Ecotoxicity of the isoxaflutole herbicide to soil invertebrates / Ecotoxicidade do herbicida isoxaflutole para invertebrados do solo

Isoxaflutole (IFT) é um herbicida utilizado para o controle em pré-emergência de uma ampla variedade de plantas daninhas de folha larga e gramíneas, especialmente quando há resistência a outros herbicidas, como glyphosate e atrazine. Apesar de seu potencial como herbicida ter sido identificado no início dos anos 90, IFT ainda é considerado um ingrediente ativo novo no Brasil e pouco se sabe sobre seus efeitos, principalmente acerca da ecotoxicidade dos produtos formulados para grupos da macro e mesofauna do solo. Este estudo teve como objetivo avaliar efeitos comportamentais, agudos e crônicos (fuga, letalidade e reprodução) do produto comercial Provence® 750 WG (750 g i.a. L-1 isoxaflutole) nos organismos de teste Eisenia andrei (minhoca) e Folsomia candida (colêmbolo) usando normas padronizadas ISO. Os resultados mostraram que as minhocas apresentam comportamento de fuga apenas em doses >300 vezes a dose de campo e redução na reprodução em doses >150 vezes a dose de campo. Para os colêmbolos não foi obtida resposta de fuga, letalidade ou reprodução nas doses avaliadas. A partir dos resultados de laboratório, presume-se que o produto comercial Provence® não apresenta toxicidade para minhocas e colêmbolos, mesmo em doses muito acima à dose de campo, garantindo a segurança das comunidades do solo.(AU)

Isoxaflutole (IFT) is a pre-emergence herbicide used to control of a wide range of broadleaf and grass weeds, especially those resistant to other herbicide classes, such as glyphosate and atrazine. Although its herbicidal potential was identified in the early 90s, IFT is still a new active ingredient in Brazil and little is known about its effects, mainly regarding to ecotoxicity of formulated products to soil macro and mesofauna groups. This study aimed to assess behavioral, acute, and chronical effects (avoidance, lethality, and reproduction) of the commercial product ProvenceTM 750 WG (750 g a.i. L-1 isoxaflutole) on the test organisms Eisenia andrei (earthworms) and Folsomia candida (collembolans) using standardized ISO guidelines. The results showed the avoidance of the earthworm species only at >300 times the predicted field doses, as well as a decrease in reproduction over >150 times the predicted field dose. Neither the avoidance, nor lethality or reproduction response were found for the collembolan species. The laboratory results showed that it is possible to assume that ProvenceTM is not toxic to earthworms and collembolans, even at the highest field dose applied, ensuring the safety of soil communities.(AU)

Ecotoxicity of the isoxaflutole herbicide to soil invertebrates / Ecotoxicidade do herbicida isoxaflutole para invertebrados do solo

Isoxaflutole (IFT) é um herbicida utilizado para o controle em pré-emergência de uma ampla variedade de plantas daninhas de folha larga e gramíneas, especialmente quando há resistência a outros herbicidas, como glyphosate e atrazine. Apesar de seu potencial como herbicida ter sido identificado no início dos anos 90, IFT ainda é considerado um ingrediente ativo novo no Brasil e pouco se sabe sobre seus efeitos, principalmente acerca da ecotoxicidade dos produtos formulados para grupos da macro e mesofauna do solo. Este estudo teve como objetivo avaliar efeitos comportamentais, agudos e crônicos (fuga, letalidade e reprodução) do produto comercial Provence® 750 WG (750 g i.a. L-1 isoxaflutole) nos organismos de teste Eisenia andrei (minhoca) e Folsomia candida (colêmbolo) usando normas padronizadas ISO. Os resultados mostraram que as minhocas apresentam comportamento de fuga apenas em doses >300 vezes a dose de campo e redução na reprodução em doses >150 vezes a dose de campo. Para os colêmbolos não foi obtida resposta de fuga, letalidade ou reprodução nas doses avaliadas. A partir dos resultados de laboratório, presume-se que o produto comercial Provence® não apresenta toxicidade para minhocas e colêmbolos, mesmo em doses muito acima à dose de campo, garantindo a segurança das comunidades do solo.

