Regions Of Costa Rica Research Articles

A wood density and aboveground biomass variability assessment using pre-felling inventory data in Costa Rica

BackgroundThe high spatio-temporal variability of aboveground biomass (AGB) in tropical forests is a large source of uncertainty in forest carbon stock estimation. Due to their spatial distribution and sampling intensity, pre-felling inventories are a potential source of ground level data that could help reduce this uncertainty at larger spatial scales. Further, exploring the factors known to influence tropical forest biomass, such as wood density and large tree density, will improve our knowledge of biomass distribution across tropical regions. Here, we evaluate (1) the variability of wood density and (2) the variability of AGB across five ecosystems of Costa Rica.ResultsUsing forest management (pre-felling) inventories we found that, of the regions studied, Huetar Norte had the highest mean wood density of trees with a diameter at breast height (DBH) greater than or equal to 30 cm, 0.623 ± 0.182 g cm-3 (mean ± standard deviation). Although the greatest wood density was observed in Huetar Norte, the highest mean estimated AGB (EAGB) of trees with a DBH greater than or equal to 30 cm was observed in Osa peninsula (173.47 ± 60.23 Mg ha-1). The density of large trees explained approximately 50% of EAGB variability across the five ecosystems studied. Comparing our study's EAGB to published estimates reveals that, in the regions of Costa Rica where AGB has been previously sampled, our forest management data produced similar values.ConclusionsThis study presents the most spatially rich analysis of ground level AGB data in Costa Rica to date. Using forest management data, we found that EAGB within and among five Costa Rican ecosystems is highly variable. Combining commercial logging inventories with ecological plots will provide a more representative ground level dataset for the calibration of the models and remotely sensed data used to EAGB at regional and national scales. Additionally, because the non-protected areas of the tropics offer the greatest opportunity to reduce rates of deforestation and forest degradation, logging inventories offer a promising source of data to support mechanisms such as the United Nations REDD + (Reducing Emissions from Tropical Deforestation and Degradation) program.Electronic supplementary materialThe online version of this article (doi:10.1186/s13021-014-0009-y) contains supplementary material, which is available to authorized users.

Systematics of the Neotropical SnakeDendrophidion paucicarinatum(COPE), with a Description of its Hemipenis (Serpentes: Colubridae)

Abstract We present the first modern comprehensive systematic treatment of the Central American snake Dendrophidion paucicarinatum (Cope). We redescribe the species on the basis of a large sample from throughout its range, redescribe and illustrate the holotype, and provide a detailed treatment of its hemipenial morphology. Dendrophidion paucicarinatum is distinguished from other species of the genus by a combination of having more ventrals (>175), fewer subcaudals (<140), very weak keels on the dorsal scales, and distinct transverse dark lines across each ventral in adults. It is an upland species found almost exclusively above 1,000 m in mountainous regions of Costa Rica and western Panama, primarily in premontane and montane humid to wet forests and cloud forests. It is a large species attaining a total length of 1.5 m and is diurnal and anurophagous like other species of Dendrophidion. Known clutch sizes are 3–12. Evidence from the Monteverde region in Costa Rica suggests that populations of D. paucic...

Vector-borne pathogens in dogs from Costa Rica: First molecular description of Babesia vogeli and Hepatozoon canis infections with a high prevalence of monocytic ehrlichiosis and the manifestations of co-infection

