Diversity of social wasps (Hymenoptera, Vespidae, Polistinae) in three fragments of semideciduous seasonal forest in the northwest of São Paulo State, Brazil

Human exploitation of the forest in the northwest of São Paulo State has generated enormous fragmentation of that forest. Such disturbance has reduced the populations of insects in general. This work was a survey of social wasps (Hymenoptera, Vespidae; Polistinae) in three areas in different stages of regeneration: Paulo de Faria - SP (435 ha), Pindorama - SP (128 ha) and Neves Paulista - SP (1 ha). These three areas were chosen for comparative purposes. To capture the wasps, it was used: active collecting with attractant liquid (solution of water, salt and sugar) with the aid of a dorsal spray bag. During the period from July to December 2006, 414 social wasps were collected in Paulo de Faria, constituting seven species belonging to four genera; 111 social wasps were collected in Pindorama, constituting six species belonging to four genera, and 129 social wasps were collected in Neves Paulista constituting 12 species belonging to seven genera. In order to compare these three areas ecological indexes were calculated. Neves Paulista had the greatest diversity, and Paulo de Faria presented greater abundance. These factors were probably caused by neighboring areas and ecological corridors, which were limited in Paulo de Faria and Pindorama.

Diversity of social wasps (Hymenoptera, Vespidae, Polistinae) in three fragments of semideciduous seasonal forest in the northwest of São Paulo State, Brazil

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

Diversity of social wasps on semideciduous seasonal forest fragments with different surrounding matrix in Brazil

We surveyed social wasps (Polistinae) present in forest fragments of northwest of So Paulo state with different surroundings composed of a matrix of citrus crops and sugarcane in the expectation that the former matrix would be more diverse than the latter. We collected specimens actively using attractive liquids. We obtained 20 species in Magda, 13 in Bebedouro, 13 in Mato, and 19 in Barretos. The most common genus was Agelaia in all of the areas. The greatest Shannon-Wiener index of diversity was obtained in Magda (H' = 2.12). Species such as Brachygastra moebiana, Metapolybia docilis, Mischocyttarus ignotus, M. paulistanus and M. consimilis had not been recorded on recent surveys in the state. Furthermore M. consimilis is a new record for the state. We concluded that, with our data, a relation between the occurrence of social wasps and the surrounding matrix was not detected. © 2011 Getulio Minoru Tanaka Junior and Fernando Barbosa Noll.

Mite (Acari; Arachnida) diversity of two native plants in fragments of a semideciduous seasonal forest in Brazil

Studies to determine mite species richness in natural environments are still scarce, and have been conducted mainly in tropical ecosystems. The aim of this study was to determine the species richness of mites on two common native plants in fragments of the semideciduous seasonal forest in the Northwest of São Paulo State, Brazil. In each of eight fragments, 10 specimens of Actinostemon communis (Euphorbiaceae) and 10 of Trichilia casaretti (Meliaceae) were selected and marked. In total, 124 species of mites belonging to 21 families were found on the two plants. Tarsonemidae had the highest diversity (34 species), followed by Phytoseiidae (31), Tetranychidae (9) and Tenuipalpidae (8). Species accumulation curves for the two sampled plants did not reach an asymptote, even with the large sampling effort. Hence, it is estimated that a greater sampling effort may lead to an increase in species richness compared with what was found in this study. The richness of this mite fauna suggests that preservation of these plant species is important to maintain the mite diversity in these forest fragments. © 2013 Taylor & Francis Group, LLC.

Distribution of tree species in a geomorphological and pedological gradient of submontane semidecidual seasonal forest in the vicinity of Rio Doce state park, Minas Gerais

The objective of this study was to test the hypothesis that the distribution of tree species in a fragment of submontane seasonal semideciduous forest, a buffer zone in the Parque Estadual do Rio Doce, Minas Gerais, is influenced by geomorphological and weather and soil variables, therefore it can represent a source of information for the restoration of degraded areas where environmental conditions are similar to those of the study area. A detailed soil survey was conducted in the area by sampling three soil profiles per slope segment, totaling 12 profiles. To sample the topsoil, four composite samples were collected from the 10-20 cm layers in each topographic range totaling 16 composite samples. In the low ramp and the lower and upper concave slopes, the texture ranged from clay to sandy-clay. The soil and topographic gradient was characterized by changes in the soil physical-chemical properties. The soil in the 10-20 cm sampled layer was sandier, slightly more fertile and less acid in the low ramp than the clayer soil, nutrient-poor and highly acid soil at the top. The soil conditions in the lower and upper slope of the sampled layers, in turn, were intermediate. The P levels were limiting in all soils. The species distribution along the topographic gradient was associated with variations in chemical fertility, acidity and soil texture. The distribution of Pera leandri, Astronium fraxinifolium, Pouteria torta, Machaerium brasiliense and Myrcia rufipes was correlated with high aluminum levels and to low soil fertility and these species may be indicated for restoration of degraded areas on hillsides and hilltops in regions where environmental conditions are similar. The distribution of Pouteria venosa, Apuleia leiocarpa and Acacia polyphylla was correlated with the less acid and more fertile soil in the environment of the low ramps, indicating the potential for the restoration of similar areas.

