Vanesca Korasaki

A social and ecological assessment of tropical land uses at multiple scales: the Sustainable Amazon Network

Science has a critical role to play in guiding more sustainable development trajectories. Here, we present the Sustainable Amazon Network (Rede Amazônia Sustentável, RAS): a multidisciplinary research initiative involving more than 30 partner organizations working to assess both social and ecological dimensions of land-use sustainability in eastern Brazilian Amazonia. The research approach adopted by RAS offers three advantages for addressing land-use sustainability problems: (i) the collection of synchronized and co-located ecological and socioeconomic data across broad gradients of past and present human use; (ii) a nested sampling design to aid comparison of ecological and socioeconomic conditions associated with different land uses across local, landscape and regional scales; and (iii) a strong engagement with a wide variety of actors and non-research institutions. Here, we elaborate on these key features, and identify the ways in which RAS can help in highlighting those problems in most urgent need of attention, and in guiding improvements in land-use sustainability in Amazonia and elsewhere in the tropics. We also discuss some of the practical lessons, limitations and realities faced during the development of the RAS initiative so far.

Dung Beetle Community and Functions along a Habitat-Disturbance Gradient in the Amazon: A Rapid Assessment of Ecological Functions Associated to Biodiversity

Although there is increasing interest in the effects of habitat disturbance on community attributes and the potential consequences for ecosystem functioning, objective approaches linking biodiversity loss to functional loss are uncommon. The objectives of this study were to implement simultaneous assessment of community attributes (richness, abundance and biomass, each calculated for total-beetle assemblages as well as small- and large-beetle assemblages) and three ecological functions of dung beetles (dung removal, soil perturbation and secondary seed dispersal), to compare the effects of habitat disturbance on both sets of response variables, and their relations. We studied dung beetle community attributes and functions in five land-use systems representing a disturbance gradient in the Brazilian Amazon: primary forest, secondary forest, agroforestry, agriculture and pasture. All response variables were affected negatively by the intensification of habitat disturbance regimes, but community attributes and ecological functions did not follow the same pattern of decline. A hierarchical partitioning analysis showed that, although all community attributes had a significant effect on the three ecological functions (except the abundance of small beetles on all three ecological functions and the biomass of small beetles on secondary dispersal of large seed mimics), species richness and abundance of large beetles were the community attributes with the highest explanatory value. Our results show the importance of measuring ecological function empirically instead of deducing it from community metrics.

Do space-for-time assessments underestimate the impacts of logging on tropical biodiversity? An Amazonian case study using dung beetles

Human alteration of the global environment is leading to a pervasive loss of biodiversity. Most studies evaluating human impacts on biodiversity occur after the disturbance has taken place using spatially distinct sites to determine the undisturbed reference condition. This approach is known as a space-for-time (SFT) substitution. However, SFT substitution could be underestimating biodiversity loss if spatial controls fail to provide adequate inferences about pre-disturbance conditions. We compare the SFT substitution with a before–after control–impact (BACI) approach by assessing dung beetles before and after a logging exploration in the Brazilian Amazon. We sampled 34 logging management units, of which 29 were selectively logged with different intensities after our first collection. We used dung beetle species richness, species composition and biomass as our biodiversity response metrics and the gradient of selective logging intensity as our explanatory metric. Only the BACI approach consistently demonstrated the negative impacts of logging intensification on all dung beetle community metrics. Moreover, the BACI approach explained significantly more of the variance in all the relationships and it doubled the estimates of species loss along the gradient of logging intensity when compared to SFT. Synthesis and applications. Our results suggest that space-for-time (SFT) substitution may greatly underestimate the consequences on local species diversity and community turnover. These results have important implications for researchers investigating human impacts on biodiversity. Incentivizing before–after control–impact (BACI) approaches will require longer-term funding to gather the data and stronger links between researchers and landowners. However, BACI approaches are accompanied by many logistical constraints, making the continued use of SFT studies inevitable in many cases. We highlight that non-significant results and weak effects should be viewed with caution.

