Artículos científicos

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Heartwood, sapwood and bark contents of bombacopsis quinata in Costa Rica
(Instituto de Investigación Forestal de Malasia, 2004-07) Pérez, D.; Kanninen, M.; Matamoros, F.; Fonseca, W.; Chaves, E.
The Costa Rican government has promoted the establishment of high yielding plantations, expecting to produce high quality timber. Nowadays the management of some species have been uncertain, since wood quality and yield are becoming lower than expected. Heartwood content is a determinant characteristic for Bombacopsis quinata, a widely appreciated species in the country. The aim of this study was to evaluate the heartwood, sapwood and bark content of young and advanced aged B. quinata trees. The research was based on the hypothesis that heartwood content increases with increasing age. By means of stem analysis, the heartwood, sapwood, and bark volume was measured on trees of different ages (10 to 27 years). The highest heartwood proportion found in B. quinata was 13.6%, and the lowest 0.1%. The sapwood ranged between 70.0 and 87.2% while the bark, from 9.4 to 23% of the total stem volume. No clear differences in heartwood content could be observed between trees of similar age from dry and wet zones. Rotation periods for B. quinata in Costa Rica should be extended to produce high quality timber with increased heartwood content.
Climate Change-Based Modeling of Potential Land use Arrangements for Coffee (coffea arabica) and Forest in Costa Rica
(CIGR Oficial Publication, 2018-01-17) Coto Fonseca, Alberto F.; Rojas, Carlos; Molina-Murillo, Sergio
Besides the need to reduce its own emissions, the challenge of the agricultural sector worldwide is also to adapt to a changing and more variable climate. Coffee is an important crop in Costa Rica based on cultivated area and the number of families connected to this activity that has a long historical tradition. In this context, the potential distribution shifts of coffee production based on climate change scenarios have been identified and targeted in this study. Bioclimatic variables along withelevation were used to evaluate changes in suitable areas for coffee production under the framework of four climate change scenarios for the year 2070. Results suggest that the highlands have a high probability of being suitable for coffee under allfour scenarios, and unsuitability seems to be associated with the lowlands. All four climate change scenarios showed high overlap between the projected suitable areas for coffee and current forested areas. This investigation suggests that the long-term management of coffee production in Costa Rica should carefully consider climate change given its potential conflict with other land uses and associated socioeconomic implications.
FRUTA DORADA (VIROLA KOSCHNYI WARB.) UNA ESPECIE PROMISORIA PARA LA REFORESTACION EN EL BOSQUE HUMEDO Y MUY HUMEDO TROPICAL
(Universidad Nacional de Costa Rica, 1990-04-30) Eladio, Chaves S; Rodríguez, Johnny; González, Eugenio
We present forestry experiences on the establishment and management of Virola koschyni Warb (Myristicaceae), a tree species from the tropical wet forest. In the nursery, plants were successfully produced by keeping soil brick and pruning the roots. Data from permanent thinning and yield plots showed that after six years, Virola koschyni reached an average 13.3 cm of DBH and 10.5 m of height. In addition, we include ecological and silvicultural information on this little known species.
Southern Hemisphere Additional Ozonesondes (SHADOZ) ozone climatology (2005–2009): Tropospheric and tropical tropopause layer (TTL) profiles with comparisons to OMI-based ozone products
(Universidad Nacional de Costa Rica, 2012-12-01) Thompson, Anne M.; Miller, Sonya K.; Tilmes Simone; Kollonige, Debra W.; Witte, Jacquelyn C.; Oltmans, Samuel J.; Johnson, Bryan J.; Fujiwara, Masatomo; Schmidlin, F. J.; Coetzee, G. J. R.; Komala, Ninong; Maata, Matakite; Mohamad, Maznorizan ; Nguyo, J.; Mutai, C.; Ogino, S-Y; Da Silva, F. Raimundo; Paes Leme, N. M.; Posny, Francoise; Scheele, Rinus; Selkirk, Henry B.; Shiotani, Masato; Stübi, René; Levrant, Gilbert; Calpini, Bertrand; Thouret, Valérie; Tsuruta, Haruo; Valverde Canossa, Jessica; Vömel, Holger; Yonemura, S.; Diaz, Jorge Andrés; Tan Thanh, Nguyen T.; Thuy Ha, Hoang T.
