Conservation of Latin America freshwater biodiversity: beyond political borders

Latin America’s tremendous socio-cultural and biological diversity has evolved along tightly intertwined, far-reaching river networks. Decisions taken by any one country, may have strong impacts on the regional and even global biodiversity conservation agenda, such as the Convention on Biological Diversity. Here we comment on four perspectives complementing actions suggested by Azevedo-Santos et al. (2021) in their Commentary “Conservation of Brazilian freshwater biodiversity: Thinking about the next 10 years and beyond”. This contribution aims at attaining an effective conservation of freshwater biodiversity in Latin America, particularly in the context of the ongoing negotiations on the Global Biodiversity Framework. Our suggestions put forward cross-border perspectives, urging governments to engage in actions that consider the reality of and threats to transnational ecosystems such as many river basins of Latin America and elsewhere

Global trends in research on the effects of climate change on Aedes aegypti: international collaboration has increased, but some critical countries lag behind

Background: Mosquito‑borne diseases (e.g., transmitted by Aedes aegypti) affect almost 700 million people each year and result in the deaths of more than 1 million people annually. Methods: We examined research undertaken during the period 1951–2020 on the effects of temperature and climate change on Ae. aegypti, and also considered research location and between‑country collaborations. Results: The frequency of publications on the effects of climate change on Ae. aegypti increased over the period examined, and this topic received more attention than the effects of temperature alone on this species. The USA, UK, Australia, Brazil, and Argentina were the dominant research hubs, while other countries fell behind with respect to number of scientific publications and/or collaborations. The occurrence of Ae. aegypti and number of related dengue cases in the latter are very high, and climate change scenarios predict changes in the range expansion and/or occurrence of this species in these countries. Conclusions: We conclude that some of the countries at risk of expanding Ae. aegypti populations have poor research networks that need to be strengthened. A number of mechanisms can be considered for the improvement of international collaboration, representativity and diversity, such as research networks, internationalization programs, and programs that enhance representativity. These types of collaboration are considered important to expand the relevant knowledge of these countries and for the development of management strategies in response to climate change scenarios

EDITORIAL - MONITORAMENTO DA CONSERVAÇÃO DA BIODIVERSIDADE: APRENDENDO COM EXPERIÊNCIAS VIVIDAS, COM ÊNFASE NAS UNIDADES DE CONSERVAÇÃO

Com este número temático buscamos reunir e divulgar experiências em geral dispersas, com ênfase naquelas que envolvem monitoramento in situ. Esperamos que a diversidade de artigos cobrindo o tema seja de estimulante leitura e promova reflexões e ações em várias escalas; que este conjunto de iniciativas, reforçado, resulte em sempre melhor comunicação à sociedade sobre a biodiversidade brasileira, o papel das áreas protegidas e a efetividade das ações de conservação; e que o monitoramento da biodiversidade, com boa articulação de seus componentes, aumente nossa capacidade de gerir a biodiversidade visando sua conservação e uso sustentável

Loss of Cultural and Functional Diversity Associated With Birds Across the Urbanization Gradient in a Tropical City

Birds provide many ecosystem services to people, including provisioning, regulating and cultural services. People attribute multiple cultural values to ecosystems and biodiversity and the diversity of these cultural values can be considered as cultural diversity. While human-nature interactions occur more frequently in cities and urbanization negatively affects different facets of avian biodiversity, little is known about its consequence for cultural diversity. Here, we assess how the urbanization gradient in Campo Grande, a Brazilian city in the Cerrado biodiversity hotspot, affects functional and cultural diversity associated with birds and if functional and cultural diversity are congruent. We also investigate the relation between urbanization gradient with functional traits and cultural values, weighted by species abundance. We used a dataset based on bird surveyed in 61 landscapes along a gradient of impervious surface cover. To estimate functional and cultural diversity, we used indices that estimate richness and divergence of functional traits and cultural values. We found that urbanization affected functional and cultural richness negatively, while there was no effect on functional and cultural divergence. Functional and cultural richness and functional and cultural divergence were weakly, but significantly correlated. Bird species that nest on trees decreased and those that nest in artificial structures and on the ground increased along the impervious surface gradient. Body size, diet, habitat, mating system, flock behavior, and all cultural values (number of times the species was mentioned by football teams, music or poetry, city flags and anthems, and folklore tales) were not significantly affected by impervious surface. The negative relationship between impervious surface and bird cultural richness may indicate that people living in more urbanized areas experience nature less compared to people in less urbanized areas, which can affect their psychological well-being. In these highly urbanized areas, contact with culturally valued birds and cultural services provided by birds may also diminish. The negative relationship between functional richness and urbanization also indicate that highly urbanized areas may be losing important ecosystems services provided by birds

Warning signals of biodiversity collapse across gradients of tropical forest loss

