Variations in tree community composition and structure in a fragment of tropical semideciduous forest in southeastern Brazil related to different human disturbance histories

In an area of tropical seasonal semideciduous forest, the soil characteristics, floristic composition, physiognomic structure, and the distribution of three regeneration and three dispersal guilds were studied for four stands within the forest that had documented histories of varying degrees of human disturbance. The aim was to study forest regeneration in areas of preserved forest and secondary forest, with parts of both types of forest experiencing either 'intensive' or 'occasional' cattle trampling. The study was carried out in the Sebastiao Aleixo da Silva Ecological Station, Bauru, São Paulo State, Brazil. Two stands were called 'secondary' because they corresponded to forest tracts that were felled and occupied by crops and pastures in the past and then abandoned to forest regeneration ca. 40 years before this study. The other two stands, called 'preserved', corresponded to areas of the fragment where the forest has been maintained with only minor human impacts. The arboreal component of the tree community (diameter at breast height or dbh greater than or equal to 5 cm) was sampled in 20 plots of 40 m x 40 m, and the subarboreal component (diameter at the base of the stem or dbs < 5 cm and height greater than or equal to 0.5 m) in subplots of 40 m x 2 m. Physiognomic features, such as canopy height and density of climbing plants, were registered all over a 5 m x 5 m gridline laid on the sample plots. Soil bulk samples were collected for chemical and textural analyses. Most detected differences contrasted the secondary to the preserved forest stands. The soils of the secondary stands showed higher proportions of sand and lower levels of mineral nutrients and organic matter than those of the preserved stands, probably due to higher losses by leaching and erosion. Compared to the secondary stands, the preserved ones had higher proportions of tall trees, higher mean canopy height, lower species diversity, higher abundance of autochorous and shade-tolerant climax species, and lower abundance of pioneer and light-demanding climax species. Despite the high proportion of species shared by the preserved and secondary stands (108 out of 139), they differed consistently in terms of density of the most abundant species. on the other hand, the secondary and preserved stands held similar values for tree density and basal area, suggesting that 40 years were enough to restore these features. Effects of cattle trampling on the vegetation were detected for the frequency of trees of anemochorous and zoochorous species, which were higher in the stands under occasional and intensive cattle trampling, respectively. The density of thin climbers was lower in the stands with intensive trampling. (C) 2004 Elsevier B.V. All rights reserved.

The tadpole of Scinax catharinae (Anura : Hylidae) with description of the internal oral morphology, and a review of the tadpoles from the Scinax catharinae group

We present a description of the external morphology and internal oral features of the tadpole of Scinax catharinae and comparisons with the known tadpoles of the S. catharinae group. Two characters of the external morphology present some intraspecific variation: the row of submarginal papillae, which can be uniseriate or absent, and the tail tip, which can be large or small, truncated or not. That said, the tadpole of S. catharinae presents some distinguishing features that differentiate it from other tadpoles in the S. catharinae group: i) the marginal row of papillae with alternate disposition, ii) the spiracle opening on the midline of the body, iii) longest snout length, and iv) largest interorbital distance. The studied species were segregated into five ecomorphological guilds, characterized by external morphological features, tadpole habitat use and vegetation formation of species range. The taxonomy of the S. catharinae group is complex, due to the morphological similarities among the adults. Larval characters could help in the resolution of the taxonomic and phylogenetic complexities, since the morphological differences among the tadpoles in this group seem more conspicuous than those found among the adults.

Bird species of black water inundation forests in the Jau National Park (Amazonas state, Brazil): their contribution to regional species richness

We compared the relative contribution of blackwater inundation forest (igapo) and unflooded (terra firme) forest for regional bird species diversity in the lower Rio Negro region. For analyses of habitat preference we used mist-net samples and an unpublished bird species check-list. The igapo forest had lower bird species diversity than the terra firme forest. However, some 14% of the forest bird species in the region are restricted to igapo forest. Species composition was found to be distinct between the understories of the two forest types. Common forest bird guilds in the Neotropics such as ant-following birds avoid igapo forest. The differential habitat selection among birds in the inundated and unflooded forest is likely to result from vegetation structure and biological interactions such as aggressive behaviour. Since the inundated forest has a typical biota, conservation efforts needs to be directed to protect these habitats. Unfortunately, inundation forests are threatened by several human actions, especially dam construction. The extent of protected areas in the Brazilian Amazon is insufficient for the adequate protection of the inundated habitats, because it includes only 3% of the total area.