We present a regional and seasonal climatology of SHADOZ ozone profiles in the troposphere and tropical tropopause layer (TTL) based on measurements taken during the first five years of Aura, 2005–2009, when new stations joined the network at Hanoi, Vietnam; Hilo, Hawaii; Alajuela/Heredia, Costa Rica; Cotonou, Benin. In all, 15 stations operated during that period. A west-to-east progression of decreasing convective influence and increasing pollution leads to distinct tropospheric ozone profiles in three regions: (1) western Pacific/eastern Indian Ocean; (2) equatorial Americas (San Cristóbal, Alajuela, Paramaribo); (3) Atlantic and Africa. Comparisons in total ozone column from soundings, the Ozone Monitoring Instrument (OMI, on Aura, 2004-) satellite and ground-based instrumentation are presented. Most stations show better agreement with OMI than they did for EP/TOMS comparisons (1998–2004; Earth-Probe/Total Ozone Mapping Spectrometer), partly due to a revised above-burst ozone climatology. Possible station biases in the stratospheric segment of the ozone measurement noted in the first 7 years of SHADOZ ozone profiles are re-examined. High stratospheric bias observed during the TOMS period appears to persist at one station. Comparisons of SHADOZ tropospheric ozone and the daily Trajectory-enhanced Tropospheric Ozone Residual (TTOR) product (based on OMI/MLS) show that the satellite-derived column amount averages 25% low. Correlations between TTOR and the SHADOZ sondes are quite good (typical r2= 0.5–0.8), however, which may account for why some published residual-based OMI products capture tropospheric interannual variability fairly realistically. On the other hand, no clear explanations emerge for why TTOR-sonde discrepancies vary over a wide range at most SHADOZ sites.
Detailed structure of the tropical upper troposphere and lower stratosphere as revealed by balloon sonde observations of water vapor, ozone, temperature, and winds during the NASA TCSP and TC4 campaigns
(Advancing Earth and Space Sciences, 2010-09-21) Selkirk, Henry B.; Vömel, Holger; Valverde Canossa, Jéssica María; Pfister, Leonhard; Diaz, Jorge Andrés; Fernández, Walter; Amador, Jorge; Stolz, Werner; Peng, Grace S.
We report on balloon sonde measurements of water vapor and ozone using the cryogenic frost point hygrometer and electrochemical concentration cell ozonesondes made at Alajuela, Costa Rica (10.0°N, 84.2°W) during two NASA airborne campaigns: the Tropical Convective Systems and Processes (TCSP) mission in July 2005 and the Tropical Composition, Clouds, and Climate Coupling Experiment (TC4), July–August 2007. In both campaigns we found an upper troposphere that was frequently supersaturated but no evidence that deep convection had reached the tropopause. The balloon sondes were complemented by campaigns of 4 times daily high‐resolution radiosondes from mid‐June through mid‐August in both years. The radiosonde data reveal vertically propagating equatorial waves that caused a large increase in the variability of temperature in the tropical tropopause layer (TTL). These waves episodically produced cold point tropopauses (CPTs) above 18 km, yet in neither campaign was saturation observed above ∼380 K or 17 km. The averages of the water vapor minima below this level were 5.2 ppmv in TCSP and 4.8 ppmv in TC4, and the individual profile minima all lay at or above ∼360 K. The average minima in this 360–380 K layer provide a better estimate of the effective stratospheric entry value than the average mixing ratio at the CPT. We refer to this upper portion of the TTL as the tropopause saturation layer and consider it to be the locus of the final dehydration of nascent stratospheric air. As such, it is the local equivalent to the tape head of the water vapor tape recorder.
NUEVAS ESPECIES DE INGA MILLER (MIMOSACEAE) PARA MESOAMERICA
(Universidad Nacional de Costa Rica, 1990-07-16) Zamora V, Nelson.
A partir de un estudio de las Mimosaceae de Costa Rica, se describen aquí nueve especies de Inga nuevas para la ciencia. Se incluye su distribución y afinidades taxonómicas.
Desarrollo larval de cichlasoma sp (pisces : cichlidae) cultivados en laboratorio
(Universidad Nacional de Costa Rica, 1988-09-29) Murillo Sánchez, Roger E.
Se describe el desarrollo embrionario y larvario de Cichlasoma sp. tras la fecundación natural de los huevos. Los huevos se obtuvieron de adultos capturados en la Hacienda Santiago, Heredia, Costa Rica. Se mantuvieron en acuarios a 24,5 ± 10,2 °C, 6,4 ppm de O₂ y un fotoperiodo de 12:12 horas. Los huevos son oblongos, de 2,1 mm de longitud y 1,6 mm de ancho. La eclosión ocurre entre las 48 y 52 horas posteriores a la fecundación. Al eclosionar, las larvas miden 4,6 ± 0,1 mm de longitud. El alimento se consume al noveno día después de la eclosión; la alimentación comienza al séptimo día. La fase juvenil comienza con una longitud de 15,5 ± 0,6 mm. La secuencia de desarrollo de las aletas es: pectorales, caudal, anal y pélvicas.
Sulfate, nitrate and chloride in PM10 in the city of San Jose, Costa Rica: 2004-2006
(Escuela de Ciencias Ambientales, 2009-11-23) Herrera, M. J.; Rojas, M, J. F.; Rodríguez, R. S.; García-Martínez, R.
Se realizó la determinación de los niveles de PM10 en dos sitios de la ciudad de San José (Catedral Metropolitana y Junta de Educación) durante un período de 2.5 años (abril 2004–octubre 2006) obteniendo una mediana de 39 ± 8 y 27 ± 8 µg m–3, respectivamente. En forma adicional, se midieron las concentraciones de SO42–, NO3– y Cl– registrando promedios que no son significativamente diferentes para ambos sitios de medición. Al aplicar el análisis de componentes principales a los datos, se obtuvieron dos factores que explican un 65% del total de la varianza. El factor PC1 incluye a la concentración de Cl– y la velocidad del viento sugiriendo la posible contribución marina de este anión. El factor PC2 muestra una relación entre las concentraciones de SO42–, NO3– y PM10, demostrando su origen antropogénico.
Chemical composition of bulk precipitation in the metropolitan area of Costa Rica, Central America
(Universidad Nacional de Costa Rica, 2009-05-04) Herrera, M. J.; Rodríguez, R. S.; Báez, A. P.
Tracemetals and inorganic ionswere measured in bulk precipitation sampled at eleven sites in the metropolitan area of Costa Rica. The ions were analyzed by ion chromatography, and the trace metals by atomic absorption spectrometer with a graphite furnace attachment. The results indicated that Na+ and SO4 2− were the most abundant ions, and of the metals, that Al and Fe had the highest concentrations. Spearman's correlation applied to all data showed a high correlation among SO4 2−, NO3− and NH4+, indicating a common anthropogenic origin. In addition, the correlation found between Na+, K+ and Cl−indicated a sea aerosol contribution. High positive correlations between tracemetalswere found for Al–Mn, Ni–Mn, Ni–Al, Cu–Ni, Pb–Cu, Pb–Ni and Pb–Mn.
Chemical characterization and source apportionment of PM10 and PM2.5 in the metropolitan area of Costa Rica, Central America
(Universidad Nacional de Costa Rica, 2013-02-28) Herrera, M. J.; Rodriguez, R. S.; Rojas-Marin, J. F.; Campos, R. A.; Blanco, J. S.; Cárdenas, G. B; Gibson, B. D.
