Water balance and hydrologic characteristics of a rain forest catchment in the Central Amazon Basin

1993 ◽  
Vol 29 (3) ◽  
pp. 759-773 ◽  
Author(s):  
Lance F. W. Lesack
Author(s):  
B.R. FORSBERG, ◽  
M. GASTIL, ◽  
S.K. HAMILTON, ◽  
L.L. HESS, ◽  
I.B.T. LIMA, ◽  
...  
Keyword(s):  

2014 ◽  
Vol 44 (1) ◽  
pp. 9-18 ◽  
Author(s):  
Eliane Gomes Alves ◽  
Peter Harley ◽  
José Francisco de C. Gonçalves ◽  
Carlos Eduardo da Silva Moura ◽  
Kolby Jardine

Isoprene emission from plants accounts for about one third of annual global volatile organic compound emissions. The largest source of isoprene for the global atmosphere is the Amazon Basin. This study aimed to identify and quantify the isoprene emission and photosynthesis at different levels of light intensity and leaf temperature, in three phenological phases (young mature leaf, old mature leaf and senescent leaf) of Eschweilera coriacea (Matamatá verdadeira), the species with the widest distribution in the central Amazon. In situ photosynthesis and isoprene emission measurements showed that young mature leaf had the highest rates at all light intensities and leaf temperatures. Additionally, it was observed that isoprene emission capacity (Es) changed considerably over different leaf ages. This suggests that aging leads to a reduction of both leaf photosynthetic activity and isoprene production and emission. The algorithm of Guenther et al. (1999) provided good fits to the data when incident light was varied, however differences among E S of all leaf ages influenced on quantic yield predicted by model. When leaf temperature was varied, algorithm prediction was not satisfactory for temperature higher than ~40 °C; this could be because our data did not show isoprene temperature optimum up to 45 °C. Our results are consistent with the hypothesis of the isoprene functional role in protecting plants from high temperatures and highlight the need to include leaf phenology effects in isoprene emission models.


Phytotaxa ◽  
2017 ◽  
Vol 311 (1) ◽  
pp. 77
Author(s):  
FERNANDA NUNES CABRAL ◽  
VOLKER BITTRICH ◽  
MARIA DO CARMO ESTANISLAU DO AMARAL

Two new species of Caraipa (Calophyllaceae) are described and illustrated: Caraipa glabra and C. iracemensis. Both species are known only from the municipality of Presidente Figueiredo, Amazonas state, Brazil. They both occur on patches of white-sand vegetation and they are locally abundant. Caraipa glabra is a small tree and can be distinguished from other Caraipa species by the complete absence of hairs on the leaf lamina, pedicel and fruits. Caraipa iracemensis is morphologically similar to C. grandifolia and C. caespitosa, and can be distinguished by its habit, leaves and petiole size, as well as fruit surface and size.


2021 ◽  
Author(s):  
Claire Ansart ◽  
Cécile Gautheron ◽  
Djamila Demri ◽  
Thierry Allard ◽  
Damien Calmels ◽  
...  
Keyword(s):  

2018 ◽  
Author(s):  
Luciana Varanda Rizzo ◽  
Pontus Roldin ◽  
Joel Brito ◽  
John Backman ◽  
Erik Swietlicki ◽  
...  

Abstract. The Amazon Basin is a unique region to study atmospheric aerosols, given their relevance for the regional hydrological cycle and large uncertainty of their sources. Multi-year datasets are crucial when contrasting periods of natural conditions and periods influenced by anthropogenic emissions. In the wet season, biogenic sources and processes prevail, and the Amazonian atmospheric composition resembles pre-industrial conditions. In the dry season, the Basin is influenced by widespread biomass burning emissions. This work reports multi-year observations of high time resolution submicrometer (10–600 nm) particle number size distributions at a rain forest site in Amazonia (TT34 tower, 60 km NW from Manaus city), between years 2008–2010 and 2012–2014. Median particle number concentration was 403 cm−3 in the wet season and 1254 cm−3 in the dry season. The Aitken mode (~ 30–100 nm in diameter) was prominent during the wet season, while accumulation mode (~ 100–600 nm in diameter) dominated the particle size spectra during the dry season. Cluster analysis identified groups of aerosol number size distribution influenced by convective downdrafts, nucleation events and fresh biomass burning emissions. New particle formation and subsequent growth was rarely observed during the 749 days of observations, similar to previous observations in the Amazon Basin. A stationary 1D column model (ADCHEM – Aerosol Dynamics, gas and particle phase CHEMistry and radiative transfer model) was used to assess importance of processes behind the observed diurnal particle size distribution trends. Three major particle source types are required in the model to reproduce the observations: (i) a surface source of particles in the evening, possibly related to primary biological emissions (ii) entrainment of accumulation mode aerosols in the morning, and (iii) convective downdrafts transporting Aitken mode particles into the boundary layer mostly during the afternoon. The latter process has the largest influence on the modelled particle number size distributions. However, convective downdrafts are often associated with rain and thus act both as a source of Aitken mode particles, and as a sink of accumulation mode particles, causing a net reduction in the median total particle number concentrations in the surface layer. Our study shows that the combination of the three mentioned particle sources are essential to sustain particle number concentrations in Amazonia.


1981 ◽  
Vol 11 (1) ◽  
pp. 87-92 ◽  
Author(s):  
Cari F. Jordan ◽  
Jochen Heuveldop

Abstract In a tropical rain forest near San Carlos de Rio Negro, Venezuela, average yearly precipitation from September 1, 1975, through August 31, 1977 was 3664 mm. Throughfall was 87% of precipitation, stem flow was 8%, transpiration was 47%, evaporation from leaf surfaces was 5%, and sub-surface runoff was 48%. These results conform closely to the prediction of Marques et al. (1977) that 48% of the precipitation that falls on the central Amazon Basin is derived from evapotranspiration within the Basin.


1997 ◽  
Vol 11 (3) ◽  
pp. 295-311 ◽  
Author(s):  
Michael E. McClain ◽  
Jeffrey E. Richey ◽  
Jay A. Brandes ◽  
Tania P. Pimentel

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