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Environmental Sciences |
Arce, Jeannette; Gilbes, Fernando. Geology Department, UPR-Mayagüez.
Remote sensing of coral reefs in Southwestern Puerto Rico
Benthic habitats were characterized in southwestern Puerto Rico using remote sensing techniques. We used IKONOS and Hyperion imagery in order to compare spatial and spectral resolutions. Coral reef, mangrove, seagrass, and sand were detected by using supervised and unsupervised classifications with ENVI. IKONOS proved to have the most appropriate spatial resolution (1 m) for our study site, but it was very limited in spectral information (4 bands). This sensor also showed problems with the atmospheric corrections, which introduced errors in the calibration procedure. The high spectral resolution (220 bands) of Hyperion demonstrated to be excellent for our study area. This sensor provided us with a better atmospheric correction and better calibration. However, its spatial resolution (30 m) presented a limitation for an accurate classification of our benthic habitats. Image classifications were compared with field data in order to evaluate the processing performance. Based on our preliminary analyses the most appropriate remote sensing technique for benthic habitats classification in the southwestern Puerto Rico is merging the data of these two sensors.
Burgos-Caraballo, Sofía; Noraida Martinez-Rivera; Emarie Ayala-Diaz. Department of Biology, UPR Humacao.
Estudio descriptivo de la Laguna Tortuguero
La Laguna Totuguero es la laguna de agua dulce más grande de Puerto Rico. Esta se mantiene similar a sus condiciones naturales, excepto por un canal artificial que regula su tamaño. Investigaciones previas sugieren altas concentraciones de nutrientes en la laguna que podrían llevar a la posible eutroficación. Nuestro objetivo fue investigar si estas condiciones aún prevalecen. Se tomaron muestras de agua para realizar pruebas de NO3, NO2, NH3 y PO4, clorofila, fitoplancton y zooplancton. Utilizamos el método Winkler para medir productividad primaria y el Hidrolab para análisis físicos. Las aguas son claras y la visibilidad es hasta el fondo, aunque se observaron plantas acuáticas que podrían impedir la penetración de luz hasta el fondo. La salinidad muestra una laguna oligohalina y la columna de agua es mezclada. La penetrancia de luz y el oxígeno disuelto nos sugieren que la mayor biomasa de fototrofos se encuentran en las capas superficiales del sedimento. La productividad primaria y la clorofila indican baja actividad metabólica por organismos fotosintéticos. La concentración de oxígeno disuelto en la laguna está cerca de los niveles de saturación. La posible eutroficación del sistema sugerida no fue evidenciada por los datos obtenidos en este viaje. Aún así no se descarta que exista una eutroficación puntual. En uno de los brazos de la laguna se percibió olores fuertes y el color del agua no era homogéneo en comparación con el resto. Se continúan haciendo estudios a largo plazo para ver si estas condiciones de eutroficación prevalecen.
Chiques, Gretchen; Gilbes, Fernando; Department of Geology, UPR-Mayagüez.
Spectral characterization of sandy beaches
Sand sediment composition provides important clues about the location of origin of the individual. Previous work in beaches has determined sand sediment composition, profiles of the beach and sediment transport, but few of them had used remote sensing Sand sediment in four beaches in the west of Puerto Rico were analyze to determine how the characteristically feature of the sand can be observed using remote sensing. Cameron in 2003 took reflectance measurement if the field using the spectroradiometer GER 1500 and related to sand composition. This data was used a compared with satellite image. IKONOS satellite image with spatial resolution of 1m pixel was use to compare the values with the GER 1500. Band ratio technique from GER 1500 and IKONOS was use to relate field data to satellite image. Relation between the field data and the images was establish.