Isoxaflutole (IFT) is a pre-emergence herbicide used to control of a wide range of broadleaf and grass weeds, especially those resistant to other herbicide classes, such as glyphosate and atrazine. Although its herbicidal potential was identified in the early 90s, IFT is still a new active ingredient in Brazil and little is known about its effects, mainly regarding to ecotoxicity of formulated products to soil macro and mesofauna groups. This study aimed to assess behavioral, acute, and chronical effects (avoidance, lethality, and reproduction) of the commercial product ProvenceTM 750 WG (750 g a.i. L-1 isoxaflutole) on the test organisms Eisenia andrei (earthworms) and Folsomia candida (collembolans) using standardized ISO guidelines. The results showed the avoidance of the earthworm species only at >300 times the predicted field doses, as well as a decrease in reproduction over >150 times the predicted field dose. Neither the avoidance, nor lethality or reproduction response were found for the collembolan species. The laboratory results showed that it is possible to assume that ProvenceTM is not toxic to earthworms and collembolans, even at the highest field dose applied, ensuring the safety of soil communities.

Soil mesofauna in consolidated land use systems: how management affects soil and litter invertebrates

Soil mesofauna consists of small invertebrates that live in the soil or litter and are sensitive to climatic conditions, management systems, plant cover and physical or chemical soil attributes. These organisms are active in the cycling of nutrients, since they fragment the organic matter hereby accelerating microbial decomposition. The aim of this study was to evaluate the invertebrate community in no-tillage, conventional tillage, minimum tillage and secondary forest in regeneration to determine the relationship of mesofauna to litter, soil attributes, management and seasonality. Therefore, ten soil samples in each system and eight litter samples in no-tillage and the forest were taken over four seasons. These samples remained in Berlese extractors for seven days for quantification and identification of mesofauna. For each fauna sample, soil samples were collected for chemical analysis. Next, diversity indices and richness were calculated and multivariate analyses were used to establish relationships between the mesofauna, soil attributes and management. In the soil, mites were more abundant in the agricultural systems than in the forest, but the springtails, sensitive to low moisture and high temperature, were more abundant in the forest. Diversity and richness were higher in soil from the forest than under other systems. In no-tillage, there was a lower density of soil mesofauna, however, under this system, many invertebrates live in litter, since litter is the main food resource for them. In forest litter, we found lower invertebrate density and higher diversity than in no-tillage. Carbon, basic cations, pH, Al and V% were the attributes that best explained fauna variability in the systems.

Soil mesofauna in consolidated land use systems: how management affects soil and litter invertebrates

Soil mesofauna consists of small invertebrates that live in the soil or litter and are sensitive to climatic conditions, management systems, plant cover and physical or chemical soil attributes. These organisms are active in the cycling of nutrients, since they fragment the organic matter hereby accelerating microbial decomposition. The aim of this study was to evaluate the invertebrate community in no-tillage, conventional tillage, minimum tillage and secondary forest in regeneration to determine the relationship of mesofauna to litter, soil attributes, management and seasonality. Therefore, ten soil samples in each system and eight litter samples in no-tillage and the forest were taken over four seasons. These samples remained in Berlese extractors for seven days for quantification and identification of mesofauna. For each fauna sample, soil samples were collected for chemical analysis. Next, diversity indices and richness were calculated and multivariate analyses were used to establish relationships between the mesofauna, soil attributes and management. In the soil, mites were more abundant in the agricultural systems than in the forest, but the springtails, sensitive to low moisture and high temperature, were more abundant in the forest. Diversity and richness were higher in soil from the forest than under other systems. In no-tillage, there was a lower density of soil mesofauna, however, under this system, many invertebrates live in litter, since litter is the main food resource for them. In forest litter, we found lower invertebrate density and higher diversity than in no-tillage. Carbon, basic cations, pH, Al and V% were the attributes that best explained fauna variability in the systems.(AU)

Effects of habitat heterogeneity on epiedaphic Collembola (Arthropoda: Hexapoda) in a semiarid ecosystem in Northeast Brazil