A comparison of dung beetle assemblage structure (Coleoptera: Scarabaeidae: Scarabaeinae) between an Atlantic forest fragment and adjacent abandoned pasture in Paraná, Brazil

The study was conducted at the Mata dos Godoy State Park in Londrina, state of Parana, Brazil. Baited pitfall traps were installed in the forest, in adjacent abandoned pasture land, and on the borders between these two environments. Every two weeks, from June 1999 to May 2000, the traps were placed for 24 hours and the material was collected every 12 hours. The 4687 specimens of Scarabaeinae collected belong to 13 genera and 27 species. The most frequent species were Onthophagus catharinensis (Paulian, 1936) (22.1%), Onthophagus hirculus (Mannerhein, 1829) (20.1%), Dichotomius mormon (Ljungh, 1799) (13.1%), Sulcophanaeus menelas (Laporte, 1840) (12.8%), and Eurystemus parallelus (Dalman, 1824) (10.6%). The other species collected amounted to less than 4.7%. The difference in numbers of specimens collected in the three environments was not significant (K(2.72) = 0.63, p = 0.729). The distribution patterns of species composition for the different environments (ANOSIM R = 0.29, p < 0.01) and activity periods (ANOSIM R = 0.18, p < 0.01) were different. Sulcophanaeus menelas, Canthidium aff. trinodosum, O. hirculus, and E. parallelus were the most abundant species, being predominantly diurnal; the first three species were more active on abandoned pasture. Most of the Dichothomius assifer (Eschscholtz, 1822) and D. mormon specimens were captured at night. The latter species was the most abundant in edges, whereas D. assifer, Scybalochantum aff. zischkai, and O. catharinensis can be considered bioindicators because they were either exclusively or highly predominant in the best preserved areas. A larger number of individuals was observed from December 1999 through March 2000, which is the time of the year when adults of Scarabaeinae normally emerge and fly, in the studied region. The highest diversity (88.89%) was observed in February.

Are Dung Beetles Driving Dung-Fly Abundance in Traditional Agricultural Areas in the Amazon?

We evaluated the effects of different land-use systems on the ability of dung beetles to control the population of detritus-feeding flies. We tested the hypotheses that intensification of land use will reduce dung beetles richness, abundance and biomass and, consequently, their dung burial ability, affecting the interaction between dung beetles and flies and reducing its effectiveness as a natural biological control. In the Brazilian Amazon we sampled dung beetles, fly larvae and adults; and recorded the rate of dung removal by dung beetles across a gradient of land-use intensity from primary forest, secondary forest, agroforestry, agriculture to pasture. Our results provide evidence that land-use intensification results in a reduction of the richness, abundance and biomass of dung beetles, and this in turn results in lower rates of dung removal in the most simplified systems. We found no significant differences in the abundance of fly larvae between the different systems of land use. However, the number of adult flies differed significantly between land-use systems, presenting higher abundance in those sites with greater intensity of use (pasture and agriculture) and a lower abundance of adult flies in forested systems (primary and secondary forests, and agroforestry). Information-theoretic model selection based on AICc revealed strong support for the influence of land-use systems, dung removal rates and dung beetle abundance, biomass and richness on adult dung-fly abundance. Our results also reveal that dung beetles are not solely responsible for fly control and that other factors linked to land use are influencing the populations of these detritus-feeding insects.

Using dung beetles to evaluate the effects of urbanization on Atlantic Forest biodiversity

We used dung beetles to evaluate the impact of urbanization on insect biodiversity in three Atlantic Forest fragments in Londrina, Paraná, Brazil. This study provides the first empirical evidence of the impact of urbanization on richness, abundance, composition and guild structure of dung beetle communities from the Brazilian Atlantic Forest. We evaluated the community aspects (abundance, richness, composition and food guilds) of dung beetles in fragments with different degrees of immersion in the urban matrix using pitfall traps with four alternative baits (rotten meat, rotten fish, pig dung and decaying banana). A total of 1 719 individuals were collected, belonging to 29 species from 11 genera and six Scarabaeinae tribes. The most urban‐immersed fragment showed a higher species dominance and the beetle community captured on dung presented the greatest evenness. The beetle communities were distinct with respect to the fragments and feeding habits. Except for the dung beetle assemblage in the most urbanized forest fragment, all others exhibited contrasting differences in species composition attracted to each bait type. Our results clearly show that the degree of urbanization affects Atlantic Forest dung beetle communities and that the preservation of forest fragments inside the cities, even small ones, can provide refuges for Scarabaeinae.

Conservation value of alternative land-use systems for dung beetles in Amazon: valuing traditional farming practices

Land-use systems (LUS), placed in originally forested areas, represent different degrees of opportunity for species conservation. In this study, we examined the dung beetle communities in order to identify the conservation value of different LUS: primary forest, old secondary forest, young secondary forest, agroforestry, agriculture and pasture in Western Amazon. The LUS were sampled in two campaigns during the highest precipitation period and dryest period. The primary forest has a high number of total and exclusive species. Large beetles show a continuous decreasing in richness and abundance from primary forest to pastures, while small ones are not sensible to intermediate systems (secondary forest to agriculture) in terms of species richness and exhibit a increase in abundance at agroforest and agriculture when contrasted to secondary forest and pasture The beetle community composition was not sensible to secondary forest recovering time. Secondary forests and agroforestry stood out as harboring many species shared with primary forests. Cloud-point dispersion (average dissimilarity) increased from primary forest towards LUS’s submitted to more intense use. The higher sampling points similarity observed in primary forest might be the result of the relative stability of this system, given that environmental impacts might increase variability in community structure and beta diversity. Increase in beta diversity as expressed by greater dispersion of sites in multivariate space suggests that these areas are dependent on nearby species pools, possibly primary forests, and harbor a higher spatial heterogeneity in species composition. This high variability can overestimate the importance of occasional species, thus biasing the actual value of alternative LUS for biodiversity conservation.

Abundance and diversity of coprophagous beetles (Coleoptera: Scarabaeidae) caught with a light trap in a pasture area of the Brazilian Cerrado

Coprophagous beetles (Coleoptera: Scarabaeidae) play an important ecological role in grazing agroecosystems, especially for the removal and bury of herbivore feces. In this study we identified coprophagous Scarabaeidae species found in an area of Brachiaria brizantha (Poaceae) pasture in the Brazilian Cerrado, analyzing community structure with environmental variables in the area. The insects were captured with a light trap from November 2007 to October 2008 every 15 days, totaling 24 hours of sampling/month. A total of 2541 individuals were collected and from two subfamilies (Aphodiinae and Scarabaeinae), 17 genera and 33 species. The numbers of individuals and species captured were positively correlated with monthly precipitation. Os besouros coprófagos (Coleoptera: Scarabaeidae) desempenham importante papel ecológico em agroecossistemas de pastagens, com ênfase na remoção e enterrio das fezes de herbívoros. Nesse estudo nós identificamos as espécies de Scarabaeidae coprófagos que ocorrem em área de pastagem de Brachiaria brizantha (Poaceae) no Cerrado brasileiro, analisando a estrutura da comunidade com as variáveis ambientais da área. Os insetos foram capturados com uma armadilha luminosa a cada quinze dias de novembro de 2007 a outubro de 2008, totalizando 24 horas de amostragem/mês. Um total de 2.541 indivíduos foram capturados e estão distribuídos em duas subfamílias (Aphodiinae e Scarabaeinae), 17 gêneros e 33 espécies. O número de indivíduos e de espécies capturadas foram positivamente correlacionados com a precipitação mensal.

Biodiversity of Cetoniinae beetles (Coleoptera: Scarabaeidae) in introduced and native habitats in the Brazilian Atlantic Forest

The ecology of the beetles of the subfamily Cetoniinae (Coleoptera: Scarabaeidae) is relatively poorly known worldwide. In the neotropics in particular, there are far less studies than in other biogeographic regions. In part due to this lack of knowledge, cetoniines are not considered indicators of habitat quality in the Neotropical region. In this study, we compare the abundance, diversity, and species composition of cetoniines in three different habitats in Brazil: two exotic (Brachiaria pasturelands and eucalyptus plantation) and one native (Brazilian Atlantic Forest). We also provide diagnostic images of both sexes and of the genitalia of males of all species to facilitate species identification in further studies. The beetles were collected weekly from September to December 2012 with traps baited with fermented fruit, in five eucalyptus plantations (Eucalyptus grandis Hill ex Maiden), five exotic pasturelands (Brachiaria spp.), and five patches of Brazilian Atlantic Forest. The abundance and diversity of cetoniines was found to be lower in the eucalyptus plantations and about the same in the forest and pasturelands. The low diversity found and the little information available on the ecology of Neotropical Cetoniinae is insufficient to propose these beetles as candidates for the habitat evaluation in Brazil.

Deltochilini and Phanaeini dung beetles (Coleoptera: Scarabaeidae: Scarabaeinae) in introduced and native ecosystems of Brazil

The dung beetle tribes Deltochilini and Phanaeini (Coleoptera: Scarabaeidae: Scarabaeinae) play an important ecological role in the habitats in which they live. Despite much field work on these beetles in the Neotropical region, biological information on many taxa is still unknown. Here we provide information on species of Deltochilini and Phanaeini including temporal distribution of adults, sex ratio (Male : Female) and measurements of the individuals as well as on ecology and general biology of all species sampled in introduced (pasturelands of Brachiaria spp.) and native (patch of the Brazilian savanna) ecosystems of Brazil. Furthermore, our findings may help to understand the complexity of the effects of mixed ecosystems on the biodiversity of dung beetles.