Colón, Marilé; Soto-García, Lydia L.; Mayol-Bracero, Olga L. Chemistry Department & Institute for Tropical Ecosystem Studies, University of Puerto Rico, Rio Piedras
Size-resolved concentrations of carbonaceous aerosol in marine and urban sites in the island of Puerto Rico
Carbonaceous aerosols, composed mainly of organic (OC) and elemental carbon (EC), comprise a significant fraction of the submicron aerosol mass. These aerosols may play a significant role in radiative forcing, affecting the extinction of solar radiation and thus having an influence on climate. EC has also been associated with health problems. As part of this project, we collected samples in urban and marine sites in the island of Puerto Rico. A Dekati low-pressure impactor (DLPI) with 13 stages was used to collect size-segregated particles with diameters in the range of 0.03 to 10 m using quartz filters (volume sampled ca. 19 m3). Stacked-Filter Units (SFUs) were used parallel to the DLPI to collect particles with diameters < 1.0 µm (volume sampled ca. 33 m3). We will present results for urban and marine sites, including the size-resolved mass concentrations of TC, OC, EC, water-soluble organic carbon, and the differences between day and nighttime samples. Preliminary, the urban site had average total concentrations of 6.2 µg/m3 for TC with an EC/TC ratio of 0.11, and average fine mode (Dp < 1 µm) concentrations of 4.0 µg/m3 for TC with an EC/TC ratio of 0.18. EC was absent at the marine site. The TC concentrations were equivalent to those for OC, being on average 1.3 µg/m3 for the total aerosol mass and 0.8 µg/m3 for the fine fraction. This suggests that most of the aerosol OC (about 60%) is fine aerosol that might come from secondary production.
Galarza, Karylin. Departamento de Ciencias Ambientales, PUCPR - Infante, Gabriel A. Departamento de Química, Pontificia Universidad Católica de Puerto Rico.
Análisis de metales pesados en las aguas subterráneas circundantes a vertederos de desperdicios sólidos del suroeste de Puerto Rico (Hormigueros y Yauco)
Utilizando la técnica de Espectroscopía de Emisión de Plasma Acoplado Inducido y el método analítico establecido por la Agencia de Protección Ambiental (EPA) se determinaron cualitativa y cuantitativamente los metales: Li, Na, K, Ca, Mg, Ba, Fe, Mn, Pb, V y Zn en las aguas subterráneas circundantes a los vertederos de desperdicios sólidos en las municipalidades de Hormigueros y Yauco en Puerto Rico. Las determinaciones de estos metales se realizarón a dos largos de ondas diferentes para limitar posibles interferencias. Las concentraciones de algunos de estos metales, especialmente Fe, Mn y Zn sobrepasaron los límites establecidos por las agencias reguladoras. Se discutirá la implicación de estos resultados en la contaminación ambiental de los acuíferos de la región suroeste de Puerto Rico.
Hernandez, Hector; Roubert Rivera, Mayra; Hernandez, Hector; Feliciano, Abdul; Ortiz, Nancy. Biologia, Universidad Católica de Ponce.
El impacto de las polleras en las concentraciones de nitratos en el suelo y el agua del sector El Húcar en Salinas, Puerto Rico
Durante el periodo de agosto de 2002 hasta el presente, se ha estado realizando un estudio descriptivo, cuyo objetivo pretende relacionar el manejo de la gallinaza en las fincas avícolas de Salinas, Puerto Rico, con las concentraciones de nitratos en los suelos y en el agua subterránea de dicho municipio. Es de conocimiento público que la presencia de altas concentraciones de nitratos en las aguas constituyen un gran riesgo para la salud humana, ya que estas altas concentraciones pueden causar enfermedades gastrointestinales y ocasionar el Síndrome del Bebé Azul o Bebé Cianótico. Los resultados obtenidos de esta área se compararán versus las concentraciones de otras dos áreas, cuenca arriba y cuenca abajo del área de investigación. En cada finca se identificaron los ranchos de pollos parrilleros que tienen cada una de las mismas y se tomaron muestras de suelo alrededor de cada estructura, así como de los pozos sépticos, pozos de agua potable, quebradas, pozos de enterramiento de pollos, hortalizas y demás cultivos de frutos menores. Las concentraciones de nitratos preliminares obtenidos en el suelo de las fincas avícolas hasta el momento reflejan valores promedios desde un mínimo de 4 mg/l hasta un máximo de 260 mg/l. Sin embargo la finca control, el Albergue Olímpico, refleja concentraciones promedio desde un mínimo de 4 mg/l hasta un máximo de 20 mg/l. La relación entre estos valores de nitratos obtenidos en el suelo, el agua y el manejo de la gallinaza aún está en proceso de recolección de datos.
Hernandez, Shamayla; Gonzalez, Susimar. Departamento de Quimica e Instituto para el Estudio de Ecosistema Tropicales, UPR-Río Piedras.