The spatial distribution of abiotic resources and environmental conditions can vary at small scales within terrestrial ecosystems, influencing the composition of soil fauna. Epiedaphic springtails (Collembola) of a semiarid Caatinga ecosystem were studied to determine if factors related to vegetation structure, such as species richness, aerial biomass, litterfall, and soil characteristics (pH, granulometry and soil organic matter), influence species richness and abundance of this group. A total of 5,513 individuals were collected of 15 species distributed in 13 genera and 9 families. The most abundant species were Temeritas sp., with 2,086 (38% of the total abundance) individuals, and Neotropiella meridionalis (Arlé, 1939), with 1,911 (35% of the total abundance) individuals. None of the variables in the regression model were significantly related to Collembola species richness, but abundance was significantly related to plant species richness, aerial biomass and soil pH. Thus, even at a small spatial scale, habitat heterogeneity influences the epiedaphic Collembola in the Caatinga ecosystem, especially their abundance.(AU)

Effects of habitat heterogeneity on epiedaphic Collembola (Arthropoda: Hexapoda) in a semiarid ecosystem in Northeast Brazil

The spatial distribution of abiotic resources and environmental conditions can vary at small scales within terrestrial ecosystems, influencing the composition of soil fauna. Epiedaphic springtails (Collembola) of a semiarid Caatinga ecosystem were studied to determine if factors related to vegetation structure, such as species richness, aerial biomass, litterfall, and soil characteristics (pH, granulometry and soil organic matter), influence species richness and abundance of this group. A total of 5,513 individuals were collected of 15 species distributed in 13 genera and 9 families. The most abundant species were Temeritas sp., with 2,086 (38% of the total abundance) individuals, and Neotropiella meridionalis (Arlé, 1939), with 1,911 (35% of the total abundance) individuals. None of the variables in the regression model were significantly related to Collembola species richness, but abundance was significantly related to plant species richness, aerial biomass and soil pH. Thus, even at a small spatial scale, habitat heterogeneity influences the epiedaphic Collembola in the Caatinga ecosystem, especially their abundance.

Soil mesofaunal in constructed coal mining area / Mesofauna de solo construído em área de mineração de carvão

The objective was to evaluate the presence of meso-fauna soil in constructed soil after open pit coal mining in the Lauro Müller region, SC, Brazil. An experimental area of the Mina do Apertado and two reference areas (naturalized field and native forest) were used. The meso-fauna was collected using a 17 cm diameter metal cylinder, at 5 cm depth, and the extraction was performed by using the modified Berlese method, followed by the identification of organisms. The soil fauna was assessed by individual density and richness of groups and submitted to variance analysis and multivariate analysis of the data by correspondence analysis. A total of 19 taxa were found, and Acari, Collembola and Formicidae showed higher densities. The correspondence analysis showed a clear separation of anthropogenic sites (Mina do Apertado and naturalized field) from the reference area (native forest). Mina do Apertado recovery model groups showed similar reference to the native forest, satisfying the ecosystem services provided by them, promoting a suitable environment for groups of mesofaunal soil.

O objetivo foi avaliar a presença da mesofauna edáfica em solos construídos após a mineração de carvão a céu aberto na região de Lauro Müller, SC, Brasil. Utilizou-se a área experimental da Mina do Apertado e duas áreas de referência (campo naturalizado e mata nativa). A fauna do solo foi coletada utilizando-se de um cilindro metálico de 17 cm de diâmetro, na profundidade de 5 cm, e a extração foi realizada pelo método de Berlese modificado, seguido da identificação dos organismos. A mesofauna foi avaliada pela densidade de indivíduos e riqueza de grupos submetidos à análise de variância e análise multivariada dos dados através da análise de correspondência. Ao total foram encontrados 19 táxons, sendo que Acari, Collembola e Formicidae apresentaram as maiores densidades. A análise de correspondência evidenciou clara separação dos locais antropizados (Mina do Apertado e campo naturalizado) da área de referência (mata nativa). Os modelos de recuperação da Mina do Apertado apresentaram grupos semelhantes à referência mata nativa, satisfazendo os serviços do ecossistema prestados por eles, promovendo um ambiente adequado para os grupos da mesofauna edáfica.

