16 research outputs found
Nuevos registros para la flora ficológica marina de Cuba
From the inventory data on the marine biodiversity of Cuba´s northern and south-eastern coasts collected during the period from July 2011 to April 2012, three new genus and five new species of Cuban algae were for the first time collected: two from the phylum Rhodophyta, one from the phylum Ochrophyta and two from the phylum Chlorophyta. The three genus are Taonia, Rhipiliopsis and Apoglossum, and the five species are Taonia abbottiana, Rhipiliopsis reticulata, Apoglossum ruscifolium, Caulerpa nummularia and Liagora tsengii. The last one is considered rare since it had only been seen in its locality type and more recently found in Cozumel (Mexico). Specimens were collected on rocky substratum from 2 to 15 meters deep. A detailed description on morphology, reproduction and distribution is presented herein as well as illustrations of the five species. Specimens were deposit in the marine collections of the Coastal Ecosystems Research Center (HCIEC), with copies at the National Aquarium of Cuba (HNAC). These findings were made in poorly studied areas of the Cuban archipelago and contribute to know about their distribution in the West Atlantic.Se registran por primera vez tres nuevos géneros y cinco nuevas especies de macroalgas para Cuba, dos del phylum Rhodophyta, una de Ochrophyta y dos de Chlorophyta, a partir de inventarios de la biodiversidad marina en las costas norte y sur oriental de Cuba, durante el periodo de julio del 2011 a abril del 2012. Los tres géneros son Taonia, Rhipiliopsis y Apoglossum, y las cinco especies son Taonia abbottiana, Rhipiliopsis reticulata, Apoglossum ruscifolium, Caulerpa nummularia y Liagora tsengii. Esta última es considerada como rara dado que hasta el momento solo había sido registrada en la localidad tipo y más recientemente de la Isla Cozumel (México). Los especímenes fueron recolectados sobre sustrato rocoso entre 2 y 15 m de profundidad. Se presenta una descripción detallada de su morfología, reproducción y distribución en el Atlántico occidental, así como ilustraciones de las cinco especies. El material fue depositado en las colecciones marinas del Centro de Investigaciones de Ecosistemas Costeros (HCIEC) con duplicados en las del Acuario Nacional de Cuba (HANC). Estos hallazgos se realizaron en zonas poco estudiadas del archipiélago cubano y contribuyen a ampliar el conocimiento de su distribución en el Atlántico occidental
Effects of Gamma Ray Bursts in Earth Biosphere
We continue former work on the modeling of potential effects of Gamma Ray
Bursts on Phanerozoic Earth. We focus on global biospheric effects of ozone
depletion and show a first modeling of the spectral reduction of light by NO2
formed in the stratosphere. We also illustrate the current complexities
involved in the prediction of how terrestrial ecosystems would respond to this
kind of burst. We conclude that more biological field and laboratory data are
needed to reach even moderate accuracy in this modelingComment: Accepted for publication in Astrophysics & Space Scienc
Estudios etnobotánicos sobre plantas medicinales en la provincia de Camagüey (Cuba)
An ethnobotanical study has been conducted on traditional medicinal plant uses in seven communities of the Province of Camagüey, Cuba. Ethnobotanical information on 111 plant species from 96 genera and 55 families have been recorded along with 116 different vernacular names. These species are used in the treatment of 173 local health problems (mainly in respiratory, digestive, liver and gallbladder, and skin disorders). Chemistry composition of 39 species is unknown and ethnopharmacological use of 18 species has not been reported previously in the literature. The data collected in this study contribute to the pharmacological and toxicological evaluation of some of the studied species.Como resultado del trabajo de campo realizado en siete comunidades de la provincia de Camagüey, Cuba, sobre el uso popular e indicaciones de plantas medicinales, se presenta información etnobotánica sobre 111 especies de plantas pertenecientes a 96 géneros y a 55 familias. Se obtuvieron 173 indicaciones de uso medicinal, principalmente para afecciones respiratorias, digestivas, hepatobiliares y dermatológicas. Se listaron 116 nombres vernáculos de especies vegetales. Se desconoce la composición química de 39 de las especies y de 18 no se encontraron referencias de su utilización en farmacia. Los datos empíricos obtenidos sobre usos de plantas estimularon la validación farmacológica y toxicológica de algunas de ellas