Black carbon concentrations in urban and marine sites in Puerto Rico
To understand the impact of anthropogenic aerosols in climate forcing we must first improve our knowledge of their chemical (composition) and physical (concentration, size) properties at polluted as well as background locations. Online measurements of total aerosol particle number and black carbon (BC) concentrations were performed together with the determination of mass concentrations for the carbonaceous aerosol (organic carbon, OC and elemental carbon, EC) fine fraction. Sampling locations were at an urban site in the city of Río Piedras (UPR - Facundo Bueso building) and a marine site at Las Cabezas de San Juan (CSJ, Fajardo). Particle number concentrations were measured with a condensation particle counter and BC concentrations with an aethalometer. The OC and EC concentrations were obtained using filter samples collected with stacked-filter units (SFUs) and analyzed using a thermo/optical analyzer. Preliminary results showed averaged particle concentrations of 350 cm-3 at the marine site and over 8000 cm-3 at the urban location. BC concentrations were on average 70 ng/m3 at the marine and 275 ng/m3 at the urban location. The high BC concentrations observed in the urban site are probably mainly from the high vehicular traffic- and are representative of highly polluted environments. The low to non-detectable levels of BC at CSJ showed the suitability of this site for background studies. The high OC concentrations (~1.0 g of Carbon per m3) at the marine site, preliminary obtained from the analysis of some SFUs samples, together with the lack of anthropogenic sources as shown by the low levels of BC, suggested that the ocean was the source of this OC aerosol. EC and OC detailed results from the analysis of the SFUs will be presented at the meeting.
López, Mariela. Biología, UPR-Arecibo - Alonso, José. Observatorio Radiotelescopio de Arecibo – Ramos, Maiella. Física y Química, UPR-Arecibo – Arbelo, José; Román, Yadira; Mercado, Xiomara, Sánchez, Sureliz. Biología, UPR-Arecibo – Méndez, Nancy, Acevedo, Glamil; Rodríguez, Marilyn. Física-Química, UPR-Arecibo.
Proyecto para la diversidad de las Geociencias en Arecibo
En un esfuerzo para atender la necesidad de aumentar el número de profesionales en las geociencias, el Observatorio de Arecibo y la Universidad de Puerto Rico en Arecibo (UPRA), han establecido el proyecto “Arecibo Geoscience Diversity Program”. Este es auspiciado por la Fundación Nacional de las Ciencias (NSF) por un periodo de tres años. Las geociencias, o “Ciencias de la Tierra”, incluyen la geología, la meteorología y la oceanografía, entre otros. El programa proveerá a un grupo de maestros y estudiantes de escuela superior que comprenden la región educativa de Arecibo, y a estudiantes subgraduados de la UPRA una oportunidad de investigación en las ciencias atmosféricas y ambientales, utilizando el radio telescopio de Arecibo y los laboratorios de investigación en la UPRA. El estudio de la atmósfera se llevará a cabo en el Observatorio de Arecibo. Los participantes estudiarán las variaciones en la temperatura y la densidad de la ionosfera. La investigación ambiental estará enfocada en la reserva natural del Caño Tiburones, y se llevará a cabo en la UPRA. Los participantes diseñarán y desarrollarán un programa para monitorear las variables físicas y bioquímicas del estuario entre otros proyectos.
Malavé Orengo, Josué; Ríos Velázquez, C. Microbiología Industrial, Universidad de Puerto Rico, Mayagüez – Borglin, S. E.; Hazen T.C. Lawrence Berkeley National Laboratory, Berkeley, CA.
Study of microbial community structure using phospholipid fatty acid analysis (PLFA) at a chromium contaminated site
Microbial communities have always performed a crucial role in almost any type of environment. Strong evidence supports microbes being able to modify toxic metals into a more stable form. A common example is hexavalent chromium (Cr-VI), which can be reduced to non-hazardous trivalent state (Cr-III). The main focus of this study is to examine the microbial community structure in a chromium contaminated environment at Hanford, Washington. Phospholipid Fatty Acid Analysis was used as a biochemical approach to analyze the microbial community structure based on their different signature lipids biomarkers. Due to the extreme low biomass of the Hanford soil samples (<104 cells/g), various enrichment approaches were applied to increase the biomass by promoting microbial growth. Stimulation of the sediment with various electron donors increased the densities to 106 to 108 cells/g in less then 1 week. The PLFA shows that the biomass from the samples belongs mainly to bacteria, that all major groups of microbial communities are present. The PLFA analysis also showed that the original microbial community was under nutrient from the ratio of cis/trans isomers. Geobacter sp., sulfate reducers, and gram-positive bacterial species increased after the enrichments. Since the groups that increased have also been shown to reduce chromium to less toxic forms, suggesting the biostimulation may decrease mobility and toxicity of chromium in the soil at this site.