Soil mesofaunal in constructed coal mining area / Mesofauna de solo construído em área de mineração de carvão

The objective was to evaluate the presence of meso-fauna soil in constructed soil after open pit coal mining in the Lauro Müller region, SC, Brazil. An experimental area of the Mina do Apertado and two reference areas (naturalized field and native forest) were used. The meso-fauna was collected using a 17 cm diameter metal cylinder, at 5 cm depth, and the extraction was performed by using the modified Berlese method, followed by the identification of organisms. The soil fauna was assessed by individual density and richness of groups and submitted to variance analysis and multivariate analysis of the data by correspondence analysis. A total of 19 taxa were found, and Acari, Collembola and Formicidae showed higher densities. The correspondence analysis showed a clear separation of anthropogenic sites (Mina do Apertado and naturalized field) from the reference area (native forest). Mina do Apertado recovery model groups showed similar reference to the native forest, satisfying the ecosystem services provided by them, promoting a suitable environment for groups of mesofaunal soil.(AU)

O objetivo foi avaliar a presença da mesofauna edáfica em solos construídos após a mineração de carvão a céu aberto na região de Lauro Müller, SC, Brasil. Utilizou-se a área experimental da Mina do Apertado e duas áreas de referência (campo naturalizado e mata nativa). A fauna do solo foi coletada utilizando-se de um cilindro metálico de 17 cm de diâmetro, na profundidade de 5 cm, e a extração foi realizada pelo método de Berlese modificado, seguido da identificação dos organismos. A mesofauna foi avaliada pela densidade de indivíduos e riqueza de grupos submetidos à análise de variância e análise multivariada dos dados através da análise de correspondência. Ao total foram encontrados 19 táxons, sendo que Acari, Collembola e Formicidae apresentaram as maiores densidades. A análise de correspondência evidenciou clara separação dos locais antropizados (Mina do Apertado e campo naturalizado) da área de referência (mata nativa). Os modelos de recuperação da Mina do Apertado apresentaram grupos semelhantes à referência mata nativa, satisfazendo os serviços do ecossistema prestados por eles, promovendo um ambiente adequado para os grupos da mesofauna edáfica.(AU)

Formigas como bioindicadores da qualidade do solo em sistema integrado lavoura-pecuária / Ants as bioindicators of soil quality in integrated crop-livestock system

O objetivo deste trabalho foi avaliar a comunidade de formigas em sistemas envolvendo a rotação entre lavoura e pecuária, sob plantio direto, comparado a outros sistemas de manejo e com sistemas naturais da região. O estudo foi conduzido no Município de Dourados, MS, sob Argissolo Vermelho distroférrico típico, num sistema integrado lavoura-pecuária, em plantio direto, rotacionado a cada dois anos. Outros sistemas de manejo avaliados, para comparação, incluíram o sistema convencional (aração e gradagem), sistema plantio direto e pastagem cultivada continuamente com Brachiaria decumbens, além de dois fragmentos de vegetação nativa, nos biomas Cerrado e Floresta Semidecídua. A coleta de solo foi realizada no período chuvoso (safra 2009/2010), sendo as amostragens de serapilheira realizadas com a utilização de extratores do tipo mini-Winkler, seguindo o protocolo ALL (Ants of the Leaf Litter). Os resultados indicaram morfoespécies de Strumygenys sp. e Hypoponera sp. como potencial bioindicadores de qualidade do solo. O estudo demonstrou que a importância da manutenção de fragmentos florestais (Cerrado e Floresta Semidecídua) e implementação de sistemas integrados, tais como lavoura-pecuária, são menos impactantes para a mesofauna de solo e contribuem para a conservação da diversidade de formigas e manutenção da qualidade do solo.(AU)

The aim of this study was to evaluate the ant community in different systems involving the crop rotations between livestock, under no-tillage, compared to other management systems and natural systems of the Mid-Western region. The study was carried out in the Dourados, Mato Grosso do Sul State, Brazil, on a Typic Hapludox soil, in parcels including crop-livestock rotation production system under no-tillage, rotated every two years, no-tillage crop system, succession of crops under conventional tillage, continuous pasture and two fragments of native vegetation, Cerrado and Semideciduous Forest. The samples of soil were conducted during the rainy season (2009/2010), and litter sampling performed with the use of mini-Winkler extractors, following the protocol ALL (Ants of the Leaf Litter). The results indicated that the morphospecies of Strumygenys sp. and Hypoponera sp. as potential bioindicators of soil quality, depending on their frequency changes in response to different systems observed. The study have demonstrated the importance of maintaining forest fragments as stock of local biodiversity and showed that integrated systems, such as crop-livestock, are less impact ful to the meso-fauna and contribute to the conservation of ant and maintenance of soil quality.(AU)

Soil health: looking for suitable indicators. What should be considered to assess the effects of use and management on soil health?