PM10 and PM2.5 levels, concentrations of major ionic components, trace elements, and organic and elemental carbon were evaluated from samples collected in 4 sites (industrial, commercial and residential zones) located in the metropolitan area of Costa Rica. The annual mean PM levels were higher in high traffic–commercial (HE–01) and industrial (BE–02) sites, 55 μg m–3 and 52 μg m–3 for PM10 and 37 μg m–3 and 36 μg m–3 for PM2 5, respectively. The major components of PM25 were organic matter (OM) and elemental carbon (EC) (44.5–69.9%), and secondary ions (16.1–27.2%), whereas the major components of PM10 were OM+EC (32.7–59.4%), crustal material (23.5–35.6%) and secondary ions (11.4–26.9%). For the most of the sampling sites, PM10 and PM2.5 concentrations were lower during the dry season and increased gradually in the rainy season due to wind patterns. PMF model identified 8 principle sources for PM10 and PM2.5 in the industrial site (crustal, secondary sulfate, secondary nitrate, secondary organic, traffic, sea–salt aerosols, industrial and oil combustion), 6 and 5 sources in commercial and residential sites, respectively. The source contributions showed a clear seasonal pattern for all the sites.
The summertime Boreal forest field measurement intensive (HUMPPA-COPEC-2010): an overview of meteorological and chemical influences
(Copernicus Publications, 2011-10-27) Williams, J; Crowley, J.; Fischer, H.; Harder, H.; Martinez, M.; Petäjä. T.; Rinne, J.; Bäck, Jaana; Boy, M.; Dal Maso, M.; Hakala, J.; Kajos, M.; Keronen, P.; Rantala, P.; Aalto, J.; Aaltonen, H.; Paatero, J.; Vesala, T.; Hakola, H.; Levula, J.; Pohja, J.; Herrmann, F.; Auld, J.; Mesarchaki, E.; Song, W.; Yassaa, M.; Nölscher, A.; Johnson, A. M.; Custer, T.; Sinha, V.; Thieser, J.; Pouvesle, V.; Taraborrelli, D.; Tang, M. J.; Bozem, H.; Hosaynali-Beygi, Z.; Axinte, R.; Oswald, R.; Novelli, A.; Kubistin, D.; Hens, K.; Javed, U.; Trawny, K; Breitenberger, C.; Hidalgo, P.J.; Ebben, C.J.; Geiger, F.M.; Corrigan, A.L.; Russell, M.L.; Ouwersloot, H.G.; Vilà-Guerau de Arellano, J.; Ganzeveld, L.; Vogel, A.; Beck, M.; Bayerle, A.; Kampf, C.J.; Bertelmann, M.; Köllner, F.; Hoffmann, T.; Valverde, J.; González, D.; Riekkola, M.L,; Kulmala, M.; Lelieveld, j.
This paper describes the background, instrumentation, goals, and the regional influences on the HUMPPACOPEC intensive field measurement campaign, conducted at the Boreal forest research station SMEAR II (Station for Measuring Ecosystem-Atmosphere Relation) in HyytiäLä, Finland from 12 July–12 August 2010. The prevailing meteorological conditions during the campaign are examined and contrasted with those of the past six years. Back trajectory analyses show that meteorological conditions at the site in 2010 were characterized by a higher proportion of southerly flow than in the other years studied. As a result the summer of 2010 was anomalously warm and high in ozone making the campaign relevant for the analysis of possible future climates. A comprehensive land use analysis, provided on both 5 and 50 km scales, shows that the main vegetation types surrounding the site on both the regional and local scales are: coniferous forest (Scots pine and/or Norway spruce); mixed forest (Birch and conifers); and woodland scrub (e.g. Willows, Aspen); indicating that the campaign results can be taken as representative of the Boreal forest ecosystem. In addition to the influence of biogenic emissions, the measurement site was occasionally impacted by sources other than vegetation. Specific tracers have been used here to identify the time periods when such sources have impacted the site namely: biomass burning (acetonitrile and CO), urban anthropogenic pollution (pentane and SO2) and the nearby Korkeakoski sawmill (enantiomeric ratio of chiral onoterpenes). None of these sources dominated the study period, allowing the Boreal forest summertime emissions to be assessed and contrasted with various other source signatures.
