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| Pereira da SILVA,Kelly Dayane; SANTOS,João Paulo de Oliveira; ARAUJO,María Cristina Santos Pereira de; MACHADO,Célia Cristina Clemente; BARBOSA,Luciana Gomes. |
| ABSTRACT Historically, the reduction in water quality has been associated with changes in land use, especially changes in urbanization and expansion of agricultural frontiers. The objective of this study was to understand the characteristics of the diatomological community and the use and occupation of the soil around three reservoirs (Arara, Rio do Canto and Araçagi) and natural lagoon (Lagoa do Paó) (Northeast Brazil). Land use was determined using high spatial resolution satellite images. Abiotic variables of water and total phosphorus, organic matter and diatoms in surface sediments were analyzed. Abiotic variables and assemblages of diatoms were analyzed using Principal Component Analysis (PCA). Four types of land use have been identified, associated... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Bacillariophyta; Eutrophication; Geographic information system; Semi-arid zone. |
| Ano: 2022 |
URL: http://www.scielo.org.co/scielo.php?script=sci_arttext&pid=S0120-548X2022000200249 |
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| Cepeda-Pizarro,Jorge; Vega,Solange; Vásquez,Hernán; Elgueta,Mario; Pizarro-Araya,Jaime. |
| Under certain environmental conditions, several species of grasshoppers inhabiting rangeland areas (e.g., inter-valleys) of the Chilean transitional desert can irrupt demographically. One of them is Elasmoderus wagenknechti (Liebermann), an endemic species. We studied two outbreaks occurred in 1996 and 1999. The objectives of the research were to (i) estimate some demographic parameters associated with the aforementioned events, and (ii) compare between them the population parameters. The parameters we studied were density (ind/m²), sexual proportion, female fertility (i.e., eggs/female), and the relationship eggs/female versus female size. Density (ind/m²) ranged from 0.2 to 0.4 in 1996 and from 0.5 to 0.6 in 1999. ANOVA-tests registered differences in... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Rangeland insect; Population biology; Semi-arid zone; Endemic insect; Grassland ecology. |
| Ano: 2007 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1519-566X2007000400002 |
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