Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 3 de 3
Filtrar
Más filtros

Bases de datos
Tipo del documento
Intervalo de año de publicación
1.
Conserv Biol ; 34(2): 427-437, 2020 04.
Artículo en Inglés | MEDLINE | ID: mdl-31386221

RESUMEN

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.


Asunto(s)
Conservación de los Recursos Naturales , Ecosistema , Biodiversidad , Brasil , Cambio Climático , Bosques , Humanos
2.
Data Brief ; 39: 107592, 2021 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-34869806

RESUMEN

Changes observed in the current climate and projected for the future significantly concern researchers, decision-makers, and the general public. Climate indices of extreme rainfall events are a trend assessment tool to detect climate variability and change signals, which have an average reliability at least in the short term and given climatic inertia. This paper shows 12 climate indices of extreme rainfall events for annual and seasonal scales for 12 climate stations between 1969 to 2019 in the Metropolitan area of Cali (southwestern Colombia). The construction of the indices starts from daily rainfall time series, which although have between 0.5% and 5.4% of missing data, can affect the estimation of the indices. Here, we propose a methodology to complete missing data of the extreme event indices that model the peaks in the time series. This methodology uses an artificial neural network approach known as Non-Linear Principal Component Analysis (NLPCA). The approach reconstructs the time series by modulating the extreme values of the indices, a fundamental feature when evaluating extreme rainfall events in a region. The accuracy in the indices estimation shows values close to 1 in the Pearson's Correlation Coefficient and in the Bi-weighting Correlation. Moreover, values close to 0 in the percent bias and RMSE-observations standard deviation ratio. The database provided here is an essential input in future evaluation studies of extreme rainfall events in the Metropolitan area of Cali, the third most crucial urban conglomerate in Colombia with more than 3.9 million inhabitants.

3.
PeerJ ; 7: e7333, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31367486

RESUMEN

In a world where changes in land cover and climate happen faster than ever due to the expansion of human activities, narrowly distributed species are predicted to be the first to go extinct. Studies projecting species extinction in tropical regions consider either habitat loss or climate change as drivers of biodiversity loss but rarely evaluate them together. Here, the contribution of these two factors to the extinction risk of narrowly distributed species (with ranges smaller than 10,000 km2) of seed plants endemic to a fifth-order watershed in Brazil (microendemics) is assessed. We estimated the Regional Climate Change Index (RCCI) of these watersheds (areas with microendemics) and projected three scenarios of land use up to the year 2100 based on the average annual rates of habitat loss in these watersheds from 2000 to 2014. These scenarios correspond to immediate conservation action (scenario 1), long-term conservation action (scenario 2), and no conservation action (scenario 3). In each scenario, areas with microendemics were classified into four classes: (1) areas with low risk, (2) areas threatened by habitat loss, (3) areas threatened by climate change, and (4) areas threatened by climate change and habitat loss. We found 2,354 microendemic species of seed plants in 776 areas that altogether cover 17.5% of Brazil. Almost 70% (1,597) of these species are projected to be under high extinction risk by the end of the century due to habitat loss, climate change, or both, assuming that these areas will not lose habitat in the future due to land use. However, if habitat loss in these areas continues at the prevailing annual rates, the number of threatened species is projected to increase to more than 85% (2,054). The importance of climate change and habitat loss as drivers of species extinction varies across phytogeographic domains, and this variation requires the adoption of retrospective and prospective conservation strategies that are context specific. We suggest that tropical countries, such as Brazil, should integrate biodiversity conservation and climate change policies (both mitigation and adaptation) to achieve win-win social and environmental gains while halting species extinction.

SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA