Variation in mangrove forest structure and sediment characteristics in Bocas del Toro, Panama

Mangrove forest structure and sediment characteristics were examined in the extensive mangroves of Bocas del Toro, Republic of Panama. Forest structure was characterized to determine if spatial vegetation patterns were repeated over the Bocas del Toro landscape. Using a series of permanent plots and transects we found that the forests of Bocas del Toro were dominated by Rhizophora maugle with very few individuals of Avicennia germinans and Laguncularia racemosa. Despite this low species diversity, there was large variation in forest structure and in edaphic conditions (salinity, concentration of available phosphorus, Eh and sulphide concentration). Aboveground biomass varied 20-fold, from 6.8 Mg ha(-1) in dwarf forests to 194.3 Mg ha(-1) in the forests fringing the land. But variation in forest structure was predictable across the intertidal zone. There was a strong tree height gradient from seaward fringe (mean tree height 3.9 m), decreasing in stature in the interior dwarf forests (mean tree height 0.7 m), and increasing in stature in forests adjacent to the terrestrial forest (mean tree height 4.1 m). The predictable variation in forest structure emerges due to the complex interactions among edaphic and plant factors. Identifying predictable patterns in forest structure will aid in scaling up the ecosystem services provided by mangrove forests in coastal landscapes.

A Site Description of the CARICOMP Mangrove, Seagrass and Coral Reef Sites in Bocas del Toro, Panama

Bocas del Toro is located in the western region of the Republic of Panama. It is part of a province of approximately 8917 km(2) with an estimated 68% of its area covered by tropical rainforest. The area receives 2870 mm/year of rainfall. The dry and rainy seasons are not clearly defined. There are two periods each of low and high rainfall, March and September-October, and July and December, respectively. Mangrove forests, seagrass meadows and coral reefs are vast, covering large areas in the shallow waters surrounding the islands of the archipelago and along the mainland coast. The CARICOMP sites were established in 1998-99 and are periodically monitored following Level I protocol. Herein we describe the sites in a regional context and present the baseline data for each site. This paper fulfills the requirements of the formal site description for CARICOMP monitoring sites.

Estudio del entorno del centro: riberas del Torío y del Curueño : naturaleza, historia, arte, lengua, a través de las tecnologías de la información y comunicación y del periódico.

Proyecto desarrollado en el instituto de educación secundaria Ordoño II de León, en él han participado trece profesores del centro. Los objetivosplanteados son: dar a conocer el entorno del centro y su realidad educativa, elaborando materiales curriculares para los diferentes tipos de alumnado, potenciando el uso de las tecnologías de la información y la comunicación y del periódico en el aula. Se han trabajado en diferentes fases: planificación, formación, investigación, trabajo de campo y en grupo, elaboración de materiales y aplicación de los mismos en el aula. Por último, se ha evaluado el trabajo para solventar posibles errores y ver su adecuación al proceso enseñanza-aprendizaje. Considerandose que, una vez realizada la evaluación, el trabajo en general es satisfactorio puesto que se ha conseguido favorecer el aprendizaje de los alumnos y fomentar el trabajo en equipo. Los materiales elaborados son: página Web, montajes audiovisuales sobre el entorno del centro y la villa romana de Navajetera, películas sobre la Vía Bardaya en Matallana de Torío y el Día del Libro, montaje sobre la visita a distintas exposiciones pictóricas. Para la elaboración de los anteriores materiales se han realizado distintas excursiones para obtener información para elaborar los vídeos y tomar fotografías de los lugares en sus distintos aspectos. Los participantes han recibido formación sobre los programas informáticos utilizados para realizar los montajes, impartida por algunos miembros del proyecto con conocimientos más avanzados. Trabajo no publicado.

Análisis geográfico comparativo de cinco comarcas leonesas (II) : Bierzo Bajo, Babia, Valle del Torío, Tierras de la Bañeza y Picos de Europa.

Proyecto realizado por un profesora del IES 'Ornia' de La Bañeza (león). Tiene como objetivos: acercar al estudiante de bachillerato al trabajo cotidiano de un geógrafo como analista y ordenador del territorio, para lo cual elaboran una serie de fichas en las que aplicar los contenidos teóricos de la ciencia geográfica a diferentes situaciones de la realidad de Castilla y León. Los ejercicios propuestos van encaminados al análisis individual de cada una de las áreas desde los puntos de vista físico, demográfico y económico. La metodología utilizada fue la siguiente: - estudio previo de información cartográfica y documental - selección de materiales -trabajo de campo - recopilación y tratamientode la información - corrección de errores detectados - redacción definitiva. El resultado final es un dossier de material práctico de geografía aplicándose los contenidos de la materia a espacios concretos de la provincia de León. No está publicado..

