bluuebunny/crossref_metadata_2025_split huggingface dataset:
Stand Characteristics and Leaf Litter Composition of a Dry Forest Hectare in Santa Rosa National Park, Costa Rica
Authors: Burnham Robyn J. 
Published: March 2006

ABSTRACTOne hectare of tropical dry forest in Guanacaste Conservation Area, Costa Rica was mapped and all trees larger than 10 cm diameter at breast height (DBH) identified. The same hectare was sampled for leaf litter and the two data sets, forest and litter, were compared. Dominant and subdominant species of the forest are represented in the leaf litter, whereas rare tree species are highly variable in their representation in the leaf litter. Relative abundance of dominant and subdominant tree species is represented well by the litter although absolute rank‐order is nor identical between source forest basal area and leaf litter mass. The litter adds a significant component to the source forest data owing to the presence of vines and lianas, and more rarely small trees or shrubs. This indicates that litter studies may be able to add depth to forest diversity surveys. The source forest also was used to test foliar physiognomic reconstructions of climate that have been proposed recently by paleobotanists as an alternative to taxonomic affinities methods. The observed climate of the area does not conform to the climatic values that were predicted by application of these new methods.RESUMENUna hectárea de bosque seco tropical en el Area de Conservación de Guanacaste, Costa Rica fue mapeada, y todos los árboles mayores de 10 cm de dap fueron identificados. En la misma hectárea, se tomaron muestras de hojarasca y los dos colecciones de datos. bosque y hojarasca, fueron comparadas. Se encontró que las especies dominantes y subdominantes del bosque estaban representadas en las muestras de hojarasca, mientras que la presencia de especias arbóreas raras en las muestras de mojarasca fue muy variable. La abundancia relativa de especies arbóreas dominantesestá bien representada en la hojarasca aunque el área basal del bosque de origen y la masa de hojarasca no heron idénticos en rangos absolutos. La hojarasca añade un componente significativo a los datos del bosque de origen debido a la presencia de bejucos y lianas en la hojarasca, y más raramente árboles pequeños y arbustos. Estos datos indican que los estudios de hojarasca pueden incrementar la precisión de las estimaciones de la diversidad de los bosques. El bosque de origen fue usado tarnbien para examinar reconstrucciones del clima basados en la fisiognomia foliar recientemenre propuesras por paleobotánicas como una alternativa a métodos de afinidad raxonómicas. El clima observado en el área no corresponde con los valores climáticos que fueron predecidos por la aplicación de estos nuevos métodos.
Primary Herbivory by Wood‐Boring Insects along an Architectural Gradient of Rhizophora mangle
Authors: Feller Ilka C. , Mathis Wayne N. 
Published: March 2006

ABSTRACTWe investigated the distribution of primary xylovores in Rhizophora mangle (red mangrove) first‐order branches, i.e., “twigs”, along an architectural gradient on Belizean mangrove cays. Greater structural diversity in R. mangle architecture, xylovore availability, occurrence of natural enemies, and habitat do not result in variable xylovore species richness. Despite large differences in architectural complexity, tall, fringe, dwarf, and sapling trees host the same set of primary wig borers. However, tall trees support greater diversity and abundance of twig inquilines than other tree forms. Primary twig borers have a key role in structuring these mangrove communities because their galleries and pupal chambers provide habitats for numerous species of secondary xylovores and inquilines. We also measured the amount of leaf area removed from R. mangle's canopy by wood‐ and leaf‐feeding herbivores. Vigorously growing tall and sapling trees sustain greater losses because of twig borers than dwarf trees. However, xylovory in fringe trees was not different from any of the other categories. Cumulative herbivory was greatest in the tall trees. In most cases, leaf‐area loss as an indirect or collateral result of primary xylovory equaled or exceeded leaf‐area loss as a direct result of folivory.
Effects of Species, Habitat, and Distance from Edge on Post‐dispersal Seed Predation in a Tropical Rainforest1
Authors: HOll Karen D. , Lulow Megan E. 
Published: March 2006