Social Wasp Diversity (Vespidae, Polistinae) in a Forest Fragment in the Northeast of Sao Paulo State Sampled with Different Methodologies

Social wasp diversity in Semideciduous Seasonal Forests of the northeast of Sao Paulo State is poorly known, causing a lack of information on the diversity of these wasps from these areas which have been degraded. The objective of this work was to evaluate the social wasp (Vespidae, Polistinae) diversity in a Semideciduous Seasonal Forest of the northeast of Sao Paulo State and to compare three different kinds of sampling methodology. Surveys were conducted from August 2005 to September 2006 in the interior, edge and matrix of a Semideciduous Seasonal Forest fragment in Patrocinio Paulista city, Sao Paulo State. Three methodologies were used: 1. Active collection in flowers, 2. Searching for nests, 3. Active collection with attractive liquid. Thirty species of social wasps were collected in the fragment, but the diversity was highest in the edge. Active collection with attractive liquid was the most efficient methodology. Despite the high levels of deforestation, forest fragments in Sao Paulo State have a high diversity of social wasps, reinforcing the importance of their preservation.

Epigean ant communities in Atlantic Forest remnants of São Paulo: a comparative study using the guild concept

Epigean ant communities in Atlantic Forest remnants of São Paulo: a comparative study using the guild concept. The guilds constitute a valuable ecological tool, because they allow conducting comparisons among environments under different conditions. The ants can be used as ecological indicators, mainly for the monitoring of degraded forest areas. The aim of this research was to study guild organization among the epigeous Formicidae living in Atlantic forest remnants of the State of São Paulo, Brazil. Ant collections were performed in three distinct Atlantic forest biome areas: arboreal littoral vegetation ("restinga") (Cananéia), semideciduous seasonal forest (Piracicaba) and dense ombrophylousforest (Pariquera-Açu). After identification, the ants were grouped into guilds, based on the ecological attributes of behavior and habit, according to the literature. Nine guilds were found; the semideciduous seasonal forest ecosystem presented eight of them, followed by the arboreal sandbank (7) and dense ombrophylous forest (6). The guilds found were: litter omnivorous and scavengers, granivorous species, specialist predators living in litter and soil, litter generalist predators, subterranean mealybug-dependent species, army ants, dominant or subdominants arboreal, that occasionally forage on the ground, soil or litter dominant and fungus-growers, using feces and insect body fragments. The guilds found can be used in the monitoring of the mirmecofauna in the Atlantic Forest biome, supplying insights for further ecological studies.

Termite assemblages in five semideciduous Atlantic Forest fragments in the northern coastland limit of the biome

Termites are abundant organisms in tropical ecosystems and strongly influence the litter decomposition and soil formation. Despite their importance, few studies about their assemblage structures have been made in Brazilian Atlantic Forest fragments, especially in the area located north of the São Francisco River. This study aims to analyze the assemblage composition of five Atlantic Forest fragments located in the northern biome limit along the Brazilian coast. A standardized sampling protocol of termites was applied in each fragment. Thirty-three termite species belonging to twenty genera and three families were found in the forest fragments. The wood-feeder group was dominant both concerning to species richness and number of encounters in all areas. In sites northern to 7°S, there is an evident simplification of the termite assemblage composition regarding species richness and number of encounters by feeding group. This fact is apparently due to a higher sandy level in soils and to semideciduous character of the vegetation in the northern fragments. Thus, even on the north of São Francisco River, termite biodiversity is heterogeneously spread with highest density of species in the portion between 07°S and São Francisco River mouth (10°29'S).

Structure and dynamics of a woody plant community of a tropical semi-deciduous seasonal forest in the "Estação Ecológica do Panga", municipality of Uberlândia, Minas Gerais, Brazil

Studies of plant community dynamics are essential in understanding the demographic patterns of species since changes in demographic rates can affect the floristic composition and future structure. The purpose of the present study was to analyze the changes in the community structure and floristic composition of woody plants in a tropical semi-deciduous forest in Uberlândia in central Brazil, during a 10-years period. The data were collected in 1989 and in 2000 in 50 quadrats (10 m x 10 m) where all trees with a minimum circumference at breast height of 10 cm were sampled. In 1989, 93 species and 1103 individuals were registered. Over a period of 10 years, seven new species were added to the community, although eight disappeared. The main change that occurred during this period in the floristic composition was the replacement of savannah species occurring in forest gaps by those from the forest understory.

