The diversity of ant communities (Hymenoptera: Formicidae) and their connections with other arthropods from three temperate forests of Central Mexico.

Ants have been considered useful for bioindication because of their ecological characteristics. Nonetheless, among the characteristics of a bioindicator group, there must be a consistent and replicable response to disturbance. In this sense, divergent reactions have been found, even between taxons narrowly related. The objective of this work was to compare the diversity of the ant communities in three different temperate forests with different levels of disturbance, and to correlate their abundance and diversity of species, with that found in other arthropod communities of the same forests. The work was carried out in three municipalities in the North of the State of Mexico, where three types of different forests were identified by their degree of disturbance. These types include: 1) primary forest (PF), with typical species of a conserved forest; 2) mixed forest (MF), with species of a conserved forest and a reforestation effort; and 3) reforested forest (RF), with species used in reforestation efforts and indicative of disturbance. In each sample, an area of 2 500 m2 was selected. Each area had 16 pitfalls apiece and they were placed 10 m away from each other. Samples were collected twice; one from February through March 2009 (dry season) and another from August through September 2010 (rainy season), which produced a total of 192 traps. Obtained specimens were identified at the most taxonomically specific level. All data captured was transformed to √n + 0.5 and diversity index levels of Shannon and Simpson were calculated, as well as richness of species for ants, beetles, grasshoppers, true bugs, and spiders. The values of richness, diversity, and abundance were correlated with the Pearson coefficient, and to evaluate possible causal relationships between these, a path analysis was performed. Results suggested an important influence of the site over ant communities, and values of richness, abundance and diversity were correlated with the communities of spiders, beetles, grasshoppers and true bugs, but not for all the sites studied. Responses to environmental changes are not only on the numeric proportions of abundance, richness and diversity, but also in the indirect and casual ecological interactions. Finally, the data seems to indicate that the responses of the ants to the environmental changes are not necessarily reflected on other organisms' communities, so the ants' role as bioindicators can be limited.

Indicatory bacteria and chemical composition related to sulfur distribution in the river-lake systems.

Sulfate related water quality and trophic status are crucial to operation of water diversion. Though the sulfur geochemistry in the lake sediment have been well studied, the effective indicator of surrounding environment conditions related to sulfur in river-lake systems are still unknown. In this study, Dongping Lake (DPH), Weishan Lake (WSH), and Hanzhuang trunk canal (HZQ) were selected as the typical river-lake systems in the eastern of China. Different spatial variations in sedimentary sulfate, total sulfur, and elemental composition of sediments were investigated in these areas. The relatively high sulfate in surface water and sediments appeared in portions of WSH. The biodiversity of HZQ and WSH surface sediments was much higher than that of DPH. Pseudomonas, Acinetobacter, and Thiobacillus were the dominant genera of the river-lake systems. Among the different genera in distribution, genera such as Malikia, Sulfurovum and Lysinibacillus were significantly negatively correlated with sulfur related environmental factors. While the genera such as Pseudomonas, Vogesella and Acinetobacter were significantly positively correlated with these factors. Compared with connectivity in the largest interaction network, bacteria such as Proteus, Acidobacter and Chlorobacteria were identified as indicatory taxa to infer sulfate related conditions in the river-lake systems.

Molecular assessment of wild populations in the marine realm: Importance of taxonomic, seasonal and habitat patterns in environmental monitoring.

Scientists are currently faced with the challenge of assessing the effects of anthropogenic stressors on aquatic ecosystems. Cellular stress response (CSR) biomarkers are ubiquitous and phylogenetically conserved among metazoans and have been successfully applied in environmental monitoring but they can also vary according to natural biotic and abiotic factors. The reported variability may thus limit the wide application of biomarkers in monitoring, imposing the need to identify variability levels in the field. Our aim was to carry out a comprehensive in situ assessment of the CSR (heat shock protein 70 kDa, ubiquitin, antioxidant enzymes) and oxidative damage (lipid peroxidation) in wild populations across marine taxa by collecting fish, crustaceans, mollusks and cnidarians during two different seasons (spring and summer) and two habitat types (coast and estuary). CSR end-point patterns were different between taxa with mollusks having higher biomarker levels, followed by the cnidarians, while fish and crustaceans showed lower biomarker levels. The PCA showed clear clusters related to mobility/sessile traits with sessile organisms showing greater levels (>2-fold) of CSR proteins and oxidative damage. Mean intraspecific variability in the CSR measured by the coefficient of variation (% CV) (including data from all seasons and sites) was elevated (35-94%). Overall, there was a seasonal differentiation in biomarker patterns across taxonomic groups, especially evident in fish and cnidarians. A differentiation in biomarker patterns between habitat types was also observed and associated with phenotypic plasticity or local adaptation. Overall, specimens collected in the estuary had lower biomarker levels when compared to specimens collected in the coast. This work highlights the importance of assessing baseline biomarker levels across taxa, seasons and habitats prior to applying biomarker analyses in environmental monitoring. Selecting bioindicator species, defining sampling strategies, and identifying confounding factors are crucial preliminary steps that ensure the success of biomarkers as powerful tools in biomonitoring.