Soil Health refers to the ecological equilibrium and the functionality of a soil and its capacity to maintain a well balanced ecosystem with high biodiversity above and below surface, and productivity. To understand and use soil health as a tool for sustainability, physical, chemical, and biological properties must be employed to verify which respond to the soil use and management within a desired timescale. Attributes with a rapid response to natural or anthropogenic actions are considered good indicators of soil health. Among the physical indicators, soil texture, aggregation, moisture, porosity, and bulk density have been used, while among chemical indicators total C and N, mineral nutrients, organic matter, cation exchange capacity, among others are well established. However, most of them generally have a slow response, when compared to the biological ones, such as microbial biomass C and N, biodiversity, soil enzymes, soil respiration, etc., in addition to macro and mesofauna. Thus, a systemic approach based on different kinds of indicators (physical, chemical and biological) in assessing soil health would be safer than using only one kind of attribute. Many human activities have caused desertification, loss of biodiversity, disruption of aggregates, loss of organic matter and nutrients, among others. Today, it is imperious to maintain soil health and productivity with increasing emphasis on reforestation and recuperation of degraded areas through the use of organic amendments, reintroduction of plants, soil fauna and microorganisms. This review focused on an integrative view on indicators of soil health to be used as tools for prediction of sustainability in production systems.

Soil health: looking for suitable indicators. What should be considered to assess the effects of use and management on soil health?

Soil Health refers to the ecological equilibrium and the functionality of a soil and its capacity to maintain a well balanced ecosystem with high biodiversity above and below surface, and productivity. To understand and use soil health as a tool for sustainability, physical, chemical, and biological properties must be employed to verify which respond to the soil use and management within a desired timescale. Attributes with a rapid response to natural or anthropogenic actions are considered good indicators of soil health. Among the physical indicators, soil texture, aggregation, moisture, porosity, and bulk density have been used, while among chemical indicators total C and N, mineral nutrients, organic matter, cation exchange capacity, among others are well established. However, most of them generally have a slow response, when compared to the biological ones, such as microbial biomass C and N, biodiversity, soil enzymes, soil respiration, etc., in addition to macro and mesofauna. Thus, a systemic approach based on different kinds of indicators (physical, chemical and biological) in assessing soil health would be safer than using only one kind of attribute. Many human activities have caused desertification, loss of biodiversity, disruption of aggregates, loss of organic matter and nutrients, among others. Today, it is imperious to maintain soil health and productivity with increasing emphasis on reforestation and recuperation of degraded areas through the use of organic amendments, reintroduction of plants, soil fauna and microorganisms. This review focused on an integrative view on indicators of soil health to be used as tools for prediction of sustainability in production systems.

A new species of Tyrannoseira (Collembola: Entomobryidae: Seirini) from the Brazilian coastal region

A new species of Tyrannoseira Bellini & Zeppelini, 2011 (Entomobryidae) is described and illustrated. Specimens of T. diabolica sp. nov. were collected in Barreira do Inferno, state of Rio Grande do Norte, Brazil. This is the fourth described species in the genus. All males of Tyrannoseira have the femora of the first pair of legs enlarged and slender tibiotarsi, both bearing several spine-like setae. Probably the closest species to T. diabolica sp. nov. is T. sex Bellini & Zeppelini, 2011. They share many similarities in their color pattern and dorsal chaetotaxy.

A new species of Tyrannoseira (Collembola: Entomobryidae: Seirini) from the Brazilian coastal region

A new species of Tyrannoseira Bellini & Zeppelini, 2011 (Entomobryidae) is described and illustrated. Specimens of T. diabolica sp. nov. were collected in Barreira do Inferno, state of Rio Grande do Norte, Brazil. This is the fourth described species in the genus. All males of Tyrannoseira have the femora of the first pair of legs enlarged and slender tibiotarsi, both bearing several spine-like setae. Probably the closest species to T. diabolica sp. nov. is T. sex Bellini & Zeppelini, 2011. They share many similarities in their color pattern and dorsal chaetotaxy.

A new species of Tyrannoseira (Collembola: Entomobryidae: Seirini) from the Brazilian coastal region

A new species of Tyrannoseira Bellini & Zeppelini, 2011 (Entomobryidae) is described and illustrated. Specimens of T. diabolica sp. nov. were collected in Barreira do Inferno, state of Rio Grande do Norte, Brazil. This is the fourth described species in the genus. All males of Tyrannoseira have the femora of the first pair of legs enlarged and slender tibiotarsi, both bearing several spine-like setae. Probably the closest species to T. diabolica sp. nov. is T. sex Bellini & Zeppelini, 2011. They share many similarities in their color pattern and dorsal chaetotaxy.