Martinez-Santiago, Ramon. Industrial Biotechnology Program, UPR-Mayagüez - Rios-Velazquez, Carlos. Biology Department, UPR-Mayagüez - Andersen, Gary; Hazen, Terry. Center of Environmental Biotechnology, Lawrence Berkeley National Laboratory.
Molecular analysis of the microbial community structure in chromium contaminated sites before and after in situ bioreduction stimulation by lactate injection
Chromium is one of the most abundant elements on the Earth’s crust. It is one of the most common contaminants because of its use in many industries. The major concern about waste containing chromium is the effects that it has on human health. Bioremediation may be the answer to reduce chromium to a less hazardous state by adding carbon source as electron donor. The main focus of this research is to analyze the microbial community structure using molecular approaches in chromium contaminated soil from Hanford, Washington, before lactate biostimulation. Soil enrichments, and small scale microcosms were used to obtain DNA from low biomass samples. 16S rDNA amplicons using Domain and specific group primers were obtained, and T-RFLP and DNA micro array technologies were used to analyze the microbial community. The molecular methods in this study demonstrated the low biomass content of the samples, the non-complex community structure, and the dominance of members of the Proteobacteria and gram-positive bacterial divisions. Geobacter and Desulfovibio were two of the metal-reducers found in both the enrichments and small scale microcosms.
Mendoza, Annette; Hernandez, Gisela. Biology Department, UPR-Rio Piedras.
Constructed wetlands
Mercado García, Benjamín; Román, Lorainne; Arbelo, José. Biology, UPR-Arecibo - Ramos, Maiella. Physics and Chemistry, UPR-Arecibo.
Tolerance studies of the rhizobacteria Bacillus cereus and Paenibacillus alvei isolated from the aquatic plant water hyacinth in culture media with heavy metals
Two bacteria Bacillus cereus and Paenibacillus alvei, isolated from the rhizosphere of the water hyacinth aquatic plant, have been studied for tolerance to heavy metals including copper, chromium, cobalt and niquel. These microorganism were exposed separately to each element at concentrations ranging from 10 ppm to 100 ppm. It was found that P.alvei showed resistance to copper, cobalt, chromium and niquel at concentration less than 50 ppm. The bacteria B.cereus showed resistance to copper and cobalt at concentration less than 50 ppm but showed showed resistance to chromium and niquel at concentration higher than 50 ppm. B.cereus and P.alvei were exposed to higher metal concentration, the motility was significantly affected in both bacteria. Future research work includes studies on the capacity of these rhizobacteria to uptake heavy metals.
Millian, Jose; Acosta, Jaime; Mendoza, Nelson. Biology Department, UPR-Mayagüez.
Determination of the physical and chemical parameters of Rio Yagüez in Mayagüez.
The study was performed at a selected site of the Rio Yagüez in Mayagüez. The main purpose of the study was to measure the Physical and Chemicals factors of the water and use it to assess the quality of the river water. The sample site was divided in three areas and measures were made once a week. The experiment was conducted in July, October and November. Measures were taken at the site and some samples were taken to the laboratory for further analysis. The data was compare with the standards use by the Junta de Calidad Ambiental (JCA) of Puerto Rico. Water temperature range from 24 to 26 degrees; dissolve oxygen (DO) range from 6 to 8, PH range from 6 to 8 during the study. Our finding reflects that the parameters under study were always in the range selected by the JCA, and indicated that the water quality of the river was adequate to support aquatic organisms.
Morales, Lissette; Febres, Lizbell; Galanes, Ileana. Biología, UPR Río Piedras - Thomlinson, John. Institute for Tropical Ecosystems Studies, UPR Río Piedras.