Spatial Distribution and Chemical Composition of Road Dust in Two High-Altitude Latin American Cities
(Universidad Nacional de Costa Rica, 2021-08-28) Vanegas, Sebastián; Trejos, Ericka M.; Aristizábal, Beatriz H.; Pereira, Guilherme M.; Hernández, Julio M.; Herrera-Murillo, Jorge; Ramírez, Omar; Amato, Fulvio; Silva, Luis F. O.; Rojas, Néstor Y.; Zafra, Carlos; Pachón, Jorge E.
Road dust (RD) resuspension is one of the main sources of particulate matter in cities with adverse impacts on air quality, health, and climate. Studies on the variability of the deposited PM10 fraction of RD (RD10) have been limited in Latin America, whereby our understanding of the central factors that control this pollutant remains incomplete. In this study, forty-one RD10 samples were collected in two Andean cities (Bogotá and Manizales) and analyzed for ions, minerals, and trace elements. RD10 levels varied between 1.8–45.7 mg/m2, with an average of 11.8 mg/m2, in Bogotá and between 0.8–26.7 mg/m2, with an average of 5.7 mg/m2, in Manizales. Minerals were the most abundant species in both cities, with a fraction significantly larger in Manizales (38%) than Bogotá (9%). The difference could be explained mainly by the complex topography and the composition of soil derived from volcanic ash in Manizales. The volcanic activity was also associated with SO4􀀀2 and Cl􀀀. Enrichment factors and principal component analysis were conducted to explore potential factors associated to sources of RD10. Elements such as Cu, Pb, Cr, Ni, V, Sb, and Mo were mainly associated with exhaust and non-exhaust traffic emissions.
Q’eqchi’ Maya healers’ traditional knowledge in prioritizing conservation of medicinal plants: culturally relative conservation in sustaining traditional holistic health promotion
(Springer Nature, 2009-07-30) Pesek, Todd; Abramiuk, Marc; Fini, Nick; Otarola Rojas, Marco; Collins, Sean; Cal, Víctor; Sánchez Vindas, Pablo; Poveda Álvarez, Luis; Arnason, John T.
This ethnobotanical study in the spirit of transdisciplinarity, and in collaboration with Q’eqchi’ Maya traditional healers, compares traditional Q’eqchi’ Maya ecosystem constructs or environmental zones with scientific ecosystems. To determine which categorization method better accommodates Q’eqchi’ Maya medicinal plant diversity, we analized 26 transects representing 160 medicinal plant occurrences. Our transect array encompasses a representative sampling of Q’eqchi’ Maya medicinal plant repertoire with use values broadly distributed over 17 usage categories. With a cumulative frequency of 2,235 medicinal plants through ecological zones, we conducted one-way ANOVA on the mean number of medicinal plant species identified in transects of the two conceptual schemes being contested. Our analysis reveals the Q’eqchi Maya environmental zones are the most salient. That is, knowledge of the Q’eqchi’ Maya environmental zones improves one’s ability to predict whether there will be a high or low abundance of Q’eqchi’ Maya medicinal plant species in a particular region, whereas knowledge of scientific ecosystems does not accomplish this feat as well. This is a notable finding as it suggests that if indeed Q’eqchi’ Maya medicinal plant diversity is better accounted for by the zones as envisioned by the Q’eqchi’ Maya, then it should be this mode of conceptualization that should be adopted by scientists and conservationists when trying to locate and protect regional Q’eqchi’ Maya medicinal plant diversity. These efforts serve as a model internationally in the conservation of medicinal plant biodiversity supportive of culturally relative holistic health promotion.
