Priority Areas For Conservation Of Species Research Articles

Integrating ecological niche and hydrological connectivity models to assess the impacts of hydropower plants on an endemic and imperilled freshwater turtle

Abstract Hydropower is the main renewable energy source around the globe; however, cumulative impacts of hydropower plants (HPPs) come with vast environmental concerns. As freshwater species are susceptible to hydrodam‐induced environmental modifications, an understanding of how HPPs change species distribution is required to predict and mitigate the impacts of the expansion of hydroelectric matrices generation, securing energy provision and biodiversity conservation. We assessed the impacts of HPPs on the distribution of an endemic and imperilled freshwater turtle with very unique ecological requirements, the Williams' side‐necked turtle Phrynops williamsi. To prevent and mitigate impacts, we prioritized sites for species conservation by classifying planned HPP locations according to their predicted adverse effects on species distribution. We built ecological niche models to estimate the distribution of the species. Then, we contrasted the species distribution with current and planned HPPs in Brazil to (i) verify whether HPPs locations coincide with high suitability areas; (ii) assess the difference in the magnitude of impacts on species caused by HPPs regarding their licensing stage and type; and (iii) identify priority areas for species conservation over the sites where new HPPs are planned based on an integrative analysis of ecological niche and hydrological connectivity models. Finally, we assessed the risk of species extinction at multiple levels according to IUCN criteria. HPPs overlap areas of high suitability for the species, independently of type or licensing stage. Differences in adverse impacts among HPP types were determined by the affected area and the degree of disruption in connectivity. In the future, the area impacted by small HPPs will nearly equal those of large HPPs, which currently have the highest impacts on species. The conservation status of the species partially corroborated previous assessments and suggested that its extinction risk was underestimated at some levels. Synthesis and applications. Our modelling approach highlights potential conflicts between hydropower generation and species conservation. This analysis can be a complementary tool to drive decisions on the ecological sustainability of HPPs; it can reveal the patterns of cumulative impacts of HPPs on riverine species and freshwater ecosystems, informing the planning of sustainable energy provision.

Identifying optimized on-the-ground priority areas for species conservation in a global biodiversity hotspot

Threatened species are inadequately represented within protected areas (PAs) across the globe. Species conservation planning may be improved by using public species-occurrence databases, but empirical evidence is limited of how that may be accomplished at local scales. We used the Three Parallel Rivers Region of China as a case to investigate the utility of public species data in improvement in conservation planning. We mapped the distribution of each species as suitable habitat ranges using species distribution models (for 261 plants and 29 animals with ≥5 occurrences) or as point locations (for 591 plants and 328 animals with <5 occurrences). Systematic conservation planning was then applied to identify three optimized portfolios of priority conservation areas (PCAs) for achieving increasing targets of 17, 31, and 50% of the total study area. We then compared the distributions of PCAs in this study with those in two existing PCA datasets. PCAs in this study covered greater areas in the southeastern highly-disturbed regions and along valleys of great rivers than two existing datasets that had a focus on intact ecosystems in remote mountain areas. The three portfolios of PCAs had some overlap with two existing PCA datasets, with the overlapping area accounting for 26.4–39.0% of the total areas of our PCAs. Our PCAs could complement existing PCAs by identifying more priority areas in developed landscapes; this is critical for protecting biodiversity in such areas as they face greater pressures. PCAs in this study received a much lower PA coverage (32.9–43.1%) than existing PCAs (60.2–60.8%) because of biased PA distribution toward mountain areas. Our results suggest that conservation planning based on limited public species data could improve local-scale priority-setting practices. The analysis supports effective integration of species targets in China's new national park system by identifying optimized networks of PCAs.

Habitat Use Patterns and Identification of Essential Habitat for an Endangered Coastal Shark With Vertebrae Microchemistry: The Case Study of Carcharhinus porosus

Sharks are among the most endangered and data poor vertebrates in the world. The lack of information regarding their habitat use is especially concerning since these are crucial for the establishment of priority areas for species conservation. Investigating the trace elements present in shark vertebrae has become an interesting tool to analyze species habitat use over individuals’ lifetimes. Therefore, we applied vertebrae microchemistry to investigate habitat use of Carcharhinus porosus in Brazil’s Northern Coast (BNC). We also discuss methodological issues that must be addressed in the future to make microchemistry studies with elasmobranchs at low latitudes more robust. Vertebrae from seventeen individuals sampled in the 1980s (n=8), and in 2017 and 2018 (n=9) were evaluated through laser ablation inductively coupled plasma mass spectrometry. We analyzed five elements known to reflect environmental characteristics (Ba, Ca, Mg, Mn, and Sr) by sex, seasons, decades of capture, and life stages. Since Ca is the most abundant element in the vertebrae, we calculated element:Ca ratios and employed these proportions for all statistical analysis. We also used fisheries-independent catch data from the 1980s to test if the BNC is a nursery area for C. porosus. We found significant differences in element concentrations between sexes in both multi and single-element analysis, while decades differed only in the multi-element and Sr:Ca. Furthermore, seasons differed in both multi-element and Mg:Ca and Ba:Ca ratios. We did not find differences between life stages. Neonate multi-element signatures yielded three major groups, thus suggesting that the species has at least three birthing grounds in the area. Despite the occurrence of individuals of all sizes, adults show a more distinct occurrence pattern. Our results point towards the hypothesis that the BNC is an essential habitat for this species since its whole life cycle occurs in this area. Therefore, the BNC is a critical area for its conservation. We reinforce that future studies with strictly tropical species should investigate the effects of metabolism, the species’ growth rate, and the validation of other elements capable of demonstrating fine-scale changes in habitat to reduce the inherent noise in microchemistry studies.