El impacto de la fragmentación de bosques tropicales húmedos en la diversidad de milípedos terrestres, en el noreste de Puerto Rico
El crecimiento desmedido de la población humana y el aumento en el uso de la tierra, han causado cambios considerables en los ecosistemas. Debido a que los bosques tropicales poseen la mayor riqueza de especies en el planeta, la destrucción de éstos ha sido la principal causante de la disminución de la biodiversidad. En el noreste de Puerto Rico, la fragmentación de bosques ha sido causada principalmente por el desparrame urbano. El conocer los efectos biológicos y físicos de esta fragmentación, es fundamental para prevenir la pérdida de especies en el futuro. En este proyecto se estudiará el impacto de la fragmentación de los bosques en los milípedos del suelo, debido a que éstos juegan un rol esencial en la descomposición de la hojarasca y en el ciclo de nutrientes. Para estudiar las características espaciales de los parches de bosque seleccionados, se utilizaron fotografías aéreas del 2000. Estas fueron digitalizadas a SIG. Las muestras de milípedos se tomaron en un cuadrado de 0.45 m2, en seis puntos a través de un transecto de 2 x 50m localizado en el interior y en el borde de 5 parches de bosque. Se encontró que la biodiversidad fue parecida (5-6 especies) en todos los parches. Sin embargo, la abundancia de individuos dio mayor en el parche de mayor número de especies de plantas exóticas como el Tulipán africano. Además, en la mayoría de los parches hubo una mayor abundancia de individuos en el interior comparada con el borde. Es necesario recopilar una mayor cantidad de datos para llegar a unas generalizaciones sobre aquellas variables que están afectando la diversidad y abundancia de los milípedos.
Padilla, Elizabeth. Industrial Biotechnology, UPR-Mayagüez - Vacca, Dominic; Hickey, William. Department of Soil Science, University of Wisconsin-Madison.
Diversity of Burkholderia polycyclic aromatic hydrocarbons (PAH) degradation genes
A limiting factor in bioremediation of hydrophobic organics pollutants, like polycyclic aromatic hydrocarbons (PAH), found in soil is whether the pollutant is biovailable. By studying the PAH catabolic genes we may be able to assess whether differences in respective PAH metabolism play a role in accessing these PAHs of low bioavailability or whether other microbial characteristics are more important. Previously described specific primers targeting the naphthalene dioxygenase (NDO) encoding genes like the nahAaAb gene in P.putida, phnAc of Burkholderia and degenerate primers targeting a range of NDO sequences were used. All Burkholderia sp. strains showed a high identity (from 95-98%) to phnAc from Alcaligenes faecalis. The strain Eh2-1 was divergent in that identity of PCR product from the degenerate primers was unique and a second dioxygenase was observed. Amplified PCR product from the degenerate primers for strain Eh2-1 showed a high identity to pahAc from Comamonas testosteroni and the PCR product from the specific primers shared a high homology to phnAc from Burkholderia sp. strain RP007. These two PCR products were only 44% identical to each other, indicating that strain Eh2-1 has at least 2 copies of dioxygenases, which are potentially involved in PAH degradation. The fact that the phn dioxygenase gene of all strains had a very high identity with the non-mineralizing strain Cs1-4 seems to imply that the dioxygenase activity is probably not the primary factor affecting the degradation and mineralization of sorbed PAH. These results substantiate the notion that initial catabolism is not rate limiting and that mechanisms of access to sorbed compounds are more important.
Pantoja, Carlos G.; Arbelo, José. Department of Biology, University of Puerto Rico in Arecibo - Ramos, Maiella; Cruz, Solimar. Department of Physics-Chemistry, University of Puerto Rico in Arecibo - Mercado, Benjamín. Department of Biology, University of Puerto Rico in Arecibo.
Uptake of copper, iron and chromium by the non living biomass of water hyacinth
The uptake of heavy metals by the biomass of non living leaves of water hyacinth (Eichhornia crassipes) was investigated under field conditions. Experiments were conducted in the Zanja Fría sampling station from the Caño Tiburones wetland. Leaf litter samples from water hyacinth plants were distributed randomly in a homogeneous zone. Three pairs of bags were retrieved at different predetermined intervals. Samples were analyzed for its heavy metals content by means of a flame atomic absortion spectrometer. Results showed that the non living leaves of water hyacinth were excelent biosorbents for chromium. The percentage dry mass of hyacinth leaf litter remaining exhibit a decay pattern. Metal levels in the litter samples were much higher than in surface water. The findings out of this project are expected to provide an answer or the understanding of the mechanisms of its metal transport due to absortion processes.