Infection with canine vector-borne pathogens was evaluated in dogs from four different regions of Costa Rica by PCR. Demographic data, clinical signs, packed cell volume values, and the presence of tick infestation were recorded for each dog. Forty seven percent (69/146) of the dogs were infected with at least one pathogen and 12% were co-infected with two pathogens. Ehrlichia canis was detected in 34%, Anaplasma platys in 10%, Babesia vogeli in 8%, and Hepatozoon canis in 7.5% of the blood samples. No infection was detected with Leishmania spp. in blood, skin scrapings or conjunctival swabs. Thirty percent of the dogs presented at least one clinical sign compatible with vector-borne disease, and of those, 66% were infected with a pathogen. Subclinical infections were determined in 58% of the infected dogs including 82% (9/11), 58% (29/50), 42% (5/12) and 36% (5/14) of the dogs with H. canis, E. canis, B. vogeli and A. platys infections, respectively. A distinct relationship was found between infection and anemia. The mean PCV values were 34.4% in dogs with no infection, 31.5% in those who had a single infection and 23% in those with co-infection. Co-infected dogs had significantly lower PCV values compared to non-infected and single-infected dogs (p<0.0001). Thirty five percent (51/146) of the dogs were infested with ticks, 82% of them were infested with Rhipicephalus sanguineus sensu lato and 18% with Amblyomma ovale. Dogs infected with A. platys, B. vogeli, or E. canis were significantly associated with R. sanguineus s.l. infestation (p<0.029).This is the first description of infections with B. vogeli and H. canis in Costa Rica as well as in Central America. The results of this study indicate that multiple vector-borne pathogens responsible for severe diseases infect dogs in Costa Rica and therefore, increased owner and veterinarian awareness are needed. Moreover, prevention of tick infestation is recommended to decrease the threat of these diseases to the canine population.

Violencia escolar, un problema que aumenta en la escuela primaria costarricense

En este artículo se compararon los datos de investigaciones previas, sobre la presencia del matonismo escolar en muestras costarricenses, con los datos obtenidos en un estudio reciente, cuyo fin fue el de determinar si este fenómeno había aumentado en el país. Para ello se seleccionaron de forma intencional, 34 grupos de niños y niñas cuyas edades se encontraban entre los 8 y 15 años quienes cursaban estudios de tercero a sexto grado, en diferentes centros educativos, para un total de 1155 estudiantes. Una vez contabilizadas las preguntas y transformadas a porcentajes de respuestas, se compararon con los porcentajes obtenidos en estudios realizados en Costa Rica por Cabezas (2007, 2010) en grupos similares, hallándose diferencias significativas que hacen presumir que ésta es una realidad, que va en aumento en el país. This article compares previous results with those from a recent research on bullying among school children in Costa Rica to determine if this undesirable behavior had increased in the country. We selected, intentionally, 34 groups of elementary students, third through sixth grade, ages 8 through 15 years old, from different schools. The total of students participating was 1155. They were given the same survey and once the tally was converted to percentages of responses, they were compared with results obtained from previous studies done in different regions of Costa Rica by Cabezas (2007, 2010), under similar circumstances. This new results show significant differences that make us presume that bullying is a reality and is increasing in Costa Rican schools

Aislamiento e identificación de hongos nematófagos nativos de zonas arroceras de Costa Rica.

The objective of this study was to isolate and identifynematophagous fungi from rice-producing areas of CostaRica. The study was conducted between April 2008 toAugust 2009. Soil from three rice-producing regions ofCosta Rica, Central Pacifi c, Atlantic and Region HuetarChorotega were analyzed by the sprinkling plate methodin search of nematophagous fungi. The fungal isolatedwere identifi ed as Trichoderma sp., Paecilomyces sp.,Fusarium oxysporum, Fusarium tabacinum, Fusariumsp., Monacrosporium sp., Aspergillus sp., Geotrichum sp.,Phythium sp., Cladosporium, Curvularia sp., Phoma sp.,Oomycete and sterile mycelium. The results suggest a highdiversity of nematophagous fungi with potential for use asbiological control agents.