We evaluate potential warning signals that may aid in identifying the proximity of ecological communities to biodiversity thresholds from habitat loss—often termed “tipping points”—in tropical forests. We used datasets from studies of Neotropical mammal, frog, bird, and insect communities. Our findings provide only limited evidence that an increase in the variance (heteroskedasticity) of biodiversity-related parameters can provide a general warning signal of impending threshold changes in communities, as forest loss increases. However, such an apparent effect was evident for amphibians in the Brazilian Atlantic Forest and Amazonian mammal and bird communities, suggesting that impending changes in some species assemblages might be predictable. We consider the potential of such warning signs to help forecast drastic changes in biodiversity

Incorporating costs, thresholds and spatial extents for selecting stream bioindicators in an ecotone between two Brazilian biodiversity hotspots

Biomonitoring is critical for characterizing and monitoring status, spatial patterns, and long-term trends in the ecological condition of freshwater ecosystems. The selection of cost-effective bioindicators is a critical step in establishing such monitoring programs. Key indicator considerations are a reliable response to anthropogenic disturbances, a high benefit-cost-ratio and sensitivity at multiple spatial extents. We evaluated non-linear responses of Ephemeroptera, Plecoptera and Trichoptera (EPT) and fish to the effects of native vegetation loss within buffers of 100 m and 1000 m and assessed the sampling and processing costs involved for each assemblage. We sampled 37 neotropical stream sites in the Formoso River network, a karstic region of the Bodoquena Plateau, midwest Brazil, lying in the ecotone between the Cerrado and Atlantic Forest biological hotspots. We used TITAN (threshold indicator taxa analysis) to identify six indicator taxa, four EPT genera and two fish species. The four EPT genera had low negative thresholds to native vegetation loss, whereas the two fish species had positive thresholds. Thresholds were lower for the 100 m buffers than the 1000 m buffers for EPT. The most sensitive taxon (Macronema, Trichoptera) had a threshold of 0% native vegetation loss in the 100 m buffers and nearly 40% in the 1000 m buffers. For taxa richness, we found no non-linear response to the effects of native vegetation loss for buffer extent nor assemblage. The total cost for EPT biomonitoring was US$3,616; whereas for fish, the total was US$ 1,901. Although fish were less expensive than EPT, they did not respond negatively to native vegetation loss and their positive threshold started at 48%, a level of vegetation loss that was highly disruptive of EPT. Therefore, we do not recommend using fish to monitor the effects of native vegetation loss on headwater streams in the Bodoquena Plateau. Although EPT monitoring costs 52% more than fish assemblage monitoring, it detected earlier impacts of the effects of native vegetation loss on stream biota, especially in the 100 m buffer. Therefore, EPT are more cost-effective early warning indicators for monitoring the effects of native vegetation loss in Bodoquena Plateau headwaters

Seasonality modulates the direct and indirect influences of forest cover on larval anopheline assemblages in western Amazônia

Serious concerns have arisen regarding urbanization processes in western Amazônia, which result in the creation of artificial habitats, promoting the colonization of malaria vectors. We used structural equation modelling to investigate direct and indirect effects of forest cover on larval habitats and anopheline assemblages in different seasons. We found 3474 larvae in the dry season and 6603 in the rainy season, totalling ten species and confirming the presence of malaria vectors across all sites. Forest cover had direct and indirect (through limnological variables) effects on the composition of larval anopheline assemblages in the rainy season. However, during the dry season, forest cover directly affected larval distribution and habitat variables (with no indirect affects). Additionally, artificial larval habitats promote ideal conditions for malaria vectors in Amazonia, mainly during the rainy season, with positive consequences for anopheline assemblages. Therefore, the application of integrated management can be carried out during both seasons. However, we suggest that the dry season is the optimal time because larval habitats are more limited, smaller in volume and more accessible for applying vector control techniques

Small forest losses degrade stream macroinvertebrate assemblages in the eastern Brazilian Amazon