Rios, Julio D.; Rosado, Marielys; Caceres, Keyla E.; Ersan Said, Sufyan; Acevedo, Abdiel; Cordero-Orona, Moises; Valentín, Lenyshka; Velázquez, Jessica; Castro, Chavely; Galarza, Aureo. Departamento de Ciencias Naturales, UPR Aguadilla.
Uso de las cepas de Escherichia coli ATCC 700891 y Escherichia coli ATCC 15597 como receptores de colifagos en el canal de la playa de “Crash Boat” en Aguadilla, Puerto Rico
Debido a la probabilidad del riesgo de que patogenos de origen bacteriano puedan estar presentes, existen varios indicadores biologicos utilizados para determinar la contaminacion fecal en los cuerpos de agua. La tecnica del uso de colifagos es utilizada como uno de estos indicadores. Se utilizaron las cepas de E. coli ATCC 700891 y E. coli ATCC 15597 como receptores de colifagos presentes en las aguas del Canal de la Playa Crash Boat. Se realizaron pruebas de el Numero mas probable (MPN), determinacion de parametros fisicos y quimicos. En el primer muestreo, la receptividad de la cepa de E.coli ATCC 700891 fue de 3.7 X 1010 PFU/100ml, mientras que de E.coli ATCC 15597 fue de 1.55 X 107 PFU/100ml. En el segundo muestreo la receptividad de E.coli ATCC 700891 fue de 6.8 X 1010 PFU /100 ml , mientras la cepa de E. coli ATCC 15597 fue de 2.1X 106 PFU/ 100ml. Aunque ambas cepas de E. coli demostraron ser capaces de ser receptores de colifagos, la cepa de E.coli ATCC 700891 demostro poseer mayor sensitividad para la prueba. La prueba de MPN utilizada no fue suficiente para poder determinar la cantidad de coliformes por lo que se recomienda aumentar las diluciones para la prueba.
Rodriguez Guzman, Vilmaliz; Tremblay, Raymond; Diaz, Ariel. Department of Biology, University of Puerto Rico, Humacao.
Flying insects associated with the orchid Lepanthes sp. in El Verde, Puerto Rico
We examined the flying insect community associated with the orchid Lepanthes sp. in El Verde, Puerto Rico. Sticky traps, made with 3 x 5 in. styrofoam and coated with Tanglefoot, were used to sample insects every 2-3 weeks from March to November 2003. Traps were placed near Lepanthes populations, and were left on the field for 48 hr. All insects collected were identified to the family level. The insect community associated with Lepanthes is very diverse, and includes members of the insect orders Collembola (2 families), Hymenoptera (5 families), Diptera (7 families), Lepidoptera (2 families), Coleoptera (3 families) among others. Other arthropod groups (i.e. Acarina, Araneae) appeared in the samples occasionally. Dipterans of the families Mycetophilidae, Drosophilidae and Culicidae were the most abundant species. Examination of specimens collected did not reveal the presence of Lepanthes pollinaria, suggesting that none of these species is acting as a pollinator of this orchid.
Rosa, Bayrex; Fernández, Denny S. Biology Department, UPR Humacao.
