Costa Rican Montane Research Articles

Confirmed occurrence of the tribe Apameini (Lepidoptera, Noctuidae, Noctuinae) in the Neotropical region: a new genus endemic to Costa Rican montane forests.

The genus Nublapamea gen. nov. is described (type species: Tracheaaltivolans Schaus), here determined to belong to the primarily temperate Holarctic tribe Apameini (Noctuidae: Noctuinae). Currently known only from mid- to upper elevation montane forests of Costa Rica, Nublapamea is a disjunct southern extension of a largely northern hemisphere temperate region fauna. The life history of Nublapameaaltivolans is unknown; it may be associated with chusquea bamboo (Chusquea Kunth), as most Apameini are dietary specialists on graminoids.

Three new species of Tricholoma from Costa Rica

Three new species of Tricholoma are described from Costa Rican montane forests with additional collections cited from the United States. The new species are Tricholoma felschii sp. nov., Tricholoma costaricense sp. nov. and Tricholoma atratum sp. nov. A discussion of Tricholoma luteomaculosum is also included. These taxa share morphological features of strong farinaceous odor and taste, pseudoparenchymatous pileal subcutis, and rugulose pileus at some stage of development. In addition, cheilocystidia occur in two of the taxa but not the third. Phylogenies are presented based on ITS sequences.

Preliminary Evaluation of Butterfly Diversity and Rural Agriculture in Montane Costa Rica

Agriculture continues to expand in the tropics, capturing a subset of original biodiversity. Here, butterfly diversity was sampled in four land uses resulting from montane Neotropical agriculture: a forest fragment, a coffee plantation, a banana grove, and a cattle pasture. Butterflies were sampled in both traps baited with rotting fruit and visual transects during the dry season in the tropical premontane moist forest life zone near Monteverde, Costa Rica. The samples were dominated by Cissia spp., overshadowing the diversity and evenness, therefore statistical analyses were run with and without the species. Diversity was highest in the coffee, followed by the forest, then pasture, and banana. Excluding Cissia spp., diversity increased in all sites but remained highest in the coffee, then banana grove, followed by the forest fragment, with the pasture the least diverse. Coffee displayed the highest diversity presumably because it had the highest structural diversity that still allowed abundant light. The pasture may have the lowest diversity because of low structural diversity and high winds. Forest-dwelling butterfly species were less common as habitats lost structural diversity, indicating that while highest local diversity can occur with agriculture, regional species diversity may suffer.

Epidendra Nova Talamancana

Two new species of Epidendrum from the Costa Rican montane rainforest, E. hartmanniorum and E. vallis-silentii, are described, illustrated and compared with similar species. Epidendrum stolidium and E. unicallosum are reported as new records of this genus for the country.

Diversity and distribution of small terrestrial rodents along a disturbance gradient in montane Costa Rica

Se estudió la distribución y diversidad de roedores terrestres en cinco hábitats perturbados en un área de bosque montano nuboso en Costa Rica. Un total de 3 89 capturas correspondió a 185 individuos (siete especies en 2 Ca- , milias). La riqueza de especies resultó muy similar para todos los hábitats,c on 4-5 especieslhábitat. La densidad de población y la frecuencia de captura fueron más altas en hábitats con niveles intennedios de perturbación; Peromyscus mexicanus y Scotinomys xerampelinus fueron cuatro a cinco veces más comunes que otras especies de Muridae. Estas representaron el 79.4 % de todas las capturas y el 73.5 % de todos los individuos. Se capturo pocos Heteromyidae.

Genetic Diversity and Spatial Genetic Structure of an Epiphytic Bromeliad in Costa Rican Montane Secondary Forest Patches

