Repositorio UNIBAGUA - Universidad Nacional Intercultural Fabiola Salazar Leguia de Bagua
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Evaluation of heavy metals in vegetables from two origins marketed in northern Peru
Get PDFThe objective of the study was to evaluate the concentration of arsenic, chromium, cadmium, and lead in onion (Allium fistulosum and Allium cepa), tomato (Solanum lycopersicum), and celery (Apium graveolens) from two origins (local - Chachapoyas province and from the coast-province of Chiclayo) that are sold in the model market of the city of Chachapoyas.
Six samples were taken on three different dates in November 2020, which were collected by non-probabilistic sampling (by convenience), which allowed choosing the most appropriate sample (according to its origin). For the determination of heavy metals, the Agilent 4100 MP-AES spectrometer was used. The concentration of As, Cr, and Cd in the vegetables remained below the Maximum Allowable Limits of the international standards with which they were compared; however, the concentration of Pb exceeded the Maximum Allowable Limits in all the samples analyzed, obtaining the lowest value in the celery samples from the local origin (0.15 mg.kg-1) and the highest value in the tomato samples from the coast (0.21 mg.kg-1). Therefore, it is concluded that only Pb is higher than the Maximum Allowable Limits with which it was compared
Effect of geographic altitude on carbon stock in two physiographic units of the reserved forest of the Universidad Nacional Agraria de la Selva
Get PDFThe objective of the research was to evaluate the effect of geographic altitude on the carbon stock in two physiographic units of the Reserved Forest of the Universidad Nacional Agraria de la Selva, Tingo Maria-Huanuco. The methodology used was the field manual for the remeasurement and establishment of plots of the Amazon Forest Inventory Network (RAINFOR), for which 2 hectares were permanently established (one hectare in low and high hills) in which the diameter (greater than or equal to 10 cm) and the height of the trees were measured. Finally, the density of the wood was obtained from previous studies.
The pantropical model formula was used to estimate the carbon stock. The results show that geographic altitude significantly affects carbon stock (p < 0.05) in low and high-hill forests, concluding that this may be due to differences in meteorological variables such as precipitation, temperature, and humidity
Ecological risk due to heavy metal contamination in sediment and water of naturalwetlands with tourist influence in the central region of Peru
Get PDFIn this study, the quality of sediment and surface water in two natural wetlands, Paca and Tragadero, in the central region of Peru was evaluated using pollution indices, including the geoaccumulation index, pollutant load index, modified pollution degree, potential ecological risk index, and site rank index, for four heavy metals. Principal component analysis was used to identify potential metal contaminant sources. The determination of Fe, Zn, Pb, and As was performed by flame atomic absorption spectrophotometry. The average concentrations of metals in the sediments of both lagoons decreased in the order Fe > Zn > Pb > As. The analysis of the contamination indices determined that As and Pb are the elements that contribute the most to environmental degradation in both wetlands. There is a strong correlation between the values of potential ecological risk and the modified degree of contamination, revealing that the Paca wetland has a moderate degree of contamination and potential ecological risk, while Tragadero presents a high degree of contamination and considerable potential ecological risk. The application of the site rank index showed that more than 50% of the sampling sites have between high and severe contamination. The principal component analysis presented 79.2% of the total variance. Finally, the results of this study are essential in order to carry out preventive actions for environmental protection in these lake ecosystems of great importance for many activities, such as bird watching
Bacterial composition in maca (Lepidium meyenii Walp) crop soils analyzed by metagenomics: a study in the central Andes of Peru
Get PDFoai:repositorio.unibagua.edu.pe:20.500.14588/71El cambio e intensificación de uso del suelo ha dado lugar al empobrecimiento de los suelos con efectos negativos en las comunidades biológicas. Se analizó la composición bacteriana de suelos de cultivo de maca (Lepidium meyenii Walp) mediante secuenciación Illumina en la meseta de Bombón, durante el año 2019. Se definieron tres sectores de muestreo, un sector control (suelo natural) y dos sectores con presión de uso (suelos “primer uso” y “segundo uso”, respecto al cultivo de maca). Se determinaron los indicadores fisicoquímicos del suelo mediante métodos analíticos y la composición de las comunidades bacterianas mediante secuenciación Illumina de los amplicones del gen de ARNr 16S. Los resultados de pH y CE, en suelos control y con presión de uso, variaron de 7,51 a 4,53 y de 0,06 a 0,47 dS/m, respectivamente. Los contenidos más altos MO, N, P, K y Ca se registraron en los suelos control disminuyendo significativamente en suelos con presión de uso. El análisis de componentes principales (ACP) presentó un porcentaje de variación total del 97,1 %. La secuenciación Illumina reveló 3776 familias bacterianas. El análisis SIMPER mostró que los mayores porcentajes de contribución lo realizaron las familias Acidobacteriaceae (2,95%), Verrucomicrobiaceae (2,68%), Thermoactinomycetaceae (2,11%) y Akkermansiaceae (2,10%). El análisis de redundancia (AR) mostró una buena asociación entre las variables fisicoquímicas y las familias bacterianas. El análisis metagenómico ha permitido identificar familias bacterianas que pueden ser usadas como indicadores de buena y mala calidad fisicoquímica del suelo según presión de uso por cultivos de maca; así como, a los mejores indicadores fisicoquímicos predictores de los cambios de la composición de las comunidades bacterianas.The change and intensification of land use has been generating impoverishment of soils with negative effects on biological communities. It was analyzed the bacterial composition of maca (Lepidium meyenii Walp) cultivation soils by Illumina sequencing in the Bombón plateau, during 2019. Three sampling sectors were defined, a control sector (natural soil) and two sectors with use pressure ("first use" and "second use" soils). Soil physicochemical indicators were determined through analytical methods and the composition of bacterial communities through Illumina sequencing of 16S rRNA gene amplicons. The results of pH and EC, in control soils and with use pressure, varied from 7.51 to 4.53 and from 0.06 to 0.47 dS/m, respectively. The highest OM, N, P, K and Ca contents were recorded in control soils, decreasing significantly in soils with use pressure. Principal components analysis (PCA) presented a percentage of total variation of 97.1%. Illumina sequencing revealed 3776 bacterial families. SIMPER analysis showed that the highest contribution percentages were made by the Acidobacteriaceae (2.95%), Verrucomicrobiaceae (2.68%), Thermoactinomycetaceae (2.11%) and Akkermansiaceae (2.10%) families. Redundancy analysis (RDA) showed a good association between physicochemical variables and bacterial families. The metagenomic analysis has allowed the identification of bacterial families that can be used as indicators of good and bad soil physicochemical quality according to the pressure of use by maca crops. As well as the best physicochemical indicators predictive of changes in the composition of bacterial communities