Los encierros de Villanueva del Pardillo, la cultura del toro.

Se desarrolla una experiencia de apertura de la escuela a la vida social del pueblo por medio de las fiestas del patrón. Los objetivos son: conocer las tradiciones del propio pueblo y su evolución, conocer y comprender la acción solidaria que conlleva la realización de unas fiestas tradicionales, y fomentar el espíritu de investigación a través de lo cotidiano. Los temas tratados son: los encierros de Villanueva del Pardillo, las actividades paralelas a los encierros: fiesta religiosa, otras fiestas o manifestaciones vigentes o desaparecidas, y el toro como protagonista de las fiestas. Los trabajos y reportajes gráficos y sonoros componen una exposición titulada 'Los encierros en Villanueva del Pardillo'. La evaluación se realiza por medio de los materiales elaborados por el alumnado, la opinión de autoridades y personas de la comunidad, y la autoevaluación del alumnado.

Disertacion de las aguas minerales en gral., y en especial del agua mineral de la Fuente del Toro /

Mode of access: Internet.

Tratado del ganado vacuno : en el cual se describen las cualidades del toro y de la vaca destinados para la ...

Mode of access: Internet.

[¿Cuáles son los caracteres diferenciales de la monomanía y de la pasión?] : discurso leído en la Universidad Central por el Licenciado en Medicina y Cirugía D. Calletano del Toro y Quartiellers, en el acto solemne de recibir la investidura de Doctor en la misma facultad.

Mode of access: Internet.

Memoria de las aguas minerales en general y en particular de las de la villa del Molar, provincia de Madrid, fuente llamada del Toro /

Mode of access: Internet.

Discurso sobre las aguas minerales en general,y en particular sobre las de la Fuente del Toro,en la villa del Molar /

Mode of access: Internet.

The effect of nutrient enrichment on growth, photosynthesis and hydraulic conductance of dwarf mangroves in Panama

1. Dwarf stands of the mangrove Rhizophora mangle L. are extensive in the Caribbean. We fertilized dwarf trees in Almirante Bay, Bocas del Toro Province, north-eastern Panama with nitrogen (N) and phosphorus (P) to determine (1) if growth limitations are due to nutrient deficiency; and (2) what morphological and/or physiological factors underlie nutrient limitations to growth. 2. Shoot growth was 10-fold when fertilized with P and twofold with N fertilization, indicating that stunted growth of these mangroves is partially due to nutrient deficiency. 3. Growth enhancements caused by N or P enrichment could not be attributed to increases in photosynthesis on a leaf area basis, although photosynthetic nutrient-use efficiency was improved. The most dramatic effect was on stem hydraulic conductance, which was increased sixfold by P and 2.5-fold with N enrichment. Fertilization with P enhanced leaf and stem P concentrations and reduced C : N ratio, but did not alter leaf damage by herbivores. 4. Our findings indicate that addition of N and P significantly alter tree growth and internal nutrient dynamics of mangroves at Bocas del Toro, but also that the magnitude, pattern and mechanisms of change will be differentially affected by each nutrient.

A new genus and new species of fan worms (Polychaeta: Sabellidae) from Atlantic and Pacific Oceans-the formal treatment of taxon names as explanatory hypotheses

Members of Parasabella minuta Treadwell, 1941, subsequently moved to Perkinsiana, were collected during a survey of rocky intertidal polychaetes along the state of Sao Paulo, Brazil. Additional specimens, which are referred to two new species, were also found in similar habitats from the Bocas del Toro Archipelago, Caribbean Panama, and Oahu Island, Hawaii. A phylogenetic analysis of Sabellinae, including members of P. minuta and the two new species, provided justification for establishing a new generic hypothesis, Sabellomma gen. nov., for these individuals. Formal definitions are also provided for Sabellomma minuta gen. nov., comb. nov., S. collinae gen. nov., spec. nov., and S. harrisae gen. nov., spec. nov., along with descriptions of individuals to which these hypotheses apply. The generic name Aracia nom. nov., is provided to replace Kirkia Nogueira, Lopez and Rossi, 2004, pre-occupied by a mollusk.

