8 research outputs found

    Gradientes ambientais como filtros na composição de insetos aquáticos do Cerrado-Caatinga, Brasil

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    The patterns of aquatic insect diversity are influenced by landscape structure and environmental gradients that can be altered significantly through changes in land use. The aim of the present study was to verify if the patterns of diversity of the orders Odonata and Trichoptera vary significantly between preserved and altered sites, along a gradient of environmental impact. Data were collected on the structural and environmental characteristics of the stream, and the assemblages of aquatic insects at seven sampling points in a Cerrado-Caatinga ecotone of northeastern Brazil, in the dry seasons of 2018 and 2019. The results indicated that altered streams had higher electrical conductivity and lowest HII (habitat integrity index) values in comparison with the preserved ones, being determinant in the distribution of genera, and low pH values increased genera richness, informations that can guide management strategies for biodiversity conservation. Which supports the conclusion that the diversity of aquatic insects is determined by the influence of environmental filters in the streams.Os padrões de diversidade de insetos aquáticos são influenciados pela estrutura da paisagem e gradientes ambientais que podem ser alterados significativamente através de mudanças no uso da terra. O objetivo do presente estudo foi verificar se os padrões de diversidade das ordens Odonata e Trichoptera variam significativamente entre locais preservados e alterados, ao longo de um gradiente de impacto ambiental. Foram coletados dados sobre as características estruturais e ambientais do córrego e das assembleias de insetos aquáticos em sete pontos de amostragem em um ecótono Cerrado-Caatinga do Nordeste, Brasil, nas estações secas de 2018 e 2019. Os resultados indicaram que córregos alterados apresentaram maiores valores de condutividade elétrica e menores valores de IIH (índice de integridade de habitat) em comparação aos preservados, sendo determinantes na distribuição de gêneros, e baixos valores de pH aumentaram a riqueza de gêneros, informações que podem orientar estratégias de manejo para a conservação da biodiversidade. Reforçando a conclusão de que a diversidade de insetos aquáticos é determinada pela influência de filtros ambientais nos riachos

    Trichomes are effective against folivory

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    Ecosystems that show greatest heterogeneity have a greater amount of interactions between organisms that are part of their food chains, among these relationships exists the herbivory, thus the present study aims to evaluate the feeding preference of herbivory insects for plants in an area of capoeira vegetation, the hypothesis tested is that insects prefer plants with less trichomes. The survey was performed at the Federal Institute of Maranhão Campus Caxias, in November 2016, during which 600 leaves of different species were sampled, most of which did not show pilosity, and the association test by chi-square indicated that for plants present in "capoeira" there are a greater folivory for those that do not present trichomes on its leaf limb.&nbsp

    Food preference of insects in capoeira area in east of state of Maranhão, Brazil

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    In the relation between plants and herbivores, both organisms developed along their evolutionary histories mediating mechanisms for these relationships. Considering that the present work had the objective to evaluate the herbivory food preference of plants by insects in an area of capoeira phytophysiognomy and the hypothesis tested was that insects prefer plants with lower leaf tenacity. The study was carried out in Caxias, Maranhão, Brazil, in November 2016, in which 600 leaves were analyzed with half of tenacious leaves and one of soft leaves. The chi-square test indicated an association between the variables tested pointing an occurrence of herbivory preference for plants with tenacious leaves

    ATLANTIC ANTS: a data set of ants in Atlantic Forests of South America

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    NEOTROPICAL ALIEN MAMMALS: a data set of occurrence and abundance of alien mammals in the Neotropics

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    Biological invasion is one of the main threats to native biodiversity. For a species to become invasive, it must be voluntarily or involuntarily introduced by humans into a nonnative habitat. Mammals were among first taxa to be introduced worldwide for game, meat, and labor, yet the number of species introduced in the Neotropics remains unknown. In this data set, we make available occurrence and abundance data on mammal species that (1) transposed a geographical barrier and (2) were voluntarily or involuntarily introduced by humans into the Neotropics. Our data set is composed of 73,738 historical and current georeferenced records on alien mammal species of which around 96% correspond to occurrence data on 77 species belonging to eight orders and 26 families. Data cover 26 continental countries in the Neotropics, ranging from Mexico and its frontier regions (southern Florida and coastal-central Florida in the southeast United States) to Argentina, Paraguay, Chile, and Uruguay, and the 13 countries of Caribbean islands. Our data set also includes neotropical species (e.g., Callithrix sp., Myocastor coypus, Nasua nasua) considered alien in particular areas of Neotropics. The most numerous species in terms of records are from Bos sp. (n = 37,782), Sus scrofa (n = 6,730), and Canis familiaris (n = 10,084); 17 species were represented by only one record (e.g., Syncerus caffer, Cervus timorensis, Cervus unicolor, Canis latrans). Primates have the highest number of species in the data set (n = 20 species), partly because of uncertainties regarding taxonomic identification of the genera Callithrix, which includes the species Callithrix aurita, Callithrix flaviceps, Callithrix geoffroyi, Callithrix jacchus, Callithrix kuhlii, Callithrix penicillata, and their hybrids. This unique data set will be a valuable source of information on invasion risk assessments, biodiversity redistribution and conservation-related research. There are no copyright restrictions. Please cite this data paper when using the data in publications. We also request that researchers and teachers inform us on how they are using the data