Peperitas en Costa Rica

El presente trabajo describe petrográfica y genéticamente, una serie de hallazgos de peperitas como ejem-plos de coexistencia espacial y temporal del magmatismo con la sedimentación en Costa Rica. Los casos se presentanen complejos ígneos básicos (ofiolitas) variando desde mezclas incompletas (megabloques de radiolaritas con diabasasen el Complejo de Nicoya) hasta mezclas completas en varios grados de calizas pelágicas del Maastrictiano-Paleoceno (Formación Golfito) o del Paleoceno con basaltos (Subcomplejo Quepos o Formación Tulín) para dar peperitas bre-choides y bulbosas. Dentro del arco Oligo-Mioceno, se tienen ejemplos a lo largo de la cordillera de Talamanca y susestribaciones, así como en las llanuras de Sarapiquí, representados por peperitas brechoides, fluidales y bulbosas encuerpos de lava latiandesíticos (Formación Pacacua) o chimeneas peperíticas brechoides en ignimbritas (MiembroMata de Limón), o posibles peperitas brechoides en los depósitos de flujos de lava del prospecto minero de Crucitas(Formación Cureña), o simples posibles peperitas brechoides en flujos de lava andesíticas (Formación Pacacua en Tala-manca), o como brechas hidroclásticas con fragmentos de composición dacítica de Carbonal en Guanacaste, justamenteentre las playas Cabuyal y Naranjo. Todas ellas serían los equivalentes proximales del vulcanismo explosivo, efusivoy subvolcánico (domos endógenos y criptodomos) y su concomitancia con la sedimentación fluvial. En el Cuaternario,un ejemplo se da en la base de la Formación Tiribí al contacto con el lacustre de Palmares. Se incluyen en el presentetrabajo, además, casos posibles o potenciales. Se espera que la descripción e interpretación de este tipo de rocas ayudea su identificación en otras regiones de Costa Rica y Centroamérica en general, así como una fuente potencial para laprospección de metales valiosos.

Isolation and molecular characterization of Xylella fastidiosa from coffee plants in Costa Rica

Coffee plants exhibiting a range of symptoms including mild to severe curling of leaf margins, chlorosis and deformation of leaves, stunting of plants, shortening of internodes, and dieback of branches have been reported since 1995 in several regions of Costa Rica's Central Valley. The symptoms are referred to by coffee producers in Costa Rica as "crespera" disease and have been associated with the presence of the bacterium Xylella fastidiosa. Coffee plants determined to be infected by the bacterium by enzyme linked immunosorbent assay (ELISA), were used for both transmission electron microscopy (TEM) and for isolation of the bacterium in PW broth or agar. Petioles examined by TEM contained rod-shaped bacteria inside the xylem vessels. The bacteria measured 0.3 to 0.5 microm in width and 1.5 to 3.0 microm in length, and had rippled cell walls 10 to 40 nm in thickness, typical of X. fastidiosa. Small, circular, dome-shaped colonies were observed 7 to 26 days after plating of plant extracts on PW agar. The colonies were comprised of Gram-negative rods of variable length and a characteristic slight longitudinal bending. TEM of the isolated bacteria showed characteristic rippled cell walls, similar to those observed in plant tissue. ELISA and PCR with specific primer pairs 272-l-int/272-2-int and RST31/RST33 confirmed the identity of the isolated bacteria as X. fastidiosa. RFLP analysis of the amplification products revealed diversity within X. fastidiosa strains from Costa Rica and suggest closer genetic proximity to strains from the United States of America than to other coffee or citrus strains from Brazil.

4 Breaking Down Binaries: Gender, Art, and Tools in Ancient Costa Rica

ABSTRACT Giant metate‐like stone sculptures, found in all regions of Costa Rica, though in various forms, continue to fascinate researchers. Archaeologists contrast these sculptures with other, more utilitarian metates in order to determine their purpose and meaning. They create two groups—metates used by women for grinding subsistence foods and elaborate metates used by men for ritual purposes. This chapter challenges the binaries of tool/art, utilitarian/elaborate, and female/male that essentialize gender and homogenize historical variability. Figurine and burial data demonstrate women's connection to elaborate metates and ritual. In addition, ceramic figurines depict flexibility in gender roles at least within the stratum of ancient Costa Rican society that they depicted. This instance of stereotyped gender attribution and the absence of attention to the possible dynamism of women's lives shows the importance of a feminist approach to archaeology and the need to draw on multiple lines of evidence to answer archaeological questions.

