Permeability of riparian forest strips in agricultural, small subtropical watersheds in south-eastern Brazil

If riparian buffer zones are ineffective in preventing C-4 plant carbon from upland areas reaching the stream sediment, the composition of stream fauna can be significantly altered. The permeability of riparian forest strips in agricultural, small subtropical watersheds in south-eastern Brazil was measured in nine watersheds categorised according to the predominant land cover of the legally required 30-m buffer riparian zone. Four watersheds with well preserved riparian forest along the 30-m buffer zone were designated as FOREST watersheds; three watersheds, with a predominance of C-4 grasses from sugarcane to pasture, mixed with preserved riparian forests, were designated MIXED watersheds; and two watersheds were termed PASTURE-SUGAR because their entire 30-m buffer zone was covered by C-4 plants. Stable carbon (delta C-13) isotopes were used as tracers of upland C-4 carbon in sediments, suspended particulate organic carbon, terrestrial and aquatic invertebrates and two species of neotropical fish. Although the intact 30-m buffer zone of riparian forests did not entirely prevent the input of C-4 to the river environment and food web, there was a significant increase in C-4 carbon in those watersheds where the buffer zone was not covered by riparian forests. These findings emphasise the importance of riparian forests in mitigating disturbance in streams and support efforts to preserve such riparian corridors.

Application of dendrogeomorphology on the study of soil sediment deposition in the stems of Guarea guidonea trees in a disturbed riparian forest in Goias state, Brazil

The sediments resulting of natural or anthropic erosion are deposited on the soil surface and around the trunks of trees occurring in riparian forests. For assessment of the erosion, tree-rings of roots and stems were analyzed. Guarea guidonea trees from a riparian forest affected by the sedimentation of soil erosion from pastures and soybean fields in state of Goias were selected. Wood samples were extracted through a non-destructive method at three heights from trunks of trees located in three positions (top, middle and bottom) of a riparian slope. The evaluation revealed a deposition of a thick sediment layer up to 34 cm around the base of tree trunks during the past 24 years. The inter-correlations between the tree-rings widths present in wood samples at the base and at 50 and 100 cm from Guarea guidonea tree trunks presented low, medium and high values. These values resulted from the low tree-rings distinctiveness in the wood; the absence of some rings as well as the eccentricity of the pith. The analyses of dendrogeomorphology allowed the determination of the date of seed germination and tree growth and inference on the periods of sediment deposition in the trunk of the trees.

NEW RECORDS OF ANOPHELES HOMUNCULUS IN CENTRAL AND SERRA DO MAR BIODIVERSITY CORRIDORS OF THE ATLANTIC FOREST, BRAZIL

Two new records of Anopheles homunculus in the eastern part of the Atlantic Forest are reported. This species was found for the first time in Barra do Ouro district, Maquine municipality, Rio Grande do Sul state, located in the southern limit of the Atlantic Forest. The 2nd new record was in the Serra Bonita Reserve, Camacan municipality, southeast Bahia state. These records extend the geographical distribution of An. homunculus, suggesting that the species may be widely distributed in coastal areas of the Atlantic Forest. It is hypothesized that the disjunct distribution of the species may be caused by inadequate sampling, and also difficulties in species identification based only on female external characteristics. Species identification was based on morphological characters of the male, larva, and pupa, and corroborated by DNA sequence analyses, employing data from both 2nd internal transcribed spacer of nuclear ribosomal DNA and of mitochondrial cytochrome c oxidase subunit I.

Diet of Astyanax paranae (Characidae) in streams with different riparian land covers in the Passa-Cinco River basin, southeastern Brazil

An analysis of the diet of Astyanax paranae Eigenmann, 1914 in nine streams located in the Passa-Cinco River basin (upper Parana River system) was performed to investigate the feeding habits of this species, check for possible spatial variations in diet and to investigate the influence of riparian vegetation in the composition of the diet. Stomach contents of 243 specimens were analyzed by the methods of relative frequency of occurrence and volume, and the diet was characterized by the alimentary index (AI(i)). The species showed insectivorous feeding habits, with a predominance of terrestrial and aquatic insects in the diet, varying by location. In most streams, resources of allochthonous origin were the most consumed. The participation of aquatic insects and terrestrial plants were high in most streams, while terrestrial insects and invertebrates were highest in streams with a greater presence of riparian forest. The two streams located draining pasture fields were the only places were A. paranae consumed algae and macrophyte fragments. These results were corroborated by the analysis of similarity (ANOSIM): the descriptor "percentage of riparian forest" was the highest environmental influence on the diet of A. paranae. The study shows that riparian forest percentage on the stream reach determines the species diet composition, but A. paranae is also able to gather enough food resources in a variety of severely degraded environments.

