Humid tropical forests play a dominant role in the functioning of Earth but are under increasing threat from changes in land use and climate. How forest vulnerability varies across space and time and ...what level of stress forests can tolerate before facing a tipping point are poorly understood. Here, we develop a tropical forest vulnerability index (TFVI) to detect and evaluate the vulnerability of global tropical forests to threats across space and time. We show that climate change together with land-use change have slowed the recovery rate of forest carbon cycling. Temporal autocorrelation, as an indicator of this slow recovery, increases substantially for above-ground biomass, gross primary production, and evapotranspiration when climate stress reaches a critical level. Forests in the Americas exhibit extensive vulnerability to these stressors, while in Africa, forests show relative resilience to climate, and in Asia reveal more vulnerability to land use and fragmentation. TFVI can systematically track the response of tropical forests to multiple stressors and provide early-warning signals for regions undergoing critical transitions.
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•An index to track vulnerability of global rainforests to climate and land use•Four decades of satellite data show widespread vulnerability across the tropics•Response of rainforests to heat and drying varies across the continents•Early warning from the index can identify regions for conservation and restoration
Rainforests are being lost at an alarming rate due to deforestation and degradation. As these forests lose their intactness and diversity, their resilience to climate change declines and they become more vulnerable to droughts and wildfires. Here, we built a spatially explicit tropical forest vulnerability index (TFVI) based on observations of forest cover, carbon, and water fluxes to identify areas where rainforests are losing resilience to disturbance and are changing toward an irreversible state, a “tipping point.” Our findings show how and where tipping points may occur, either as a gradual downhill decline of ecosystem services or an abrupt change. We present TFVI as an index to monitor tropical forests and provide early-warning signals for regions that are in need of policies that simultaneously promote conservation and restoration to increase resilience and climate mitigation.
Rainforests take hundreds of years to be formed into a diverse and complex structure that is lush but fragile. The reason for their fragility is the difficulty to recover from disturbance. Using satellite observations, we show how increasing threats from large-scale deforestation and severe climate conditions over the past four decades have substantially impacted the ecological functions of these forests regionally, pushing them toward a critical point of no recovery and a dryer and less diverse state.
Objetivo. Correlacionar el temor, estrés, conocimientos frente al COVID-19 en estudiantes y recién egresados de enfermería en México. Métodos. Diseño correlacional, muestra constituida por 912 ...estudiantes de enfermería y egresados en los últimos 18 meses de universidades públicas y privadas de México. Para medir las variables se aplicó el instrumento Fear of COVID-19 Scale, subescala de conocimientos de la escala Knowledge, attitudes, and practices towards COVID-19, y el instrumento COVID Stress Scale. Resultados. Se encontró relación de la variable edad con temor, peligro de contaminación, estrés traumático, conocimientos y menores consecuencias socioeconómicas (p<0.05). De igual forma, se observó relación del temor con estrés ante el COVID-19, peligro de contaminación, consecuencias socioeconómicas, xenofobia, estrés traumático, y comprobación compulsiva (p<0.05). El estrés y los conocimientos explican la presencia del temor ante el COVID-19 en un 50.3 %, así como el temor y conocimiento explican el estrés ante el COVID-19 en un 50.4 %. Conclusión. Los estudiantes y recién egresados de enfermería tienen altos niveles de estrés y temor, además de bajo nivel de conocimientos. La presencia de alto estrés y bajos conocimientos predicen el temor ante del COVID-19. Se requieren intervenciones sobre los conocimientos, estrés y temor ante el covid-19 en la población estudiada. Descriptores: miedo; estrés psicológico; conocimiento; estudiantes de enfermería; enfermeras y enfermeros; infecciones por coronavirus; pandemias. Objective. The study sought to correlate fear, stress, knowledge regarding COVID-19 in Nursing students and recent graduates in Mexico. Methods. Correlational design, sample comprising 912 nursing students and graduates during the last 18 months from public and private universities of Mexico. To measure the variables, the study applied the instrument Fear of COVID-19 Scale, knowledge subscale of the scale Knowledge, attitudes, and practices towards COVID-19, and the instrument COVID Stress Scale. Results. Relationship was found of the age variable with fear, danger of contamination, traumatic stress, knowledge and minor socioeconomic consequences (p<0.05). Likewise, relationship was observed of fear with stress regarding COVID-19, danger of contamination, socioeconomic consequences, xenophobia, traumatic stress, and compulsive checking (p<0.05). Stress and knowledge explain the presence of fear regarding COVID-19 in 50.3%, and fear and knowledge explain stress regarding COVID-19 in 50.4%. Conclusion. Nursing students and recent graduates have high levels of stress and fear, besides low level of knowledge. The presence of high stress and low knowledge predict fear regarding COVID-19. Interventions are required on knowledge, stress, and fear regarding COVID-19 in the population studied. Descriptors: fear; stress, psychological; knowledge; students, nursing; nurses; coronavirus infections; pandemics. Objetivo. Correlacionar medo, estresse, conhecimento contra COVID-19 em estudantes e recém-formados em enfermagem no México. Métodos. Desenho correlacional, amostra composta por 912 estudantes e graduados de enfermagem nos últimos 18 meses de universidades públicas e privadas do México. Para mensurar as variáveis, foram aplicados o instrumento Escala de Medo do COVID-19, a subescala Conhecimento da escala Conhecimento, atitudes e práticas em relação ao COVID-19 e o instrumento Escala de Estresse C0VID. Resultados. Foi encontrada relação entre a variável idade e medo, perigo de contaminação, estresse traumático, conhecimento e menores consequências socioeconômicas (p<0.05). Da mesma forma, foi observada relação entre medo e estresse frente ao COVID-19, perigo de contaminação, consequências socioeconómicas, xenofobia, estresse traumático e verificação compulsiva (p<0.05). O estresse e o conhecimento explicam a presença do medo do COVID-19 em 50.3%, assim como o medo e o conhecimento explicam o estresse do COVID-19 em 50.4%. Conclusão. Estudantes de enfermagem e recémformados apresentam altos níveis de estresse e medo, bem como baixo nível de conhecimento sobre o COVID-19. A presença de alto estresse e baixo conhecimento prediz medo de COVID-19. Se faz necessário intervenções sobre o conhecimento, estresse e medo de covid-19 na população estudada. Descritores: medo; estresse psicológico; conhecimento; estudantes de enfermagem; enfermeiras e enfermeiros; infecções por coronavirus; pandemias.
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