32 research outputs found
Ecological characterization of the rocky shores of Príncipe Island, Gulf of Guinea
Tese de Mestrado, Ecologia Marinha , 2021, Universidade de Lisboa, Faculdade de CiênciasO ecossistema intertidal é um modelo ideal para o estudo da ecologia de comunidades biológicas, pois exibe uma múltipla variedade de fatores que influenciam os padrões associados à composição, abundância e distribuição de espécies. É um ambiente altamente dinâmico, variando ao longo dos ciclos ambientais como a maré, que provoca períodos alternantes de emersão e submersão, e o ciclo lunar, que induz variações da amplitude da maré. O gradiente ambiental vertical que assim se constitui submete as espécies marinhas a um intenso e progressivo stress ao longo do perfil da zona intertidal. Sabe-se, no entanto, que os stresses associados ao gradiente vertical variam com a latitude e entre localidades. Nas latitudes mais baixas dos trópicos, a dessecação intensifica-se devido ao efeito combinado das elevadas temperaturas e a reduzida humidade relativa nas zonas intertidais expostas ao sol. Já à escala local, a diferenciação de stresses deve-se fundamentalmente à exposição a diferentes fatores ambientais, sendo os principais os gradientes de hidrodinamismo e a salinidade. Dependendo da intensidade da ação das ondas e da presença próxima de rios, os padrões de zonação e a extensão do gradiente intertidal vertical são afetados de diferentes maneiras. As costas rochosas apresentam condições geomorfológicas que facilitam a colonização e fixação da grande maioria de espécies que vivem entre marés. Consequentemente, é neste ambiente que melhor se destacam os gradientes verticais e padrões de distribuição de espécies. A retenção de água devido à natureza geomorfológica das costas rochosas também as caracteriza pela abundância de poças de maré, criando refúgios para muitos organismos marinhos como peixes e invertebrados. O presente trabalho visa a estudar o ecossistema intertidal da costa rochosa da ilha do Príncipe, uma das duas principais ilhas oceânicas que compõem o país insular de São Tomé e Príncipe. De formação vulcânica e fazendo parte da cadeia de vulcões extintos da Linha dos Camarões, a ilha do Príncipe situase no Golfo da Guiné a 350 km da costa africana. Apesar de ser uma ilha oceânica e estar relativamente distante do continente, o mar envolvente é influenciado pelas massas de água quente e salobra da pluma dos rios Congo e Níger, atingindo à superfície temperaturas entre 27°C-30°C e salinidade tratando-se principalmente de listagens de alguns grupos taxonómicos, nomeadamente algas, moluscos e peixes. Como tal, o presente trabalho teve duas abordagens ao estudo do ecossistema intertidal das costas rochosas da ilha do Príncipe. A primeira é essencialmente descritiva, abordando a composição e os padrões de distribuição vertical das comunidades em dois ambientes intertidais distintos: um exposto a influência estuarina e o outro exposto a condições marinhas. A segunda abordagem foca-se na ictiofauna intertidal, onde se procurou determinar a importância das condições abióticas e bióticas das poças de maré na estrutura da população de peixes. A dissertação está dividida em quatro capítulos, sendo o primeiro a introdução teórica aos temas abordados, onde é apresentado o enquadramento ecológico, a contextualização da área de estudo a nível oceanográfico, climático, biogeográfico, e estudos realizados, seguido dos objetivos deste trabalho. O segundo e terceiro capítulo englobam, respetivamente, a primeira e segunda abordagem e incluem os resultados e discussão do trabalho apresentados em formato conciso de publicação científica. Por fim, o quarto capítulo apresenta as conclusões finais. Para o estudo descritivo da costa rochosa da ilha (Capítulo 2) foi amostrada a comunidade intertidal da costa rochosa de duas regiões, Abade e Bom-Bom, e comparadas entre si. Enquanto Abade representa uma zona intertidal numa baía abrigada do vento e das ondas e influenciada por rios próximos, a costa do ilhéu Bom-Bom representa uma zona intertidal exposta ao mar, sujeita à ação das ondas e sem rios nas proximidades. No total foram amostrados 47 taxa, dos quais 17 macroalgas, uma espécie de líquene preto (Verrucaria sp.) e 29 taxa de macrofauna epibentónica. A zona intertidal de Bom-Bom apresentou em média maior riqueza de espécies por transecto, tanto de macroalgas como de metazoários. No entanto, a composição geral das comunidades intertidais entre as duas regiões não foi significativamente diferente. Ainda assim, a presença e ausência de espécies-chave revela a diferença entre comunidades biológicas expostas a diferentes condições ambientais. A presença de mais espécies de macroalgas e de filtradores no Bom-Bom traduz condições típicas de uma zona intertidal exposta à ondulação, com maior oxigenação e dispersão de nutrientes e partículas de alimento. No entanto, a maior diferença encontrada entre as costas