Width of buccal and posterior corridors: differences between cases treated with asymmetric and symmetric extractions

OBJECTIVE: To verify if there is difference in the buccal and posterior corridor width in cases treated with extraction of one and four premolars. METHODS: Through posed smile photographs of 23 Class II patients, subdivision, treated with extraction of one premolar and 25 Class I and Class II patients, subdivision, treated with extraction of four premolars, the percentage of buccal and posterior corridor width was calculated. The two protocols of extractions were compared regarding the buccal and posterior corridor width by independent t tests. RESULTS: There was no statistically significant difference on the buccal and posterior corridor widths between patients treated with symmetric and asymmetric extraction. CONCLUSION: The buccal and posterior corridor did not differ between the evaluated protocols of extractions.

Threatened fishes of the world: Brycon nattereri Gunther, 1864 (Characidae)

Brycon nattereri (Ostariophysi: Characiformes: Characidae), a threatened South American freshwater fish, occurs in the Parana, Tocantins and Sao Francisco river basins in central Brazil. It is a middle-sized (up to 50 cm SL), omnivorous species, which occurs in swift, clear-water rivers with well-preserved riparian vegetation. Main threats to the species are water pollution, dam building, and deforestation.

Influence of land use changes on water chemistry in streams in the State of Sao Paulo, southeast Brazil

Streamwater is affected by several processes in the watershed including anthropogenic activities that result in changes in water quality as well as in the functioning of these stream ecosystems. Therefore, this work aims to evaluate the concentration of major ions (Ca2+, Mg2+, Na+, K+, NH4+, NO3-, NO2-, Cl-, SO42-, PO43-, HCO3-) in streams in the state of Sao Paulo (southeast Brazil). The sampling sites are located at undisturbed (ombrophilus dense forest, semideciduous forest and savanna - cerrado) and disturbed areas (pasture, urbanization and sugar cane crops). Streamwater chemistry varied according to land use change and, in general, was higher in disturbed sites. Streams located in undisturbed sites at Ribeira de Iguape/Alto Paranapanema watershed (streams 1, 2 and 3) seem to be regulated by soil characteristics, as the disturbed streams located at the same watershed covered by pasture (stream 7) showed high concentration for the most of the variables. Exception to streams located at Pontal do Paranapanema watershed where both disturbed (stream 8) and undisturbed streams (stream 4 and 5) presented similar patterns for almost all variables measured.

Description of Two New Sand Fly Species Related to Nyssomyia antunesi (Diptera, Psychodidae, Phlebotominae)

Both sexes of two new Brazilian phlebotomine sand flies of the genus Nyssomyia Barretto 1962 [= Lutzomyia (Nyssomyia) sensu Barretto], Nyssomyia delsionatali n. sp. and Nyssomyia urbinattii n. sp., presenting close affinity with Nyssomyia antunesi (Coutinho), are described and illustrated. N. delsionatali n. sp was captured on the edge of a riparian Amazonian forest on the Juruena river in the northwest of Mato Grosso state and N. urbinattii n. sp in a riparian Amazonian forest on the Teles Pires river between Mato Grosso and Para states. Some measurements of both sexes of N. antunesi and illustration of the male genitalia and the female spermathecae as well as an identi_cation key for males and females of the genus Nyssomyia are provided.

A new species of the Bokermannohyla circumdata group (Anura: Hylidae) from southeastern Brazil, with bioacoustic data on seven species of the genus

We describe a new species of the Bokermannohyla circumdata group from the Estacao de Pesquisa e Desenvolvimento Ambiental Galheiro (EPDA-Galheiro) (19 degrees 12'S; 47 degrees 08'W), Municipality of Perdizes, State of Minas Gerais, a mid-altitudinal (similar or equal to 850 m above sea level) riparian forest environment in the Cerrado of southeastern Brazil. Bokermannohyla napolii sp. nov. is allied to the large-sized species of the group, diagnosed on the basis of adult morphology/morphometrics, and mainly vocalizations. Adult specimens of the new species are most closely related to those of B. luctuosa and B. circumdata, but can be differentiated from the former by having distal subarticular tubercle of finger III bifid/divided in males, and finger IV bifid/divided in males and females; and from both B. luctuosa and B. circumdata by a distinctive advertisement call structure. We also provide bioacoustic data on seven other species of the genus, including previously unknown advertisement calls of B. circumdata and B. carvalhoi, and re-description of the advertisement calls of B. luctuosa, B. ibitiguara, B. nanuzae, B. sazimai, and B. hylax.