Biological Activity of Extracts of Trichilia Species and the Limonoid Hirtin Against Lepidopteran Larvae
(Elsevier Science Ltd, 1994) Xie, Y. S.; Isman, M. B.; Gunning, P.; Mackinnon, S.; Arnason, J. T.; Taylor, D. R.; Sánchez. V, P.; Hasbun, C; Towers, G. H. N.
Crude extracts of several Trichilia species (Meliaceae) were evaluated for their behavioral and physiological effects on the polyphagous lepidopterans Peridroma saucia and Spodoptera litura. A majority of extracts of nine Trichilia species, collected primarily from Costa Rica, significantly deter larval growth of P. saucia. Extracts of wood and bark are generally more active than those of foliage. Effects of various tissue extracts from T. connaroides on P. saucia and S. litura were comparatively studied. Extracts of bark, the most active tissue compared to those of wood, seed, exocarp and leaf, reduced larval growth of P. saucia and S. litura by 50% at dietary concentrations of 29.1 and 185.1 ppm, respectively. The limonoid hirtin, a constituent of Trichilia hirta, significantly inhibited larval growth of P. saucia in a dose-dependent manner, with a dietary EC50 (effective concentration to inhibit growth by 50% relative to controls) of 13.0 ppm. Hirtin and various extracts from T. connaroides significantly reduced larval growth and consumption rates, as well as dietary utilization, indicating that these substances possess both behavioral effects and post-ingestive toxicity.
Screening of Costa Rican Trichilia species for biological activity against the larvae of Spodoptera litura (Lepidoptera : Noctuidae)
(Elsevier Science Ltd, 2001-04) Wheeler, Deborah A.; Isman, Murray B.; Sanchez Vindas, Pablo; Arnason, John T.
Crude methanolic extracts made from the twigs of 39 plant samples from six species of Trichilia collected in Costa Rica, were incorporated into arti®cial diet and fed to neonate Spodoptera litura larvae. All six plant species tested signi®cantly reduced larval growth after 7 and 10 days. The most active species was T. americana, reducing growth, on average, to 3.9% of control at 1000 ppm fresh weight. The least active, on average, was T. glabra. A twig extract of T. americana proved to be more active than wood, bark or leaf extracts, with the twigextract reducing growth of S. litura larvae by 50% (EC50) at a dietary concentration of 17.2 ppm. When T. americana wood extract was incorporated into arti®cial diet (10, 25, 50 and 75 ppm) and fed to S. litura larvae throughout larval development, growth was slowed and the nal weight of pupae and adults was reduced. At higher extract concentrations (50 and 75 ppm) larvae entered one or two supernumerary instars before pupation occurred. This was shown to be due to both starvation and to post-ingestive activity of the extract.
Summertime total OH reactivity measurements from boreal forest during HUMPPA-COPEC 2010
(Copernicus Publications, 2012-09) Nölscher, Anke C.; Williams, Jonathan; Sinha, Vinayak; Custer, Thomas G.; Wei, Song; Axinte, R.; Bozem, Heiko; Fischer, H.; Pouvesle, N.; Phillips, Gavin; Crowley, J. N.; Rantala, P.; Rinne, Janne; Rantala, P.; Rinne, Janne; Kulmala, Markku; González, D.; Valverde-Canossa, jessica; Vogel, Alexander; Hoffmann, Thorsten; Ouwersloot, H.G.; Vilà-Guerau de Arellano, j.; Lelieveld, j.
