Computer intensive methods for controlling bias in a generalized species diversity index

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Comunidades macrofaunais bênticas associadas às algas de deriva e à grama marinha Halodule wrightii Ascherson na Ilha do Japonês, Cabo Frio, RJ

As extensas pradarias submersas formadas pelas gramas marinhas são importantes habitats da costa, onde ocorrem interações ecológicas entre diversas espécies da vegetação subaquática, invertebrados bentônicos e peixes. As gramas marinhas e algas de deriva são conhecidas como macrófitas marinhas e, por ocuparem o mesmo tipo de substrato, são normalmente encontradas juntas, proporcionando oxigênio, alimento, proteção, abrigo além de sítios de reprodução e pastagem para os animais associados a essas pradarias. Amostras de algas de deriva e de H. wrightii foram coletadas, ao longo de transectos fixos de 50 m paralelos à Ilha do Japonês, a fim de analisar a existência de relações positivas entre as espécies de macrófitas marinhas e sua macrofauna associada, comparar as duas comunidades e avaliar a estruturação da comunidade macrofaunal bêntica do local. Os transectos foram alocados de acordo com a posição do banco de grama marinha. Observou-se que a densidade de eixos e a biomassa de H. wrightii não explicam a variação da biomassa, riqueza de espécies e diversidade (Índice de Simpson) das algas de deriva. A grande movimentação das algas de deriva ao longo do banco de grama marinha faz com que elas se homogeneízem e ocupem diferentes lugares ao acaso na pradaria, muitos desses locais com baixa biomassa de H. wrightii devido à grande variabilidade na distribuição dessa espécie no local de estudo. Os descritores ecológicos da grama marinha também não tiveram relações positivas com sua macrofauna bêntica associada. A comunidade macrofaunal associada às gramas marinhas foi mais densa, rica e diversa do que a comunidade macrofaunal associada às algas de deriva. Os moluscos Anomalocardia flexuosa, Cerithium atratum, Ostrea sp, Tellina lineata e Divalinga quadrissulcata dominaram o ambiente de gramas marinhas. A maior complexidade estrutural das algas de deriva forneceu um habitat protegido mais atrativo para os crustáceos como, Pagurus criniticornis, Cymadusa filosa e Batea catharinensis. A malacofauna associada às algas não foi abundante, mas um novo registro foi a ocorrência do bivalve invasor Lithopaga aristatus, perfurando uma concha de Ostrea sp. As relações entre os descritores da biomassa algal foram comprovadas para a maioria dos descritores de sua fauna associada. As relações das macrófitas marinhas com a macrofauna total associada seguiram o mesmo padrão das relações das algas de deriva. As análises de agrupamento e ordenação mostraram que as comunidades macrofaunais bênticas do local são estruturadas de acordo com os táxons dos organismos associados mais dominantes influenciados pelo tipo de vegetação basibionte (algas de deriva ou grama marinha). Destaca-se com o presente estudo a importância de medidas de maior proteção no local para a preservação e manutenção do ecossistema da Ilha do Japonês, RJ, Brasil

Ecological impact of Mahshahr petrochemical activities on abundance and diversity of macrobenthic fauna in Zangi Creek (Persian Gulf)