Associations of Forest Cover, Fragment Area, and Connectivity with Neotropical Understory Bird Species Richness and Abundance

Theoretical and empirical studies demonstrate that the total amount of forest and the size and connectivity of fragments have nonlinear effects on species survival. We tested how habitat amount and configuration affect understory bird species richness and abundance. We used mist nets (almost 34,000 net hours) to sample birds in 53 Atlantic Forest fragments in southeastern Brazil. Fragments were distributed among 3 10,800-ha landscapes. The remaining forest in these landscapes was below (10% forest cover), similar to (30%), and above (50%) the theoretical fragmentation threshold (approximately 30%) below which the effects of fragmentation should be intensified. Species-richness estimates were significantly higher (F = 3715, p = 0.00) where 50% of the forest remained, which suggests a species occurrence threshold of 30-50% forest, which is higher than usually occurs (<30%). Relations between forest cover and species richness differed depending on species sensitivity to forest conversion and fragmentation. For less sensitive species, species richness decreased as forest cover increased, whereas for highly sensitive species the opposite occurred. For sensitive species, species richness and the amount of forest cover were positively related, particularly when forest cover was 30-50%. Fragment size and connectivity were related to species richness and abundance in all landscapes, not just below the 30% threshold. Where 10% of the forest remained, fragment size was more related to species richness and abundance than connectivity. However, the relation between connectivity and species richness and abundance was stronger where 30% of the landscape was forested. Where 50% of the landscape was forested, fragment size and connectivity were both related to species richness and abundance. Our results demonstrated a rapid loss of species at relatively high levels of forest cover (30-50%). Highly sensitive species were 3-4 times more common above the 30-50% threshold than below it; however, our results do not support a unique fragmentation threshold.

Cross-taxon congruence of alpha and beta diversity among five leaf litter arthropod groups in Colombia

In this study alpha and beta diversity patterns of five leaf litter arthropod groups (ants, predatory ants, oribatid mites, spiders and other arachnids) were described and compared in 39 sampling patches of a transformed landscape in southwestern Colombia, that represented five vegetation types: secondary forest, riparian forest, giant bamboo forest, pasture and sugarcane crop. It was also assessed whether some taxa could be used as diversity surrogates. A total of 6,765 individuals grouped in 290 morphospecies were collected. Species richness in all groups was lower in highly transformed vegetation types (pasture, sugarcane crop) than in native ones (forests). In contrast, there were no clear tendencies of beta diversity among vegetation types. Considering sampling patches, 0.1-42% of the variation in alpha diversity of one taxonomic group could be explained from the alpha diversity of another, and 0.2-33% of the variation of beta diversity of a given taxon was explained by that in other groups. Contrary to recent findings, we concluded that patterns of alpha diversity are more congruent than patterns of beta diversity. This fact could be attributed to a sampling effect that promotes congruence in alpha diversity and to a lack of a clear regional ecological gradient that could promote congruent patterns of beta diversity. We did not find evidence for an ideal diversity surrogate although diversity patterns of predatory ants had the greatest congruencies. These results support earlier multi-taxon evaluations in that conservation planning should not be based on only one leaf litter arthropod group.

Immunohistochemical study of pituitary cells in wild and captive Salminus hilarii (Characiformes: Characidae) females during the annual reproductive cycle

Freshwater fish that live exclusively in rivers are at particular risk from fragmentation of the aquatic system, mainly the species that migrate upriver for reproduction. That is the case of Salminus hilarii, an important migratory species currently classified as “almost threatened” in the São Paulo State (Brazil), facing water pollution, dam construction, riparian habitat destruction and environmental changes that are even more serious in this State. Additionally, this species show ovulation dysfunction in captivity. Our studies focused on the identification and distribution of the pituitary cell types in the adenohypophysis of S. hilarii females, including a morphometric analysis that compares pituitary cells from wild and captive broodstocks during the reproductive annual cycle. The morphology of adenohypophysial cells showed differences following the reproductive cycle and the environment. In general, optical density suggested a higher cellular activity during the previtellogenic (growth hormone) and vitellogenic (somatolactin) stages in both environments. Additionally, the nucleus/cell ratio analysis suggested that growth hormone and somatolactin cells were larger in wild than in captive females in most reproductive stages of the annual cycle. In contrast, prolactin hormone showed no variation throughout the reproductive cycle (in both environments). Morphometrical analyses related to reproduction of S. hilarii in different environmental conditions, suggest that somatolactin and growth hormone play an important role in reproduction in teleost and can be responsible for the regulation of associated processes that indirectly affect reproductive status.