La reactividad ambiental total de OH se midió en la estación forestal boreal finlandesa SMEAR II en Hyytiälä (Latitud 61°51' N; Longitud 24°17' E) en julio y agosto de 2010 utilizando el Método de Reactividad Comparativa (MRC). El MRC (método de reactividad total de OH) es una determinación directa in situ de la tasa total de pérdida de radicales hidroxilo (OH) causada por todas las especies reactivas en el aire. Durante la campaña de campo intensiva HUMPPA-COPEC 2010 ( H yytiälä United M easurements of P hotochemistry and P articles in Air – C omprehensive Organic P recursor Emission and C oncentration study) la reactividad total de OH se monitoreó tanto dentro (18 m) como directamente sobre el dosel forestal (24 m) por primera vez. Aquí se ha analizado la comparación entre estas dos mediciones de reactividad total de OH, los valores absolutos y la variación temporal. Las condiciones estables de la capa límite durante la noche y la mezcla turbulenta durante el día indujeron una variabilidad a corto plazo baja y alta, respectivamente. El impacto de las emisiones biogénicas y los productos fotoquímicos asociados en la reactividad total del OH se midió en condiciones normales y de estrés (es decir, con altas temperaturas prolongadas). La advección de las emisiones de la quema de biomasa al sitio provocó un cambio marcado en el perfil vertical de la reactividad total del OH. Al comparar la contribución de la reactividad del OH de los compuestos medidos individualmente y la reactividad total del OH medida directamente, se puede deducir el tamaño de cualquier sumidero no contabilizado o "faltante" para diversas influencias atmosféricas. Para condiciones boreales "normales" se determinó una reactividad del OH faltante del 58%, mientras que para condiciones boreales "estresadas" se determinó una reactividad del OH faltante del 89%. Se proponen diversas fuentes de especies reactivas al OH no cuantificadas como posible explicación de la alta reactividad del OH faltante.
Resistance and resilience in a directly regenerating rainforest: Nicaraguan trees of the Vochysiaceae after Hurricane Joan
(Elsevier, 1994-10) Boucher, Douglas H.; Vandermeer, John H.; Mallona, María Antonia; Zamora, Nelson; Perfecto, Ivette
Two trees of the family Vochysiaceae, Vochysiaferruginea and Qualea paraensis, were abundant in a Nicaraguan rainforest which was heavily damaged by Hurricane Joan in 1988, and both had recovered their previous densities by 1993. However, their regeneration followed quite different paths. Vochysia suffered complete mortality of adult trees in the hurricane, but rapid growth and high survivorship of its abundant seedlings and sprouts of saplings, restored its population density (though not yet its mean diameter at breast height) and indeed led to spatial expansion. Qualea, however, showed 100% survival of trees during the hurricane but substantial mortality in the following years. Although seedlings and sprouts of Qualea are quite rare, ingrowth is sufficient to maintain the population so far. However, vine growth on Qualea (unlike Vochysia) is substantial. These two species are thus contrasting elements of the 'direct regeneration' which has been observed in this rainforest. The Vochysia pattern of death and recovery can be described as 'resilience', while the Qualea pattern of survival can be called 'resistance'. The regenerating Vochysia population is mostly seedlings and saplings, while that of Qualea is mostly adult trees. Depending on the pattern of regeneration, different management strategies will be appropriate for maintaining tree species subject to natural disturbances such as hurricanes and/or artificial ones such as logging.
Gestión de los residuos peligrosos, especiales y prioritarios en Costa Rica, 2022-2023
(2025-03-11) Tania Vega Godínez
El presente artículo científico es producto de una investigación orientada a examinar la gestión de los residuos peligrosos, de manejo especial y prioritarios en Costa Rica. Con este propósito, se aplicó un diagnóstico y un análisis FODA que involucró a los actores directos, para su respectivo análisis y vista de oportunidades de mejora. La información se recopiló aplicando un proceso que integró las siguientes acciones: revisión de legislación, datos en línea y entrevistas con actores clave. El artículo destaca información detallada sobre legislación, clasificación y gestión de residuos, incluyendo la responsabilidad extendida del productor. Además, aborda la necesidad evidente de mejorar la fiscalización y coordinación interinstitucional, e implementar sistemas que permitan la trazabilidad de los datos. El análisis respaldado por consulta bibliográfica en la fase de discusión, concluye en la importancia de reglamentar residuos prioritarios, fijar metas y promover la responsabilidad del productor, así como mejorar el control y fiscalización de residuos peligrosos.
