A snapshot of the limnological features in tropical floodplain lakes: the relative influence of climate and land use

Abstract

Aim This study aimed to investigate the relative influence of climate (temperature and precipitation) and land use on limnological features of 30 floodplain lakes in the Araguaia River, in Central Brazil, an important river that drains in the Brazilian Cerrado. Methods The lakes were sampled in one same period, at a large spatial scale (900 km along the river) covering climate and landscape variability. For decomposing the relative importance of land use and climate, we used the RDA and partitioning variance techniques. Results The lakes presented limnological gradient along the floodplain; in general, the lakes presented low transparency, nutrients concentrations (total nitrogen and total phosphorus) and oxygen saturation. The water pH was considered weakly acidic. Considering land use in Araguaia river basin, lakes in downstream presented more remnant vegetation and lakes in upstream presented more livestock and agriculture soil use. The climate conditions were the most important in explaining the variation in limnological characteristics of the lakes, while the individual analysis of limnological variables showed that land use was important to explain to the pH and transparency of the water. Conclusions Finally, this study showed the importance of investigating regional climatic attributes and land use information to explain the limnological characterization of floodplain lakes. Thus, it highlights the importance of the possible impacts of global climate change on limnological conditions.

A history of over 40 years of potentially pathogenic free-living amoeba studies in Brazil - a systematic review

“… 142 , 143 , 144 Global warming can favor the spreading of thermophilic pathogenic FLA 145 , 146 and intra-FLA pathogenic bacteria. 147 In Brazil, a tropical zone directly exposed to global warming effects, 148 the presence of potentially pathogenic FLA strains described in water-related samples ( Table II ) can pose a health concern. Although the country’s regulatory legislation of water quality does not address FLA risks for humans, 149 the need for research on tools to detect them is identified in the global literature.…”

Diversity of free-living amoebas in the Monjolinho River in São Paulo state – morphological and molecular approaches

“…Black and white scale bars = 10 µm. Source: A1-A3: By the author; B1-B3: Adapted from PAGE 24 ; C1: adapted from LIANG et al 25 ; C2: Adapted from INIT et al 143 ; and C3: Adapted from REYES-BATLLE et al 262 The eruptive pseudopodia, which is characteristic of the locomotive activity of Naegleria like vegetative stage, (25,26) was visualized to all trophozoites displayed in Figure 3.27, A1, B1, and C1. Naegleria is termed as a "limax" amoeba in recognition to the monopodial cylindrical amoeba forms, according to F. C. PAGE (23), as well termed as limacine by the literature (25) due to the eruptive locomotion advancing in a unidirectional region.…”

“…: total organic carbon, phosphate, and nitrate) was not performed, these analytes are very elusive to determining water quality. (261) Afterwards, the literature has been statistically interpreting this chemical analysis along with the canonical physicochemical parameters by using principal component analysis (PCA) and partial redundancy analysis (pRDA) (169,(262)(263). Limnological parameters of freshwater systems have been compared against Brazilian regulations concerned with establishing standards to classify water bodies according to its quality, ecological status, availability as drinking water supply, risks to human health, and human impacts acting in the aqueous ecosystem.…”

“…In this regard, the Resolution No. 357/2005 is one of the most commonly assessed documents, provided by the National Environmental Council (CONAMA) (224,260,262,(264)(265). This resolution classifies water bodies in four levels of environmental quality, in which the level 1 defines the water as highly pure and suitable for several purposes including human water supply, after a mild disinfection process.…”

“…Black and white scale bars = 10 µm. Source: A1-A3: By the author; B1-B3: Adapted from PAGE24 ; C1: adapted from LIANG et al25 ; C2: Adapted from INIT et al143 ; and C3: Adapted from REYES-BATLLE et al262…”