AbstractInformation on genetic variation and its distribution in tropical plant populations relies mainly on studies of ground‐rooted species, while genetic information of epiphytic plants is still limited. Particularly, the effect of forest successional condition on genetic diversity and structure of epiphytes is scanty in the literature. We evaluated the genetic variation and spatial genetic structure of the epiphytic bromeliad Guzmania monostachia (Bromeliaceae, Tillandsioideae) in montane secondary forest patches in Costa Rica. The sampling design included plants on the same trees (i.e., populations), populations within forest patches and patches within secondary forest at two different successional stages (early vs. mid‐succession). Six microsatellites revealed low levels of population genetic variation (A = 2.06, AE = 1.61, HE = 0.348), a marked deficiency of heterozygotes (HO = 0.031) and high inbreeding (f = 0.908). Genetic differentiation was negligible among populations within the same forest patch, but moderate (GST = 0.123 ± 0.043) among forest patches. Genetic relatedness between individuals was significantly higher for plants located within the same forest patch and separated by <60 m and decreased as distance between plants increased, becoming significantly negative at distances >400 m. An analysis of molecular variance (AMOVA) showed significant genetic variation between forest patches, but non‐significant variation between successional stages. The selfing breeding system and limited seed dispersal capabilities in G. monostachia could explain the observed levels and partitioning of genetic diversity at this geographic scale. However, these results also suggest that forest fragmentation is likely to influence the degree of local genetic structuring of epiphytic plants by limiting gene flow.

Rubiacearum Americanarum Magna Hama Pars XXI. A New Species of Palicourea (Psychotrieae) from Costa Rica

A new species of Palicourea Aublet (Rubiaceae, Psychotrieae) is described and illustrated: P. palustris A. C. Gilman & C. M. Taylor from montane Costa Rica. This species differs from P. salicifolia Standley by its large stipules that have well-developed lobes and are persistent with age, and by its larger corollas with relatively longer lobes.

Climate change scenario for Costa Rican montane forests

Tropical montane cloud forests are characterized by persistent immersion in clouds, an important source of moisture during the dry season. Future changes in temperature and precipitation could alter cloud cover at the vegetation level and seriously affect mountain ecosystems. A regional climate modeling study that focuses on changes in the distributions of temperature and precipitation in Costa Rica shows, in general, an increase in temperature and a decrease in precipitation under the A2 scenario. At high elevations, warming is amplified and future temperature distribution lies outside the range of present‐day distribution. Compared to the Caribbean side, temperature changes are greater at high elevations on the Pacific side. Model results also show significant changes in precipitation amounts and variability and an increase in the altitude of cloud formation on the Pacific side that may have serious implications for mountain ecosystems in and around Costa Rica.

The foliicolous lichen flora of Mexico. V. Biogeographical affinities, altitudinal preferences, and an updated checklist of 293 species

An inventory of foliicolous lichens in Mexican lowland and montane rainforest revealed a total of 288 species, 238 of which are new records for the country, raising the number of reported lichen species to c. 1800. Among the new records, there are 29 recently described species and four new records for the Neotropics and the Americas, while five taxa are for the first time reported for Central America. The 293 species now known from Mexico comprise nearly two-thirds pantropical to cosmopolitan or intercontinentally distributed taxa, whereas little more than one-third are Neotropical or American, and only 6% are potentially endemic to the country. A comparison with other lowland and montane rainforest sites in Guatemala, Costa Rica and Ecuador shows that on average lowland sites have twice as many species as montane sites. Also, the differentiation in species composition between lowland and montane sites within the same region is more pronounced (63–75% similarity) than that between adjacent regions (96–99% similarity for lowland sites and 83–87% similarity for montane sites). This means that altitudinal preferences affect species composition more strongly than geographical differentiation. The latter is a function of distance, however, while Mexican and Guatemalan lowland (montane) sites share 96% (83%) of the species, these values drop to 74% (72%) when comparing Mexico with Ecuador. Nevertheless, overall floristic similarity is very high, with the lowest value of 54% shared species found between Mexican lowland and Costa Rican montane forest.

Demographic response of tree juveniles to reduced-impact logging in a Costa Rican montane forest

We assessed diameter and height growth, and mortality in seedlings (individuals ≥0.3, but <1.5 m tall) and saplings (individuals ≥1.5 m tall, but <10 cm DBH) of five common canopy tree species in an oak–bamboo forest in the Costa Rican highlands (2600–2800 m elevation) 5 years after a controlled logging operation under two harvesting intensities (20 and 30% basal area removal of stems ≥10 cm DBH, respectively). The species were Quercus costaricensis, Q. copeyensis, Drymis granadensis, Ocotea austinii, and Weinmania pinnata. For seedlings, the overall 5-year mortality rate (exponential model) was significantly higher under the lightest harvest intensity while for saplings, no significant differences in mortality were detected among harvesting intensities. Also for all species combined, annual 5-year diameter and height growth rates did not differ significantly among harvesting intensities for seedlings, although saplings grew significantly better under the higher harvest intensity. Our results suggest that, as a whole, saplings of the study species were more responsive to overstory removal than seedlings. At the species level, however, Quercus showed the largest significant differences in growth rates across harvest intensities and also with respect to the other studied species in both size classes. Based on our findings, and given the high abundance of advance regeneration at the study site (especially for Quercus), we propose that Costa Rican oak–bamboo forests show promising silvicultural potential for timber management under low-impact logging prescriptions.

