Seed dispersal and spatial distribution of Attalea geraensis (Arecaceae) in two remnants of Cerrado in Southeastern Brazil

The seed dispersal system of Attalea geraensis (Arecaceae), an acaulescent palm, was investigated during one year in two Cerrado fragments in the state of S��o Paulo, southeastern Brazil. A. geraensis had inflorescences and infrutescences throughout the year. Two scatter-hoarding rodents (the spiny rat, Clyomys bishopi and agoutis, Dasyptocta azarae) were identified as seed predators/dispersers, able to move seeds up to 30 in from the palms, although most of the fruits (57.5%) were dispersed less than 2 in. The removal rates were high and after 20 days, 97.2% of the fruits were removed. Fruit fate was not related to fruit mass, length and diameter. The application of Morisita's index showed a more clumped distribution of adults in the smaller fragment, probably because of the absence of agoutis. Higher seed removal by rodents in the large Cerrado remnant may decrease seed predation by beetles. (C) 2007 Elsevier Masson SAS. All rights reserved.

Spatial distribution of nests of Nasutitermes sp (Isoptera : Termitidae) in a Cerrado area in southeastern Brazil

The density and aggregation patterns of nests of a species of Nasutitermes were determined in an area of 12,750 m(2). We found 131 nests in this area, and the distribution pattern was regular, with a density equaling 102.74 nests per hectare. Nest volume was determined from the height and diameter of 105 nests and varied from 1.59 to 192.46 dm(3). of the colonies, 70.5% had a volume below the mean value: 51.4% of these had volumes lower than 9 dm(3). Regression between the mean volumes and the distance of the 2 nearest nests was positive and significant (P < 0.001), suggesting competition between colonies.

Density and Spatial Distribution of Buffy-tufted-ear Marmosets (Callithrix aurita) in a Continuous Atlantic Forest

Funda����o de Amparo �� Pesquisa do Estado de S��o Paulo (FAPESP)

Larval competition for patchy resources in Chrysomya megacephala (Dipt., Calliphoridae): implications of the spatial distribution of immatures

In the present study, a single procedure was established to investigate the effect of the spatial distribution of immatures in patchy resources, on the outcome of larval competition for food. in experimental populations of Chrysomya megacephala. A theoretical model of intraspecific competition was extended and applied to experimental data on survival to adulthood for 20 larval densities, to obtain the theoretical mean number of individuals that will survive, considering a hypothetical previous random adult oviposition in a system of homogeneous patches. The survival curve obtained suggests that the larval competition for food in C. megacephala is of the scramble/exploitative type, which corroborates results from previous studies, although the latter did not consider the correlation between local and global abundances. The present model allows that experimental data could be perfectly applicable, and it incorporates fundamental assumptions about the spatial context of competition for patchy resources in blowflies, and may be applied to the optimization of mass rearing techniques and to the maintenance of insect colonies under experimental conditions.

Spatial distribution of canine Visceral Leishmaniasis in Ilha Solteira, S��o Paulo, Brazil

A Leishmaniose Visceral (LV) �� causada por protozo��rios do g��nero Leishmania e transmitida por flebotom��neos do g��nero Lutzomyia, os quais v��m adaptando-se ao ambiente peridomiciliar, onde o c��o �� sua principal fonte de alimento, aumentando assim o risco de casos em humanos. Neste trabalho, foram utilizadas t��cnicas de geoprocessamento e de estast��stica espacial como contribui����o �� compreens��o da din��mica epidemiol��gica da LV na ��rea urbana de Ilha Solteira-SP.

Spatial distribution of arboviral mosquito vectors (Diptera, Culicidae) in Vale do Ribeira in the South-eastern Brazilian Atlantic Forest

Funda����o de Amparo �� Pesquisa do Estado de S��o Paulo (FAPESP)

Spatial distribution of dengue in the city of Cruzeiro, S��o Paulo State, Brazil: use of geoprocessing tools

Este artigo tem por objetivo identificar padr��es na distribui����o espacial dos casos de dengue ocorridos no munic��pio de Cruzeiro/SP, no ano de 2006. Trata-se de um estudo ecol��gico e explorat��rio que utiliza as ferramentas de an��lise espacial na elabora����o de mapas tem��ticos, com dados obtidos do SinanNet. Foi feita uma an��lise por ��rea, tomando-se como unidade o setor censit��rio do IBGE; a an��lise considerou quatro meses do ano de 2006 que mostra a ocorr��ncia da doen��a no munic��pio. Os mapas tem��ticos foram constru��dos pelo programa computacional TerraView 3.3.1; assim como os valores dos ��ndices de Moran Global (I M) m��s a m��s e o estimador de Kernel. Foram georreferenciados 691 casos de dengue (taxa de 864,2 casos/100.000 habitantes); os ��ndices de Moran e p-valores obtidos foram I M = 0,080 (mar��o) p = 0,11; I M = 0,285 (abril) p = 0,01; I M = 0,201 (maio) p = 0,01 e I M = 0,002 (junho) p = 0,57. Os primeiros casos foram identificados na regi��o nordeste e central e os ��ltimos casos, na regi��o norte, nordeste e central. Foi poss��vel identificar os setores censit��rios onde a epidemia teve in��cio e como ocorreu t��mporo-espacialmente no munic��pio.

