Amazon western

As shown in Figure 14.8, kaolinite concentrations are highest in tropical and equatorial latitudes, particiflarly off the western coasts of North Africa and Australia (>40%) and the northeastern coasts of Australia and South America (30%). The first two are the result of aeolian transport by the Trade Winds from the Saharan and Australian deserts, respectively. The other two are the result of river input from the eastern Australian continent and the Amazon River. 

This is a family of the warm regions, especially those of South America, where Banisteriopsis and its relatives supply one of the major hallucinogenic preparations of the western Amazon area. 

Knudsen J. T. (2002) Variation in floral scent composition within and between populations of Geonoma macrostachys (Arecaceae) in the western Amazon. Am. J. Bot. (in press). 

B. J. FeigI, and C. C. Cerri. 1995. "Nitrogen dynamics in soils of forests and active pastures in the western Brazilian Amazon basin." Soil Biology and Biochemistry. 27 1167-1175. 

Alves, D. S., J. V. Soares, S. Amaral, E. M. Mello, S. A. Almeida, O. F. Da Silva, and A. M. Silveiia. 1997. Biomass of primary and secondary vegetation in Rondonia, Western Brazilian Amazon. Global Change Biology 3 451-461. 

Table 11.2 Soil carbon content for the 0-100 cm layer of the main soil type of the western Amazon, calculated using an exponential modelisation of the vertical carbon profile.

More recently Bemoux (1998), Bemoux et al. (1998b) and Cerri et al. (2(XX)) studied an area of 334,000 km of the western Brazilian Amazon basin. These authors applied a first correction assuming that the soil fraction > 2 mm is carbon ftee. Soil bulk densities were often lacking in previous studies, and soil carbon content not always determined for several horizons. Bemoux (1998) proposed several methods to estimate the missing information. 

Bernoux, M., D. Amouays, C. Cerri, and H. Bourennane. 19S)8a. Modeling vertical distribution of carbon in Oxisols of the Western Brazilian Amazon (Rondonia). Soil Science. 163(12) 941-951. 

At the confluence of the Japura and Solimoes rivers, two forest sites of Mamiraua are described by Ayres (1993) with respect to the influence of inundation period on species composition. From the western Amazon there are inventories from the Rio Uyacali (Marmillod 1982), Rio Jurua (Campbell et al. 1992) and Rio Napo (Balsev et al. 1987), and in the eastern Amazon there are inventories from the Rio Guama (Pires and Koury 1959) and the Rio Xingu (Campbell et al. 1986). An overview of sample size, number of species and stems of these inventories is given on Table 13.5. 

On nonflooded sites in Amazonia, species richness increases from east to west, from 87 species ha i near Belem (Black et al. 1950) to over 179 species ha near Manaus (Prance et al. 1976) and more than 200 species in Ecuador (Balslev et al. 1987). Gentry (1982, 1990) explained species richness generally increases as annual precipitation increases. However in the same direction diversity increases in the floodplain forests from 53 species per ha in Para (Pires and Koury 1959) to over 135 species in Mamiraua (Ayres 1993) to 149 species at the Rio Napo (Balslev et al. 1987). The human influence on species composition in floodplain forests is a poorly investigated factor however, forests of the eastern Amazon have been exposed to deforestation and severe exploitation for longer times than western forests. In the varzea of the Solimoes river, selective logging nearly caused the extinction of... 

Campbell, D. G., J. L. Stone, and A. Rosas. 1992. A comparison of the phytosociology and dynamics of three floodplain (VSrzea) forests of known ages, Rio Juru4, western Brazilian Amazon." Botanical Journal of the Limnean Society 108 213-237. 

Ryther, J. H., D. W. Menzel, and N. Corwin. 1967. "Influence of the Amazon River outflow on the ecology of the western tropical Atlantic, I Hydrology and nutrient chemistry." Journal of Marine Research 25 69-82. 

In the Amazon Basin there are two different rainfall regimes — in the central part and a portion of the western area of the Basin there is a definite dry period, but in the eastern and western end of the Basin there... 

Poster, R. A., Capone, D. G., Carpenter, E. J., Mahaffey, C., Subramaniam, A., and Zehr, J. P. (2007). Influence of the Amazon River plume on distributions of free-living and symbiotic cyanobacteria in the western tropical north Atlantic Ocean. Limnol. Oceanogr. 52, 517—532. 

Some of the highest numbers for the Hemiaulus-Richelia symbioses were reported in the western tropical North Atlantic (WTNA). Carpenter et al. (1999) observed an extensive bloom off the NE coast of South America in autumn of 1996. They reported cell densities from 10 to 10 Richelia Recently, in the same vicinity as the study of Carpenter et al. (1999), Foster et al. (2007) reported extremely high niJH gene copy (>10 copies L ) abundances (proxy for cell abundances) for Richelia associated H. hauckii and Rhizosolenia clevei. In addition, they found within the plume waters of the Amazon River runoff a positive correlation between salinity and the abundance of the H. hauckii-Richelia abundance (Foster et al, 2007). 

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