A importância das áreas ripárias para a sustentabilidade hidrológica do uso da terra em microbacias hidrográficas

Zonas ripárias são áreas de saturação hídrica, permanente ou temporária, cuja principal função é a proteção dos recursos hídricos de uma microbacia. Essa pesquisa comparou a adequação do uso do solo de dois cenários de planejamento agrícola de uma microbacia: o cenário convencional, representando o método usualmente empregado, que apenas considera as classes de capacidade de uso da terra, e o cenário hidrológico, que inclui a delimitação e avaliação das zonas ripárias. Um estudo de caso foi realizado na Microbacia do Ribeirão São João (3.656 ha), no município de Mineiros do Tietê (São Paulo, Brasil). Mapas de Classe de Capacidade de Uso da Terra e de Adequação do Uso do Solo foram elaborados, utilizando o Sistema de Informação Geográfica (SIG), para a construção dos cenários convencional e do proposto. Excluindo a Área de Preservação Permanente (APP), o cenário convencional indicou que 59,0% da área destinada à agricultura está adequadamente utilizada, 28,2% está subutilizada e 2,6% está sobreutilizada. O cenário proposto ou hidrológico, com inclusão da identificação da zona ripária (24,9% da microbacia) mostrou que muitas áreas que, no cenário convencional, possuem pouca restrição para o cultivo intensivo, como as classes II e III, são zonas ripárias, de sensibilidade hidrológica. Existem dentro dos limites da zona ripária 38,9% de classe de capacidade de uso III e 49,5% de classe IV. O planejador, desconsiderando a zona ripária, pode colocar em risco áreas vitais que, se degradadas, representam danos para a saúde e resiliência da microbacia.

Participação em políticas públicas para conservação de matas ciliares no Estado de São Paulo

O presente artigo visa a contribuir para os diálogos sobre políticas públicas relacionadas à conservação e restauração de matas ciliares no estado de São Paulo, considerando as possibilidades de participação social em sua formulação e implementação. A pesquisa que gerou as considerações aqui apresentadas baseou-se na análise da implementação e dos resultados do Projeto de Recuperação de Matas Ciliares (PRMC), uma intervenção conduzida pela Secretaria de Estado de Meio Ambiente do Estado de São Paulo (SMA-SP) visando a gerar subsídios para a elaboração de um programa de longo prazo de conservação e restauração de matas ciliares nesse Estado. O método de pesquisa incluiu a análise de documentos oficiais referentes ao projeto de intervenção; entrevistas qualitativas com funcionários dos quadros da SMA-SP e da Secretaria de Agricultura e Abastecimento do Estado de São Paulo - SAA-SP, esta última corresponsável pela implantação do projeto; além de entrevistas semi-estruturadas com proprietários rurais e representantes das organizações não governamentais envolvidas na execução dos projetos-piloto implementados durante o PRMC. A pesquisa mostra que as dificuldades de integração intra e interinstitucional - entre as coordenadorias e departamentos da SMA-SP, e desta com a SAA-SP - bem como a falta de priorização da participação, mobilização social e educação ambiental no PRMC, foram os principais fatores limitantes para o sucesso do Projeto no recorte aqui tratado.

Species of Drosophila (Diptera: Drosophilidae) attracted to dung and carrion baited pitfall traps in the Uruguayan Eastern Serranías

This study investigates the species richness and abundance of Drosophila Fallén, 1823 attracted to dung and carrion baited pitfall traps in natural areas with heterogeneous habitats at the Sierra de Minas, Eastern Serranías, southeastern Uruguay. Collecting was carried out on a monthly basis (May 2002 through April 2003). Drosophilids accounted for 0.84% (n = 131) and 3.61% (n = 158) of the Diptera collected from dung (n = 15,630) and carrion (n = 4,382) pitfall traps, respectively. A total of 12 species were identified, 11 of which belong to the subgenus Drosophila (the richest) and one to the subgenus Sophophora Sturtevant, 1939. Over 90% of the Drosophila specimens collected belong to five species of the subgenus Drosophila, namely D. gaucha Jaeger & Salzano, 1953, D. immigrans Sturtevant, 1921, D. mediovittata Frota-Pessoa, 1954, D. aff. nappae Vilela, Valente & Basso-da-Silva, 2004, and D. ornatifrons Duda, 1927. Drosophila cardini Sturtevant, 1916 is recorded for the first time from Uruguay. Drosophila abundance and species richness in the four habitats sampled in the Uruguayan Eastern Serranías, namely woodlands sierra, riparian forest, pine plantation and grazing grassland, were considered to be a function of habitat conservation. Diversity indices were low in all habitats. Different habitats supported particular coprophilous and necrophilous Drosophila species. The woodland sierra represents the most preserved habitat, and contributed with the highest species richness observed. Drosophila ornatifrons was the dominant species, with a restricted habitat distribution. On the other hand, grazed grassland, an environment modified by livestock management, had the lowest species richness: only a few specimens of D. repleta Wollaston, 1858. Regarding species composition, significant differences were found in some pairwise comparisons of groups of Drosophila species that included D. ornatifrons. Fly attraction to dung can be exploited as an alternative and/or complementary collecting method in ecological studies of Drosophila assemblages in natural areas.