Useful Plants Within a Campesino Community in a Costa Rican Montane Cloud Forest

An ethnobotanical survey was carried out among a campesino community in a Costa Rican montane cloud forest. Campesino families were interviewed about how they used indigenous and introduced vascular plants along an altitudinal gradient (2000–3000 m). From a total of 590 species known in the area, 23.8% of 189 useful plant species were used for medicinal purposes, 39.7% for food, and 24.3% for construction (timber) or as combustibles (fuelwood, charcoal). Less important uses included dye, ornament (ecotourism), fodder, gum, oil, and poison. A total of 61.9 % of the plants were used for one purpose only. The introduced and exotic woody species Cupressus lusitanica and Eucalyptus globulus showed the highest diversity in types of use (7), together with the native Alnus acuminata. Trunks (53%) and fruits (47%) were the main plant organs used, followed by leaves (33%) and branches (30%). Over 27.5% of all plants were used on a daily basis, while 34.9% were used occasionally. About 11.6% of the species were rarely used. At present, use of indigenous species is becoming less common; the trend is to favor introduced and economically important species. In the short or medium term, local knowledge of medicinal plants will probably disappear in this rural community that is undergoing modernization, with a focus on new undertakings such as fruticultural export, rainbow trout hatcheries, and ecotourism.

Vegetation structure and composition along an interior-edge-exterior gradient in a Costa Rican montane cloud forest

A study was carried out in the Costa Rican Cordillera de Talamanca in order to assess changes in vegetation structure and floristic composition along a gradient from the interior of tropical upper montane cloud forest into adjacent pastureland. At four sites a 150 × 10 m belt transect was established perpendicular to the forest/pasture edge. Vegetation transect censusing included recording of seed plant species presence and abundance (aerial crown/shoot cover), as well as assessment of seedling, sapling and tree stem diameter and height. A total of 290 seed plant species were found in 159 genera and 85 families. Asteraceae is with 47 species the most speciose family. Shannon–Wiener's diversity index showed no significant difference between forest and pastureland, with the exception of a pastureland site which had experienced intensive land use. Sørensen's similarity index showed significant differences in species composition between forest and pastureland. Vegetation at the forest edge consisted mainly of secondary shrub and tree species. From the forest interior towards the edge, numbers of seedlings, saplings and secondary trees increased, while numbers of mature forest trees declined. Edge effects are expressed in a reduction of canopy height and an increase in subcanopy stature from the forest interior towards the edge, causing the merging of forest canopy and subcanopy layers at the edge. Intensively used pasturelands only harboured a low herbaceous vegetation, while their abandoned equivalents showed the presence of patches of secondary shrub vegetation and recovering forest in a grassland matrix. Expected spatio-temporal changes at the forest edge include the encroachment of secondary vegetation and the levelling of the forest/pasture border as time advances and land use becomes less intense. Transitional second growth edge vegetation may buffer the remaining mature forest core and simultaneously induce forest recovery processes in adjacent abandoned pasturelands. It is recommended to include forest edge tree species in programs focused at the ecological restoration of tropical montane cloud forests.