ABSTRACTWe examined the effects of species, habitat type (open pasture, forest, and beneath isolated pasture trees), and distance from the forest/pasture edge (25 m and 250 m) on post‐dispersal seed predation of ten animal‐dispersed species near the Las Alturas Biological Station in southern Costa Rica. We also compared the amount of seed predation due to vertebrate and insect predators. Levels of seed predation were extremely species‐specific, ranging from 20–100 percent of seeds consumed during the 30 day study period. However, the proportion of seeds remaining was not correlated with seed size. Overall, seed mortality did not differ between the forest and open pasture habitats, but was significantly lower under isolated pasture trees. Individual species differed in which habitat they suffered the highest levels of predation. For eight of ten species studied, levels of seed predation did not vary significantly with distance from the foredpasture edge in any habitat. The majority of the post‐dispersal seed predation was due to mammalian predators. The results of this and other studies suggest that post‐dispersal seed predation may influence patterns of forest regeneration in disturbed areas.RESUMENInvestigamos el efecto de la especie, el tipo de hábitat (pastizal abierto, bosque, y debajo de árboles aislados en el pastizal), y la distancia a la orilla del bosque, sobre la depredación de semillas de diez especies dispersadas por animales cerca de la Estación Biológica Las Alturas en el sur de Costa Rica. Además comparamos la depredación causada por vertebrados e insectos. Los niveles de depredación fueron muy variables entre especies, entre el 20 y 100 por ciento fué depredado durance los 30 dias del estudio. No hubo correlación entre la proporción de semillas no depredadas y su tamaño. No existió una diferencia entre el bosque y el pastizal en la mortalidad total de las semillas, pero la mortalidad fue menor debajo de 10s árboles aislados. La depredación de semillas de diferentes especies varió en relación al hábitat. Para ocho de las diez especies los niveles de depredación no variaron en relación con la distancia a la orilla del bosque en ninguno de 10s hábitats. La mayoría de la depredación fué ocasionada por mamíferos. Los resultados de éste y otros estudios sugieren que la depredación de semillas influye en la regeneración del bosque en tierras degradadas.
Bird Populations in Rustic and Planted Shade Coffee Plantations of Eastern Chiapas, México
Authors: Greenberg Russell , Bichier Peter , Sterling John 
Published: March 2006

ABSTRACTMuch of the remaining “forest” vegetation in eastern Chiapas, Mexico is managed for coffee production. In this region coffee is grown under either the canopy of natural forest or under a planted canopy dominated by Inga spp. Despite the large differences in diversity of dominant plant species, both planted and rustic shade coffee plantations support a high overall diversity of bird species; we recorded approximately 105 species in each plantation type on fixed radius point counts. We accumulated a combined species list of 180 species on repeatedly surveyed transects through both coffee plantation types. These values are exceeded regionally only by moist tropical forest. Of the habitats surveyed, shade coffee was second only to acacia groves in the abundance and diversity of Nearctic migrants. The two plantation types have similar bird species lists and both are similar in composition to the dominant woodland—mixed pine‐oak. Both types of shade coffee plantation habitats differ from other local habitats in supporting highly seasonal bird populations. Survey numbers almost double during the dry season—an increase that is found in omnivorous migrants and omnivorous, frugivorous, and nectarivorous resident species. Particularly large influxes were found for Tennessee warblers (Vermivora peregrina) and northern orioles (Icterus galbula) in Inga dominated plantations.
Tree and Liana Enumeration and Diversity on a One‐Hectare Plot in Papua New Guinea1
Authors: Wright Debra D. , Jessen J. Heinrich , Burke Peter , de Silva Garza Hector Gomez 
Published: March 2006

ABSTRACTEnumeration of a one hectare plot at 900 m a.s.l in Papua New Guinea revealed 693 individuals of 228 tree and liana species ≥ 10 cm DBH. A 0.1 hectare subplot contained 302 individuals of 106 species 2.5 ≥ DBH < 10 cm. Lauraceae, Moraceae, and Myristicaceae were the most important families in both size classes. This site is very diverse compared with other tropical forests, and like other species‐rich sites worldwide, it has high aseasonal rainfall and high rates of natural disturbance.
Microhabitats and Water Relations of Epiphytic Cacti and Ferns in a Lowland Neotropical Forest1
Authors: Andrade José Luis , Nobel Park S. 
Published: March 2006

