Wood growth patterns of Macrolobium acaciifolium (Benth.) Benth. (Fabaceae) in Amazonian black-water and white-water floodplain forests

In the Central Amazonian floodplains, several hundred tree species grow in areas that are periodically flooded by nutrient-rich white-water rivers (várzea) and by nutrient poor black-water rivers (igapó). Seed masses of 31 species from várzea and 27 species from igapó were compared taking into consideration their taxonomic relatedness. Overall average seed mass was higher (mean = 7.08 g) in nutrient-poor igapó than in nutrient-rich várzea (mean = 1.16 g). In igapó, the species growing at high elevations on the flooding gradient had significantly higher seed masses than the species growing at low elevations. In várzea, no difference was found between species growing at high and low elevations. Four large-seeded species from igapó occurring at high elevations on the flooding gradient were responsible for most of the difference in average seed mass between forest types. These data suggest that at low positions in the flooding gradient in igapó, selection pressure on seed size is probably the same as in várzea. At sites with short periods of flooding in igapó forests, on high levels in the flooding gradient, the need for rapid height growth may have selected for species with larger seeds which enable seedlings to be less dependent on soil nutrients.

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Calcium fluxes in Hoplosternum littorale (tamoatá) exposed to different types of Amazonian waters

Neotropical Ichthyology ◽

10.1590/s1679-62252009005000002 ◽

2009 ◽

Vol 7 (3) ◽

pp. 465-470 ◽

Cited By ~ 3

Author(s):

Bernardo Baldisserotto ◽

Carlos Eduardo Copatti ◽

Levy Carvalho Gomes ◽

Edsandra Campos Chagas ◽

Richard Philip Brinn ◽

...

Keyword(s):

Organic Carbon ◽

Water Transfer ◽

Well Water ◽

Acidic Ph ◽

Clear Water ◽

Black Water ◽

Neutral Ph ◽

Different Types ◽

White Water ◽

Hoplosternum Littorale

Fishes that live in the Amazonian environment may be exposed to several kinds of waters: "black waters", containing high dissolved organic carbon and acidic pH, "white waters", with ten fold higher Ca2+ concentrations than black waters and neutral pH, and "clear waters", with two fold higher Ca2+ concentrations than black waters and also neutral pH. Therefore, the aim of the present study was to analyze Ca2+ fluxes in the facultative air-breather Hoplosternum littorale (tamoatá) exposed to different Amazonian waters. Fishes were acclimated in well water (similar to clear water) and later placed in individual chambers for Ca2+ fluxes measurements. After 4 h, water from the chambers was replaced by a different type of water. Transfer of tamoatás to ion-poor black or acidic black water resulted in net Ca2+ loss only in the first 2 h of experiment. However, transfer from black or acidic black water to white water led to only net Ca2+ influxes. The results obtained allowed us to conclude that transfer of tamoatás to ion-poor waters (black and acidic black water) led to transient net Ca2+ loss, while the amount of Ca2+ in the ion-rich white water seems adequate to prevent Ca2+ loss after transfer. Therefore, transfer of tamoatás between these Amazonian waters does not seem to result in serious Ca2+ disturbance.

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Composition and community structure of mangroves distributed on the east coast of Marajó Island, Brazil

10.21203/rs.3.rs-1196739/v1 ◽

2022 ◽

Author(s):

Barbara Luzia Santos de Oliveira Faro ◽

Priscila Sanjuan de Medeiros-Sarmento ◽

Norma Ely Santos Beltrão ◽

Paulo Weslem Portal Gomes ◽

Ana Cláudia Caldeira Tavares-Martins

Keyword(s):

Floristic Composition ◽

Distribution Patterns ◽

Major Influence ◽

Structural Development ◽

Black Water ◽

Composition And Structure ◽

Marine System ◽

Marajó Island ◽

White Water ◽

Degree Of Similarity

Abstract Mangroves in the Amazon are influenced by several environmental conditions that determine the composition and structural development of the arboreal flora, which results in different distribution patterns. In this study, we sought to answer two questions: (1) what is the composition and structure of the mangroves near the mouth of the Amazon River in Marajó Island? (2) Are the fringe and inland mangroves more similar or dissimilar in terms of floristic composition? For this, we delimited a fringe zone and an inland zone about 1 km apart from each other. In each zone, we distributed five 400-m2 plots. The individuals were grouped into diameter and height classes and structural and phytosociological parameters were calculated. Ten species were recorded in the mangroves, of which seven are typical of white-water (várzea) and black-water (igapó) flooded forest ecosystems. We believed the adjacent ecosystems and the hydrological network are inducing the establishment of such species. The composition and structure of mangroves did not differ statistically between zones, and the degree of similarity may be a result of similar environmental factors in these zones such as low relief and high frequency of macrotides. We conclude that the vegetation of the studied mangroves has a major influence of the fluvial-marine system of the great rivers of the Amazon associated with a diversity of ecosystems that, together, generate greater floristic richness when compared to mangroves in other regions.