The Landscape Ecology of Tropical Secondary Forest in Montane Costa Rica

Multinomial logistic models of land use/land cover in montane Costa Rica and landscape pattern analysis showed that relative to agriculture, secondary forest occurred closer to old-growth forest, further from roads, in forest reserves, and at higher elevations. Collinearity between explanatory variables yielded simple multivariate models; proportion of surrounding old growth predicted secondary forest most accurately. An old-growth matrix [mean patch size (MPS) 24.5 ha], located mainly within protected areas, dominated elevations greater than 2500 m. A matrix of agriculture (MPS 23.5 ha), with smaller patches (approximately 9 ha) of secondary forest and old growth, dominated elevations from 1500 to 2500 m. Combining secondary forest with old growth decreased forest patch number and increased MPS from 7.3 to 37.1 ha. I concluded that: (a) secondary forest pattern is nonrandom, so ancillary data will aid its mapping with satellite imagery. The variables elevation, agriculture distance, road distance, and population density distinguished secondary forest from old growth with 74% accuracy; (b) socioeconomic and biological forces probably interact to create these secondary forest patterns; and (c) the strong association between secondary forest and old growth supports the concept that tropical forest recovery depends on the landscape structure of remnant forest.

Vegetation and climate history of montane Costa Rica since the last glacial

New palynological evidence from the Cordillera de Talamanca (Costa Rica) is presented. The La Chonta-1 core (2310 m a.s.l) shows the development of montane vegetation during the late Quaternary. A shorter core (La Trinidad-III) shows the Lateglacial-Holocene transition, including the La Chonta stadial based on earlier published evidence. A soil section from the paramó belt at 3100 m shows vegetation recovery after fire. Modern pollen rain was studied along an altitudinal transect from 2100 m to 3800 m at Mt Chirripó. A comparison with other palaeoecological data of the region is given to elucidate climatic and vegetational changes throughout the Central American region. Data show a cooling of 7–8°C during the Last Glacial Maximum (LGM) for montane Costa Rica, which is in accordance with data from lowland Guatemala. A 1.5° to 2.5°C temperature drop is recorded during the Younger Dryas Chron in both Costa Rica and Guatemala, but apparently not in Panama. The Lateglacial-Holocene transition in montane Costa Rica is established at 10,400 BP. Between 9000 and 8500 BP moist forest developed in mountainous Costa Rica as well as in lowland Guatemala and Panama. Environmental change during the mid-Holocene seems more affected by changes in humidity than temperature change throughout Central America. Distribution maps of paramó and montane vegetation in Costa Rica are reconstructed for 10 ka, 14 ka and 18 ka based on currently available palynological data. These data indicate that during the LGM a paramó vegetation corridor existed between northern Costa Rica and probably northern Panama.

Changes in Leaf Morphology and Foliar Nutrient Status Along a Successional Gradient in a Costa Rican Upper Montane Quercus Forest

Morphology and mineral levels of leaves of 19 secondary and 22 primary tree species were studied in Quercusdominated upper montane 10-year-old Early Secondary Forest (ESF), 30-year-old Late Secondary Forest (LSF) and undisturbed Primary Forest (PF) in the Costa Rican Cordillera de Talamanca. In general, the predominant leaf is simple, elliptic, entire, and pinnately veined. Notophyllous and microphyllous-sized leaves dominate all spectra. During secondary succession the mean leaf area of secondary species tends to reduce 30 to 65 percent, while the average leaf area of primary species doubles. Primary species exhibit a greater mean leaf dry weight per unit area than secondary species. As succession proceeds, the mean leaf water content drops among secondary species and rises among primary species. During forest recovery levels of foliar nitrogen, phosphorus, and potassium decline significantly. In leaves of species in ESF nitrogen, phosphorus, and potassium are significantly correlated. Values for leaf characteristics recorded in Costa Rican montane ESF, LSF, and PF fall mainly within the ranges known from other tropical montane forests.

Changes in diversity along a successional gradient in a Costa Rican upper montane Quercus forest

Changes in terrestrial vascular plant diversity along a successional gradient were studied in a Costa Rican upper montane Quercus forest. In 1991 and 1992 species presence and cover were recorded in 12 successional 0.1 ha forest plots. A total of 176 species in 122 genera and 75 families were found. Asteraceae was the most speciose family. With the help of TWINSPAN three successional phases were classified: (i) Early Secondary Forest (ESF, 145 spp.), (ii) Late Secondary Forest (LSF, 130 spp.) and (iii) Primary Forest (PF, 96 spp.). Detrended Correspondence Analysis (DCA) species ordination using DECORANA illustrates that different ecological species groups can be distinguished along the time sequence. Alpha diversity (Shannon-Wiener index, among others) in ESF and LSF was significantly greater than in PF. This is probably explained by downslope migration of numerous sub(alpine) species to cleared and recently abandoned montane sites. Beta diversity applying Sorensen's similarity coefficients declined during succession. Using linear regression, the minimum time required for floristic recovery following disturbance and abandonment was calculated at 65.9 years. A comparison with other studies shows that secondary forests in upper montane Costa Rica can be as diverse as in neotropical lowlands.

