Abstract：
:A great extension (615,000 ha) of native savannas of the eastern plains of Venezuela have been replaced by plantations of Pinus caribaea var. hondurensis; however, only scarce information exists about the impact of this land use on carbon dynamics in soils. We studied the effect of temporal variability and the substitution on the total organic carbon (TOC), water-soluble carbon (WSC), microbial biomass C (Cmic), basal respiration (BR), microbial metabolic quotient (qCO2) and Cmic/Corg ratio. Selected chemical properties and biological parameters of soils were measured under 3 and 29 year old forest plantations of P. caribaea and an adjacent native savanna which was considered the control. At each site, nine soil composite samples were collected (0-10 cm depth). The studied parameters did not show a defined pattern in relation to temporal variability. Higher carbon preservation occurs in soil microbial biomass under pine plantations. The basal respiration rate and qCO2 suggests that there is a more efficient microbial carbon utilization in the plantations. The Cmic/Corg ratio shows that the microbial biomass has an important stock of soil carbon in pine plantations. The conversion of savannas to pine plantations can increase soil carbon in the eastern plains of Venezuela, but this must be balanced with the ecological importance of natural savannas ecosystems.
journal_name
Rev Biol Tropjournal_title
Revista de biologia tropicalauthors
Gómez Y,Paolini J,Hernández RMsubject
Has Abstractpub_date
2008-12-01 00:00:00pages
2041-53issue
4eissn
0034-7744issn
2215-2075journal_volume
56pub_type
杂志文章abstract：:In Costa Rica, cervical cancer is the second most common female cancer, despite accessibility of screening through the universal health care system. There is little understanding of knowledge levels of the adolescent population on cervical cancer, although this population is the most exposed to risk factors. This stud...
journal_title：Revista de biologia tropical
pub_type： 杂志文章
doi：10.15517/rbt.v62i3.14063
更新日期：2014-09-01 00:00:00
abstract：:Huperzia brevifolia is one of the dominant species of the genus Huperzia living in paramos and superparamos from the Colombian Andes. A detailed study of the sporangium's ontogeny and sporogenesis was carried out using specimens collected at 4200m above sea level, in Parque Natural Nacional El Cocuy, Colombia. Small p...
journal_title：Revista de biologia tropical
pub_type： 杂志文章
doi：
更新日期：2009-12-01 00:00:00
abstract：:The anti-inflammatory properties of Loasa speciosa and Loasa triphylla (Loasaceae), Urtica leptuphylla and Urera baccifera (Urticaceae), and Chaptalia nutans (Asteracene) were studied using the carregeenan induced rat paw edema model. Aqueous extracts of each plant were made according to the ethnobotanical use. The hi...
journal_title：Revista de biologia tropical
pub_type： 杂志文章
doi：
更新日期：1999-12-01 00:00:00
abstract：:Resident and migratory shorebirds inhabit different kinds of wetlands such as lagoons, rivers and seashores among others. In recent years, these areas have been importantly affected by urban, agriculture and touristic activities, such as the Barra de Navidad lagoon, for which little information is available to support...
journal_title：Revista de biologia tropical
pub_type： 杂志文章
doi：
更新日期：2012-09-01 00:00:00
abstract：:River floodplains have a high biological diversity that is intensely influenced by vegetation dynamics, changes in space and time scales, and the river's hydrological regime. The vegetation composition of the medium and lower Paraná River has been analyzed previously, with different approaches and criteria that cannot...
journal_title：Revista de biologia tropical
pub_type： 杂志文章
doi：
更新日期：2010-06-01 00:00:00
abstract：:Clinical evidence has long pointed to the existence of Clostridium tetani in Costa Rica. Thirty soil samples were studied for clostridia, and two yielded six strains of C. tetani, four of which proved to be toxigenic when mice were inoculated intraperitoneally with the culture supernates. These four isolates could be ...
journal_title：Revista de biologia tropical
pub_type： 杂志文章
doi：
更新日期：1991-06-01 00:00:00
abstract：:The spatial distribution of individuals is a fundamental property of most species and constitutes essential information for the development of restoration and conservation strategies, especially for endangered plant species. In this paper we describe the spatial distribution of different size classes of the endangered...