ABSTRACTThe pattern of canopy distribution and some water relations characteristics of the epiphytic cacti Epiphyllum phyllanthus and Rhipsalis baccifera and the epiphytic ferns Polypodium crassifolium and Polypodium phyllitidis were examined in the tropical forest of Barro Colorado Island, Panama. The epiphytic cacti were 6‐fold more succulent than the epiphytic ferns, which had a 9‐fold higher root: shoot ratio. The four species, especially the cacti, were more abundant on the deciduous trees Ceiba pentandra, Platypodium elegans. and Tabebuia guayacan than on the evergreen Anacardium excelsum. The water‐holding capacity of the bark was 2‐fold higher for A. excelsum and T. guayacan than for C. pentandra and P. elegans; the main crotches of the latter species intercepted 2‐fold more rainfall than those of the former. Well‐watered plants of all epiphytic species showed similar total daily transpiration. After 2 weeks of drought, daily transpiration decreased an average of 48 percent for the cacti and 73 percent for the ferns. After 4 weeks of drought, daily transpiration decreased 80 percent for the cacti and was eliminated for the ferns; succulence then decreased an average of 29 percent for the cacti and 98 percent for the ferns, but all species recovered fully within 2 d after rewetting. The epiphytic ferns had a low relative capacitance (0.16 M/Pa), causing these presumably C3 plants often to be under water stress. A high relative capacitance (0.50 M/Pa) and crassulacean acid metabolism allowed the epiphytic cacti to occur most frequently on the driest sites of this tropical forest.
Within‐Crown Flowering Synchrony in Strangler Figs, and Its Relationship to Allofusion1
Authors: Thomson James D. , Dent‐Acosta Sara , Escobar‐Píramo Patricia , Nason John D. 
Published: March 2006

ABSTRACTWe studied flowering phenology at the level of individual branches within strangler fig trees to determine (1) whether branches bloomed asynchronously within trees and (2) whether asynchrony, if observed, could be ascribed to genetically different branches of mosaic trees (i.e., trees formed by spontaneous grafting of genetically different individuals) undergoing individual flowering cycles that were out of phase with each other. Although asynchrony was fairly common, it most often reflected individual branches failing to bloom during one flowering episode, then coming back to bloom in synchrony at the next episode. We detected fewer mosaic trees than expected, and found only a very weak suggestion that mosaic trees may show less within‐tree synchrony than simple trees.
Pollen Flow, Fecundity, and the Adaptive Significance of Heterostyly in Palicourea padifolia (Rubiaceae)1
Authors: Ree Richard H. 
Published: March 2006

ABSTRACT Palicourea padifolia is a distlous shrub visited primarily by hummingbirds and bees in mid‐elevation rain forests in Costa Rica. At Las Cruces Biological Station, the population of P. padifolia is composed of equal numbers of pin and thrum plants and morphs are randomly distributed. Like the majority of distylous species, P. padifolia exhibits a self and intramorph‐incompatible mating system. The analysis of stigmatic pollen loads obtained from emasculated flowers shows that pollen flow between floral morphs is disassortative, which supports the Darwinian hypothesis concerning the adaptive significance of heterostyly. Pins experience greater disassortative pollination than thrums. Pins also set more seed than thrums, suggesting that the higher frequency of compatible pollen deposited on pin stigmas results in greater fecundity; alternatively, greater seed set in pins could be due to the differential allocation of resources to male and female function between morphs. Overall, seed set for the Las Cruces popularion of P. padifolia is much lower than the potential maximum. Factors which could contribute to seed set limitation include the frequency and/or spatial pattern of pollinator visits, pollen availability, and resource availability.
Reproductive Biology of the Monoecious Understory Palm Prestoea schultzeana in Amazonian Ecuador1
Authors: Ervik Finn , Feil Jan P. 
Published: March 2006

ABSTRACT Prestoea schultzeana is a monoecious, protandrous palm in the forest understory of Amazonian Ecuador. We studied its leaf production, population density, sexual expression, phenology, pollination, and the specificity of the floral visitors. On average, 1.4 leaves and 0.9 inflorescences are produced per individual per year. The number of staminate flowers per inflorescence is relatively constant compared with the number of pistillate flowers which varies greatly. Flowering occurs in staminate and pistillate phases of approximately 19 and 0–7 days duration, respectively. Flowers open in the morning, and staminate flowers abscise in the afternoon of the same day whereas pistillate flowers last for two days. Flowers are whitish‐yellow with a sweet odor and produce nectar. They were visited by Coleoptera (Chrysomelidae, Curculionidae, Nitidulidae, Ptiliidae, Staphylinidae), Hemiptera, Diptera (Drosophilidae, Syrphidae, Ceratopogonidae), Lepidoptera (Nymphalidae), and Hymenoptera (Formicidae, Halictidae). All examined individuals of the syrphid fly Copestylum sp. visiting pistillate flowers carried 100–500 grains of P. schultzeana pollen. Pollen occurred on all body parts, but especially on the legs, and this makes Copestylum sp. the most important pollinator. Most floral visitors were also frequent on the flowers of co‐occurring plant species; notably the palm Hyospathe elegans shared most visitor species with P. schultzeana.
Global Patterns of Pre‐Dispersal Propagule Predation in Mangrove Forests1
Authors: Farnsworth Elizabeth J. , Ellison Aaron M. 
Published: March 2006

