Showing papers by "Luis Mauricio Bini published in 2021"

Lakes in the era of global change: moving beyond single-lake thinking in maintaining biodiversity and ecosystem services.

Abstract: The Anthropocene presents formidable threats to freshwater ecosystems. Lakes are especially vulnerable and important at the same time. They cover only a small area worldwide but harbour high levels of biodiversity and contribute disproportionately to ecosystem services. Lakes differ with respect to their general type (e.g. land-locked, drainage, floodplain and large lakes) and position in the landscape (e.g. highland versus lowland lakes), which contribute to the dynamics of these systems. Lakes should be generally viewed as 'meta-systems', whereby biodiversity is strongly affected by species dispersal, and ecosystem dynamics are contributed by the flow of matter and substances among locations in a broader waterscape context. Lake connectivity in the waterscape and position in the landscape determine the degree to which a lake is prone to invasion by non-native species and accumulation of harmful substances. Highly connected lakes low in the landscape accumulate nutrients and pollutants originating from ecosystems higher in the landscape. The monitoring and restoration of lake biodiversity and ecosystem services should consider the fact that a high degree of dynamism is present at local, regional and global scales. However, local and regional monitoring may be plagued by the unpredictability of ecological phenomena, hindering adaptive management of lakes. Although monitoring data are increasingly becoming available to study responses of lakes to global change, we still lack suitable integration of models for entire waterscapes. Research across disciplinary boundaries is needed to address the challenges that lakes face in the Anthropocene because they may play an increasingly important role in harbouring unique aquatic biota as well as providing ecosystem goods and services in the future.

Large-scale Degradation of the Tocantins-Araguaia River Basin.

Abstract: The Tocantins-Araguaia Basin is one of the largest river systems in South America, located entirely within Brazilian territory. In the last decades, capital-concentrating activities such as agribusiness, mining, and hydropower promoted extensive changes in land cover, hydrology, and environmental conditions. These changes are jeopardizing the basin’s biodiversity and ecosystem services. Threats are escalating as poor environmental policies continue to be formulated, such as environmentally unsustainable hydropower plants, large-scale agriculture for commodity production, and aquaculture with non-native fish. If the current model persists, it will deepen the environmental crisis in the basin, compromising broad conservation goals and social development in the long term. Better policies will require thought and planning to minimize growing threats and ensure the basin’s sustainability for future generations.

Beta diversity of stream insects differs between boreal and subtropical regions, but land use does not generally cause biotic homogenization

Abstract: Previous studies have found mixed results regarding the relationship between beta diversity and latitude. In addition, by influencing local environmental heterogeneity, land use may modify ...

A Cautionary Note on Phylogenetic Signal Estimation from Imputed Databases

Abstract: Given the prevalence of missing data on species’ traits – the Raunkiaeran shortfall-, several methods have been proposed to fill sparse databases. However, analyses based on these imputed databases can introduce several biases. Here, we evaluated potential estimation biases caused by the use of imputed databases. In the evaluation, we considered the estimation of descriptive statistics, regression coefficient, and phylogenetic signal for different missing and imputing scenarios. We found that percentage of missing data, missing mechanisms and imputation methods were important in determining estimation errors. Imputation errors are not linearly related to estimate errors. Adding phylogenetic information provides better estimates of the evaluated statistics, but this information should be combined with other variables such as traits correlated to the missing data variable. Using an empirical dataset, we found that even traits that are strongly correlated to each other, such as brain and body size of primates, can produce biases when estimating phylogenetic signal from missing data datasets. We advise researchers to share both their raw and imputed data as well as to consider the pattern of missing data to evaluate methods that perform better for their goals. In addition, the performance of imputation methods should be mainly based on statistical estimates instead of only in imputation error.

Estimating counterfactuals for evaluation of ecological and conservation impact: an introduction to matching methods.