The Moosa Creek extends from its opening into the Persian Gulf, with some sub narrow creeks leading to it. Zangi creek is one of the main branches of Moosa creek. The creek contains numerous sources of organic pollution, including sewage outlet flows and boat waste. After establishing the Petrochemical special Economic Zone (PETZONE) in 1997 near to the Zangi Creek, the pipelines, streets and railway made it distinct from eastern and western parts of this creek. Industrial activities have released sludge and effluents in this creek along these years. A survey of the Zangi creek was performed, assessing water properties, organic pollution, and the population density, distribution and diversity of macrobenthic fauna through bi-monthly sampling from July 2006 to September 2007. Samples were collected from water near the bottom and sediment at 7 stations include 2 stations inside the distinct Zangi creek and 4 stations along a transect with 1 km distances between them in eastern free part and one reference station located at the Persian Gulf entrance to the Moosa creek. The environmental parameters such as temperature, salinity, pH, dissolved oxygen, COD, turbidity, EC and heavy metals include Hg, Cd, Pb, Ni as well as percentage silt-clay and total organic matter of the sediment were measured. The faunal population density and their distribution are discussed in relation to the environmental changes. Results showed spatial heterogeneity in faunal distribution of the Zangi creek. Nine groups of macrofauna were identified out of distinct zangi creek. Polychaets formed the dominant group (48%) followed by bivalves (13%), gastropods (10%), Decapods (2%), Tanaids (5%), and all other groups (22%). The distinct creek was heavily polluted without any macrofauna communities probably as a consequence of the high pH, COD, low salinity and heavy metals contamination specially Cd and Pb. The other stations near to the disposal site were found with macrofauna communities commonly tolerant to organic pollution, At 3 km east of the disposal site, macrofauna is comparable to the surrounded creek, whereas macrofauna still indicate environmental degradation. Farther a way, faunal density decreases and equilibrium taxa gradually replace opportunistic species, while the other stations were far from polluted area contained lower pollution and relatively healthy macrofauna. The mean biomass of macrobenthic fauna were estimated for the whole studied area. The results are considered in Minimum density and biomass in surrounded creek and maximum density and biomass in 3 km of surrounded area. Biodiversity Indices were low in surrounded creek. The Shanon-weaver information index was used to describe the spatially variations in diversity. Macrofauna density, shanon and simpson index were significantly variable between surrounded and free parts of Zangi creek (p<0.05). The numerical abundance of macrobenthose varied from 221. m-2 in polluted area to 4346 m-2 in free part of Zangi creek. The Shanon-weaver information index varied from 0.4 in distinct area to 2.9 in reference station. The physico- chemical changes between distinct and free creeks showed significant variations such as pH, salinity and EC. Salinity and EC were significantly positive correlate to macrofauna density, whereas pH and TOM percentage indicated significantly negative correlation to density. Heavy metals concentrations in sediments were higher than water samples. Concentration pattern of heavy metals in sediments and water samples were Ni>Pb>Cd>Hg. Salinity and pH were significantly correlated to metals in sediments (p<0.01). No significant correlation were found between Macrofauna density and heavy metals (p<0.05).

Feasibility of cyanobacterial inoculation for biological soil crusts formation in desert area

Practical testing of the feasibility of cyanobacterial inoculation to speed up the recovery of biological soil crusts in the field was conducted in this experiment. Results showed that cyanobacterial and algal cover climbed up to 48.5% and a total of 14 cyanobacterial and algal species were identified at the termination of inoculation experiment; biological crusts' thickness, compressive and chlorophyll a content increased with inoculation time among 3 years; moss species appeared in the second year; cyanobacterial inoculation increased organic carbon and total nitrogen of the soil; total salt, calcium carbonate and electrical conductivity in the soil also increased after inoculation. Diverse vascular plant communities composed of 10 and 9 species are established by cyanobacterial inoculation on the windward and leeward surface of the dunes, respectively, after 3 years. The Simpson index for the above two communities are 0.842 and 0.852, while the Shannon-Weiner index are 2.097 and 2.053, respectively. In conclusion, we suggest that cyanobacterial inoculation would be a suitable and effective technique to recover biological soil crusts, and may further restore the ecological system. (C) 2008 Published by Elsevier Ltd.

Biodiversity of Collembola in urban soils and the use of Folsomia candida to assess soil 'quality'

The effects of metal contamination on natural populations of Collembola in soils from five sites in the Wolverhampton area ( West Midlands, England) were examined. Analysis revealed that metal concentrations were elevated above background levels at all sites. One location in particular (Ladymoor, a former smelting site) was highly contaminated with Cd, Cu, Pb and Zn at more than 20 times background levels. Biodiversity indices ( Shannon - Weiner, Simpson index, Margalef index, alpha index, species richness, Shaneven ( evenness) and Berger - Parker dominance) were calculated. Of these indices, estimates of species richness and evenness were most effective at highlighting the differences between the Collembola communities. Indeed, the highest number of species were found at the most contaminated site, although the Collembola population also had a comparatively low evenness value, with just two species dominating. The number of individuals per species were allocated into geometric classes and plotted against the cumulative number of species as a percentage. At Ladymoor, there were more geometric classes, and the slope of the line was shallower than at the other four sites. This characteristic is a feature of polluted sites, where a few species are dominant and most species are rare. The Ladymoor soil also had a dominance of Isotomurus palustris, and was the only site in which Ceratophysella denticulata was found. Previous studies have shown that these two species are often found in sites subject to high metal contamination. Survival and reproduction of the "standard'' test springtail, Folsomia candida (Willem), were determined in a 4 week exposure test to soils from all five sites. Mortality was significantly increased in adults and reproduction significantly lower in the Ladymoor soil in comparison to the other four sites. This study has shown that severe metal contamination can be related to the population structure of Collembola in the field, and performance of F. candida ( in soils from such sites) in the laboratory.