Generally, habitat loss and fragmentation negatively affect biota, often in nonlinear ways. Such nonlinear responses suggest the existence of critical limits for habitat loss beyond which taxa experience substantial changes. Therefore, we identified change points for aquatic macroinvertebrate assemblages at both local-riparian and catchment extents in response to a forest-loss gradient in agriculture-altered landscapes of 51 small (1st to 3rd Strahler order) eastern Amazon streams. We used Threshold Indicator Taxa Analysis (TITAN) to identify change points for individual taxa and segmented regression analysis for assemblage richness. Considering the patterns of the cumulative frequency distributions of sum(Z−) maxima across bootstrap replications, peak changes in macroinvertebrate assemblages were at ∼9% (5–95 percentiles = 1–15%) of forest-loss at the catchment extent, and at ∼1.4% (5–95 percentiles = 0–35%) of forest-loss at the local-riparian extent. Although the assemblage change point at the site extent was less than that detected at the catchment extent, the markedly lower percentile range indicates that biotic assemblages are more clearly responsive to forest-loss at the catchment/network-riparian extents than the site extent. For catchment and site extents, segmented regression analysis determined a change point for assemblage richness at 57% and 79% of forest-loss, respectively. This indicates the low capacity of total richness to separate early and synchronous decreases of sensitive taxa from gradual increases of tolerant taxa. Our results also show that it is not enough to focus management and conservation actions on riparian zones, but that conservation strategies should be expanded to entire catchments as well. The sharp decline of sensitive taxa in response to removal of a small portion of forest cover, even at catchment extents, indicates that the Brazilian Forest Code is insufficient for protecting stream macroinvertebrates. Consequently, we recommend strategies to reverse the potential collapse of aquatic biodiversity, particularly through avoiding deforestation and forest degradation, encouraging socio-economic incentives for restoring degraded areas, creating protected areas, and maintaining the current protected areas. We argue that reducing habitat loss should be a top priority for conservation planners in tropical forests because the sensitivity of aquatic biodiversity to removal of riparian forest-cover in Amazon rainforests is higher than previously thought. Therefore, the Forest Code regulatory framework needs complementary regulation that may be achived by more restrictive State and biome policies. © 2019 Elsevier Lt

AVALIAÇÃO DA ATIVIDADE in vitro DO FIPRONIL CONTRA LARVAS NÃO ALIMENTADAS DE Dermacentor nitens

O carrapato Dermacentor nitens parasita preferencialmente equinos e é popularmente conhecido como carrapato da orelha dos cavalos. A infestação por este parasito promove prejuízos ao animal pela espoliação sanguínea, queda na produtividade, predisposição ao aparecimento de miíases e infecções bacterianas secundárias, além de ser vetor do protozoário Babesia caballi, agente causador da babesiose equina. Assim, o objetivo deste trabalho é avaliar a atividade acaricida in vitro do fipronil, em três diferentes metodologias, contra larvas não alimentadas de D. nitens. Os ensaios foram realizados em duplicata, com larvas não alimentadas de 17 dias, obtidas na colônia do Laboratório de Quimioterapia Experimental em Parasitologia Veterinária (LQEPV) no Instituto de Veterinária (IV) da Universidade Federal Rural do Rio de Janeiro (UFRRJ). As seguintes concentrações de fipronil foram testadas: 1; 2,5; 5; 10; 20; 40; 60; 80 e 100 ppm, obtidas a partir da diluição de fipronil técnico em água e triton-x para as metodologias de imersão larval (LIT) e de LIT adaptado, e em azeite de oliva extra virgem e tricloroetileno (2:1) para a metodologia de pacote de larvas (LPT). Na metodologia LIT, 300 larvas foram imersas em um microtubo com 1mL de solução por 10 minutos. Após drenar a solução, as larvas foram secas e aproximadamente 100 colocadas em envelope de papel filtro (6x6cm). Para LIT adaptado, aproximadamente 100 larvas foram depositadas em um sanduíche de papel filtro (2x2cm) impregnado com 500 µL da solução. Cada sanduíche foi acondicionado em envelope de papel filtro (6x6cm). E para LPT, o papel filtro (8,5x7,5cm) foi previamente impregnado com 670 µL de solução. Após duas horas de secagem, foram feitos envelopes e cerca de 100 larvas foram alocadas em cada. Para as três metodologias, o armazenamento foi feito em estufa climatizada com demanda controlada de oxigênio a 27ºC e 80% UR. Após 24 horas foi realizada leitura para avaliação da mortalidade, de acordo com a seguinte fórmula: % de mortalidade = total de larvas mortas x 100 / total de larvas. Os dados encontrados foram tabulados e os valores das concentrações letais CL50 e CL90 foram calculadas estatisticamente por meio da análise Probit utilizando o programa computacional R versão 3.6.1. Para LIT, a CL50 foi de 3,04 ppm (2,36-3,77 ppm), e a CL90 de 22,29 ppm (17,94-28,77 ppm). O slope obtido foi de 1,481±0,334 e o R de 0,584. Enquanto LIT adaptado, a CL50 foi de 14,32 ppm (12,79-15,98 ppm), e a CL90 de 49,19 ppm (42,48-58,30 ppm), e em LPT a CL50 foi de 20,77 ppm (18,50-23,33 ppm), e a CL90 de 80,06 ppm (67,63-97,58 ppm), maiores que as obtidas em LIT. O slope obtido foi de 2,391±0,130 e o R de 0,899 para LIT adaptado, e para LPT o slope foi de 2,187±0,418 e o R de 0,973. Portanto, o fipronil demonstrou ação larvicida in vitro contra D. nitens nas concentrações avaliadas, tornando este fenilpirazol um provável ativo utilizado para o controle deste carrapato, além de LIT ter sido a metodologia mais sensível em que se obteve as menores CLs para o fipronil