Natural Waters in Amazonia. VI-Soluble Calcium Properties ()

Brinkmann, W. L. F.; Santos, Antonio

doi:10.1590/1809-43921973032033

Cited by 22 publications

(5 citation statements)

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“…Oxisols and Ultisols on the valley slopes become progressively more eluviated with increasing distance downslope and have been classified as Orthoxic Tropohumult or Palehumult [Lucas et al, 1984]. Soils at the base of relatively short slopes (< 1 km), which dominate the region, have been termed sandy Oxisols [Brinkmann and dos Santos, 1973]. Soils covering the valley bottoms, where water table levels are shallow, are termed hydromorphic Oxisols [Brinkmann and dos Santos, 1973], however, Spodosols often develop at the base of valley slopes exceeding 1 km in length [Lucas et al, 1984].…”

Section: Regional Settingmentioning

confidence: 99%

“…Soils at the base of relatively short slopes (< 1 km), which dominate the region, have been termed sandy Oxisols [Brinkmann and dos Santos, 1973]. Soils covering the valley bottoms, where water table levels are shallow, are termed hydromorphic Oxisols [Brinkmann and dos Santos, 1973], however, Spodosols often develop at the base of valley slopes exceeding 1 km in length [Lucas et al, 1984]. The Spodosols are composed predominantly of clean quartz sand, with the dark brown spodic horizon lying at depths greater than 2 m [Klinge, 1965].…”

Section: Regional Settingmentioning

confidence: 99%

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Dissolved organic matter and terrestrial‐lotic linkages in the Central Amazon Basin of Brazil

McClain¹,

Richey²,

Brandes³

et al. 1997

Global Biogeochemical Cycles

105

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Abstract. We evaluate the hypothesis that decomposition and adsorption reactions operating in upland soils of headwater catchments control the concentration and composition of dissolved and fine particulate organic matter in rivers of the Amazon basin. In two contrasting first-order catchments characteristic of the central Amazon basin, we analyzed plant, litter, soil, groundwater, and stream water chemistry. Our results indicate that clear and persistent differences exist in the concentration and elemental composition of dissolved organic matter (DOM) in stream waters and groundwaters from the two catchments, due mainly to corresponding differences in soil texture and chemistry. Within the more oxide and clay rich Oxisols underlying terra firme forest, groundwater DOM concentrations were uniformly low (120 gMC) and C/N ratios averaged 10. Conversely, within the oxide and clay deficient Spodosols underlying campinarana forest, groundwater DOM concentrations were greatly elevated (3000 gMC), and C/N ratios averaged near 60. We found that, in the terra firme/Oxisol terrain, the majority of DOM contributions to the stream derived from the riparian zone, while in the campinarana/Spodosol terrain, upland groundwater contributions could account for the concentration and composition of DOM in the stream. The implications of our findings are that in the terra firme terrains which dominate the region, upland soil profiles are not the site of definitive processes which impart compositional signatures to organic matter carried by the largest rivers of the Amazon basin, as was hypothesized. Instead, we suggest that definitive reactions are focused primarily in the river corridor.

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Section: Regional Settingmentioning

confidence: 99%

Section: Regional Settingmentioning

confidence: 99%

Dissolved organic matter and terrestrial‐lotic linkages in the Central Amazon Basin of Brazil

McClain¹,

Richey²,

Brandes³

et al. 1997

Global Biogeochemical Cycles

105

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“…Throughfall and stemflow are the major pathways in nutrient cycling. In this study, stemflow was not taken into account because it generally constitutes only a small portion of the total deposition fluxes to the forest floor (Brinkmann and Dos Santos, 1971). Two crucial assumptions were used: Na + as a tracer was assumed to be inert with respect to the canopy (i.e., neither uptake nor leaching occurs), and the dry deposition characteristics of Na particles (including Na‐bearing droplets) represent those of other particulate matter (containing Ca 2+ , Mg 2+ , and K + and those of cloud droplets).…”

Section: Methodsmentioning

confidence: 99%

Estimating Chemical Exchange between Atmospheric Deposition and Forest Canopy in Guizhou, China