Variación en la estructura espacial de un manglar
Los manglares en Puerto Rico han experimentado diversas presiones debido a desarrollos urbanos, industriales y agrícolas, especialmente en los llanos costeros al sur de la isla. En adición huracanes recientes han afectado el área causando daños a estos bosques. Estudios de heterogeneidad espacial y variación temporal a largo plazo son importantes para analizar el comportamiento del bosque y la posible implementación de prácticas de manejo en la zona. El bosque de Aguirre es un manglar pantanoso localizado al sur de la isla y en el cual predomina la especie Avicennia germinans. La variabilidad espacial y temporal de este bosque esta siendo estudiada en una cuadrícula de 24,900 metros cuadrados con 45 puntos de referencia, uno cada 30 metros. En los puntos de referencia se toman fotografías hemisféricas utilizando un lente ojo de pez, para determinar el índice de cobertura foliar (LAI), los factores de luz directa (DSF) e indirecta (ISF) y otros parámetros de la comunidad relacionados con su estructura, tales como la cobertura, densidad de árboles, árboles muertos, diámetro de los árboles y altura máxima de la vegetación. El valor promedio del LAI es de .903, .536 ISF y .623 DSF. Se presentarán los análisis de semivarianza, autocorrelación espacial (MORAN I) y los patrones espaciales de los parámetros antes mencionados. [Este trabajo ha sido financiado por el programa FOPI – UPR-Humacao y PR-LSAMP]
Rosas Rodriguez, Keysa G; Santos-Flores, Carlos J.; Navarro, Santo. Department of Biology, UPR-Mayagüez - Sotomayor, David. Department of Agronomy and Soil Sciences, UPR-Mayagüez.
Aquatic insects within the Río Añasco watershed and their possible use as bioindicators of stream water quality
The aquatic insects in the streams of Puerto Rico have been studied only sporadically. With the exception of several streams within the El Verde LTER Field station in the northeastern part of Puerto Rico, little is known about the limnology and biodiversity of our streams. Five tributaries of Río Añasco were surveyed for aquatic insects as part of an ongoing project on water quality at the watershed scale. Three sampling stations were demarked along each stream, and 3 samples were collected within each station using a Surber sampler. The aquatic insects were sorted, fixed in 70% alcohol, and identified at least to family-level. Species richness and abundances will be correlated with limnological parameters, such as: nutrient concentrations (TN and TP), dissolved oxygen (mg/L), pH of water, chlorophyll-a concentration (mg/L), fecal coliforms (CFU/mL). Our ultimate goal is to evaluate the aquatic insects as possible bioindicators of stream water quality.
Ruiz, Jessica; Vargas, Maria; Alfaro, Monica. Biology, UPR-Mayagüez.
Halotolerant arenicolous fungi in coastlines of Mayagüez Bay, Mayagüez, Puerto Rico
Fungi are known to be present in the marine environment, since the discovery of first fungus in a marine habitat by Durieu and Montagne in 1846. As many other microorganisms in marine environment, they represent an ecological balance in the degradation of organic compounds (Eriksson, 1997). Our investigations have demonstrated that geofungi grow and develop successfully at marine conditions as halotolerant. The sand and environmental conditions are essential for fungi growth and development. In Mayagüez Bay; Mayagüez, Puerto Rico, the ecological conditions have been contaminated by commerce, tourism, maritime activities, and pollution. This study involves a comprehensive sampling effort to identify and classify halotolerant arenicolous fungi (geofungi) in Mayagüez Bay, using sampling protocols. The primary goal of this study is to provide a better understanding of the fungi that is present between the sand grains at certain conditions during the months of January -December 2003, and may be considered as halotolerant. It has been found significant difference in species variation among the sampling stations at Mayagüez Bay coastlines. El Seco have been the station that reported the larger amount if species, in comparison with the stations of Guanajibo and El Maní. The identification of the fungi in this research may help to establish a record of the organisms that are present in a specific habitat and to relate their abundance with ecological problems.
Santiago-Torres, Priscila. Chemistry Department, Pontificia Universidad Católica de Puerto Rico - Suárez, Edu B.; Montealegre, Federico. Microbiology Department, Ponce School of Medicine.
Molecular identification of the pathogenic Aspergillus species in collected dust samples from asthmatic patients’ homes in Ponce, Puerto Rico
Allergic diseases such as asthma, atopic dermatitis and rhinitis have been extensively related with molds. The Aspergillus species are one of the most studied fungi in this field, due to its pathogenicity. The allergic response is promoted by their antigenic proteins (allergens) or by the inhalation of their spores. These spores are usually identified by microscopy, but the lack of technical expertise or experience may influence the identification. As well, the ELISA test, which is an immunoassay based on antigen-antibody reaction, is limited by the integrity and amount of the proteins and by the availability of monoclonal antibodies against the fungal allergens. In this project we are proposing the use of DNA, molecular probes and PCR techniques to detect Aspergillus’ pathogenic species (A. fumigatus, A. niger, A. flavus, A. nidulans and A. terreus) in dust samples collected from 100 asthmatic patient’s homes in Ponce, P.R. We will compare the positive and negative PCR reactions to A. fumigatus with the antigenic reaction to Asp f -1 by ELISA. We hypothesized that the PCR method will provide a more sensitive and reliable detection tool to the identification of these molds in indoor dust samples. We will also search for a correlation between the presence of Aspergillus species and the clinical manifestations in asthmatic patients. Acknowledgement: This investigation was supported by NIH RLK NRSA GM07732 from the Pontificia Universidad Católica de Puerto Rico, MARC U*STAR Honor Program.
