Search

The Costa Rican highlands are considered hotspots of diversity and endemism, but studies on rodents are scarce. We compared the richness and abundance of mice between the montane forest and the paramo at the summit of the Talamanca mountain range. We selected two study sites within the Talamanca mountain range: the Cerro de la Muerte Biological Station and the paramo. The former is a montane forest dominated by oaks, and the latter is dominated by an herbaceous layer, and some scattered bushy patches. We captured mice in two different microhabitats within each montane forest and paramo, so we had four different sampling microhabitats: (1) paramo--bush, (2) paramo--Chusquea, (3) montane forest--bush, and (4) montane forest--Chusquea. Mice were marked to identify recaptures. We captured four mouse species and their abundance varied largely between habitats and among microhabitats (Table 1). The most abundant species, representing 85 % of all mouse captures, was Peromyscus nudipes. Mice were more abundant in the montane forest than in the paramo. Within the montane forest, mice were more abundant in the microhabitat containing bushes. The montane forest has a more complex vegetation structure with more diversity of food resources and shelters than the paramo. As well as at the habitat level, we argue that differences in abundance among microhabitats are directly related with the structure of vegetation. A more complex habitat structure may provide rodents with better conditions. Las tierras altas de Costa Rica son consideradas un punto caliente de diversidad y endemismo, pero los estudios sobre roedores son escasos. Comparamos la riqueza y abundancia de ratones entre el bosque de robledal y el páramo en la cima de la Cordillera de Talamanca. Seleccionamos dos sitios de estudio en la Cordillera de Talamanca: la Estación Biológica Cerro de la Muerte y el páramo. El primero es un bosque montano dominado por robles, y el segundo está dominado por una vegetación herbácea y algunos parches dispersos de arbustos. Capturamos ratones en dos microhábitats diferentes en el robledal y el páramo. Por lo que tuvimos cuatro microhábitats de muestreo: (1) páramo--arbustos, (2) páramo--Chusquea, (3) bosque montano--arbustos, y (4) bosque montano--Chusquea. Los ratones fueron marcados para identificar recapturas. Capturamos cuatro especies de ratones y sus abundancias variaron considerablemente entre hábitats y microhábitats (Tabla 1). La especie más abundante, con 85 % del total de capturas, fue Peromyscus nudipes. Los ratones fueron más abundantes en el robledal que en el páramo. Dentro del robledal, los ratones fueron más abundantes en el microhábitat compuesto por arbustos. El bosque montano posee una estructura vegetal más compleja, con mayor diversidad de recursos alimenticios y refugios que el páramo. Al igual que a nivel de hábitat, discutimos que las diferencias en abundancia entre microhábitats están directamente relacionadas con la estructura de la vegetación. Un hábitat con una estructura más compleja es de esperar que provea a los roedores de mejores condiciones. [ABSTRACT FROM AUTHOR]

The Costa Rican Paramo is a unique ecosystem with high levels of endemism that is geographically isolated from the Andean Paramos. Paramo ecosystems occur above Montane Forests, below the permanent snow level, and their vegetation differs notably from that of adjacent Montane Forests. We compared the composition and beta diversity of blooming plant species using phenological data from functional plant groups (i.e., insect-visited, bird-visited and insect C bird-visited plants) between a Paramo and a Montane Forest site in Costa Rica and analyzed seasonal changes in blooming plant diversity between the rainy and dry seasons. Species richness was higher in the Montane Forest for all plant categories, except for insect-visited plants, which was higher in the Paramo. Beta diversity and blooming plant composition differed between both ecosystems and seasons. Differences in species richness and beta diversity between Paramo and the adjacent Montane Forest are likely the result of dispersal events that occurred during the last glacial period and subsequent isolation, as climate turned to tropical conditions after the Pleistocene, and to stressful abiotic conditions in the Paramo ecosystem that limit species establishment. Differences in blooming plant composition between both ecosystems and seasons are likely attributed to differential effects of climatic cues triggering the flowering events in each ecosystem, but phylogenetic conservatism cannot be discarded. Analyses of species composition and richness based on flowering phenology data are useful to evaluate potential floral resources for floral visitors (insects and birds) and how these resources change spatially and temporarily in endangered ecosystems such as the Paramo. [ABSTRACT FROM AUTHOR]