Life history consequences of feeding versus non-feeding in a facultatively non-feeding toad larva.

Bufo periglenes, a toad endemic to montane Costa Rica, produces an unusually small clutch of large, yolk-rich eggs. The toads breed in small ephemeral pools that are unpredictable in duration and may be low in food availability. Two congeners, Bufo coniferus and Bufo marinus, occur nearby, breed in more permanent bodies of water that offer more food, and exhibit the typical toad pattern of large clutches of small eggs. Tadpoles of all three species feed on detritus and suspended organic material. By raising tadpoles of the three species individually with and without food I investigated the relationship between egg size (yolk provision) and tadpole survival. All of the unfed B. coniferus and B. marinus tadpoles grew little and died soon after developing to the hindlimb bud stage. On the other hand, all of the unfed B. periglenes tadpoles metamorphosed successfully, demonstrating that the tadpoles are facultatively non-feeding; developmental time from hatching to metamorphosis was significantly shorter for unfed tadpoles than for fed tadpoles, but fed individuals were significantly larger at transformation. Faster developmental rate and larger body size at transformation are both advantageous for frogs and toads, but cannot be attained simultaneously. Large egg size may afford flexibility in unpredictable environments. In pools where food is available, tadpoles presumably eat, take longer to metamorphose, but are larger at transformation than tadpoles developing in nutrient-poor sites. Small body size at transformation (a consequence of not eating) has potential costs, but the large quantity of yolk provided by a large egg enhances the probability of metamorphosis in food-limited environments.

Harlequin Frogs Along a Tropical Montane Stream: Aggregation and the Risk of Predation by Frog-Eating Flies

We observed larvae of the fly Notochaeta bufonivora (Sarcophagidae) feeding on harlequin frogs, Atelopus varius (Bufonidae), along a gallery forest stream in montane Costa Rica during the dry season. Harlequin frogs tended to aggregate in areas containing waterfall spray, and in these areas an individual's probability of attack by Notochaeta was greater than in areas lacking waterfall spray zones. To ascertain whether this increased risk to a frog resulted from its choosing an area with a waterfall spray zone or from being in an area of high frog density, we manipulated the density of frogs in a series of quadrats. The results of this experiment suggest that the increased risk of attack in the environs of waterfalls was a hazard associated with patch choice by the frogs rather than with aggregation per se. AGGREGATIONS OF ANIMALS have often been viewed in the context of predator avoidance (e.g., Hamilton 1971, Bertram 1978). However, because predation events in nature are usually brief and unpredictable in space and time, one can rarely assess the relationship between an individual's risk of predation and its proximity to conspecifics. We studied an extraordinary predator-prey interaction between the harlequin frog, A. varius (Bufonidae), and a frogeating fly, N. bufonivoraz (Sarcophagidae), along a montane stream in Costa Rica. Harlequin frogs, which are brightly variegated with yellow and black, contain the potent nerve poison tetrodotoxin in their integument (Kim et al. 1975). Although tetrodotoxin probably discourages most predators, or at least most predaceous vertebrates, Notochaeta larvae, which feed internally, appear unaffected by this chemical defense (Crump & Pounds 1985). Because a frog lives several days after attack by Notochaeta, the probability of detecting predation events is much higher than is usually the case for predator-prey systems involving anuran prey. This paper focuses on the relationship between aggregation behavior of harlequin frogs and risk of predation by these frog-eating flies. Male frogs and toads commonly exhibit a clumped pattern of dispersion within the breeding habitat (Whitney & Krebs 1975, Wells 1977), and this pattern may reflect a patchy distribution of resources such as suitable oviposition sites. On the other hand, a clumped pattern of dispersion within the habitat may also be attributable to the advantages of aggregation itself. In theory, being in a group may dilute an individual's probability of being eaten should a predator arrive (Hamilton 1971); this may be especially important for aposematic prey, as a naive predator may avoid the rest of the group after sampling one individual. Also, if females are more attracted to groups of males than to solitary displaying males, the average mating success may be higher for males in groups (Wells

