Effects of soils and topography on the distribution of tree species in a tropical riverine forest in south-eastern Brazil

1994 ◽  
Vol 10 (4) ◽  
pp. 483-508 ◽  
Author(s):  
Ary T. Oliveira-Filho ◽  
Enivanis A. Vilela ◽  
Douglas A. Carvalho ◽  
Manuel L. Gavilanes

ABSTRACTThe relationships between soil properties, topography and tree species distribution were analysed in a tropical riverine forest at the margins of the Rio Grande, in Bom Sucesso, state of Minas Gerais, south-eastern Brazil. The forest was sampled by three 0.18 ha plots, with each plot made up of eight contiguous 15 m X 15 m quadrats, four of which were placed at the river margin and the remaining four in the forest interior. A canonical correspondence analysis indicated that the species' density distribution was significantly correlated with some soil chemical characteristics and topographical features. The soils of the three sample plots showed statistically significant differences for the levels of Ca, Mg, K and pH, with the fertility (expressed by the cation exchange capacity) increasing from Plot I to Plot III. These variations were mainly explained by the first canonical axis while the second was strongly correlated with topographical variables, separating the quadrats into two groups: those of the higher and steeper sites from those of the lower sites. The only soil property that was significantly different in lower and upper sites was the concentration of phosphorus. No significant difference in tree species distribution was found between river margin and interior quadrats, certainly because this forest sector lies on the outer side of a curve of the river where erosion is currently building high and steep river banks and forcing the forest to retreat. A tentative ecological classification of the 30 most abundant species according to their habitat preference in terms of soil fertility and topographical sites, and to their growth strategy in the forest dynamics, is presented. It is suggested that these factors play an important role in promoting the coexistence of tree species in this type of forest.

2005 ◽  
Vol 53 (1-2) ◽  
pp. 23-38 ◽  
Author(s):  
Rosebel C. Nalesso ◽  
Jean-Christophe Joyeux ◽  
Cintia O. Quintana ◽  
Evelise Torezani ◽  
Ana Clara Paz Otegui

The present work describes and analyses the structure of the macrobenthic epi- and infaunal assemblage of the estuarine system of Vitória Bay, South-eastern Brazil, from January 1998 to June 1999. Replicated sampling at intertidal and subtidal levels was conducted quarterly at ten stations. Intertidal and subtidal sediment composition was characterised. Water physico-chemical parameters were measured in situ. A total of 10,695 individuals, belonging to 144 taxa, were collected. Molluscs, crustaceans and polychaetes were the most abundant groups. The bivalves Anomalocardia brasiliana, Mytella guyanensis and M. falcata were the most abundant species. Locally, significant discharges of residential and industrial wastewater resulted in high organic content in the sediment (up to 30%) and low dissolved oxygen concentration in the water (< 1mg.l-1). Near the two entrances of the bay, high hydrodynamic activity and coarse sand reduced the detrimental effects of raw and treated sewage inputs. Species richness (S), diversity (H') and total abundance (A) decreased from outer-bay stations (22 < S < 72; 1.99 < H' < 2.85; 320 < A < 1737) towards inner-bay stations (2 < S < 45; 0.59 < H' < 2.67; 2 < A < 1317), where salinity and dissolved oxygen were lowest and organic matter content highest.


2012 ◽  
Vol 518-523 ◽  
pp. 5324-5329 ◽  
Author(s):  
Xiang Lin Wang ◽  
Jing Peng Li ◽  
Yan Zhang ◽  
Zhi Yao Su

Distribution pattern of 1148 indigenous tree species in Guangdong province and their relations to the environment were investigated based on the 0.5°×0.5° latitude-longitude grid system. The results showed that indigenous tree species richness increased with increasing latitude. Richness peaked in the middle of the study area with longitudinal gradient. Four ecological areas for indigenous tree species distribution were delimited using cluster analysis and TWINSPAN (two-way indicator species analysis). Indicator Species Analysis showed a significant difference was found in indicator species distribution across latitude gradient and the 4 ecological areas. Northern mountain areas and southern coastal areas possessed most of the indicator species (IV ≥ 0.7), among which Celtis philippensis, Gironniera cuspidata and Symplocos chunii were strongly indicative of the environmental characteristics. The study of distribution patterns and classification of ecological areas, which reflects different geographical and climatic characteristics, will be of significant implications for introduction of indigenous tree species from natural ecological areas.