    NEOTROPICAL XENARTHRANS: a data set of occurrence of xenarthran species in the Neotropics

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    Xenarthrans—anteaters, sloths, and armadillos—have essential functions for ecosystem maintenance, such as insect control and nutrient cycling, playing key roles as ecosystem engineers. Because of habitat loss and fragmentation, hunting pressure, and conflicts with domestic dogs, these species have been threatened locally, regionally, or even across their full distribution ranges. The Neotropics harbor 21 species of armadillos, 10 anteaters, and 6 sloths. Our data set includes the families Chlamyphoridae (13), Dasypodidae (7), Myrmecophagidae (3), Bradypodidae (4), and Megalonychidae (2). We have no occurrence data on Dasypus pilosus (Dasypodidae). Regarding Cyclopedidae, until recently, only one species was recognized, but new genetic studies have revealed that the group is represented by seven species. In this data paper, we compiled a total of 42,528 records of 31 species, represented by occurrence and quantitative data, totaling 24,847 unique georeferenced records. The geographic range is from the southern United States, Mexico, and Caribbean countries at the northern portion of the Neotropics, to the austral distribution in Argentina, Paraguay, Chile, and Uruguay. Regarding anteaters, Myrmecophaga tridactyla has the most records (n = 5,941), and Cyclopes sp. have the fewest (n = 240). The armadillo species with the most data is Dasypus novemcinctus (n = 11,588), and the fewest data are recorded for Calyptophractus retusus (n = 33). With regard to sloth species, Bradypus variegatus has the most records (n = 962), and Bradypus pygmaeus has the fewest (n = 12). Our main objective with Neotropical Xenarthrans is to make occurrence and quantitative data available to facilitate more ecological research, particularly if we integrate the xenarthran data with other data sets of Neotropical Series that will become available very soon (i.e., Neotropical Carnivores, Neotropical Invasive Mammals, and Neotropical Hunters and Dogs). Therefore, studies on trophic cascades, hunting pressure, habitat loss, fragmentation effects, species invasion, and climate change effects will be possible with the Neotropical Xenarthrans data set. Please cite this data paper when using its data in publications. We also request that researchers and teachers inform us of how they are using these data

    Neotropical freshwater fisheries : A dataset of occurrence and abundance of freshwater fishes in the Neotropics

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    The Neotropical region hosts 4225 freshwater fish species, ranking first among the world's most diverse regions for freshwater fishes. Our NEOTROPICAL FRESHWATER FISHES data set is the first to produce a large-scale Neotropical freshwater fish inventory, covering the entire Neotropical region from Mexico and the Caribbean in the north to the southern limits in Argentina, Paraguay, Chile, and Uruguay. We compiled 185,787 distribution records, with unique georeferenced coordinates, for the 4225 species, represented by occurrence and abundance data. The number of species for the most numerous orders are as follows: Characiformes (1289), Siluriformes (1384), Cichliformes (354), Cyprinodontiformes (245), and Gymnotiformes (135). The most recorded species was the characid Astyanax fasciatus (4696 records). We registered 116,802 distribution records for native species, compared to 1802 distribution records for nonnative species. The main aim of the NEOTROPICAL FRESHWATER FISHES data set was to make these occurrence and abundance data accessible for international researchers to develop ecological and macroecological studies, from local to regional scales, with focal fish species, families, or orders. We anticipate that the NEOTROPICAL FRESHWATER FISHES data set will be valuable for studies on a wide range of ecological processes, such as trophic cascades, fishery pressure, the effects of habitat loss and fragmentation, and the impacts of species invasion and climate change. There are no copyright restrictions on the data, and please cite this data paper when using the data in publications
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