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Leaf decomposition and fine fuels in floodplain forests of the Rio Negro in the Brazilian Amazon

Journal of Tropical Ecology ◽

10.1017/s0266467413000485 ◽

2013 ◽

Vol 29 (5) ◽

pp. 455-458 ◽

Cited By ~ 16

Author(s):

Aline Ramos dos Santos ◽

Bruce Walker Nelson

Keyword(s):

Tree Mortality ◽

Brazilian Amazon ◽

Leaf Decomposition ◽

Fire Intensity ◽

Floodplain Forests ◽

Tree Roots ◽

Upland Forest ◽

Black Water ◽

Rio Negro ◽

Forest Sites

Abstract:Despite being inundated for up to 9 mo of the year, black-water floodplain forests in the Brazilian Amazon are susceptible to fire. Post-fire tree mortality is higher and fire spreads further in the floodplain, compared with adjacent upland forest. To understand these differences between the two forest types, we compared how leaf decomposition and fine-fuel loads change with inundation and soil texture. Litterbags containing leaves of Clitoria fairchildiana were placed on upland forest floor and submerged at two depths in a backwater of the Rio Negro. We used 80 bags per treatment and retrieved subsets every ~16 d from which the contents were cleaned, dried, weighed and discarded. Over the 81-d experiment, upland leaves decomposed two to three times faster than submerged leaves. Fine-fuel biomass (litter + root mat) was measured at 28 upland forest sites and 29 floodplain forest sites of the middle Rio Negro. Floodplain forests held about twice the fine fuel (25.9 ± 10.6 Mg ha−1) of uplands (10.9 ± 2.3 Mg ha−1). Upland soils had more sand but a carpet of fine apogeotropic tree roots was more common and thicker in floodplains. We infer that slow decomposition of submerged leaves leads to high tree mortality from fire in black-water floodplains by (1) increasing fire intensity due to high fine-litter fuel load and (2) making tree roots more vulnerable to burning because they form a peat-like mat to absorb nutrients from the thick litter.

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The density and biomass of mesozooplankton and ichthyoplankton in the Negro and the Amazon Rivers during the rainy season: the ecological importance of the confluence boundary

PeerJ ◽

10.7717/peerj.3308 ◽

2017 ◽

Vol 5 ◽

pp. e3308 ◽

Cited By ~ 3

Author(s):

Ryota Nakajima ◽

Elvis V. Rimachi ◽

Edinaldo N. Santos-Silva ◽

Laura S.F. Calixto ◽

Rosseval G. Leite ◽

...

Keyword(s):

Rainy Season ◽

Fish Larvae ◽

Amazon River ◽

Black And White ◽

Black Water ◽

Negro River ◽

Feeding Habitat ◽

White Water ◽

Ecological Importance ◽

Density And Biomass

The boundary zone between two different hydrological regimes is often a biologically enriched environment with distinct planktonic communities. In the center of the Amazon River basin, muddy white water of the Amazon River meets with black water of the Negro River, creating a conspicuous visible boundary spanning over 10 km along the Amazon River. Here, we tested the hypothesis that the confluence boundary between the white and black water rivers concentrates prey and is used as a feeding habitat for consumers by investigating the density, biomass and distribution of mesozooplankton and ichthyoplankton communities across the two rivers during the rainy season. Our results show that mean mesozooplankton density (2,730 inds. m−3) and biomass (4.8 mg m−3) were higher in the black-water river compared to the white-water river (959 inds. m−3; 2.4 mg m−3); however an exceptionally high mesozooplankton density was not observed in the confluence boundary. Nonetheless we found the highest density of ichthyoplankton in the confluence boundary (9.7 inds. m−3), being up to 9-fold higher than in adjacent rivers. The confluence between white and black waters is sandwiched by both environments with low (white water) and high (black water) zooplankton concentrations and by both environments with low (white water) and high (black water) predation pressures for fish larvae, and may function as a boundary layer that offers benefits of both high prey concentrations and low predation risk. This forms a plausible explanation for the high density of ichthyoplankton in the confluence zone of black and white water rivers.