Stolberg, Stephanie; Vazquez, Sujei; Galanes, Ileana. Biología, UPR Río Piedras - Thomlinson, John. Institute for Tropical Ecosystems Studies, UPR Río Piedras.
Relación entre la estructura espacial de parches de bosques tropicales y la diversidad de plantas leñosas en el noreste de Puerto Rico
El crecimiento poblacional humano desmedido y el aumento en el uso de tierras han causado cambios considerables en los ecosistemas. Esto ha ocasionado una reducción en la biodiversidad del planeta, incluyendo las regiones tropicales, las cuales poseen la mayor riqueza de especies de la Tierra. En la zona noreste de Puerto Rico, la fragmentación de los bosques tropicales ha sido causada principalmente por el desarrollo urbano y la agricultura. El entendimiento de los efectos biológicos y físicos ocasionados por esta fragmentación es fundamental para prevenir la futura pérdida de especies. Estudios previos han revelado que el aumento en el tamaño, conectividad y la calidad de parches de bosques pueden aumentar la viabilidad de muchas especies. Este proyecto estudiará la relación que existe entre las características espaciales de parches de bosques tropicales y la diversidad de especies de plantas leñosas. Los datos para estudiar la configuración espacial del lugar seleccionado fueron obtenidos a través de fotografías aéreas del año 2000. Éstas fueron digitalizadas utilizando SIG. La composición de las especies de plantas leñosas de 5 parches de bosques, se determinó por una medición florística sistemática. Se encontró que los parches de mayor tamaño (33 ha) poseen una mayor riqueza de especies que los parches de menor tamaño (7-11 ha). También, se encontró que el borde del bosque contiene menos riqueza de especies que el interior del mismo. Para poder determinar otras variables espaciales, además del tamaño, que están afectando la biodiversidad de estos bosques, es necesario continuar con el muestreo de un mayor número de parches. Estos resultados serán de gran utilidad para el manejo y conservación de estos bosques.
Vega Sepulveda, Juan A.; Rios Velazquez Carlos. Departamento de Biologia, Universidad de Puerto Rico, Recinto Universitario de Mayagüez.
Presencia de bacterias fototroficas anoxigonicas purpuras no sulfurosas en la fitotelmata de bromelias en diversos bosques de Puerto Rico
Las bromelias son plantas de la familia Bromeliaceae que forman con sus hojas una estructura llamada axila. Las mismas permiten la recoleccion de agua de lluvia, creando un microhabitat acuatico conocido como fitotelmata en la cual se han encontrado diversos organismos como copepodos, diatomeas, rotiferos, larvas de insectos, algas y bacterias. Este estudio tiene como proposito determinar la presencia de bacterias fotosinteticas, especificamente bacterias purpuras no sulfurosas, en las axilas de bromelias en diversos bosques de Puerto Rico. Este grupo de ¦Á-proteobacterias se caracteriza por su versatilidad fisiologica, ya que pueden crecer por respiracion aerobica y anaerobica, ademas de ser organismos fotosinteticos anoxigonicos. Medios selectivos y enriquecidos para bacterias purpuras no sulfurosas y tecnicas generales de microbiologia se utilizaron para el aislamiento y caracterizacion inicial de las mismas. Todas las muestras analizadas mostraron la presencia de bacterias con caracteristicas de crecimiento similares a las bacterias fototroficas purpuras no sulfurosas. Hasta el momento hemos aislado nueve candidatos siendo estos bacilos gram-negativos. Microscopia electronica de rastreo y tecnicas moleculares se han aplicando para la identificacion de las bacterias encontradas obteniendo resultados en proceso de analisis caracterizacion.