Metabolism in a deep hypertrophic aquatic ecosystem with high water-level fluctuations: a decade of records confirms sustained net heterotrophy
Long-term and seasonal changes in production and respiration were surveyed in the Valle de Bravo reservoir, Mexico, in a period during which high water-level fluctuations occurred (2006–2015). We assessed the community metabolism through oxygen dynamics in this monomictic water-body affected by strong diurnal winds. The multiple-year data series allowed relationships with some environmental drivers to be identified, revealing that water level-fluctuations strongly influenced gross primary production and respiratory rates. Production and respiration changed mainly vertically, clearly in relation to light availability. Gross primary production ranged from 0.15 to 1.26 gO2 m−2 h−1, respiration rate from −0.13 to −0.83 gO2 m−2 h−1 and net primary production from −0.36 to 0.66 gO2 m−2 h −1 within the production layer, which had a mean depth of 5.9 m during the stratification periods and of 6.8 m during the circulations. The greater depth of the mixing layer allowed the consumption of oxygen below the production layer even during the stratifications, when it averaged 10.1 m. Respiration below the production layer ranged from −0.23 to −1.38 gO2 m−2 h−1. Vertically integrated metabolic rates (per unit area) showed their greatest variations at the intra-annual scale (stratification-circulation). Gross primary production and Secchi depth decreased as the mean water level decreased between stratification periods. VB is a highly productive ecosystem; its gross primary production averaged 3.60 gC m−2 d−1 during the 10 years sampled, a rate similar to that of hypertrophic systems. About 45% of this production, an annual average net carbon production of 599 g C m−2 year−1, was exported to the hypolimnion, but on the average 58% of this net production was recycled through respiration below the production layer. Overall, only 19% of the carbon fixed in VB is buried in the sediments. Total ecosystem respiration rates averaged −6.89 gC m−2 d−1 during 2006–2015, doubling the gross production rates. The reservoir as a whole exhibited a net heterotrophic balance continuously during the decade sampled, which means it has likely been a net carbon source, potentially releasing an average of 3.29 gC m−2 d−1 to the atmosphere. These results are in accordance with recent findings that tropical eutrophic aquatic ecosystems can be stronger carbon sources than would be extrapolated from temperate systems, and can help guide future reassessments on the contribution of tropical lakes and reservoirs to carbon cycles at the global scale. Respiration was positively correlated with temperature both for the stratification periods and among the circulations, suggesting that the contribution of C to the atmosphere may increase as the reservoirs and lakes warm up owing to climate change and as their water level is reduced through intensification of their use as water sources
Metabolism in a deep hypertrophic aquatic ecosystem with high water-level fluctuations: a decade of records confirms sustained net heterotrophy
PRODUTIVIDADE PRIMÁRIA NA LAGOA LARGA, CAYO COCO. CUBA
Phytoplankton primary productivity and macrophyte biomass were determined during 2008-2009 for Laguna Larga, located on the north-central coast of Cayo Coco, Cuba. Aquatic net primary production was measured in two different sectors of the lagoon resulting in 4.32 ± 3.59 g C m-2 d-1 and 0.71 ± 0.41 g C m-2 d-1 in the eastern and western part, respectively. In regard to the annual production to respiration ratio, both sections showed autotrophic and hypertrophic levels for the oxygen and carbon metabolisms. The most productive species were Cladophoropsis sp., Halodule wrightii, Cladophora sp. and Ruppia maritima. Aquatic net production recorded for the eastern lobe was higher than the western lobe because of the macrophytobenthos contribution to total productivity. On