Effects of acute temperature increase on performance and survival of Caribbean echinoids

Climate change is occurring at a faster rate than in the past, with an expected increase of mean sea surface temperatures up to 4.8°C by the end of this century. The actual capabilities of marine invertebrates to adapt to these rapid changes has still to be understood. Adult echinoids play a crucial role in the tropical ecosystems where they live. Despite their role, few studies about the effect of temperature increase on their viability have been reported in literature. This thesis work reports a first systematic study on several Caribbean echinoids about their tolerance to temperature rise in the context of global warming. The research - carried out at the Bocas del Toro Station of the Smithsonian Tropical Research Institute, in Panama - focalized on the 6 sea urchins Lytechinus variegatus, L. williamsi, Echinometra lucunter, E. viridis, Tripneustes ventricosus and Eucidaris tribuloides, and the 2 sand dollars Clypeaster rosaceus and C. subdepressus. Mortality and neuromuscular well-being indicators - such as righting response, covering behaviour, adhesion to the substrate, spine and tube feet movements - have been analysed in the temperature range 28-38°C. The righting time RT (i.e., the time necessary for the animal to right itself completely after inversion) measured in the 6 sea urchin species, demonstrated a clearly dependence on the water temperature. The experiments allowed to determine the “thermal safety margin” (TSM) of each species. Echinometra lucunter and E. viridis resulted the most tolerant species to high temperatures with a TSM of 5.5°C, while T. ventricosus was the most vulnerable with a TSM of only 3°C. The study assessed that all the species already live at temperatures close to their upper thermal limit. Their TSMs are comparable to the predicted temperature increase by 2100. In absence of acclimatization to such temperature change, these species could experience severe die-offs, with important consequences for tropical marine ecosystems.

Evidence for selection on coloration in a Panamanian poison frog: a coalescent-based approach

Aim The strawberry poison frog, Oophaga pumilio, has undergone a remarkable radiation of colour morphs in the Bocas del Toro archipelago in Panama. This species shows extreme variation in colour and pattern between populations that have been geographically isolated for < 10,000 years. While previous research has suggested the involvement of divergent selection, to date no quantitative test has examined this hypothesis. Location Bocas del Toro archipelago, Panama. Methods We use a combination of population genetics, phylogeography and phenotypic analyses to test for divergent selection in coloration in O. pumilio. Tissue samples of 88 individuals from 15 distinct populations were collected. Using these data, we developed a gene tree using the mitochondrial DNA (mtDNA) d-loop region. Using parameters derived from our mtDNA phylogeny, we predicted the coalescence of a hypothetical nuclear gene underlying coloration. We collected spectral reflectance and body size measurements on 94 individuals from four of the populations and performed a quantitative analysis of phenotypic divergence. Results The mtDNA d-loop tree revealed considerable polyphyly across populations. Coalescent reconstructions of gene trees within population trees revealed incomplete genotypic sorting among populations. The quantitative analysis of phenotypic divergence revealed complete lineage sorting by colour, but not by body size: populations showed non-overlapping variation in spectral reflectance measures of body coloration, while variation in body size did not separate populations. Simulations of the coalescent using parameter values derived from our empirical analyses demonstrated that the level of sorting among populations seen in colour cannot reasonably be attributed to drift. Main conclusions These results imply that divergence in colour, but not body size, is occurring at a faster rate than expected under neutral processes. Our study provides the first quantitative support for the claim that strong diversifying selection underlies colour variation in the strawberry poison frog.

Sexual dimorphism and directional sexual selection on aposematic signals in a poison frog

It is commonly assumed that natural selection imposed by predators is the prevailing force driving the evolution of aposematic traits. Here, we demonstrate that aposematic signals are shaped by sexual selection as well. We evaluated sexual selection for coloration brightness in populations of the poison frog Oophaga [Dendrobates] pumilio in Panama's Bocas del Toro archipelago. We assessed female preferences for brighter males by manipulating the perceived brightness of spectrally matched males in two-way choice experiments. We found strong female preferences for bright males in two island populations and weaker or ambiguous preferences in females from mainland populations. Spectral reflectance measurements, coupled with an O. pumilio-specific visual processing model, showed that O. pumilio coloration was significantly brighter in island than in mainland morphs. In one of the island populations (Isla Solarte), males were significantly more brightly colored than females. Taken together, these results provide evidence for directional sexual selection on aposematic coloration and document sexual dimorphism in vertebrate warning coloration. Although aposematic signals have long been upheld as exemplars of natural selection, our results show that sexual selection should not be ignored in studies of aposematic evolution.