Deforestation impacts on bat functional diversity in tropical landscapes

"Functional diversity is the variability in the functional roles carried out by species within ecosystems. Changes in the environment can affect this component of biodiversity and can, in turn, affect different processes, including some ecosystem services. This study aimed to determine the effect of forest loss on species richness, abundance and functional diversity of Neotropical bats. To this end, we identified six landscapes with increasing loss of forest cover in the Huasteca region of the state of Hidalgo, Mexico. We captured bats in each landscape using mist nets, and calculated functional diversity indices (functional richness and functional evenness) along with species richness and abundance. We analyzed these measures in terms of percent forest cover. We captured 906 bats (Phyllostomidae and Mormoopidae), including 10 genera and 12 species. Species richness, abundance and functional richness per night are positively related with forest cover. Generalized linear models show that species richness, abundance and functional richness per night are significantly related with forest cover, while seasonality had an effect on abundance and functional richness. Neither forest cover nor season had a significant effect on functional evenness. All these findings were consistent across three spatial scales (1, 3 and 5 km radius around sampling sites). The decrease in species, abundance and functional richness of bats with forest loss may have implications for the ecological processes they carry out such as seed dispersal, pollination and insect predation, among others.

Glucose microfluidic fuel cell using air as oxidant

A bioanode was constructed using glucose oxidase enzyme (GOx) supported on multiwalled-carbon nanotubes (MWCNTs) in the presence of glutaraldehyde (GA) (GOx/MWCNTs-GA) and evaluated in an air-breathing hybrid glucose microfluidic fuel cell (HG-μFC). The air-breathing HG-μFC operated under physiological conditions (5 mM glucose at pH 7 with an air-exposed cathode) delivers an open circuit value of 0.72 V with 610 μW cm−2 of maximum power density, and shows potential possibilities to develop future implantable applications

The effects of electrode and catalyst selection on microfluidic fuel cell performance

A fuel cell can be best defined as an electrochemical converter of fuel and oxidant of chemical energy to electrical energy. The important components of micro fuel cells are the electrodes and catalysts because the kinetics and rates of the electrochemical reactions depend on their materials. All fuel cells consist of two electrodes: the anode, where fuel oxidation takes place, and the cathode, which is used to reduce the oxidants. The present review article highlights the use of a range of electrodes made up of different materials, a variety of catalysts that have been used in previous studies, and their fabrication materials and approaches. In this article, electrodes and catalysts are classified into two types based on the design approach applied to produce the micro fuel cell: micro fuel cell design and conventional assembly design. Most previous studies on fuel cells have demonstrated that the construction and position of the electrodes play crucial roles in improving the performance of micro fuel cells

Vertebrate Dissimilarity Due to Turnover and Richness Differences in a Highly Beta-Diverse Region: The Role of Spatial Grain Size, Dispersal Ability and Distance

<div><p>We explore the influence of spatial grain size, dispersal ability, and geographic distance on the patterns of species dissimilarity of terrestrial vertebrates, separating the dissimilarity explained by species replacement (turnover) from that resulting from richness differences. With data for 905 species of terrestrial vertebrates distributed in the Isthmus of Tehuantepec, classified into five groups according to their taxonomy and dispersal ability, we calculated total dissimilarity and its additive partitioning as two components: dissimilarity derived from turnover and dissimilarity derived from richness differences. These indices were compared using fine (10 x 10 km), intermediate (20 x 20 km) and coarse (40 x 40 km) grain grids, and were tested for any correlations with geographic distance. The results showed that total dissimilarity is high for the terrestrial vertebrates in this region. Total dissimilarity, and dissimilarity due to turnover are correlated with geographic distance, and the patterns are clearer when the grain is fine, which is consistent with the distance-decay pattern of similarity. For all terrestrial vertebrates tested on the Isthmus of Tehuantepec both the dissimilarity derived from turnover and the dissimilarity resulting from richness differences make important contributions to total dissimilarity, and dispersal ability does not seem to influence the dissimilarity patterns. These findings support the idea that conservation efforts in this region require a system of interconnected protected areas that embrace the environmental, climatic and biogeographic heterogeneity of the area.</p> </div

Study area on the Isthmus of Tehuantepec, Mexico.

<p>We show the grids used for the analyses at three grain sizes. A: fine grain, 10 x 10 km cells, B: intermediate grain, 20 x 20 km cells, and C: coarse grain, 40 x 40 km cells.</p

Relative contribution of species turnover and richness differences to the total dissimilarity.

<p>The graph shows this contribution for different groups of terrestrial vertebrates on the Isthmus of Tehuantepec, using three grain sizes. Kruskal-Wallis results for total dissimilarity are included, and equal low case letters indicate no difference in pairwise comparisons. Tests results for species turnover and richness differences are given in the text.</p

Percent of forest vegetation cover for the six sampling sites in the Huasteca region, in the state of Hidalgo, Mexico.

<p>For each site, vegetation cover was measured in three spatial scales (buffers with different radius around sampling sites).</p