Protected areas are not effective for the conservation of freshwater insects in Brazil

Karina Dias-Silva,Neusa Hamada,Thiago Bernardi Vieira,Felipe Ferraz Figueiredo Moreira,Leandro Juen

doi:10.1038/s41598-021-00700-0

Abstract

Biodiversity conservation has faced many challenges, especially the conversion of natural areas that compete with use for agriculture, energy production and mineral extraction. This problem is further aggravated by lack of knowledge of the biodiversity that exists and the geographical distribution of different groups. The objectives of our study were to examine the distributional pattern of Gerromorpha diversity in Brazil, create a map of conservation priority areas, estimate the degree of protection that the current network of protected areas guarantees to this insect group, and identify the size thresholds in geographical distributions that would allow species to be protected. We used species occurrences from the Water Bugs Distributional Database, and we used 19 bioclimatic variables to build models of the potential distributions of species using the MaxEnt program. Using the potential model results, we calculated diversity metrics and overlapped them with the current state and federal “conservation units” (protected areas for biodiversity) in Brazil. Total beta diversity and turnover portions were separated into two faunistic groups, one in northern and the other in southern Brazil. The Amazon has higher beta diversity than what was predicted by the null models. We detected a positive relationship between species distribution area and occurrence in conservation units. Conservation units with less than 250 km2 do not protect Gerromorpha species. Our results reinforce the necessity of formulating new conservation strategies for this group, contemplating species with both restricted and ample distributions, because rare and specialist species are the most harmed by habitat reduction, given that they are more sensitive to environmental disturbance.

Highlights

Biodiversity conservation has faced many challenges, especially the conversion of natural areas that compete with use for agriculture, energy production and mineral extraction
Of 208 Gerromorpha species recorded in Brazil, we found 3541 occurrences and modeled 111 species (Table S1)
The Monte Carlo simulation tests to evaluate the dependency of AUC on the number of occurrences were not significant for all classes (Table 1), which means that there is no relationship between the number of occurrences and the AUC values obtained from the model[35]

Summary

Introduction

Biodiversity conservation has faced many challenges, especially the conversion of natural areas that compete with use for agriculture, energy production and mineral extraction. One way of reducing inefficiency is by using other criteria for area selection, e.g., species richness, beta diversity, fauna complementarity and the number of endemic species[3,16] These parameters, along with use of species-distribution models (SDMs) could reduce the problem of lack of knowledge about distributions that leads to protection of marginally adequate areas. This knowledge would allow selection of areas having high probability of occurrence of a species and that provide favorable environmental conditions. Several biodiversity components, such as aquatic invertebrates, might not be included in the protected a reas[6,9]

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Conclusion