First record of entomopathogenic nematodes (Steinernematidae and Heterorhabditidae) in Costa Rica

A survey of entomopathogenic nematodes was conducted in the north Pacific (Guanacaste Conservation Area) and southeast Caribbean (Gandoca-Manzanillo Natural Refuge) regions of Costa Rica. Out of a total of 41 soil samples, 5 were positive for entomopathogenic nematodes (20.5%), with 3 (12.3%) containing Steinernema and 2 (8.2%) Heterorhabditis isolates. Morphological and molecular studies were undertaken to characterize these isolates. The Heterorhabditis isolates were identified as Heterorhabditis indica and the three Steinernema isolates were identified as two new undescribed species. H. indica was recovered from a coastal dry forest. Steinernema n. sp. 1 was isolated from a rainforest valley, between volcanoes. Steinernema sp. n. 2 was isolated from sand dunes in the Caribbean Coast (Punta Uva) near the rainforest strip along the coast. Although limited to two geographic regions, this study suggests entomopathogenic nematodes may be diverse and perhaps widely distributed in Costa Rica. A more intensive survey, covering all geographic regions is currently undergoing.

Environmental values and forest patch conservation in a rural Costa Rican community

Although conservation attention has generally focused on large forest tracts, there is increasing evidence that smaller forest patches are important for both conservation and rural development. A study of forest patch conservation in a rural Costa Rican community found that, although forest patch conservation was influenced by landholding size, material factors did not account for all the variation in forest patches conservation behavior or conservation orientations of farmers. A qualitative interpretive approach, using semi-structured interviews, found that environmental values were influenced by at least three factors. First, colonist farmers with direct experience with environmental degradation in other regions of Costa Rica were more likely to be concerned about environmental degradation. Second, childhood exposure to conservation played an important role in influencing conservation orientations. Third, the environment was frequently discussed in relation to the moral and social values present in religious doctrines. The study also found general support for forest conservation laws, and a clear indication that interest in forest conservation has grown in recent years. The study highlights the importance of environmental values, in conjunction with material factors, in influencing forest conservation in rural communities.

Genetic characteristics of Fusarium verticillioides isolates from maize in Costa Rica

Thirty‐nine isolates of Fusarium verticillioides from maize seeds from three regions of Costa Rica were classified on fertility, fumonisin production, vegetative compatibility and pathogenicity. The identity of the isolates was verified by sexual crosses with standard tester strains and by isozyme analysis. Twenty‐three isolates (59%) were mating type A− and 16 (41%) were A+; 29 (74%) were female fertile. The isolates produced high amounts of fumonisin B1 when grown on sterilized maize grits, 32 isolates producing more than 1000 μg g−1, as determined by TLC, and 7 less than 1000 μg g−1. Vegetative compatibility tests by pairing nit mutants identified 34 vegetative compatibility groups (VCGs), of which 29 had one member and 5 had two members. Isolates belonging to the same VCG were obtained from the same seed sample. Two pathogenicity tests with different inoculation methods were performed: on toothpick inoculation of 7‐week‐old maize stalks, 71% of the isolates were pathogenic according to the length of the necrosis formed in the stalk, and on sand inoculation of maize seedlings all the isolates were pathogenic, according to shoot length and dry weight production. Differences in aggressiveness between some of the isolates were recorded. It is concluded that natural populations of F. verticillioides in Costa Rica consist of genetically diverse, highly fertile and pathogenic isolates that represent a potential risk for disease development and fumonisin accumulation in maize crops.