Three New Species of Solanum Section Geminata (G. Don) Walp. (Solanaceae) from Panama and Western Colombia

Three New Species of Solanum Section Geminata (G. Don) Walp. (Solanaceae) from Panama and Western Colombia

Palicourea spathacea (Rubiaceae), an Unusual New Species from Costa Rica

Palicourea spathacea, a new species from montane Costa Rica, is noteworthy for its spathaceous calyx. This species seems best placed in Palicourea because it is closely related to several species of this genus. Palicourea is a genus of about 200 species of shrubs and small trees that are widely distributed in the moist tropical regions of the New World. Its distinguishing characteristics are persistent stipules that usually have two lobes or awns on each side and are often united intrapetiolarly as well as interpetiolarly; short, subnodal, fleshy sections of the stem that usually shrink with drying to form constrictions; baccate fruits that are bluish or purplish black at maturity; hemispherical seeds that have several longitudinal ridges on the back and a single longitudinal groove or fold on the inner face; and comparatively long (usually about 8 mm long or longer), bright white or colored corollas that are usually swollen asymmetrically at the base and bear a ring of hairs internally below the attachment of the anthers (fig. lc). Palicourea is closely related to the larger, pantropical Psychotria but differs in the features of the corolla described above. Palicourea spathacea possesses all of these characteristics and, in addition, it has an unusual spathaceous calyx. This feature is otherwise unknown in Palicourea, and it might be argued that this species would be better placed in a new genus emphasizing the unusual calyx. To do this would be to indicate that calyx morphology is more important than the other characters that hold Palicourea together. Within Palicourea, P. spathacea is not an isolated species. It is clearly very similar to P. bella (Standley) Dwyer of western Panama, which has an equally long calyx with five imbricate lobes. Several other species from Costa Rica and Panama, including P. macrocalyx Standley and P. lancifera Standley & L. 0. Williams, show successively longer corollas in a series linking P. bella with the more familiar species of Palicourea with minute calyx lobes. To place this new species in a separate genus would be to make an arbitrary break between species that clearly are very closely related to each other and would obscure far more information than it would convey. Palicourea spathacea, sp. nov., fig. 1.-TYPE: Costa Rica, Cartago, along the trail about 6 km beyond the gate to the meteorology station in Alto Patillos, Tapanti Hydroelectric Project, Utley and Utley 4538 (holotype: DUKE; isotypes: CR, F, US). Frutex; folia laminis ellipticis, abrupte acuminatis, 14-28 cm longis, 4.5-13 cm latis, subcoriaceis, glabris vel glabriusculis, nervis lateralibus utroque lat6re 15-25, petiolis 1-2 cm longis, stipulis 5-12 mm longis, lobis rotundis; paniculae glabrae, cernuae, 5-15 cm longae, 1120 cm latae, pedunculis 3.5-8 cm longis, bracteis ellipticis, 9-20 mm longis, foliaceis, purpureis; pedicelli 15-26 mm longi; calyx 9.5-20 mm longus, foliaceus, spathaceus, purpureus; corolla tubulosa, alba, tubo 32-37 mm longo; antherae 4.5-5 mm longae; semina 6-8 mm longa. Erect shrub or small tree 3-6.5 m tall. Stems quadrate and often channelled, glabrous or sparsely puberulent, with a short fleshy section usually present immediately below each node. Leaves with blades elliptic to slightly obovate, abruptly acuminate, with an acumen 1-1.5 cm long, basally cuneate and usually tapering, 1428 cm long, 4.5-13 cm wide, 1.8-2.4 times as long as broad, subcoriaceous, dark green above and glabrous or sometimes hirsutulous along the midrib, below paler with the lamina glabrous or more often puberulent, the costa, lateral veins, and lesser veins sparsely to densely strigillose with hairs 0. 1-0.2 mm long, the costa sometimes hirtellous or tomentulose as well; lateral veins 15-25 on each side of the midrib, obtusely angled to nearly patent, curving broadly to the margins, extending to them and sometimes forming a weak marginal vein; petioles angled, 1-2 cm long, glabrous or sparsely