The population genetic structure of clonal organisms generated by exponentially bounded and fat-tailed dispersal

Long distance dispersal (LDD) plays an important role in many population processes like colonization, range expansion, and epidemics. LDD of small particles like fungal spores is often a result of turbulent wind dispersal and is best described by functions with power-law behavior in the tails ("fat tailed"). The influence of fat-tailed LDD on population genetic structure is reported in this article. In computer simulations, the population structure generated by power-law dispersal with exponents in the range of -2 to -1, in distinct contrast to that generated by exponential dispersal, has a fractal structure. As the power-law exponent becomes smaller, the distribution of individual genotypes becomes more self-similar at different scales. Common statistics like G(ST) are not well suited to summarizing differences between the population genetic structures. Instead, fractal and self-similarity statistics demonstrated differences in structure arising from fat-tailed and exponential dispersal. When dispersal is fat tailed, a log-log plot of the Simpson index against distance between subpopulations has an approximately constant gradient over a large range of spatial scales. The fractal dimension D-2 is linearly inversely related to the power-law exponent, with a slope of similar to -2. In a large simulation arena, fat-tailed LDD allows colonization of the entire space by all genotypes whereas exponentially bounded dispersal eventually confines all descendants of a single clonal lineage to a relatively small area.

Biodiversity of Collembola in urban soils and the use of Folsomia candida to assess soil 'quality'

The effects of metal contamination on natural populations of Collembola in soils from five sites in the Wolverhampton area ( West Midlands, England) were examined. Analysis revealed that metal concentrations were elevated above background levels at all sites. One location in particular (Ladymoor, a former smelting site) was highly contaminated with Cd, Cu, Pb and Zn at more than 20 times background levels. Biodiversity indices ( Shannon - Weiner, Simpson index, Margalef index, alpha index, species richness, Shaneven ( evenness) and Berger - Parker dominance) were calculated. Of these indices, estimates of species richness and evenness were most effective at highlighting the differences between the Collembola communities. Indeed, the highest number of species were found at the most contaminated site, although the Collembola population also had a comparatively low evenness value, with just two species dominating. The number of individuals per species were allocated into geometric classes and plotted against the cumulative number of species as a percentage. At Ladymoor, there were more geometric classes, and the slope of the line was shallower than at the other four sites. This characteristic is a feature of polluted sites, where a few species are dominant and most species are rare. The Ladymoor soil also had a dominance of Isotomurus palustris, and was the only site in which Ceratophysella denticulata was found. Previous studies have shown that these two species are often found in sites subject to high metal contamination. Survival and reproduction of the "standard'' test springtail, Folsomia candida (Willem), were determined in a 4 week exposure test to soils from all five sites. Mortality was significantly increased in adults and reproduction significantly lower in the Ladymoor soil in comparison to the other four sites. This study has shown that severe metal contamination can be related to the population structure of Collembola in the field, and performance of F. candida ( in soils from such sites) in the laboratory.

Estrutura trófica da comunidade de peixes de riachos da bacia do rio Itanhaém, litoral sul do estado de São Paulo, Brasil

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Estudo da fauna de Euglossini (Hymenoptera, Apidae) em paisagem fragmentada na Serra da Forquilha, Jacutinga, região sul de Minas Gerais: diversidade de espécies e uso de habitats

Pós-graduação em Ciências Biológicas (Zoologia) - IBRC

Impacto da dinâmica da demanda dos frutos de açaí nas relações socioeconômicas e composição florística no estuário amazõnico