Spatial distribution of solutes and water in sucrose solution dehydrated apples

Half-fresh apples were immersed in sucrose solution (50% w/w, 27 degrees C) during different times of exposition (2, 4, and 8 h). Then each fruit was sliced from the transversal exposed surface. Density, water, and sugar content were determined for each slice. A mathematical model was fitted to experimental data of water and sucrose content considering the global flux and the tissue shrinkage. By numerical analysis, the binary effective diffusion coefficients as a function of concentration were calculated, using material coordinates and integrating simultaneously two differential equations (for water and sucrose). The coefficients obtained are one or even two orders of magnitude lower than the ones for pure solutions and present an unusual concentration dependence. This comparison shows the influence of the tissue resistance to the diffusion.

Density and spatial distribution of Atta sexdens rubropilosa and Atta laevigata colonies (Hym., Formicidae) in Eucalyptus spp. forests

Coordena����o de Aperfei��oamento de Pessoal de N��vel Superior (CAPES)

WATER BALANCE and SPATIAL DISTRIBUTION of AN ANURAN COMMUNITY FROM BRAZIL

Conselho Nacional de Desenvolvimento Cient��fico e Tecnol��gico (CNPq)

Abundance and temporal-spatial distribution of the rock shrimp Sicyonia dorsalis Kingsley, 1878 (Decapoda, Penaeoidea) from the northern coast of S��o Paulo state, Brazil.

Abundance and ecological distribution of the rock shrimp Sicyonia dorsalis from the northern coast of S��o Paulo State (Brazil) was investigated during a two-year period (July 2001 to June 2003). Monthly collections were conducted in the Ubatuba (UBA) and Caraguatatuba (CA) regions, using a commercial shrimp boat equipped with double-rig nets. In each region, seven depths were delimited (5 m to 35 m). A total of 1,752 and 1,894 shrimp were obtained at UBA and CA, respectively. The distribution of S. dorsalis differed among depths, years, and seasons. Highest abundance values were recorded in depths where silt and clay comprised more than 70% of the sediment. The majority (89%) of captured specimens were caught in the first year, in periods of lower mean temperature, mainly in the spring of 2001, when the intrusion of cold South Atlantic Central Waters (SACW) was more intense. In such period, the differences in the abundance of shrimps in each region (UBA = 1,118 and CA = 493) suggested that S. dorsalis migrated to the north (UBA), during the SACW intrusion. Thus, sediment type and water temperature are among the most important variables affecting the bathymetric distribution of S. dorsalis in these regions.

Temporal-spatial distribution of the hermit crab Loxopagurus loxochelis (Decapoda: Diogenidae) from Ubatuba Bay, S��o Paulo State, Brazil

The present work was conducted to determine the distribution of Loxopagurus loxochelis collected monthly, over a period of one year, in Ubatuba Bay (from September/95 to August/96). A total of 179 specimens were collected (138 males, 30 females and 11 ovigerous females). The greatest depth, predominance of very fine sand and highest mean value of organic matter contents of sediment, in combination with the low temperatures registered in winter (July and August), determined the presence of L. loxochelis in the subarea located at the Ubatuba Bay mouth, exposed to the open sea with high water current energy, important because this position insures that spawned larvae will enter into the oceanic circulation.

Spatial distribution of characidiin fishes (Teleostei, Crenuchidae) in the Ribeir��o Grande system, a tributary of Para��ba do Sul river basin, Brazil

This study analyses the spatial distribution of characidiin fishes Characidium lauroi and Characidium alipioi (Crenuchidae) in a forest stream system located in southeastern Brazil. Fish were sampled from Jury 2001 to April 2002. Collections were made with an electro-fishing device in five stream reaches of the Ribeir��o Grande system. Conductivity, pH, water temperature and dissolved oxygen were measured at each site. The species have different distributions in Ribeir��o Grande system. Characidium lauroi is abundant in montane-piedmont zones and Characidium alipioi occurs mainly in piedmont-plain zones. Streams' different features contribute to these species' distribution in the system.

Relief influence on the spatial distribution of the Atlantic Forest cover on the Ibi��na Plateau, SP

Several studies suggest that, on a large scale, relief conditions influence the Atlantic Forest cover. The aim of this work was to explore these relationships on a local scale, in Caucaia do Alto, on the Ibi��na Plateau. Within an area of about 78 km2, the distribution of forest cover, divided into two successional stages, was associated with relief attribute data (slope, slope orientation and altitude). The mapping of the vegetation was based on the interpretation of stereoscopic pairs of aerial photographs, from April 2000, on a scale of 1:10,000, while the relief attributes were obtained by geoprocessing from digitalized topographic maps on a scale of 1:10,000. Statistical analyses, based on qui-square tests, revealed that there was a more extensive forest cover, irrespective of the successional stage, in steeper areas (>10 degrees) located at higher altitudes (>923 m), but no influence of the slope orientation. There was no sign of direct influence of relief on the forest cover through environmental gradients that might have contributed to the forest regeneration. Likewise, there was no evidence that these results could have been influenced by the distance from roads or urban areas or with respect to permanent preservation areas. Relief seems to influence the forest cover indirectly, since agricultural land use is preferably made in flatter and lower areas. These results suggest a general distribution pattern of the forest remnants, independent of the scale of study, on which relief indirectly has a strong influence, since it determines human occupation.

Trade and sustainable development: spatial distribution of trade policies impacts on agriculture

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