A new species of Campylothorax (Collembola: Entomobryoidea: Paronellidae) from the state of Alagoas, Brazil

Campylothorax Schött, 1893 is a genus of Paronellidae known only from the Neotropical and Ethiopian zoogeographic provinces. Herein a new species of this genus is described and illustrated. Campylothorax mitrai sp. nov. was found in remains of Atlantic Rainforest at Rio Largo municipality, state of Alagoas, Brazil. It is the ninth described species of Campylothorax and the third recorded from Brazil. Campylothorax mitrai sp. nov. can be distinguished from other species of the genus by its peculiar dark blue color pattern associated to a unique set of setae in the labial triangle, where there is a large distinct seta 'E'. This condition is unique among Campylothorax species. Campylothorax mitrai sp. nov. is the first record of Collembola from Alagoas.

A new species of Campylothorax (Collembola: Entomobryoidea: Paronellidae) from the state of Alagoas, Brazil

Campylothorax Schött, 1893 is a genus of Paronellidae known only from the Neotropical and Ethiopian zoogeographic provinces. Herein a new species of this genus is described and illustrated. Campylothorax mitrai sp. nov. was found in remains of Atlantic Rainforest at Rio Largo municipality, state of Alagoas, Brazil. It is the ninth described species of Campylothorax and the third recorded from Brazil. Campylothorax mitrai sp. nov. can be distinguished from other species of the genus by its peculiar dark blue color pattern associated to a unique set of setae in the labial triangle, where there is a large distinct seta 'E'. This condition is unique among Campylothorax species. Campylothorax mitrai sp. nov. is the first record of Collembola from Alagoas.

A new species of Campylothorax (Collembola: Entomobryoidea: Paronellidae) from the state of Alagoas, Brazil

Campylothorax Schött, 1893 is a genus of Paronellidae known only from the Neotropical and Ethiopian zoogeographic provinces. Herein a new species of this genus is described and illustrated. Campylothorax mitrai sp. nov. was found in remains of Atlantic Rainforest at Rio Largo municipality, state of Alagoas, Brazil. It is the ninth described species of Campylothorax and the third recorded from Brazil. Campylothorax mitrai sp. nov. can be distinguished from other species of the genus by its peculiar dark blue color pattern associated to a unique set of setae in the labial triangle, where there is a large distinct seta 'E'. This condition is unique among Campylothorax species. Campylothorax mitrai sp. nov. is the first record of Collembola from Alagoas.

Fauna edáfica como bioindicador ambiental em áreas de Caatinga sob pastejo caprino

O presente estudo foi realizado com o objetivo de avaliar a fauna edáfica como bioindicador ambiental em áreas de Caatinga sob pastejo caprino no Semiárido Nordestino. O experimento foi realizado durante um ano (outubro de 2013 a setembro de 2014), na Fazenda Experimental, pertencente à Universidade Federal da Paraíba, localizada em São João do Cariri - PB. Foram utilizadas três áreas contíguas de caatinga, correspondentes aos tratamentos: T1 (10 caprinos), T2 (5 caprinos) e T3 (Testemunha Sem caprinos), cada área tinha um tamanho de 3,2 ha com 30 unidades amostrais distribuídas. Foram utilizados caprinos machos, adultos, sem padrão racial definido. Para as coletas mensais dos organismos da Macrofauna edáfica foi utilizada a armadilha do tipo provid, estas permaneceram nas áreas por 96 horas. Juntamente com essa coleta foi realizada a da Mesofauna edáfica que consistiu da retirada de solo e serapilheira das áreas com o auxílio de um anel metálico. No laboratório, os organismos foram identificados a nível de ordem. Para avaliação da diversidade das ordens foram utilizados os índices de Shannon e Equitabilidade, pelo programa Past. A abundância, riqueza, frequência absoluta e relativa foi calculada pelo programa Excel. Foi coletado um total de 16528 indivíduos da macrofauna edáfica distribuído em 20 ordens, e 119 individuos da mesofauna, distribuídos em 6 ordens. A área que não tinha caprinos pastejando apresentou o maior número de indivíduos da macrofauna, com 5993 e da mesofauna com 44 individuos. Os grupos mais frequentes e abundantes da Macrofauna foram: Hymenoptera, Coleoptera, Araneae e Scutigeromorpha, e da mesofauna: Acarina, Psocoptera e Collembola. A maior riqueza, diversidade e uniformidade das ordens foi encontrada na área II para a Macrofauna. A Mesofauna apresentou maior riqueza e diversidade das ordens na área III e maior uniformidade na área I. A diversidade e equitabilidade da fauna edáfica podem ser utilizadas como bioindicador auxiliar da qualidade ambiental das áreas de Caatinga sob pastejo caprino.