Ethnobotany of immunomodulatory treatments used by the Q’eqchi’ Maya of Belize
(Springer Nature Link, 2019-04-25) Walshe-Roussel, Brendan; Otarola Rojas, Marco; Sánchez Vindas, Pablo; Pesek, Todd; Cal, Víctor; Arnason, John
Using a quantitative ethnobotanical methodology, we identified 107 plant species belonging to 49 families used by Q’eqchi’ Maya healers in the treatment of symptoms from 14 usage categories related to inflammation. The families with the largest number of medicinal species were Piperaceae, Araceae, Asteraceae, Fabaceae, and Adiantaceae with five or more medicinal species. Healer consensus for plant species was high, with 56 species (52%) being used by all the healers, and consensus for usage categories was also high, as informant consensus factor (FIC) values for each category were greater than 0.4.
Sugarcane burning emissions: Characterization and emission factors
(Elsevier Ltd, 2018-11) Múgica-Álvarez Violeta; Hernández-Rosas, Francisca; Magaña-Reyes, Miguel; Herrera-Murillo, Jorge; Santiago-De La Rosa, Naxieli; Gutiérrez-Arzaluz, Mirella; Figueroa-Lara, José de Jesús; González-Cardoso, Griselda
La quema a cielo abierto de la caña de azúcar (Saccharum officinarum) tiene un gran impacto en la contaminación atmosférica regional y el cambio climático global. En esta investigación se midieron las emisiones contaminantes de la quema de residuos de caña de azúcar con el fin de determinar los factores de emisión (FEs) de carbono elemental (EC), carbono orgánico (OC), 18 hidrocarburos aromáticos policíclicos (HAPs), K, Na, Ca, Mg, NO3−ASÍ QUE42−NH4+, y Cl− contenido en el material particulado (PM), así como las FE de los contaminantes gaseosos, el dióxido de carbono (CO2), monóxido de carbono (CO), metano (CH4) y 37 compuestos orgánicos volátiles (COV). Los experimentos se llevaron a cabo en una cámara de combustión abierta equipada con muestreo isocinético, siguiendo los métodos EPA 5 y EPA 201-A modificado. Las pruebas preliminares mostraron que la alimentación continua de residuos no representa la quema a cielo abierto que se realiza en el campo, ya que se mantiene la etapa de flameado, por lo que se utilizó la alimentación por lotes de residuos para realizar alrededor de 30 experimentos. Los FE de contaminantes gaseosos fueron 1618 ± 108, 25,7 ± 2,04 y 2,29 ± 0,13 g kg−1 para CO2, CO y CH4 respectivamente, mientras que C2 Los compuestos tienen la mayor FE de COV. PM10 y PM2.5 representaron el 55% y el 36% de la masa total de PM, mientras que las especies carbonáceas (EC y OC) representaron el 66% de las PM2.5 y 58% en PM10 y la masa total de PM. Los factores de emisión de CE variaron de 0,34 a 0,37 g kg−1y la FE de CO fueron de 0,44, 0,67 y 1,2 g kg−1 para PM2.5PM10 y PM total, respectivamente. Los FE más altos de los elementos y aniones determinados fueron K y Cl−respectivamente. Los HAP pesados como el benzo[b]fluoranteno, el bezo[k]fluranteno y el benzo[a]pireno presentaron las mayores FE con 0,265 ± 0,04, 0,264 ± 0,08 y 0,254 ± 0,015 mg kg−1 respectivamente. Las pruebas de Kruskal Wallis indicaron que las FE no presentaron diferencias significativas entre las variedades de caña de azúcar cosechadas en sitios con diferentes altitudes y clima, por lo que pueden ser aplicadas para estimaciones de inventarios en regiones del mundo similares a México, así como en modelos de pronóstico de calidad del aire y modelos climáticos que permiten un mejor conocimiento de los escenarios de contaminación atmosférica y cambio climático. Los resultados de esta investigación pueden ser la base para diseñar y establecer políticas públicas con el fin de regular y eventualmente eliminar las prácticas de quema de caña de azúcar antes y después de la cosecha.

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