Testing Three Species Distribution Modelling Strategies to Define Fish Assemblage Reference Conditions for Stream Bioassessment and Related Applications.

Species distribution models are widely used for stream bioassessment, estimating changes in habitat suitability and identifying conservation priorities. We tested the accuracy of three modelling strategies (single species ensemble, multi-species response and community classification models) to predict fish assemblages at reference stream segments in coastal subtropical Australia. We aimed to evaluate each modelling strategy for consistency of predictor variable selection; determine which strategy is most suitable for stream bioassessment using fish indicators; and appraise which strategies best match other stream management applications. Five models, one single species ensemble, two multi-species response and two community classification models, were calibrated using fish species presence-absence data from 103 reference sites. Models were evaluated for generality and transferability through space and time using four external reference site datasets. Elevation and catchment slope were consistently identified as key correlates of fish assemblage composition among models. The community classification models had high omission error rates and contributed fewer taxa to the ‘expected’ component of the taxonomic completeness (O/E50) index than the other strategies. This potentially decreases the model sensitivity for site impact assessment. The ensemble model accurately and precisely modelled O/E50 for the training data, but produced biased predictions for the external datasets. The multi-species response models afforded relatively high accuracy and precision coupled with low bias across external datasets and had lower taxa omission rates than the community classification models. They inherently included rare, but predictable species while excluding species that were poorly modelled among all strategies. We suggest that the multi-species response modelling strategy is most suited to bioassessment using freshwater fish assemblages in our study area. At the species level, the ensemble model exhibited high sensitivity without reductions in specificity, relative to the other models. We suggest that this strategy is well suited to other non-bioassessment stream management applications, e.g., identifying priority areas for species conservation.

Does taxonomic diversity in indicator groups influence their effectiveness in identifying priority areas for species conservation?

AbstractThe identification of priority areas for biodiversity conservation is a cornerstone of systematic conservation planning. However, biodiversity, or even the distribution of all species, cannot be directly quantified, due to the inherent complexity of natural systems. Species indicator groups may serve as important tools for the identification of priority areas for conservation. Yet, it is unclear which factors make certain indicator groups perform better than others. In this study, using data on the Danish distribution of 847 species of plants, vertebrates and insects, we assessed whether the taxonomic diversity in species indicator groups influence their effectiveness in the identification of priority areas for species conservation. We tested whether indicator groups comprising a higher taxonomic diversity (i.e. indicator groups consisting of species from many different taxonomic groups) perform better than indicator groups comprising a lower taxonomic diversity. The performance of the indicator groups was evaluated on target groups, which, in terms of species composition, were independent of the indicator groups. Overall, we found that using taxonomically diverse indicator groups did not consistently increase the coverage of target species than when using less taxonomically diverse indicator groups. However, indicator groups chosen solely from one taxon were outperformed by taxonomically diverse groups. Second, we found that taxonomic diversity of the indicator did not influence the taxonomic diversity of the covered target species (in terms of number of represented families, orders, etc.) Thus, taxonomic diversity per se only had a marginal influence on the performance of indicator groups. Distributional characteristics, such as the proportion of species with narrow range sizes, had a larger impact on indicator performance. Our results suggest that it might be of minor importance to consider taxonomic diversity when acquiring species data for future conservation projects using indicator groups.

Estimating potential geographic ranges of armadillos (Xenarthra, Dasypodidae) in Brazil under niche-based models / Estimation de la distribution géographique potentielle des tatous (Xenarthra, Dasypodidae) au Brésil à partir de modèles basés sur les niches écologiques

Dasypodidae is the largest family of the order Xenarthra, with eight genera and 21 species. The geographic ranges of 10 species of armadillos in Brazil were analyzed together with environmental variables, such as topography and climate, using the GARP program. Maps were generated using the 20 best models per species and predicted the occurrence of eight of the 10 species in the Cerrado biome, indicating that the central region of Brazil is an important area for the preservation of armadillo species. Thus, using niche modeling it is possible to better map the geographic ranges of species, to use these maps to optimally establish priority areas for species conservation and to understand overall biodiversity patterns.