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Brazil hosts the largest expanse of tropical ecosystems within protected areas (PAs), which shelter biodiversity and support traditional human populations. We assessed the vulnerability to climate change of 993 terrestrial and coastal-marine Brazilian PAs by combining indicators of climatic-change hazard with indicators of PA resilience (size, native vegetation cover, and probability of climate-driven vegetation transition). This combination of indicators allows the identification of broad climate-change adaptation pathways. Seventeen PAs (20,611 km2 ) were highly vulnerable and located mainly in the Atlantic Forest (7 PAs), Cerrado (6), and the Amazon (4). Two hundred fifty-eight PAs (756,569 km2 ), located primarily in Amazonia, had a medium vulnerability. In the Amazon and western Cerrado, the projected severe climatic change and probability of climate-driven vegetation transition drove vulnerability up, despite the generally good conservation status of PAs. Over 80% of PAs of high or moderate vulnerability are managed by indigenous populations. Hence, besides the potential risks to biodiversity, the traditional knowledge and livelihoods of the people inhabiting these PAs may be threatened. In at least 870 PAs, primarily in the Atlantic Forest and Amazon, adaptation could happen with little or no intervention due to low climate-change hazard, high resilience status, or both. At least 20 PAs in the Atlantic Forest, Cerrado, and Amazonia should be targeted for stronger interventions (e.g., improvement of ecological connectivity), given their low resilience status. Despite being a first attempt to link vulnerability and adaptation in Brazilian PAs, we suggest that some of the PAs identified as highly or moderately vulnerable should be prioritized for testing potential adaptation strategies in the near future.

Evaluación de la Vulnerabilidad y Adaptación al Cambio Climático de Áreas Protegidas en Brasil Resumen Brasil alberga la mayor extensión de ecosistemas tropicales dentro de áreas protegidas (AP), que protegen la biodiversidad y sustentan a poblaciones humanas tradicionales. Evaluamos la vulnerabilidad al cambio climático de 993 AP brasileñas terrestres y costeras-marinas mediante la combinación de indicadores de riesgo de cambio climático con indicadores de la resiliencia de AP (tamaño, cobertura de vegetación nativa y la probabilidad de transición en la vegetación como consecuencia del cambio climático). Esta combinación de indicadores permite la identificación de amplias rutas de adaptación al cambio climático. Diecisiete AP (20,611 km2 ) fueron altamente vulnerables y se localizaron principalmente en el Bosque Atlántico (7 AP), El Cerrado (6) y la Amazonía (4). Doscientos cincuenta y ocho AP (756,569 km2 ), localizadas principalmente en la Amazonía, tuvieron vulnerabilidad media. En la Amazonía y el oeste de El Cerrado, el severo cambio climático proyectado y la probabilidad de transición de vegetación dirigida por el clima incrementó la vulnerabilidad, a pesar del estado de conservación generalmente bueno de las AP. Más de 80% de las AP con vulnerabilidad alta o media son manejadas por poblaciones indígenas. Por lo tanto, además de los riesgos potenciales para la biodiversidad, también hay amenazas para el conocimiento tradicional y las formas de vida de la gente que habita en esas AP. En por lo menos 870 AP, principalmente en el Bosque Atlántico y la Amazonía, la adaptación podría suceder con poca o ninguna intervención debido al bajo riesgo de cambio climático, estatus de resiliencia alta, o ambos. Por lo menos 20 AP en el Bosque Atlántico, El Cerrado y la Amazonía deberían ser objetivo de intervenciones mayores (e.g., mejoramiento de la conectividad ecológica), dada su estatus de resiliencia baja. A pesar de que es un primer intento para vincular vulnerabilidad y adaptación en AP brasileñas, sugerimos que algunas de las AP identificadas como alta o moderadamente vulnerables se deben priorizar para probar posibles estrategias de adaptación en un futuro próximo.

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BACKGROUND: Freshwaters are the most threatened ecosystems on earth. Although recent assessments provide data on global priority regions for freshwater conservation, local scale priorities remain unknown. Refining the scale of global biodiversity assessments (both at terrestrial and freshwater realms) and translating these into conservation priorities on the ground remains a major challenge to biodiversity science, and depends directly on species occurrence data of high taxonomic and geographic resolution. Brazil harbors the richest freshwater ichthyofauna in the world, but knowledge on endemic areas and conservation in Brazilian rivers is still scarce. METHODOLOGY/PRINCIPAL FINDINGS: Using data on environmental threats and revised species distribution data we detect and delineate 540 small watershed areas harboring 819 restricted-range fishes in Brazil. Many of these areas are already highly threatened, as 159 (29%) watersheds have lost more than 70% of their original vegetation cover, and only 141 (26%) show significant overlap with formally protected areas or indigenous lands. We detected 220 (40%) critical watersheds overlapping hydroelectric dams or showing both poor formal protection and widespread habitat loss; these sites harbor 344 endemic fish species that may face extinction if no conservation action is in place in the near future. CONCLUSIONS/SIGNIFICANCE: We provide the first analysis of site-scale conservation priorities in the richest freshwater ecosystems of the globe. Our results corroborate the hypothesis that freshwater biodiversity has been neglected in former conservation assessments. The study provides a simple and straightforward method for detecting freshwater priority areas based on endemism and threat, and represents a starting point for integrating freshwater and terrestrial conservation in representative and biogeographically consistent site-scale conservation strategies, that may be scaled-up following naturally linked drainage systems. Proper management (e. g. forestry code enforcement, landscape planning) and conservation (e. g. formal protection) of the 540 watersheds detected herein will be decisive in avoiding species extinction in the richest aquatic ecosystems on the planet.

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Tannic acid (TA) has well-described antimutagenic and antioxidant activities. The antioxidant activity of TA has been previously attributed to its capacity to form a complex with iron ions, interfering with the Fenton reaction [Biochim. Biophys. Acta 1472, 1999, 142]. In this work, we observed that TA inhibits, in the micromolar range, in vitro Cu(II) plus ascorbate-mediated hydroxyl radical (*OH) formation (determined as 2-deoxyribose degradation) and oxygen uptake, as well as copper-mediated ascorbate oxidation and ascorbate radical formation (quantified in EPR studies). The effect of TA against 2-deoxyribose degradation was three orders of magnitude higher than classic *OH scavengers, but was similar to several other metal chelators. Moreover, the inhibitory effectiveness of TA, by the four techniques used herein, was inversely proportional to the Cu(II) concentration in the media. These results and the observation of copper-induced changes in the UV spectra of TA are indications that the antioxidant activity of TA relates to its copper chelating ability. Thus, copper ions complexed to TA are less capable of inducing ascorbate oxidation, inhibiting the sequence of reactions that lead to 2-deoxyribose degradation. On the other hand, the efficiency of TA against 2-deoxyribose degradation declined considerably with increasing concentrations of the *OH detector molecule, 2-deoxyribose, suggesting that the copper-TA complex also possesses an *OH trapping activity.

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