Abstract: Matching methods encompass non-parametric approaches to estimating counterfactual states through a rigorous selection of control units with similar characteristics to units submitted to an intervention. These methods enable comparisons between treated and control units in a way that facilitates understanding of causal relationships between interventions and outcomes. Matching methods have been used only recently in ecology and conservation biology, where such applications changed the way the field investigates causal questions, for example, in impact-evaluation studies. However, the strengths and limitations of matching methods are not well understood by most ecologists and environmental scientists. Herein, we review state-of-the-art matching methods aiming to help fill this gap in understanding. First, we present relevant theoretical concepts related to matching methods and related subjects such as counterfactual states and causation. Next, we propose guidelines and strategies for the application of matching methods in ecology and conservation biology. Finally, we discuss the possibilities for future applications of matching methods in the environmental sciences.

Niche measures and growth rate do not predict interspecific variation in spatial synchrony of phytoplankton

Abstract: Spatial synchrony occurs when local populations exhibit correlated dynamics over time. Recent studies, both experimental and observational, have indicated that the magnitude of spatial synchrony, in cross-species analyses, is correlated with the level of specialization. In theory, specialist species would exhibit higher levels of synchrony than generalist species because they would be more sensitive to environmental variations. In addition, according to simulation studies, species with high growth rates should have more synchronized dynamics. In this study, we tested these hypotheses using datasets (phytoplankton populations and environmental variables) obtained in the Cana Brava Reservoir (State of Goias, Brazil). We used a multiple regression model to test whether the average level of spatial synchrony was correlated with variables that indicate environmental specialization and population growth rate. In general, the average values of spatial synchrony were low, indicating the predominance of local factors in controlling population dynamics. We found no significant relationship between synchrony and our explanatory variables. To assess the generality of correlates of spatial synchrony, we suggest that future studies should focus on a common same set of explanatory variables.

Evidence that dams promote biotic differentiation of zooplankton communities in two Brazilian reservoirs

Abstract: Human activities may change beta diversity—the spatial variation in species composition—in different ways. Positive and negative trends in beta diversity are referred as biotic differentiation and homogenization, respectively. In this context, river damming is likely to be a major cause of changes in beta diversity over time. Here, we evaluated the impact of damming on zooplankton beta diversity in two Brazilian reservoirs. We predicted that damming would cause biotic differentiation due to the creation of areas with different hydrological conditions, which would allow the colonization and population growth of species belonging to different zooplankton groups. Our results for the total zooplankton community were consistent with the hypothesis of biotic differentiation, either due to the increased mean beta diversity or due to the tendency of increasing beta diversity over time after damming. An indicator species analysis also showed that a large proportion of taxa that can be categorized as euplanktonic were mainly indicators of the period after damming, whereas the opposite was true for testate amoebae. Increased beta diversity should be interpreted as an impact of damming. However, we speculate that, under a process of water quality deterioration, biotic homogenization is likely to occur, reversing the patterns we observed.

Host diversity, phylogenetic relationships and local environmental factors drive infection patterns of a non-native parasite in tropical floodplain fish assemblages

Abstract: Biodiversity, biological traits of potential host species, and environmental conditions may mediate the emergence of new diseases. We assessed the relative influence of such factors on patterns of infection by Austrodiplostomum compactum (Digenea, Diplostomidae) in fish assemblages of the Upper Parana River floodplain, Brazil. Multiple infection parameters were modeled at the community and species levels using phylogenetic diversity (PD), abundance (total and for a main reservoir species Plagioscion squamosissimus), local environmental conditions and phylogenetic distance from P. squamosissimus (Dis_Plag). In total, 108 fish species were collected and 28 were infected. At the community level, mean parasite abundance and mean infection intensity were positively associated with PD and the interaction between PD and environmental conditions, whereas host richness was negatively associated with PD. The complementary results indicate a biodiversity sampling effect rather than dilution effect. Environmental conditions often had the strongest coefficients in community-level models and mediated associations between infection parameters and other factors. At the species level, consistent negative associations between infection parameters and Dis_Plag indicate phylogenetic niche conservatism of parasites. Integration of community and species-level analyses demonstrates that phylogenetic diversity can affect host–parasite interactions in multiple ways, but that the associations depend on phylogenetic relationships and environmental conditions.