This study was conducted to evaluate Soil fauna as environmental bioindicator in Caatinga areas under goat grazing in the Northeast Brazilian semi-arid. The experiment was conducted during one year (October 2013 to September 2014), at the Experimental Farm, belonging to the Federal University of Paraiba, located in Sao Joao do Cariri PB - Brazil. We used three contiguous areas of Caatinga corresponding to the treatments: T1 (10 goats), T2 (5 goats) and T3 (No goats), each area had a size of 3.2ha with 30 sample units distributed. Were used male goats, adults without defined breed. To organisms soil macrofauna monthly collections was used to trap the type Provid, they remained in the area for 96 hours. Along with this collection was performed the soil mesofauna collection, consisting of soil and litter areas removed with a metal ring help. At the laboratory, the organisms were identified about order. To evaluate the orders diversity were used Shannon and Equitability indices at Past program. The abundance, wealth, absolute and relative frequency was calculated by Excel program. Was collected a total of 16528 individuals of soil macrofauna distributed in 20 orders and 119 mesofauna individuals, distributed in 6 order. The area had no grazing goats had the highest number of macrofauna individuals, with 5993 and mesofauna with 44 individuals. The most common and abundant macrofauna orders groups were Hymenoptera, Coleoptera, Araneae and Scutigeromorpha, and mesofauna: Acarina, Psocoptera and Collembola. The greatest orders richness, diversity and uniformity were found in the area II for macrofauna. The mesofauna showed greater orders richness and diversity in the area III and greater uniformity in the area I. The soil fauna diversity and evenness can be used as an environmental bio-indicator auxiliary of quality in Caatinga areas under goat grazing.

DINÂMICA TEMPORAL DA FAUNA EDÁFICA EM ÁREAS DE CAATINGA SOB PASTEJO CAPRINO

A qualidade do solo não deve estar limitada somente a produtividade, mas também envolver a qualidade ambiental, a saúde do homem, dos animais em associação com qualidade do alimento. A fauna edáfica vem sendo objeto de estudos que buscam entender os efeitos das ações antrópicas sobre o ambiente e usada como bioindicadores da condição atual que determinado ambiente se encontra. O objetivo da pesquisa foi analisar a dinâmica temporal da macro e mesofauna edáfica em áreas de Caatinga sob pastejo caprino com diferentes taxas de lotação. O experimento foi realizado numa área de Caatinga de 9,6 ha subdividida em 3 subáreas de 3,2 ha com diferentes taxas de lotação (A1=10 caprinos, A2= 5 caprinos e A3= sem caprinos), na Estação Experimental de São João do Cariri PB, pertencente ao Centro de Ciências Agrárias da Universidade Federal da Paraíba,. Foram utilizadas armadilhas Provid para capturar a macrofauna; anéis de metais para coleta de solo + serapilheira e extrator Berlese Tullgren para extração da mesofauna. Dentre a macrofauna, as formigas foram os indivíduos mais abundantes nos três ambientes e para a mesofauna, os ácaros. Não houve diferença de riqueza de ordens entre as áreas. Contudo, os maiores índices de Shannon e Pielou foram encontrados na Área 3 e os maiores índices de Simpson, registrados na Área 1. O período noturno proporcionou maior diversidade e Equabilidade enquanto o diurno, maior dominância. Aranhas, centopeias e escorpiões ocorreram em maior proporção no ambiente A3 seguido de A2 e A1. A dinâmica de ácaros e colêmbolos foi mais equilibrada na Área 3, seguida da Área 2 e Área 1. A heterogeneidade de cada ambiente e a precipitação pluvial são preditores da alta variação dos dados. A inclusão de caprinos em áreas de caatinga altera a diversidade da macro e mesofauna do solo.