the contrary, phytoplankton productivity in the eastern part was lower (0.12 ± 0.07 g C m-2 d-1) than the western lobe (0.71 ± 0.41 g C m-2 d-1), probably due to the macrophyte competition for nutrients.Se determinó la productividad primaria en Laguna Larga, ubicada en la costa norte y central de Cayo Coco. La producción primaria del fitoplancton y la biomasa del macrofitobentos fueron medidas durante el 2008-2009 en dos sectores de la laguna. La producción primaria neta acuática del sector este fue de 4.32 ± 3.59 g C m-2 día-1 y en el sector oeste fue de 0.71 ± 0.41 g C m-2 día-1. Ambos sectores, atendiendo a la relación producción/respiración anual, fueron autotróficos para el oxígeno e hipertróficos para el carbono. Entre las especies más productivas del macrofitobentos estuvieron: Cladophoropsis sp., Halodule wrightii, Cladophora sp. y Ruppia maritima. La alta producción neta acuática registrada en el sector este, con respecto al oeste, se debe a la contribución del macrofitobentos a la productividad total. El fitoplancton en el sector este exhibió baja productividad (0.12 ± 0.07 g C m-2 día-1) con respecto al oeste (0.71 ± 0.41 g C m-2 día-1), lo que puede deberse a la competencia del macrofitobentos por los nutrientes.Determinou-se a produtividade primária na Lagoa Larga, localizada na costa norte e central de Cayo Coco. A produção primária do fitoplâncton e a biomassa do macrofitobentos foram medidas durante 2008-2009 em dois setores da lagoa. A produção primária líquida aquática deste setor foi de 4.32 ± 3.59 g C m-2 dia-1 e no setor oeste de 0.71 ± 0.41 g C m-2 dia-1. Ambos os setores, atendendo a relação produção/respiração anual, foram autotróficos para o oxigênio e hipertróficos para o carbono. Entre as espécies mais produtivas do macrofitobentos estiveram: Cladophoropsis sp., Halodule wrightii, Cladophora sp. e Ruppia maritima. A alta produção líquida aquática registrada no setor leste, com relação ao oeste, deve-se à contribuição do macrofitobentos à produtividade total. O fitoplâncton neste setor exibiu baixa produtividade (0.12 ± 0.07 g C m-2 dia-1) com relação ao oeste (0.71 ± 0.41 g C m-2 dia-1), o que pode ser devido à concorrência do macrofitobentos pelos nutrientes
Productividad primaria en Laguna Larga, Cayo Coco, Cuba
Phytoplankton primary productivity and macrophyte biomass were determined during 2008-2009 for Laguna Larga, located on the north-central coast of Cayo Coco, Cuba. Aquatic net primary production was measured in two different sectors of the lagoon resulting in 4.32 ± 3.59 g C m-2 d-1 and 0.71 ± 0.41 g C m-2 d-1 in the eastern and western part, respectively. In regard to the annual production to respiration ratio, both sections showed autotrophic and hypertrophic levels for the oxygen and carbon metabolisms. The most productive species were Cladophoropsis sp., Halodule wrightii, Cladophora sp. and Ruppia maritima. Aquatic net production recorded for the eastern lobe was higher than the western lobe because of the macrophytobenthos contribution to total productivity. On the contrary, phytoplankton productivity in the eastern part was lower (0.12 ± 0.07 g C m-2 d-1) than the western lobe (0.71 ± 0.41 g C m-2 d-1), probably due to the macrophyte competition for nutrients.Se determinó la productividad primaria en Laguna Larga, ubicada en la costa norte y central de Cayo Coco. La producción primaria del fitoplancton y la biomasa del macrofitobentos fueron medidas durante el 2008-2009 en dos sectores de la laguna. La producción primaria neta acuática del sector este fue de 4.32 ± 3.59 g C m-2 día-1 y en el sector oeste fue de 0.71 ± 0.41 g C m-2 día-1. Ambos sectores, atendiendo a la relación producción/respiración anual, fueron autotróficos para el oxígeno e hipertróficos para el carbono. Entre las especies más productivas del macrofitobentos estuvieron: Cladophoropsis sp., Halodule wrightii, Cladophora sp. y Ruppia maritima. La alta producción neta acuática registrada en el sector este, con respecto al oeste, se debe a la contribución del macrofitobentos a la productividad total. El fitoplancton en el sector este exhibió baja productividad (0.12 ± 0.07 g C m-2 día-1) con respecto al oeste (0.71 ± 0.41 g C m-2 día-1), lo que puede deberse a la competencia del macrofitobentos por los nutrientes