Cloud forests have been found to lose more nitrogen in stream discharge than they gain from atmospheric deposition. They also support a large diversity and biomass of tree epiphytes, predominately composed of cryptogams. Since cryptogam epiphytes harbor nitrogen fixing cyanobacteria, they may help make up for the nitrogen loss from ecosystems. We assessed cryptogam biomass on the ground, boles and branches in Quercus costaricensis dominated stands near the tree line in the Cordillera de Talamanca, Costa Rica. Nitrogen fixation was assayed using 15N2 uptake. Total cryptogam biomass was 2 977 kg ha−1, with 67% being found on the lower branches. Bryophytes and chlorolichens made up 53% and 44%, respectively, of the biomass. Half of the bryophyte mass was composed of the liverwort Plagiochila heterophylla, and 66% of the chlorolichen of Lobariella pallida. There were no significant differences in nitrogen fixation rates between the cryptogam species, with a mean rate of 5.04 µg N g−1 day−1 during the predominantly wet condition in the forest. The overall nitrogen input from fixation was 6.1 kg N ha−1 year−1, of which 78% came from bryophytes, 18% from chlorolichens, and 4% from cyanolichens. Only 2.0% of the fixation occurred in cryptogams on the ground, whereas 67%, 24%, and 7% occurred on the lower branches, boles, and upper branches, respectively. These results show that tree epiphytes constitute a significant source of nitrogen for these forests, due to the trees' large surface area, and can make up for the nitrogen lost from these ecosystems. [ABSTRACT FROM AUTHOR]

A new wild bean found in the mountainous range "Fila Cruces" of southeastern Costa Rica is described. To date, only four populations are known from different sites on the slopes of Cerro Anguciana and "Fila Cruces" where it seems to be endemic. The differences (slender curved racemes, small oval acuminate primary and pedicelar bracts, lilac inner face of standard, white wings) are presented with closely related species such as P. hygrophilus and P. oligospermus of the section Brevilegumeni to which it may belong. [ABSTRACT FROM AUTHOR]

Copyright of Biotropica is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Tropical Ecology is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Abstract: Natural regeneration of large-seeded, late-successional trees in fragmented tropical landscapes can be strongly limited by a lack of seed dispersal resulting in the need for more intensive restoration approaches, such as enrichment planting, to include these species in future forests. Direct seeding may be an alternative low-cost approach to planting nursery-raised tree seedlings, but there is minimal information on its efficacy or when in the successional process this technique will be most successful. We tested directly seeding five native tree species into habitats representing passive and active restoration approaches: (1) recently abandoned pasture; (2) naturally establishing, young secondary forests; and (3) young, mixed-species (fast-growing N-fixers and commercially valuable species) tree plantations established to facilitate montane forest recovery in southern Costa Rica. We monitored germination, survival, growth, and above- and below-ground biomass over a 2-year period. Germination in pastures, secondary forests, and tree plantations was similar (∼43%). Seedling survival after one and two years was significantly higher under tree plantations (91% year 1, 75% year 2) compared to secondary forests (76, 44%) or pastures (74, 41%). Moreover, seedlings had greater total biomass and lower root:shoot ratios in the plantations, suggesting higher nutrient availability in that treatment. Costs for direct seeding were 10- to 30-fold less per 100 seedlings after 2-year compared to nursery-raised seedlings planted at the same sites; however, there are important trade-offs to the two restoration approaches. Planting nursery-raised seedling is a more effective but higher cost approach for rapidly establishing canopy cover and restoring large areas whereas direct seeding is a more efficient way to enrich an existing system. We particularly recommend using direct seeding as a complimentary measure to the more intensive restoration approach of planting fast-growing and N-fixing trees. [Copyright &y& Elsevier]

We present a taxonomic revision of the lichenized basidiomycete genus Acantholichen, species of which produce a characteristic blue-gray, microsquamulose thallus with spiny apical hyphal cells known as acanthohyphidia. Since its discovery, the genus was thought to be monospecific, only including the generic type, A. pannarioides. However, a detailed morphological and anatomical study of recently collected specimens from the Galápagos, Costa Rica, Brazil and Colombia, combined with a molecular phylogenetic analysis of the internal transcribed spacer (ITS1-5.8S-ITS2) region and 28S of the nuc rDNA and RPB2 sequences, revealed a much more diverse and widespread species assemblage. Based on the results of these analyses, we describe five new species in the genus: A. albomarginatus, A. campestris, A. galapagoensis, A. sorediatus and A. variabilis. We also provide an identification key to all species, anatomical and morphological descriptions, photographs and a table comparing main characters of each species., (© 2016 by The Mycological Society of America.)