ANTI-HERBIVORE PROTECTION BY MUTUALISTIC SPIDERS and THE ROLE of PLANT GLANDULAR TRICHOMES

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Resource partitioning among epigaeic and hypogaeic ants (Hymenoptera: Formicidae) of a Brazilian cocoa plantation

Patterns of dietary and foraging strata utilization by the ground ant community of a Brazilian cocoa planatation were examined using sugar, meat and flour baits on the surface as well as buried. A total of 49 ant species was recorded, including 10 species of Pheidole. Strong dominance was exercised by Solenopsis geminata at both surface and subterranean strata, and at all food resources. The dissimilarity matrix of the epigaeic ant fauna was much greater than that for the hypogaeic species. At least four guilds were identified: the fungus-growing ants, epigaeic nectivores, epigaeic carnivores, and hypogaeic foragers. Niche breadth reduction, leading to the formation of guilds, permits the coexistence of many species in the this ground ant community from a tropical cocoa plantation. -Authors

Hypogaeic anti epigaeic ant (Hymenoptera: Formicidae) assemblages of atlantic costal rainforest and dry mature and secondary amazon forest in Brazil: Continuums or communities

Meat, flour and sugar baits were used on the soil surface and buried to examine species composition of the ant fauna in three separate tropical forests in Brazil, and to control for the effect of the regional faunal pool. Compositional mosaic diversities were comparable among areas, bait types and foraging strata. Mosaic diversity was independent of mean assemblage size. The number of unique species per sampling unit was correlated with mean assemblage size. Canonical correspondence analysis ordered species first by foraging substrate, second by geographic location, and third by diet. The first axis was significantly correlated with mean similarity and affinity. Mean Mahanalobis distances between centroids of groups based upon foraging strata were significantly larger than between localities, indicating local ecological pressures stronger than regional species pool constraints. As most. species foraged in only one stratum in one geographical position and were not omnivorous, the response of species to environmental gradients (continuums) showed a lower coherency with these patterns than did communities, structured around guilds based upon foraging strata and diet.

La sostenibilidad del desarrollo a 20 años de la cumbre para la tierra: avances, brechas y lineamientos estratégicos para América Latina y el Caribe

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Amazonia posible y sostenible

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Categorização functional trófica das comunidades de macroinvertebrados de dois reservatórios na região centro-oeste do Estado de São Paulo, Brasil

The use of the concept of guild can be useful for the functional trophic categorization of communities, because there is no requirement identification of organisms in the level of species and not to treat each species as a separate entity. The aim of this study was to analyze the functional feeding groups (collectors-gatherers, collectors-filterers, shredders, predators and grazer-scrapers) of the macroinvertebrate communities of two reservoirs in the Midwestern region of São Paulo State. Sampling was carried out in rainy (March/April - 2001) and dry (July/August - 2001) seasons and the data obtained indicate that 'collectors-gatherers' is the most frequent guild. This fact suggests a great importance of organic matter as a food source in the diet of the macroinvertebrates analyzed.

El desarrollo sustentable: transformación productiva, equidad y medio ambiente

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Temas sobre el desarrollo de tecnologías para pequeños productores campesinos

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Avaliação preliminar do potencial turístico do município de rifaina (SP) e os impactos decorrentes do uso público de seus atrativos paisagísticos

This paper attempts to assess both the touristic potential of scenic attractions and the environmental impacts resulting from the public use of such attractions in the Rifaina Municipality, State of São Paulo, Southeastern Brazil. In the recent past, this municipality had its economy concentrated in rural activities (livestock, corn, rice and bean crops) and in the ceramic industry (production of bricks, tiles and shackles),which was largely developed in the floodplain of the Rio Grande before the construction of the Jaguara Power Plant Dam. The impacts resulting from touristic activities were evaluated by applying the VIM - Visitor Impact Management method, with emphasis on biophysical indicators. The main touristic attractions analyzed were: (1) Rifaina artificial beach; (2) Jaguara Reservoir; (3) Morro do Chapéu (scenic hill); (4) Touristic railroad; and (5) Cuestas cliffs. Attractions (1) and (2) are the most exploited ones, including, in the second case, nautical sports, sportive and craft fishing, and summer lodging. Although currently disabled, the touristic railroad presents potential conditions to be re-explored. Attractions (3) and (5), despite keeping high landscape and ecological ecotouristic potential, are the least visited places. In the present paper, a preliminary characterization of the major issues of tourism industry in the Rifaina municipality is made, including suggestions for the sustainable exploitation of tourism resources. The final results of the environmental impact evaluation of the tourism activities include small impacts in attractions (4) and (5) and moderate impacts to the three first attractions. In order to keep the sustainable touristic potential for that municipality this study proposes the improvement of the following measures: to foster research projects on technical or scientific aspects of the touristic attractions, improvement of tourism infrastructure and the creation of an Environmental Protection Area (APA) of the cuestas' scarps.

Biocombustibles líquidos para transporte en América Latina y el Caribe

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Aportes de los biocombustibles a la sustentabilidad del desarrollo en América Latina y el Caribe

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Efectos del cambio climático en la costa de América Latina y el Caribe: vulnerabilidad y exposición

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