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Germinative behaviour of ten tree species in white-water floodplain forests in central Amazonia

Folia Geobotanica ◽

10.1007/s12224-017-9284-1 ◽

2017 ◽

Vol 53 (1) ◽

pp. 89-101 ◽

Cited By ~ 2

Author(s):

Auristela Conserva ◽

José Luís Campana Camargo ◽

Denise Garcia De Santana ◽

Maria Teresa Fernandez Piedade

Keyword(s):

Tree Species ◽

Floodplain Forests ◽

Central Amazonia ◽

White Water

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Small Mammal Communities in Upland and Floodplain Forests along an Amazonian White Water River

Mammalian DiversificationFrom Chromosomes to Phylogeography ◽

10.1525/california/9780520098534.003.0011 ◽

2006 ◽

pp. 334-375 ◽

Cited By ~ 1

Author(s):

Jay R. Malcolm ◽

James L. Patton ◽

Maria Nazareth F. da Silva

Keyword(s):

Small Mammal ◽

Floodplain Forests ◽

Small Mammal Communities ◽

White Water ◽

Mammal Communities

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Population abundance and biomass of large-bodied birds in Amazonian flooded and unflooded forests

Bird Conservation International ◽

10.1017/s0959270908000130 ◽

2008 ◽

Vol 18 (2) ◽

pp. 87-101 ◽

Cited By ~ 28

Author(s):

Torbjørn Haugaasen ◽

Carlos A. Peres

Keyword(s):

Community Dynamics ◽

Bird Species ◽

Line Transect ◽

Terra Firme ◽

Black Water ◽

White Water ◽

Igapó Forest ◽

Seasonally Flooded ◽

Várzea Forests ◽

Aggregate Population

AbstractLittle is known about the contribution of different forest types to the beta-diversity, abundance and biomass of the avifauna in lowland Amazonia. This paper presents data on the large-bodied bird assemblages of adjacent upland (terra firme) and seasonally flooded (várzea and igapó) forests in the lower Rio Purús region of central-western Brazilian Amazonia. We focus our analysis on 23 large-bodied canopy and terrestrial bird species from 10 families, on the basis of 2,044 bird sightings obtained during line-transect censuses conducted over a two-year period. Large toucans comprised the most numerically abundant large birds in terra firme and igapó forests, whereas macaws were the most abundant in nutrient-rich várzea forests that were seasonally inundated by white-water. The aggregate population density of all bird species in terra firme forest was slightly higher than that in várzea forest. Igapó forest, which was seasonally inundated by black-water, sustained the lowest population densities. Terra firme and várzea forests differed considerably in species composition and abundance whereas igapó forest shared many species with both terra firme and várzea. Our results suggest that Amazonian floodplain forests play a major role in the persistence and community dynamics of the large-bodied forest birds.Pouco se sabe sobre a contribuição de diferentes tipos de florestas aos padrões de beta-diversidade, abundância e biomassa da avifauna na região amazônica. Este artigo apresenta dados à respeito das aves de médio a grande porte em florestas de terra firme e florestas adjacentes sujeitas a inundação sazonal (várzea e igapó) na região do baixo Rio Purús da Amazonia centro-ocidental. Nossa análise, baseada num total de 2,044 observações obtidas durante censos ao longo de transectos, foi direcionada a 23 espécies de aves de médio a grande porte pertencentes a 10 famílias. As aves mais abundantes em florestas de terra firme e igapó foram os tucanos, e as araras as mais abundantes em florestas de várzea. A densidade de população agregada de todas as espécies na terra firme foi ligeiramente mais elevada do que na várzea. A floresta de igapó sustentaram as mais baixas densidades populacionais. Terra firme e várzea diferem consideravelmente na composição e abundância de espécies, visto que a avifauna do igapó é intermediária entre a da terra firme e a da várzea. Os resultados sugerem que as florestas inundáveis tem uma papel muito importante na manutenção das comunidades de aves de grande porte na Amazônia, e pricipalmente aquelas espécies que usam grandes mosaicos de floresta.

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