journal_title：Revista de biologia tropical
pub_type： 杂志文章
doi：10.15517/rbt.v61i3.11981
更新日期：2013-09-01 00:00:00
abstract：:An avirulent T. gondii strain isolated from a owl (Glaucidium brasilianum) produces randomly distributed cysts in the brain of mice which can survive to inocula as high as 1000 oocysts. Cysts appeared for the first time after 15 days of infection. Regarding to humoral immunity development due to our TCR-2 strain, dete...
journal_title：Revista de biologia tropical
pub_type： 杂志文章
doi：
更新日期：1990-11-01 00:00:00
abstract：:Paulownia tomentosa is a fast-growing tree species with a considerable economic potential because of its value for wood as well as its high biomass production, and elevated stress tolerance. The objective of the present study was to evaluate the development of adventitious buds in leaves obtained from four-week-old sh...
journal_title：Revista de biologia tropical
pub_type： 杂志文章
doi：
更新日期：2014-06-01 00:00:00
abstract：:The venom of female spiders (Aphonopelma seemanni) induces necrosis of skeletal muscle in mice. This effect was demonstrated by histology and by the increase in the plasma levels of the enzyme creatine kinase (CK). ...
journal_title：Revista de biologia tropical
pub_type： 杂志文章
doi：
更新日期：1984-06-01 00:00:00
abstract：:Bottom trawling has been considered a fishing activity that affects and modifies habitats, because of its impacts in species composition and abundance, and the alteration in the structure and function of the eco-system, that generates biodiversity loss. The Northern part of the Gulf of California has been considered a...
journal_title：Revista de biologia tropical
pub_type： 杂志文章
doi：
更新日期：2015-09-01 00:00:00
abstract：:Abstract: The phenotypic structure within and between plant populations is generally influenced by their distribution patterns in space and time; therefore, the study of their divergence is a central issue for the understanding of their microevolutive processes. We boarded the hypothesis that three populations of Espe...
journal_title：Revista de biologia tropical
pub_type： 杂志文章
doi：10.15517/rbt.v58i4.5410
更新日期：2010-12-01 00:00:00
abstract：:The octopus (Octopus maya) is one of the most important fish resources in the Mexican Gulf of Mexico with a mean annual yield of 9000 ton, and a reasonable number of jobs created; O. maya represents 80% of the total octopus catch, followed by Octopus vulgaris. There are two artisanal fleets based on Octopus maya and a...
journal_title：Revista de biologia tropical
pub_type： 杂志文章
doi：
更新日期：2000-06-01 00:00:00
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journal_title：Revista de biologia tropical
pub_type： 杂志文章
doi：10.15517/rbt.v54i1.13977
更新日期：2006-03-01 00:00:00
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journal_title：Revista de biologia tropical
pub_type： 杂志文章
doi：
更新日期：2011-03-01 00:00:00
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journal_title：Revista de biologia tropical
pub_type： 杂志文章
doi：
更新日期：1995-04-01 00:00:00
abstract：:Pine plantations in the tropics are often employed to recondition eroded slopes from mudslides, as the Pinus caribaea plantation that shields the Universidad Simón Bolívar campus in Caracas (Venezuela). However, mismanagement of this plantation has led to its rapid degradation. The best option to maintain the protecti...
journal_title：Revista de biologia tropical
pub_type： 杂志文章
doi：10.15517/rbt.v64i2.19632
更新日期：2016-06-01 00:00:00
abstract：:Limnocytherina is a genus conformed by 12 species; its distribution in the American continent is known to be exclusively on the North (neartics), but little is reported about its distribution from Mexico (transition zone) and Central America (Neotropics). Different sampling campaigns were undertaken in three crater la...
journal_title：Revista de biologia tropical
pub_type： 杂志文章
doi：
更新日期：2014-03-01 00:00:00
abstract：:We surveyed the trophic components in six species of Bahía de Navidad and Bahía de Chamela: Microlepidotus brevipinnis, Caranx caballus, Haemulon flaviguttatum, Lutjanus guttatus, L. argentiventris and Mulloidichthys dentatus. Two main seasonal periods were considered: 1) North Equatorial Counter Current NECC period i...