Nos últimas décadas a demanda pelo açaí no estado do Pará cresceu gradualmente, já que a produção e mercado da fruta de açaí são a base da economia de mais de 20 municípios paraenses. A prática do extrativismo do açaizeiro é praticada pelos homens, mulheres e crianças, voltada para autoconsumo e para a comercialização. Devido a este fato, a dinâmica do extrativismo do açaizeiro começou a mudar pelo aumento da demanda do açaí para o mercado, principalmente pelo valor de importância e interesse econômico. O presente trabalho teve como objetivo avaliar os impactos das mudanças da demanda dos frutos de açaí na (i) relação econômica da renda do açaí e na (ii) densidade e composição florística das áreas agroflorestais manejadas pelos ribeirinhos. O estudo realizou-se na comunidade São João Batista, município de Abaetetuba, Pará - Brasil. A população tem como principal fonte de trabalho a extração do fruto de açaí. Foram feitas entrevistas semi-estruturadas e abertas às famílias residentes na comunidade considerados pequenos e médios produtores de açaí. As entrevistas abarcaram dois componentes, o aspecto econômico e o aspecto social. Além disso, coletaram-se dados diários sobre a quantidade de rasa de açaí coletada, consumida e vendida, e o preço de cada rasa, com a finalidade de caracterizar a produção e preço nas diferentes temporadas da safra. Também se realizou o levantamento florístico mediante um inventário com a finalidade de caracterizar a vegetação, avaliar a densidade e composição florística dos açaizeiros. Para isso estabeleceu-se um total de 10 parcelas de 20 x 50 m (1000 m² ou 0.1 ha) distribuídas em cinco propriedades selecionadas, medindo o diâmetro de todos os indivíduos adultos > 10 cm de DAP (diâmetro à altura do peito) e para palmeiras com DAP > 2 cm e estimou-se a altura total (H) de cada individuo da base até o ponto mais alto das folhas. A análise da diversidade dos açaizais utilizou-se o índice de Shannon-Wiener e o índice de Simpson através do programa estatístico PAST – PAlaentologicalSTatistics, ver. 1,27. Como principais resultados obtiveram-se que na comunidade de São João Batista, a venda da produção de açaí é realizada para intermediários (marreteiros) (55%), no mercado de Abaetetuba (29%), no mercado de Belém (10%) e para marreteiro e/ou no mercado de Abaetetuba (6%). O município de Abaetetuba desde o ano 2005 teve uma queda na produção extrativa passando de 10.500 t (2004) a 900 t (2005) e progressivamente diminuindo até 770 t (2008). A quantidade da produção de açaí cultivada aumentou de 15.625 t (2003) a 131.250 t (2008) representando 99,4% da produção total. Na comunidade, foi inventariado 1043 indivíduos de árvores com um total de 11 famílias e 28 espécies, ocupando áreas basais maiores as famílias Arecaceae (8.83) e Fabaceae (6.77) e com maiores números de indivíduos (831 e 147 respectivamente). As espécies com maiores índices de valor de importância (IVIs) e de densidade registraram-se a Euterpe oleracea (777 indivíduos), Pterocarpus sp. (126) e Mauritia flexuosa (50). Obtiveram-se valores baixos nos índices de Simpson: 0.4275 e Shannon: 1.071, o que indica que se tem uma baixa diversidade resultante da atividade de manejo e extração de palmito e frutos de açaí levando a uma monocultura para o consumo e venda dos frutos. Concluindo, que o aumento do preço é forçado pelo crescimento da demanda, provocando a ampliação das áreas de cultivo e plantio de açaí para o aumento da produção. O impacto socioeconômico do manejo e cultivo dos açaizais sobre a economia ribeirinha e a economia extrativa do estuário amazônico gera grandes oportunidades de emprego, renda e qualidade de vida para as populações das várzeas e dos centros urbanos, sobretudo favorecendo aos mais pobres.

Entomological surveillance, spatial distribution, and diversity of culicidae (diptera) immatures in a rural area of the atlantic forest biome, state of sao paulo, brazil

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Diversidade de Formicidae (Hymenoptera) em um fragmento de Floresta Estacional Semidecídua no Noroeste do Estado de São Paulo, Brasil.

(Ant diversity (Hymenoptera) in a fragment of Semidecidual Seasonal Forest in Northwest of São Paulo State, Brazil). Due to scarce knowledge about ant fauna from Northwestern São Paulo State, the present study aimed to know the taxonomic diversity of Formicidae, relating the results to climatic variation along of one year. The samples were gotten monthly, using pitfall traps. It was sampled 25 species of 15 genera and seven subfamilies. Myrmicinae was the sampled richest subfamily, follows by Formicinae and Ponerinae. According Wilcoxon test, the species richness, equability and diversity estimated by Simpson index were significantly higher in the rain season. The obtained results suggest that the abundance of ants is significantly related to the temperature variation, while the ant assemblage structure is related to thermal and pluviometric variations.

Caracterização e análise das comunidades e infracomunidades de parasitos metazoários de Plagioscion squamosissimus (Heckel, 1840) capturados no reservatório de Promissão, rio Tietê, estado de São Paulo

Pós-graduação em Medicina Veterinária - FCAV