Author(s):  
Debora De Souza Silva-Camacho ◽  
Rafaela De S. Gomes ◽  
Joaquim N.S. Santos ◽  
Francisco Gerson Araújo

We examined the benthic fauna in four areas along a mangrove tidal channel in south-eastern Brazil, between October 2008 and August 2009. The tested hypothesis is that the most abundant groups avoid competition as they occupy different types of substrata and that the longitudinal distance from the sea also affects the occurrence of benthic fauna along the channel. We also examined the prop root epibiont fauna to describe this different community. Polychaeta was the dominant group in the sediment whereas Isopoda and Tanaidacea were the dominant groups on the prop roots. We found a tendency for higher infauna species richness and diversity in the innermost channel area during the summer. Higher abundance of epibiont fauna was also found in summer with tidal movements allowing the colonization of the prop roots of the mangrove forest by some taxa. The polychaetes Ceratocephale sp. and Laeonereis acuta had indication of habitat partitioning, with the first occurring mainly in very fine sand sediment whereas the latter preferred medium sand sediment. The microcrustaceans Chelorchestia darwini and Tanaidacea sp. 1 occurred in high abundance colonizing the prop roots. Exosphaeroma sp. was found in high abundance in infauna and epibiont fauna. The tested hypothesis of spatial partitioning of the mangrove channel by the benthic fauna was confirmed with the most abundant species occupying the substrata with different grain fractions and prop roots in different stations.


Author(s):  
Laura Busin Campos ◽  
Xênia Moreira Lopes ◽  
Ednilson da Silva ◽  
Marcos César de Oliveira Santos

AbstractThis study evaluated the feeding habits of the franciscana dolphin (Pontoporia blainvillei) in south-eastern Brazil. Stomach contents were collected from a total of 145 dead specimens found incidentally caught by fishing vessels or stranded between 2005 and 2015. Fish otoliths, cephalopod beaks and whole non-digested prey were used for prey species identification. A total of 9337 prey items were identified, including 26 species of teleost fishes and three species of cephalopods. The most important prey families were Sciaenidae among fish and Loliginidae among cephalopods. Franciscana dolphins tended to feed on small fish (mean = 5.25 cm) and cephalopods (mean = 8.57 cm). The index of relative importance (IRI) showed that Pellona harroweri and Doryteuthis plei were the most important prey for both males and females. The PERMANOVA test confirmed that there is no significant difference between the feeding habits of different sexes, but detected a significant difference among seasons. Overall, our results show that franciscana dolphins are predominantly ichthyophagous and non-selective in relation to the type of prey, feeding on pelagic, demersal and pelagic-demersal prey.


2013 ◽  
Vol 11 (3) ◽  
pp. 615-623 ◽  
Author(s):  
Alessandro Loureiro Paschoalini ◽  
Violeta da Rocha Perini ◽  
Dirceu Marzulo Ribeiro ◽  
Paulo Sérgio Formagio ◽  
Elizete Rizzo ◽  
...  

The alterations to the hydrologic regime downstream from hydroelectric dams may cause an impact on the reproductive success of fishes. This study aimed to analyse the influence of the physical and chemical parameters of the water of the Grande and Pardo Rivers on gonadal maturation, oocyte diameter, follicular atresia and biological indices of Pimelodus maculatus collected from three river sections: Grande River, downstream from the Porto Colômbia dam (S1), Grande River, downstream from the confluence with the Pardo River (S2) and in the Pardo River channel (S3). Males and females captured in S1 presented significantly higher average values for total length and body weight than those captured in S2 and S3. The gonadosomatic index values were significantly higher in fish collected in S3 and the Fulton condition factor did not show significant differences in fish collected from the three sections. The oocyte diameter, the follicular cells height and the zona pellucida thickness did not show any statistical differences between the sections. Conductivity presented a significant difference between S1 and S3 and during the reproductive period, water transparency presented similar values in the two sampling sections of the Grande River, but a much lower value in the Pardo River. A low frequency of fish with reproductive activity was registered in S1, whereas in S2 and S3 higher frequencies were recorded, emphasising the need of preserving the tributaries for the reproductive success of P. maculatus of the Grande River in south-eastern Brazil.


