Thiago Vieira

Bamboo dominance in tropical forests drives changes in floristic composition and vegetation structure. However, the role of bamboo dominance over ecosystem functions-including those related to forest regeneration-has received less attention. This study evaluated the fine-scale effects of the dominance of native bamboo Guadua weberbaueri Pilg. (Poaceae) on seed rain in a terra-firme forest in the southwest of the Brazilian Amazon to understand how bamboos remain a dominant element where they occur. We tested the hypothesis that bamboo dominance (i) reduces seed diversity and biomass and (ii) changes floristic composition and frequencies of seed dispersal mechanisms. For one year, we sampled seeds from seed rain in adjacent bamboo-dominated (BD) and bamboo-free (BF) environments in a forest without major anthropogenic disturbances. We found lower seed species richness in the BD environment and similar seed biomass between BD and BF. In addition, the seed species composition differed between BD and BF, with higher frequency of abiotic mechanisms to seeds dispersal in BD. We conclude that the dominance of bamboos acts as a filter for species that arrive via seed rain, modifying the floristic composition and dispersal mechanisms and, consequently, the dynamics of natural regeneration processes of terra-firme forests in the Amazon. This process can promote the permanence and expansion of the distribution area of bamboos in tropical forests.

We tested if linear spatial distance between two sites, environmental variables or river distance, are important drivers of aquatic insect assemblages composition in impounded rivers, located at the transition between Cerrado/ Amazonia. Regarding the scale of the study, we believe that flying adults have no dispersal limitation. Hence, our hypothesis is that species composition is structured mainly by environmental variables. We tested our hypothesis with partial Mantel. The model, which included environmental variables was the one that better explained the species composition in impounded rivers. We believe that the strong relationship between assemblages and environment is due to aspects related to acquisition of shelter and food resources.

The Brazilian Cerrado, one of the world's 34 biodiversity hotspots, is today under increasing pressure from the intensification of agriculture, with the replacement of traditional extensive pastures by arable crops. Manmade ponds are currently widespread in rural areas of the Cerrado and provide many ecosystem services such as cattle watering, fish production, irrigation and erosion protection. As in other parts of the world, ponds are also likely to play a critical role in the conservation of freshwater biodiversity, although in the Cerrado there is still very little known about their biota. Good water quality, in particular the level of eutrophication, is a key factor in maintaining aquatic biodiversity at the regional scale. Therefore, we aimed here to assess the water quality of ponds in the Cerrado. We also assessed whether the main types of socioeconomic pond uses have an impact on their water quality. We focused on measures of primary production and conducted socioeconomic inquiries for 56 waterbodies in the Goiânia Cerrado region (GO, Brazil) at the beginning of the 2012 dry season. Overall, differences in water quality appeared to be linked to the type of pond use. The trophic level, as indicated by the chlorophyll concentration and conductivity, was greater in fish ponds and seemed to be related to management practices such as fish feeding and the type of water supply, in particular relatively low inflow volume. This contrasted with ponds used for cattle watering in extensive agricultural landscapes characterized by a low trophic level potentially beneficial for regional biodiversity. Good water quality in pasture ponds may be maintained by spring water inflow or heavy precipitation. Overall, the water quality of the Cer-rado ponds was good compared with the same type of waterbodies in other regions of the world. These results highlight the high potential of the Cerrado ponds in extensive agricultural landscapes to provide an important habitat for aquatic biodiversity. Biodiversity inventories and assessments are now needed to increase our knowledge of these waterbodies and inform management activities at the local and regional scale.

There is a worldwide concern on the loss
of pond biodiversity in human dominated landscapes.
Nevertheless, agricultural activities appear to increase
pond number in the Brazilian Cerrado through damming streams for cattle raising. These man-made
ponds may represent important landscape features, but
their importance to regional biodiversity has not yet
been studied. Here, we evaluated differences in alpha
and beta diversity under a multi-taxonomic approach,
as well as tested pond size as the main driver of local
species richness. We also assessed the importance of
environmental heterogeneity through the analysis of
the regional species accumulation curves (SAC). The
overall result suggests that species turnover was the
major component of regional biodiversity for all
groups. Major physical and chemical water conditions
had no effects on algae, macrophytes, water bugs, and
birds species richness. Pond size had a significant
effect on Odonata and fish species richness, while
water beetles and amphibians were influenced by
trophic conditions. Results from regional SAC show
variations among different taxonomic groups regarding landscape heterogeneity: only algae, fish, and birds
do not reached to an asymptote and had higherzvalues. Our results highlight the importance of ponds
for biodiversity conservation in increasingly agricultural landscapes in central Brazil.

Bats of the genus Artibeus are among the most important seed dispersers in early successional forests. We report observations on the foraging behavior of Artibeus lituratus in Pedra da Cebola Municipal Park, an urban park in the city of Vitória, Espírito Santo, southeastern Brazil. Observations were made during six consecutive days (April 1st to April 6th, 2006). Three mist-nets were opened each night close to a Maclura tinctoria tree (Moraceae), remaining open from 18:00 to 22:00, totaling four hours per night, and 24 hours of sampling effort. We observed two peaks of feeding activity at the tree, one between 18:20 and 19:30, and a second one at 21:00. This is the first observation of Artibeus lituratus feeding on M. tinctoria fruits, therefore adding a new item to the known diet of the species. M. tinctoria fruits have large seeds that are not swallowed by bats, they consume the fruit pulp and discard the seeds. A diet of fruits with large seeds may indicate an important resource not detected in dietary studies based on fecal samples, but better detected by direct observation or by studying feeding roosts. It is important to use different sampling techniques in dietary studies since they complement each other and, together, provide a better knowledge on the diet of bats.