Soil quality should not be limited to the productivity of the same, but should also involve environmental quality, human and animal health in association with food quality. The soil fauna has been the subject of studies that seek to understand the effects of human actions on the environment and used as bio-indicators of the current condition that certain environment. The objective of the research was to analyze the temporal dynamics of edaphic macrofauna and mesofauna in Caatinga areas under goat grazing with different stocking rates. The experiment was conducted in a Caatinga area of 9,6 ha divided into three subarea of 3,2 ha there with different stocking rates (A1 = 10 goats, A2 = 5 goats and A3 = no goats), in the Estação Experimental de São João do Cariri- PB, belonging to the Federal University of Paraiba, Agricultural Science Center. Provid traps were used to capture the macrofauna; metal rings for soil + litter collect and extractor Berlese Tullgren for mesofauna extraction. Among the macrofauna, ants were the most abundant individuals in the three environments and the mites for mesofauna. There was no difference in orders wealth between areas. However, the higher Shannon and Pielou index were found in Area 3 and the highest Simpson index, registered in Area 1. Nighttime proposed higher diversity and Equitability while the daytime, higher dominance. Spiders, centipedes and scorpions occurred in greater proportion in the A3 environment then by A2 and A1. The dynamics of mites and springtails was more balanced in Area 3, then Area 2 and Area 1. The heterogeneity of each environment and rainfall reflected in the high variation in the data. In general, the soil fauna tends to emerge after rain events and how mouch best distributed these events, there is a predisposition to a larger in the dynamics balance of soil fauna.

Origin of microaggregates in soils with ferralic horizons

Microaggregates that characterize ferralic soils have been hypothesized to have physical, geochemical and/or biological origins. Despite of many studies, the hierarchy between these processes that form microaggregates has seldom been reported. The objective of this work was to study the genesis of microaggregates in a sequence of Ferralic Nitisols developed on Quaternary red clayey sediments and diabase in Piracicaba (SP), Brazil. This issue was tackled by combining optical microscopy, image analysis, scanning electron microscopy and elemental iron quantifications by X-ray fluorescence. Micromorphological investigations showed three different types of microaggregates: (i) oval microaggregates with well sorted quartz grains in their interior; (ii) oval microaggregates without or with poorly sorted quartz grains in their interior; and (iii) dense polyedric microaggregates. These morphological evidences, together with the elemental iron determinations and scanning electron microscopy, revealed the contribution of more than one process for microaggregate formation: (i) the mechanical action of the mesofauna would form the first type of microaggregates (ii) geochemical and biological processes would form the second type and (iii) the fissuration of the soil matrix by expansion and compression processes would form the third type.

Os microagregados, característicos do horizonte B latossólico, podem ser formados a partir de processos físicos, geoquímicos e biológicos. Apesar da quantidade de trabalhos realizados sobre este tema, poucos tem discutido a hierarquia entre os processos que formam estes microagregados. O objetivo deste trabalho foi estudar a gênese dos microagregados numa seqüência de solos localizada em Piracicaba (SP), Brasil. Os solos foram classificados como Nitossolos Vermelhos Eutroférricos latossólicos e desenvolvem-se a partir de sedimentos argilosos vermelhos do Quaternário e diabásio. Para atingir o objetivo deste trabalho foram utilizadas técnicas de microscopia ótica, análise de imagens, microscopia eletrônica de varredura e quantificações elementares de ferro através de fluorescência de raio-X. As investigações micromorfológicas mostraram a presença de três tipos de microagregados: (i) microagregados ovais com grãos de quartzo bem selecionados no seu interior; (ii) microagregados ovais sem grãos de quartzo ou grãos de quartzo mal selecionados no seu interior; e (iii) microagregados poliédricos densos. Estas evidencias morfológicas junto com os dados elementares de ferro e a microscopia eletrônica de varredura mostraram a contribuição de mais de um processo na formação dos microagregados: (i) a ação mecânica da mesofauna seria responsável pela formação do primeiro tipo de microagregados; (ii) processos geoquímicos e biológicos estariam formando o segundo tipo de microagregados; e (iii) a fissuração da matriz do solo por processos de contração e expansão formariam o terceiro tipo de microagregados.