ABSTRACTMangroves in disparate families produce viviparous seedlings (propagules) that are attacked by many crab and insect predators both before and after dispersal. While post‐dispersal predation is viewed as an important factor in structuring many mangrove communities, pre‐dispersal predation rates and agents have been characterized for few species. Ten species of mangrove and 3299 propagules were surveyed for pre‐dispersal propagule predation at 42 sites around the world. Pre‐dispersal predation rates were variable among sites and species, ranging from 0 to 93 percent within sands, with a global total predation rate of 23.3 percent (across all propagules examined) and a mean level of 28.3 percent across sites. Grapsid crabs, Coleoptera and Lepidoptera were the primary predators identified. Forests near human population centers and stands occurring at high intertidal sites exhibited higher levels of propagule predation than those in unpopulated or low‐intertidal sites. Predation rates on a species were weakly, negatively correlated with conspecific seedling density at a site. To explore temporal variation in, and ramifications of pre‐dispersal predation for propagule growth and abscission dynamics, Rhizophora mangle propagules were monitored over two years at three sites in Belize, Central America. Predation did not significantly reduce hypocotylar growth of germinated propagules on the parent tree, but nearly doubled the abscission rate of premature propagules. Pre‐dispersal propagule predation is a ubiquitous feature of mangrove forests world‐wide, and must be accounted for in estimates of reproductive output, stand health, and propagule availability for forestry and restoration efforts.
Factors Influencing the Selection of Basking Perches on Cardon Cacti by Spiny‐Tailed Iguanas (Ctenosaura hemilopha)1
Authors: Blízquez M. Carmen , Rodríguez‐Estrella Ricardo 
Published: March 2006

ABSTRACTThe selection of optimal basking perches to achieve preferred body temperatures and avoid predation risks is one of the most important behavioral decisions that a lizard makes. We studied perch selection by the spiny‐tailed Iguana (Ctenosaura hemilopha) in Baja California Sur where they bask on elevated cacti. The more important factor determining cardon selection by iguanas was the presence of old woodpecker holes which could be used as refuges within the top 50 cm of a branch. Other factors are the height of the cardon, the presence of some other holes and the number of branches of the plant. These data suggest that predation risk is the strongest factor affecting the selection of certain cardons as basking structures by spiny‐tailed iguanas. Because the holes are mainly old woodpecker nests, the choice of a cardon as a refuge‐perching site has to be related to a prior selection by woodpeckers.
The Contribution of Ant‐Plant Protection Studies to Our Understanding of Mutualism1
Authors: Bronstein Judith L. 
Published: March 2006

ABSTRACTOne common class of ant‐plant mutualism involves ants that defend plants from natural enemies in return for food and sometimes shelter. Studies of these interactions have played a major role in shaping our broad understanding of mutualism. Their central contribution has come via their development of approaches to measuring the benefits, costs, and net outcomes of mutualism, and their explicit consideration of variability in all of these phenomena. Current research on these interactions is suggesting ecological and evolutionary hypotheses that may be applicable to many other forms of mutualism. It is also generating comparative data for testing the few general theories about mutualism that currently exist.
Density Patterns ofPiperAnt‐Plants and Associated Arthropods: Top‐Predator Trophic Cascades in a Terrestrial System?1
Authors: Letourneau D. K. , Dyer L. A. 
Published: March 2006