1991 ◽  
Vol 7 (1) ◽  
pp. 59-67 ◽  
Author(s):  
Jader S. Marinho-Filho

ABSTRACTCarollia perspicillata and Sturnira lilium are two species of abundant and widely distributed phyllostomid bats. Both are frugivorous and frequently found coexisting in the same areas. A study on feeding habits and morphology of C. perspicillata and S. lilium was conducted at Serra do Japi, Sấo Paulo, south-eastern Brazil, investigating the mechanisms associated with their coexistence. The two species are fairly similar in morphology and feeding habits. Analysis of faeces produced by captured bats revealed that there is a significant difference in diet between the two species. C. perspicillata tends to specialize in fruits of the genus Piper and S. lilium specializes in Solarium fruits. The fruiting periods of the four species of Piper eaten by bats at the study site are successive, with little overlap and high productivity. The species of Solarium have long and overlapping fruiting periods, with very low productivity. Piper and Solarium provide food resources almost all year, allowing the food specialization that may be an important mechanism of resource partitioning between C. perspicillata and S. lilium.


2005 ◽  
Vol 22 (4) ◽  
pp. 839-843 ◽  
Author(s):  
Edsel A. Moraes Junior ◽  
Adriano G. Chiarello

Micoureus demerarae (Thomas, 1905) is a medium-sized marsupial, around 130 g, with a nocturnal habit and insectivorous-omnivorous diet. From August 2001 to July 2002, seven individuals, three males and four females, were monitored with radio-telemetry in Reserva Biológica União, state of Rio de Janeiro, Brazil, aiming to investigate and describe the sleeping sites used by this marsupial. Fifty eight sleeping sites were located, most of which (70,7%) in palm trees Astrocaryum aculeatissimum (Schott) Burret, and the remaining in other tree species (29,3%), a significant difference (chi2 test; p < 0.005). The preference for this palm tree was not different between sexes (chi2 test; p = 0.920). It was possible to locate the exact place where the animal was hiding in 31 sleeping sites (53.4% of total) in palm trees the animals were always in the junction point of petioles and tree trunks, at an average height of 4.66 ± 1.36 m, while in the remaining tree species, seven individuals were in liana tangles and two in tree holes, at an average height of 10.67 ± 2.75 m. This height difference was significant (Mann Whitney test; p < 0.001). Results indicate that palm trees are important resources for M. demerarae. The observed preference for A. aculeatissimum is probably due to higher protection against predators made by the numerous spines of this palm tree species.


2021 ◽  
Vol 14 ◽  
pp. 194008292110103
Author(s):  
Patrick Jules Atagana ◽  
Eric Moïse Bakwo Fils ◽  
Sevilor Kekeunou

We aimed to assess how bats are affected by habitat transformation by comparing bat assemblages in four habitat types: primary forest, secondary forest, cocoa plantations and human habitations in the Dja Biosphere Reserve of southern Cameroon. Bats were sampled in the four habitat types using mist nets. During 126 nights, a total of 413 bats were captured, belonging to four families, 16 genera and 24 species. Ninety three individuals (17 species) were captured in the primary forest, followed by plantations (105 individuals, 14 species), human habitations (159 individuals, 10 species), and secondary forest (55 individuals, eight species). Megaloglossus woermanni was recorded in all the four habitats, and was the most abundant species (105 individuals). The analysis of bat assemblage between habitat types showed a statistically significant difference in species composition. The distribution of the six most abundant species ( Epomops franqueti, Megaloglossus woermanni, Rousettus aegyptiacus, Dohyrina cyclops, Hipposideros cf. caffer and Hipposideros cf. ruber) was influenced by habitat types. Our results suggest that the decrease in species richness observed in disturbed habitats may be due to habitat perturbations of primary forest habitats. Therefore, it is important to examine the effects of habitat conversion at species level, as responses are often species-specific.


Sign in / Sign up

Export Citation Format

Share Document