Gao

Liao

2013

J. Environ. Qual.

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To evaluate the effects of atmospheric deposition on forest ecosystems, wet-only precipitation and throughfall samples were collected in two forest types (Masson pine [ Lamb.] forests and mixed conifer and broadleaf forests) in the Longli forest in the Guizhou province of southwestern China for a period of 21 successive months from April 2007 to December 2008. The pH and chemical components of precipitation and throughfall were analyzed. In addition, the canopy budget model was applied to distinguish between in-canopy and atmospheric sources of chemical compounds. Canopy leaching and total potentially acidifying deposition fluxes were calculated. The results showed that the average pH and the concentration of ions in throughfall were higher than those in precipitation, with the exception of the NH concentration. Dry deposition of S and N accumulated more in Masson pine forests than in mixed conifer and broadleaf forests. Canopy leaching was the most significant source of base cations in forest throughfall, which was higher in the mixed forests than in the coniferous forests. Anions in throughfall deposition in Masson pine forests exceeded those in the mixed forests. Higher total potentially acidifying deposition fluxes reflected the more effective amounts of acid delivered to Masson pine forests compared with mixed conifer and broadleaf forests. In addition, acid deposition induced the leaching and loss of nutrient ions such as Mg, K, and Ca. Although the trees of the studied areas have not shown any symptoms of cation loss, a potentially harmful influence was engendered by atmospheric deposition in the two forest types in the Longli area.

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“…As águas dos três locais foram ácidas (pH 4,0), pouco mineralizadas (condutividade < 12 µS/cm), bem oxigenadas (saturação > 60%) e quentes (25,4 o C), características de ambientes de água preta na região (Sioli, 1950;Brinkmann & Santos, 1973;Fittkau et al, 1975;Furch et al, 1982). A proposta deste estudo foi mostrar para os alunos a importância da caracterização física do local para o estabelecimento de comunidades de macroalgas, mas para isso seria preciso que eles confirmassem que não havia diferença na "química das águas" entre os três sítios de amostragem.…”

Section: Igarapézinhounclassified

Características Físicas E Comunidades De Macroalgas Em Um Igarapé De Terra Firme Na Reserva Florestal Adolpho Ducke (Manaus/Am)

Pascoaloto

Pinto²,

Takano³

2008

RCG

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Este estudo foi realizado em três segmentos do igarapé Barro, em novembro de 2005, como parte de um projeto em educação ambiental voltado para alunos do ensino médio, com o objetivo de destacar a importância das variáveis físicas na composição das espécies de macroalgas. O segmento "campoâ€? foi um local natural, sombreado; o "laguinhoâ€?, uma área represada, pouco sombreado; o "igarapézinhoâ€?, novamente um segmento natural, sombreado. A velocidade média superficial variou de zero a 43,48 cm.s-1. No "campoâ€? não foram observadas macroalgas; no "laguinhoâ€? foram encontradas quatro; no "igarapézinhoâ€?, duas. Não foram observadas diferenças na química da água. No "campoâ€? o substrato predominante foi areia; no "laguinhoâ€?, raízes; no "igarapézinhoâ€?, areia. Estudos anteriores, no "campoâ€?, revelaram a presença de grandes quantidades de uma rodofícea; como não foram identificadas alterações nas características da água, mas foram observadas alterações na profundidade do canal e na quantidade de troncos e galhos caídos, confirmou-se a hipótese de que as características físicas do local são os fatores determinantes na configuração das comunidades de macroalgas desse igarapé.

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Natural Waters in Amazonia. VI-Soluble Calcium Properties ()

Cited by 22 publications

References 0 publications

Dissolved organic matter and terrestrial‐lotic linkages in the Central Amazon Basin of Brazil

Dissolved organic matter and terrestrial‐lotic linkages in the Central Amazon Basin of Brazil

Estimating Chemical Exchange between Atmospheric Deposition and Forest Canopy in Guizhou, China

Características Físicas E Comunidades De Macroalgas Em Um Igarapé De Terra Firme Na Reserva Florestal Adolpho Ducke (Manaus/Am)

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