ABSTRACTTop‐predator (fourth‐trophic‐level) controlled trophic cascades are thought to be uncommon in terrestrial systems, but actual quantitative tests and comparisons of bottom‐up and top‐down forces in systems with more than three linear trophic levels are rare. Here, we describe the density patterns of the arthropod community associated withPiperant‐plants in Costa Rican wet forests. Consumers in this community comprise a complex, interacting web of herbivores, predaceous ants, and predators of ants. Although the hollow stems and petioles of thePiperplants provide some protection to resident ants from predation, specializedDipoenaspiders andPhyllobaenusbeetles exploitPheidoleants inhabitingPiperplants. We report abundance patterns of plants, ants and predators in four forests. These patterns of abundance are consistent with predictions of top‐down cascades across four trophic levels when the top predators are effective (beetles). We discuss how top‐down and bottom‐up forces may interact in systems with less effective top predators (spiders).
Interactions between Fungus‐Growing Ants (Attini), Fruits and Seeds in Cerrado Vegetation in Southeast Brazil1
Authors: Leal Inara R. , Oliveira Paulo S. 
Published: March 2006

ABSTRACTWe surveyed the material collected for fungus culturing by attine ants in the cerrado vegetation of southeast Brazil. Six genera of the so‐called lower attines (Cyphomyrmex, Mycetarotes, Mycocepurus, Myrmicocrypta, SericomyrmexandTrachymyrmex) collect a wide variety of plant material as fungal substrate. Plant diaspores of nonmyrmecochorous species comprise a large portion of the items brought to the nest, especially in the rainy season. Removal experiments using fruits of selected plant species revealed that attine ants (including the leaf‐cuttersAttaandAcromyrmex) not only actively clean the seeds (remove fruit pulp), but also carry them up to 12 m in the cerrado. Germination tests showed that removal of fruit pulp by attine ants increases germination rate inOcotea pulchella(Lauraceae),Prunus sellowii(Rosaceae),Ouratea spectabilis(Ochnaceae),Rapanea umbellata(Myrsinaceae) andPsychotria stachyoides(Rubiaceae). ForP. stachyoides, however, ants had no effect on germination if seeds had already passed the digestive tract of birds. Aril removal by attines also increases germination success ofCopaifera langsdorffii(Leguminosae) andVirola sebifera(Myristicaceae) seeds. The results indicate that attine‐fruit/seed interactions are particularly conspicuous in the cerrado, suggesting that fungus‐growing ants may play a relevant role in fruit/seed biology in this vegetation type. Potential ant‐derived benefits to diaspores of nonmyrmecochorous plants in the cerrado would include secondary seed dispersion and/or increased germination success by ant‐handled seeds.
Geographical and Seasonal Variation in the Richness of Ant‐Plant Interactions in México1
Authors: Rico‐Gray Victor , García‐Franco José G. , Palacios‐Rios Mónica , íz‐Castelazo Cecilia , Parra‐Tabla Victor , Navarro Jorge A. 
Published: March 2006

ABSTRACTThe richness and seasonal variation of ant‐plant interactions were compared in four habitats in México: lowland tropical dry forest (La Mancha, Veracruz), coastal sand dune matorral (San Benito, Yucatán), semiarid highland vegetation (Zapotitlán, Puebla), and lower montane humid forest (Xalapa, Veracruz). The effects of temperature and precipitation on the seasonal distribution of the number of ant‐plant interactions differed among habitats. The general linear models fitted to the ant‐plant interaction curves explained 78.8 percent of the variation for La Mancha, 80.1 percent for Zapotitlán, 18 percent for San Benito, and 29.5 percent for Xalapa. Even though rainfall is low in Zapotitlán and San Benito, minimum temperature was the most important factor accounting for the seasonal distribution and low number of interactions. At La Mancha, with milder minimum temperatures and higher water availability, temperature alone did not account for the seasonal distribution and number of interactions, whereas the effect of the precipitation × temperature interaction was highly significant. Xalapa exhibits the lowest temperatures and the highest precipitation, but the role of these factors was only marginal. We suggest that the vegetation at Xalapa, a mixture of tropical and temperate floristic elements, constrains ant‐plant interactions due to a limited presence of nectaries. Also, ants are less abundant in cool and relatively aseasonal habitats. The other habitats have tropical floristic elements that are abundant and frequently have nectar‐producing structures. We report considerable variation among habitats in the number and seasonal distribution of ant‐plant interactions, and suggest that it is due to the effect of variation in environmental parameters, the richness of plants with nectaries in the vegetation, and habitat heterogeneity.