rochosas de Abade e Bom-Bom foram os padrões de distribuição e zonação das comunidades intertidais. O maior hidrodinamismo na costa do Bom-Bom permite às espécies mais em baixo no perfil de maré subsistir até à zona de humectação e acima do limite superior teórico das marés. Já em Abade, a combinação de fraca ondulação e baixa salinidade causada pela proximidade de rios impede a expansão das espécies que vivem mais em baixo no perfil de maré. Esta diferença é evidente comparando o limite superior da banda infralitoral das duas regiões, sendo em Bom-Bom 0.7 m mais alto do que em Abade. Acima deste limite, a riqueza específica baixa drasticamente. Os padrões de distribuição e zonação na costa rochosa da ilha do Príncipe apresentaram semelhanças com outras comunidades intertidais do continente no Golfo da Guiné. Assim sendo, a zona intertidal das costas rochosas do Príncipe pode ser dividida em três zonas principais, que podem variar em largura consoante as condições marinhas. Mais acima encontra-se a zona supralitoral, dominada por Echinolittorina soroziczac e principalmente E. granosa; seguida pela zona eulitoral caraterizada pelo líquene preto Verrucaria sp., a ostra Saccostrea cucullata e a craca Chthamalus dentatus; e por fim a zona infralitoral de maior riqueza específica, mas maioritariamente dominada por alga incrustante rosa e pelo coral mole Palythoa caribaeorum. O gastrópode Neritta senegalensis foi a espécie com a distribuição mais vasta, ocupando sempre todo o intertidal. Para o estudo da ictiofauna intertidal (Capítulo 3), foram amostradas 60 poças em três localizações na costa norte: ilhéu Bom-Bom, Ponta Marmita e Praia Uba. Apenas poças da zona eulitoral foram amostradas, nas quais foram registados um total 746 peixes pertencentes a 18 espécies diferentes, representando 13 famílias. As cinco espécies mais abundantes foram, por ordem decrescente Bathygobius burtoni, Abudefduf taurus, Entomacrodus cadenati, Microlipophrys velifer e Prionurus biafraensis, que em conjunto representam 81% do total de observações. As quatro espécies mais abundantes corresponderam às que apresentaram maior adaptabilidade a uma maior variação de condições físico-químicas nas poças de maré. Foram avistadas outras 10 espécies fora do período de amostragem em poças de maré da zona eulitoral nas mesmas costas rochosas e outras semelhantes, representando mais cinco famílias. Destas, Lutjanus griseus trata-se de um novo registo para São Tomé e Príncipe, sendo apenas o segundo do Atlântico Este. As espécies foram agrupadas em três categorias consoante o seu ciclo de vida nas poças de maré: residentes, residentes secundárias e transientes. As espécies residentes e algumas residentes secundárias foram as que contribuíram mais para a abundância de peixes. Dado o contexto geográfico, climático e oceanográfico da ilha do Príncipe, os peixes demonstraram, no geral, preferência por poças de maré volumosas, com reduzida cobertura biológica (algas e coral) e maior salinidade. Poças com estas características provaram ter condições físico químicas (temperatura, salinidade e pH) mais estáveis, representando microhabitats mais favoráveis. No entanto, algumas espécies apresentaram um certo grau de especificidade de habitat, nomeadamente a presença ou ausência de cobertura de biológica. Peixes com uma natação mais ativa preferiram poças mais fundas.The present work took place in the tropical rocky shores of Príncipe Island, São Tomé and Príncipe, Gulf of Guinea. This work comprises a theoretical framework (chapter 1), two scientific articles (chapter 2 and 3) which includes the results and discussion, and the final remarks (chapter 4). In Chapter 2, two rocky shores, representing each an estuarine-influenced and a marine environment, were sampled to describe and compare distribution patterns of intertidal biological assemblages. A total of 47 taxa were documented, comprising 17 macroalgae, one marine lichen, and 29 epibenthic macrofauna taxa. Bom-Bom rocky shore presented higher species richness, and although not significantly different compared to Abade, the presence of key species suggests a noteworthy difference between the two biological communities. The biggest difference, however, was reflected in the zonation patterns between the two shores. The upper limits of the zones in Bom-Bom are uplifted compared to Abade due the effect of stronger wave action and a broader splash zone. In Chapter 3, rock pools from three locations were sampled to describe the composition, abundance and distribution of fish assemblages and their relation to the pools physical structure, water mass and biological parameters. A total of 18 species were observed during sampling and grouped into three categories according to their life cycle in the tide pools: residents, secondary residents and transients. The residents Bathygobius burtoni, Entomacrodus cadenati and Microlipophrys velifer and the secondary residents Abudefduf taurus and Prionurus biafraensis were the most abundant species, representing together 81% of the total number of fish recorded during this study. Overall, larger rock pools with minimal biological cover and higher salinity supported higher fish abundance and species richness. However, some species presented a degree of habitat specificity, such as the absence or presence of biological cover and the pools dept