Photosynthesis and carbon gain under contrasting light levels in seedlings of a pioneer and a climax tree from a Brazilian Semideciduous Tropical Forest

In this study we evaluated photosynthetic characteristics and patterns of biomass accumulation in seedlings of two tree species from a Semideciduous Tropical Forest of Brazil. Seedlings of Trema micrantha (L.) Blum. (pioneer) and Hymenaea courbaril (L.) var. stilbocarpa (Hayne) Lee & Langenh. (climax) were grown for 4 months under low light (LL) (5%-8% of sunlight) and high light (HL) (100% of sunlight). Under HL, T. micrantha showed higher CO2 assimilation rates (A CO2) and light saturation than H. courbaril. Under LL, A CO2 were higher in H. courbaril. Under LL, total chlorophyll and carotenoid contents per unit leaf area were higher in H. courbaril. Chlorophyll a/b ratio was higher in T. micrantha under both light regimes. A CO2 and Fv/Fm ratio at both pre-dawn and midday in H. coubaril were lower in HL indicating chronic photoinhibition. Thus, the climax species was more susceptible to photoinhibition than the pioneer. However, H. courbaril produced higher total biomass under both treatments showing high efficiency in the maintenance of a positive carbon balance. Thus, both species expressed characteristics that favor growth under conditions that resemble their natural microenvironments, but H. courbaril also grew under HL. The ecophysiological range of responses to contrasting light levels of this climax plant seems to be broader than generally observed for other rainforest climax species. We propose that this could be related to the particular spatio-temporal light regime of the semideciduous forests.

Seasonal development of secondary xylem and phloem in Schizolobium parahyba (Vell.) Blake (Leguminosae : Caesalpinioideae)

The cambial activity and periodicity of secondary xylem and phloem formation have been less studied in tropical tree species than in temperate ones. This paper describes the relationship between seasonal cambial activity, xylem and phloem development, and phenology in Schizolobium parahyba, a fast growing semideciduous seasonal forest tree from southeastern Brazil. From 2002 to 2003, wood samples were collected periodically and phenology and climate were recorded monthly in the same period. S. parahyba forms annual growth increments in wood, delimited by narrow initial parenchyma bands. The reduction of the cambial activity to a minimum correlates to the dry season and leaf fall. The higher cambial activity correlates to the wet season and the presence of mature leaves. In phloem, a larger conductive region was observed in the wet season, when the trees were in full foliage. The secondary phloem did not exhibit any incremental zone marker; however, we found that the axial parenchyma tends to form irregular bands.

Social Wasp Diversity (Vespidae, Polistinae) in a Forest Fragment in the Northeast of São Paulo State Sampled with Different Methodologies

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Floristic composition of the tree stratum of a semideciduous mesophytic forest in the municipality of Jahu, SP, Brazil

A floristic study was carried out in an area of semideciduous mesophytic forest, lied in the municipality of Jahu, São Paulo State, Brazil. Due to the fact of the forest be crossed by three small rivers, for the sampling process, the forest was divided in two sampling areas: Area I (under the influence of the rivers) and Area II (without this influence). Differences in the abundance of some species between the two sampling areas were observed.

Phytosociological study on the tree stratum of a semideciduous mesophytic forest in the municipality of Jau, SP, Brazil

Through the point-centered quarter method, a phytosociological study was carried out in an area of semideciduous mesophytic forest with 190 ha, in the municipality of Jahu,SP. Due to the fact of the forest be crossed by three small rivers, for the sampling process, the Total Area was divided in two sampling areas: the Area I (under the influence of the rivers) and the Area II (without this influence). Some differences between the two regions were observed.

Floristic composition of the tree stratum of a semideciduous mesophytic forest in the municipality of Botucatu, São Paulo state

The floristic composition was studied in an area of semideciduous mesophytic forest, with 120 ha, in the municipality of Botucatu, SP, Brazil. This forest lies on the ascent of the Cuesta of Botucatu. Due to the heterogeneity of the relief, for the sampling process, the forest was divided in three regions: the upper one (comprising the strip of forest on the plateau), middle on (the forestal area lied on the ascent properly said) and the lower one (the strip of forest on the plain). The tree sampling regions showed some differences among them and this must be connected to the differences in the soil.