Occurrence of Fumonisin B1 in Maize Grown in Costa Rica

Fusarium moniliforme is one of the most frequent fungal pathogens found in corn. Samples of corn grown in three different regions of Costa Rica were collected and analyzed for the presence of fumonisins, metabolites produced by F. moniliforme. Results indicate that fumonisin B1 was present in 89% of the samples. Maize grown in Costa Rica is therefore contaminated with fumonisin B1, and contamination depends on geographical region and period of collection. Microbiological analysis revealed the presence of F. moniliforme-type isolates in 86% of the maize samples. Average levels of fumonisin B1 per regionBrunca, Huetar Norte, and Huetar Atlanticawere 2.50, 3.58, and 1.81 ppm, respectively. Mean fumonisin B1 values were 2.13 ppm with a minimum of 0.00 ppm and a maximum of 6.32 ppm. Maize from the Huetar Atlantica region showed significantly (a = 0.05) higher levels of F. moniliforme-type isolates than maize from the Brunca and Huetar Norte regions. Keywords: Fumonisin; maize; Costa Rica

Osteology of the paca (Cuniculus paca) waist and limbs

SummaryApendicular Skeleton of the Paca (Cuniculus paca)Six specimens (4 male and 2 female) were used to describe the apendicular skeleton of the paca. These animals were captured in various regions of Costa Rica and prepared for maceration and radiographic studies of skeletal structures. The results of this study are compared with those carried out in domestic carnivora.

Vegetation management systems and insect responses in the humid tropics of Costa Rica

Abstract Humid tropical regions of Costa Rica have ideal environmental conditions for vigorous weed growth. Vegetation management before and after planting requires more time and resources than any other activity in small‐scale maize (Zea mays L.) production. No‐tillage vegetation management systems tested were superior to traditional no‐tillage or mechanised systems. Insect damage to maize from Diabrotica balteata Leconte, Spodoptera frugiperda (J. E. Smith), Cyrtomenus bergi Froeschner and Phyllophaga spp. was significantly less with no‐tillage in contrast to ploughed systems.

The genus Anastrepha (Diptera; Tephritidae) in the principal fruits of Costa Rica and its reduction to human pseudomyiasis

Three species of Anastrepha are usually found independently in 9 fruits from different regions of Costa Rica. A striata was found in 5, and A. serpentina and A. obliqua in each of 3 different fruits. During the harvest season, these larvae frequently produce intestinal pseudomyiasis, especially in children.

Foraging for Insects by a Tropical Hummingbird

Evolutionary-ecological studies of tropical plants and animals have illustrated that certain tropical organisms respond to differences between wet and dry seasons. Certain species of trees show distinct flowering and fruiting patterns in relation to the dry season in various regions of Costa Rica (Janzen 1967). It has been hypothesized that wetter habitats could be expected to contain a greater proportion of those predators specialized for feeding upon small insects than would drier habitats (Janzen and Schoener 1968). This reasoning stems primarily from the observation that there is a distinct paucity of small insects associated with drier habitats, because of problems of desiccation associated with small body size (Janzen and Schoener 1968). Similar arguments can be made for changes in local distributions and abundances of these predators between wet and dry seasons. Despite these interesting ideas, studies on seasonal patterns of interactions between insectivorous vertebrates and their prey have not appeared in the literature. Such experimental studies are needed as a vehicle for increasing our understanding of tropical communities and the impact of season upon their temporal and spatial persistence. This paper discusses foraging for insects in one Costa Rican species, the Long-tailed Hermit Hummingbird, Phaethornis superciliosus (hereafter referred to as Phaethornis). This species ranges from southern M6xico to Bolivia and Brazil, inhabiting thinned forests and woodland borders (Slud 1964). Certain aspects of the biology of this species and the Little Hermit (P. longuemareus) have been studied in Costa Rica (Skutch 1951, 1964), while other species of Phaethornis have been similarly studied elsewhere (Skutch 1950; Snow and Snow 1964). However, there are no published accounts of long-term, systematic studies on foraging for any members of this large genus. While it has been suggested that most species of hummingbirds spend relatively little time foraging for insects (at least from data available on the Anna Hummingbird; see Pearson 1954), Slud (1964) alludes briefly to active insect foraging by Phaethornis, and Wagner (1946) contends that insects are a major food source for many species of hummingbirds. However, quantitative data on such foraging for any species are lacking. The data discussed here are from two