Pervasive gaps in Amazonian ecological research
Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear un derstanding of how ecological communities respond to environmental change across time and space.3,4
While the increasing availability of global databases on ecological communities has advanced our knowledge
of biodiversity sensitivity to environmental changes,5–7 vast areas of the tropics remain understudied.8–11 In
the American tropics, Amazonia stands out as the world’s most diverse rainforest and the primary source of
Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepre sented in biodiversity databases.13–15 To worsen this situation, human-induced modifications16,17 may elim inate pieces of the Amazon’s biodiversity puzzle before we can use them to understand how ecological com munities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus
crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced
environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple or ganism groups in a machine learning model framework to map the research probability across the Brazilian
Amazonia, while identifying the region’s vulnerability to environmental change. 15%–18% of the most ne glected areas in ecological research are expected to experience severe climate or land use changes by
2050. This means that unless we take immediate action, we will not be able to establish their current status,
much less monitor how it is changing and what is being lostinfo:eu-repo/semantics/publishedVersio
ATLANTIC EPIPHYTES: a data set of vascular and non-vascular epiphyte plants and lichens from the Atlantic Forest
Epiphytes are hyper-diverse and one of the frequently undervalued life forms in plant surveys and biodiversity inventories. Epiphytes of the Atlantic Forest, one of the most endangered ecosystems in the world, have high endemism and radiated recently in the Pliocene. We aimed to (1) compile an extensive Atlantic Forest data set on vascular, non-vascular plants (including hemiepiphytes), and lichen epiphyte species occurrence and abundance; (2) describe the epiphyte distribution in the Atlantic Forest, in order to indicate future sampling efforts. Our work presents the first epiphyte data set with information on abundance and occurrence of epiphyte phorophyte species. All data compiled here come from three main sources provided by the authors: published sources (comprising peer-reviewed articles, books, and theses), unpublished data, and herbarium data. We compiled a data set composed of 2,095 species, from 89,270 holo/hemiepiphyte records, in the Atlantic Forest of Brazil, Argentina, Paraguay, and Uruguay, recorded from 1824 to early 2018. Most of the records were from qualitative data (occurrence only, 88%), well distributed throughout the Atlantic Forest. For quantitative records, the most common sampling method was individual trees (71%), followed by plot sampling (19%), and transect sampling (10%). Angiosperms (81%) were the most frequently registered group, and Bromeliaceae and Orchidaceae were the families with the greatest number of records (27,272 and 21,945, respectively). Ferns and Lycophytes presented fewer records than Angiosperms, and Polypodiaceae were the most recorded family, and more concentrated in the Southern and Southeastern regions. Data on non-vascular plants and lichens were scarce, with a few disjunct records concentrated in the Northeastern region of the Atlantic Forest. For all non-vascular plant records, Lejeuneaceae, a family of liverworts, was the most recorded family. We hope that our effort to organize scattered epiphyte data help advance the knowledge of epiphyte ecology, as well as our understanding of macroecological and biogeographical patterns in the Atlantic Forest. No copyright restrictions are associated with the data set. Please cite this Ecology Data Paper if the data are used in publication and teaching events. © 2019 The Authors. Ecology © 2019 The Ecological Society of Americ
Pervasive gaps in Amazonian ecological research
Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear understanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5,6,7 vast areas of the tropics remain understudied.8,9,10,11 In the American tropics, Amazonia stands out as the world's most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepresented in biodiversity databases.13,14,15 To worsen this situation, human-induced modifications16,17 may eliminate pieces of the Amazon's biodiversity puzzle before we can use them to understand how ecological communities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple organism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region's vulnerability to environmental change. 15%–18% of the most neglected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lost