The diversity of ant communities (Hymenoptera: Formicidae) and their connections with other arthropods from three temperate forests of Central Mexico / Diversidad de comunidades de hormigas (Hymenoptera: Formicidae) y sus conexiones con otros artrópodos en tres bosques templados del centro de México

AbstractAnts have been considered useful for bioindication because of their ecological characteristics. Nonetheless, among the characteristics of a bioindicator group, there must be a consistent and replicable response to disturbance. In this sense, divergent reactions have been found, even between taxons narrowly related. The objective of this work was to compare the diversity of the ant communities in three different temperate forests with different levels of disturbance, and to correlate their abundance and diversity of species, with that found in other arthropod communities of the same forests. The work was carried out in three municipalities in the North of the State of Mexico, where three types of different forests were identified by their degree of disturbance. These types include: 1) primary forest (PF), with typical species of a conserved forest; 2) mixed forest (MF), with species of a conserved forest and a reforestation effort; and 3) reforested forest (RF), with species used in reforestation efforts and indicative of disturbance. In each sample, an area of 2 500 m2 was selected. Each area had 16 pitfalls apiece and they were placed 10 m away from each other. Samples were collected twice; one from February through March 2009 (dry season) and another from August through September 2010 (rainy season), which produced a total of 192 traps. Obtained specimens were identified at the most taxonomically specific level. All data captured was transformed to √n + 0.5 and diversity index levels of Shannon and Simpson were calculated, as well as richness of species for ants, beetles, grasshoppers, true bugs, and spiders. The values of richness, diversity, and abundance were correlated with the Pearson coefficient, and to evaluate possible causal relationships between these, a path analysis was performed. Results suggested an important influence of the site over ant communities, and values of richness, abundance and diversity were correlated with the communities of spiders, beetles, grasshoppers and true bugs, but not for all the sites studied. Responses to environmental changes are not only on the numeric proportions of abundance, richness and diversity, but also in the indirect and casual ecological interactions. Finally, the data seems to indicate that the responses of the ants to the environmental changes are not necessarily reflected on other organisms’ communities, so the ants’ role as bioindicators can be limited. Rev. Biol. Trop. 64 (2): 571-585. Epub 2016 June 01.

ResumenPor sus características ecológicas las hormigas se han considerado útiles para la bioindicación. Sin embargo, entre los rasgos de un grupo bioindicador, debe haber una respuesta consistente y repetible a la perturbación. En este sentido, se han encontrado respuestas divergentes, incluso entre taxones estrechamente relacionados. El objetivo de este trabajo fue comparar la diversidad de las comunidades de hormigas en tres tipos de bosque templado con diferente nivel de perturbación y correlacionar su abundancia, riqueza de especies y la diversidad con aquella que se encuentra en otras comunidades de artrópodos en los mismos bosques. El trabajo se realizó en tres localidades del norte del Estado de México donde fueron identificados tres tipos de bosque diferenciados por grado de disturbio: 1) bosque primario (PF), con especies típicas de un bosque conservado; 2) bosque mixto (MF) con especies de bosque conservado y propias de reforestación y 3) bosque reforestado (RF) con especies utilizadas en reforestación e indicadoras de pertubación. En cada tipo de bosque se seleccionó un área de 2 500 m2 donde fueron colocadas 16 trampas de caída con una separación de 10 m. Fueron realizadas dos recolectas una de febrero a marzo 2009 (estación seca) y otra de agosto a septiembre 2010 (estación lluviosa), lo que dio un total de 192 trampas. Los especímenes obtenidos fueron identificados al nivel taxonómico más específico posible. Todos los datos de las capturas fueron transformados a √n+0.5 y fueron calculados los índices de diversidad de Shannon y Simpson y riqueza de especies tanto para hormigas como para escarabajos, chapulines, chiches y arañas. Los valores de riqueza, diversidad y abundancia fueron correlacionados con el coeficiente de Pearson y para evaluar posibles relaciones causales entre estos se realizó un análisis de sendero. Los resultados sugieren una influencia importante del sitio sobre las comunidades de hormigas y sus valores de riqueza, abundancia y diversidad están correlacionadas con las comunidades de arañas, escarabajos, chapulines y chinches, pero no para todos los sitios estudiados. Las respuestas a los cambios ambientales no sólo están en las proporciones numéricas de la abundancia, riqueza y diversidad sino también en las interacciones ecológicas indirectas y causales. Los resultados sugieren que las respuestas de las hormigas a los cambios ambientales no necesariamente se reflejan sobre comunidades de otros organismos por lo que su papel como bioindicadores puede ser limitado.