Atmospheric Environment | Year: 2015

Wetlands play an important role in modulating atmospheric concentrations of Greenhouse Gases (GHGs), such as methane (CH4), nitrous oxide (N2O) and carbon dioxide (CO2). Despite the fact that ~30% of wetlands in the world occur in tropical latitudes, little is known about GHG emissions from these ecosystems and the variables that control such emissions. We investigated the CH4, N2O and CO2 emissions in tropical freshwater marshes (FM) and swamps (FS) on the coastal plain of Veracruz, Mexico. GHGs were measured every two months using the closed chamber technique from April 2010 to February 2012 (CH4 and N2O) and during the last year for CO2. The ranges of the emissions were 20-2000mgC-CH4 m-2d-1, -2-16mgN-N2O m-2d-1 and 0.5-18gC-CO2 m-2d-1. There were not significant differences in the emissions between FM and FS (P=0.314, 0.528 and 0.213 for CH4, N2O, and CO2, respectively). However, significant differences (P<0.001) in CH4 and CO2 emissions were found in the different seasons. During the rainy and windy seasons, the water level was higher than during dry season, this enhanced reduced conditions in the soils and caused significantly higher (P<0.05) CH4 emissions (>364mgm-2d-1) than during dry season (<150mgm-2d-1). The opposite was observed for CO2 emissions, during dry season, wetland soils were more aerobic and CO2 fluxes increased (FM: 11±2, FS: 12±1gm-2d-1). N-N2O emissions (FM: 1.5±0.96, FS: 2.4±0.9mgm-2d-1) were similar during different climatic season (P=0.056). Based on the global warming potential, CH4 was the main contributor to total GHGs emission during the rainy and windy seasons (75-93%), while CO2 was predominant during the dry season (79.6%) and N2O contributed with less than 7% in the three seasons. Water level and redox potential were found to be main factors influencing GHG emissions in these wetlands. © 2015 Elsevier Ltd. Source


Gaitan-Hernandez R.,Institute of Ecology AC | Cortes N.,Institute of Ecology AC | Mata G.,Institute of Ecology AC
Brazilian Journal of Microbiology | Year: 2014

The research evaluated the interactions of two main factors (strain / types of spawn) on various parameters with the purpose to assess its effect on yield and biochemical composition of Lentinula edodes fruiting bodies cultivated on pasteurized wheat straw. The evaluation was made with four strains (IE-40, IE-105, IE-124 and IE-256). Different types of spawns were prepared: Control (C) (millet seed, 100%), F1 (millet seed, 88.5%; wheat bran, 8.8%; peat moss, 1.3%; and CaS04, 1.3%) and F2 (the same formula as F1, but substituting the wheat bran with powdered wheat straw). Wheat straw was pasteurized by soaking it for 1 h in water heated to 65 °C. After this the substrate (2 kg wet weight) was placed in polypropylene bags. The bags were inoculated with each spawn (5% w/w) and incubated in a dark room at 25 °C. A proximate analysis of mature fruiting bodies was conducted. The mean Biological Efficiency (BE) varied between 66.0% (C-IE-256) and 320.1% (F1-IE-124), with an average per strain of 125.6%. The highest mean BE was observed on spawn F1 (188.3%), significantly different from C and F2. The protein content of fruiting bodies was high, particularly in strain IE-40-F1 (17.7%). The amount of fat varied from 1.1 (F1-IE-40) to 2.1% (F2-IE-105) on dry matter. Carbohydrates ranged from 58.8% (F1-IE-40) to 66.1% (F1-IE-256). The energy value determined ranged from 302.9 kcal (F1-IE-40) to 332.0 kcal (F1-IE-256). The variability on BE observed in this study was significantly influenced by the spawn's formulation and genetic factors of the different strains. © 2014, Sociedade Brasileira de Microbiologia. All rights reserved. Source

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