Pervasive gaps in Amazonian ecological research
Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear understanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5,6,7 vast areas of the tropics remain understudied.8,9,10,11 In the American tropics, Amazonia stands out as the world's most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepresented in biodiversity databases.13,14,15 To worsen this situation, human-induced modifications16,17 may eliminate pieces of the Amazon's biodiversity puzzle before we can use them to understand how ecological communities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple organism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region's vulnerability to environmental change. 15%–18% of the most neglected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lost
Outcomes from elective colorectal cancer surgery during the SARS-CoV-2 pandemic
This study aimed to describe the change in surgical practice and the impact of SARS-CoV-2 on mortality after surgical resection of colorectal cancer during the initial phases of the SARS-CoV-2 pandemic
Worldwide trends in hypertension prevalence and progress in treatment and control from 1990 to 2019: a pooled analysis of 1201 population-representative studies with 104 million participants
Background
Hypertension can be detected at the primary health-care level and low-cost treatments can effectively control hypertension. We aimed to measure the prevalence of hypertension and progress in its detection, treatment, and control from 1990 to 2019 for 200 countries and territories.
Methods
We used data from 1990 to 2019 on people aged 30–79 years from population-representative studies with measurement of blood pressure and data on blood pressure treatment. We defined hypertension as having systolic blood pressure 140 mm Hg or greater, diastolic blood pressure 90 mm Hg or greater, or taking medication for hypertension. We applied a Bayesian hierarchical model to estimate the prevalence of hypertension and the proportion of people with hypertension who had a previous diagnosis (detection), who were taking medication for hypertension (treatment), and whose hypertension was controlled to below 140/90 mm Hg (control). The model allowed for trends over time to be non-linear and to vary by age.
Findings
The number of people aged 30–79 years with hypertension doubled from 1990 to 2019, from 331 (95% credible interval 306–359) million women and 317 (292–344) million men in 1990 to 626 (584–668) million women and 652 (604–698) million men in 2019, despite stable global age-standardised prevalence. In 2019, age-standardised hypertension prevalence was lowest in Canada and Peru for both men and women; in Taiwan, South Korea, Japan, and some countries in western Europe including Switzerland, Spain, and the UK for women; and in several low-income and middle-income countries such as Eritrea, Bangladesh, Ethiopia, and Solomon Islands for men. Hypertension prevalence surpassed 50% for women in two countries and men in nine countries, in central and eastern Europe, central Asia, Oceania, and Latin America. Globally, 59% (55–62) of women and 49% (46–52) of men with hypertension reported a previous diagnosis of hypertension in 2019, and 47% (43–51) of women and 38% (35–41) of men were treated. Control rates among people with hypertension in 2019 were 23% (20–27) for women and 18% (16–21) for men. In 2019, treatment and control rates were highest in South Korea, Canada, and Iceland (treatment >70%; control >50%), followed by the USA, Costa Rica, Germany, Portugal, and Taiwan. Treatment rates were less than 25% for women and less than 20% for men in Nepal, Indonesia, and some countries in sub-Saharan Africa and Oceania. Control rates were below 10% for women and men in these countries and for men in some countries in north Africa, central and south Asia, and eastern Europe. Treatment and control rates have improved in most countries since 1990, but we found little change in most countries in sub-Saharan Africa and Oceania. Improvements were largest in high-income countries, central Europe, and some upper-middle-income and recently high-income countries including Costa Rica, Taiwan, Kazakhstan, South Africa, Brazil, Chile, Turkey, and Iran.
Interpretation
Improvements in the detection, treatment, and control of hypertension have varied substantially across countries, with some middle-income countries now outperforming most high-income nations. The dual approach of reducing hypertension prevalence through primary prevention and enhancing its treatment and control is achievable not only in high-income countries but also in low-income and middle-income settings