journal_title：Revista de biologia tropical
pub_type： 杂志文章
doi：
更新日期：2010-03-01 00:00:00
abstract：:A total of 260 Costa Rican patients (106 males) with clinical diagnosis of Bronchial Asthma and 100 non atopic subjects were studied with skin prick tests for all Poaceae tribes. Allergic Type I Hypersensitivity to these pollens among the Bronchial Asthma patients reached 51.2% positivity to at least one tribe (2% in ...
journal_title：Revista de biologia tropical
pub_type： 杂志文章
doi：
更新日期：1994-04-01 00:00:00
abstract：:Lime juice killed millions of Vibrio cholerae O1, El Tor, Inaba, present on cabbage and lettuce contaminated in the laboratory. The lethal effect was evident within 5 min of exposure to lime juice. No vibrios could be recovered at dilution 1:10 using alkaline peptone water (APW) and thiosulfate-citrate-bile salts-sacc...
journal_title：Revista de biologia tropical
pub_type： 杂志文章
doi：
更新日期：1994-12-01 00:00:00
abstract：:The Cuban archipelago has 79 Phyllophaga species with a 98.6 % of endemism, which makes the group ecologically and economically important, as some species are classified as crop pests. The aim of this study was to determine the relationship between the composition and structure of the Phyllophaga assemblages with thei...
journal_title：Revista de biologia tropical
pub_type： 杂志文章
doi：10.15517/rbt.v65i1.23286
更新日期：2017-03-01 00:00:00
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journal_title：Revista de biologia tropical
pub_type： 杂志文章
doi：
更新日期：1982-07-01 00:00:00
abstract：:Megalopta Smith, 1853, is a Neotropical genus of nocturnal or crepuscular bees. Two subgenera are recognized with most of its nearly 30 species placed in the nominate subgenus. Species of Megalopta s. str. are more commonly collected than species of Noctoraptor Engel et al. 1997, all presumably parasites of Megalopta ...
journal_title：Revista de biologia tropical
pub_type： 杂志文章
doi：10.15517/rbt.v58i1.5207
更新日期：2010-03-01 00:00:00
abstract：:A four year study was conducted on a natural population of immature stages of Aedes aegypti after the re-invasion of Argentina by this vector in 1987. Thirty six plastic containers with 700 ml of dechlorinated water were placed in the La Plata Zoological Garden, La Plata, Argentina. A strip of filter paper around each...
journal_title：Revista de biologia tropical
pub_type： 杂志文章
doi：
更新日期：2006-09-01 00:00:00
abstract：:The need to propose recommendations for the management of over 80 species of bivalves and gastropod mollusks exploited commercially in Mexico, led to look for trends on the population and reproductive biology in relation to prevailing environmental conditions of the habitats where they are exploited. The reproductive ...
journal_title：Revista de biologia tropical
pub_type： 杂志文章
doi：
更新日期：2003-06-01 00:00:00
abstract：:The food habits of Trachinotus paitensis, in San Ignacio Lagoon B.C.S., Mexico, were investigated. We observed that T. paitensis is carnivorous, feeding mainly on benthic invertebrates (the gastropods Anachis spp., Bittium spp., and the crustacean larvae). We concluded that T. paitensis is an opportunist predator that...
journal_title：Revista de biologia tropical
pub_type： 杂志文章
doi：10.15517/rbt.v52i1.14762
更新日期：2004-03-01 00:00:00
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journal_title：Revista de biologia tropical
pub_type： 杂志文章
doi：
更新日期：2007-06-01 00:00:00
abstract：:The structural and ultrastructural features of gonads from endemic Mexican fish have received scarce attention. This study describes the histological and ultrastructural characteristics of oocyte from Chirostoma humboldtianum. The ovary is asynchronic, and as such, most phases of oocyte development are found in the sa...
journal_title：Revista de biologia tropical
pub_type： 杂志文章
doi：
更新日期：2008-09-01 00:00:00
abstract：:The fish and invertebrates community structure in the Sabancuy estuary was analyzed in two seasons and 14 sampling stations (13 along the estuary and one in the marine adjacent coast). No significant differences were found between seasons. The environmental frame defines two zones within the estuary, the first extends...
journal_title：Revista de biologia tropical
pub_type： 杂志文章
doi：
更新日期：2001-03-01 00:00:00
