bluuebunny/crossref_metadata_2025_split huggingface dataset:
Ants, Stem Borers, and Pubescence in Endospermum in Papua New Guinea1
Authors: Letourneau Deborah K. , Barbosa Pedro 
Published: March 2006

ABSTRACTThe stems of the ant‐plant, Endospermum labios Schodde, serve as colonization sites for the ant, Camponotus quadriceps F. Smith. They are also subject to damage by insect borers. We sampled young E. labios trees in distutbed forest to compare evidence of stem boring insect and stem miner damage in plants with and without colonies of C. quadriceps. Dissections of a subsample of plants showed that dipteran stem borers and stem miner damage were significantly more common in plants lacking C, quadriceps colonies than in plants with established colonies. Evidence from these dissections and from field counts of meristem damage caused by emerging borers suggested that coleopteran stem borers were also more abundant when ants were not present.In addition to the incidence of stem boring insects and ant colonies, we examined relative levels of leaf pubescence by measuring trichome density and leaf size for E. labios trees. We found that trichome density was significantly greater in trees with evidence of prior shoot damage (presumably from stem borer emergence at the meristem) but was not significantly related to the presence or absence of an ant colony. This prompted us to compare trichome density on leaves of nearby small trees and of different branches of the same tree, pairing a stem/branch that appeared damaged with one that appeared healthy. Trichome densities on leaves from damaged stems and branches were significantly greater than were trichome densities on healthy branches and stems. Based on these empirical data, we present several possible explanations for the patterns of association between ants, stem borers, and pubescence. Although feeding preference tests with a common folivore showed no effect of trichome densities on leaves, we suggest further study on how trichomes may affect ovipositing stem borers.
Evaporative Water Loss in Insular Populations of the Anolis cristatellus Group (Reptilia: Sauria) in the British Virgin Islands II: The Effects of Drought1
Authors: Perry Gad , Dmi'el Razi , Lazell James 
Published: March 2006

ABSTRACTPrevious work has shown that water loss in some populations of Anolis cristatellus from the British Virgin Islands is closely tied to the conditions available on the islands they inhabit. This manifested itself in a strong correlation between habitat aridity and several water loss rate parameters. Here we report on a similar study conducted in the same locations in 1994, a year of extreme drought.We hypothesized that lizards caught at the height of the drought will experience lower rates of water loss than those measured during a normal year. Our findings show that in 1994, as in 1993, habitat aridity and water loss parameters were strongly correlated. Also as before, the Guana Island population of A. cristatellus displayed higher resistance to water loss than expected by the island's aridity. However, a striking change occurred within populations. All were at least as good at retaining water (measured as integumentary resistance to water loss, R) as in 1993, and some were over 3.5 times better. Existing evidence is insufficient to determine whether these changes were the result of phenotypic plasticity or attributable to differential mortality of nonresistant individuals.
Roosting and Foraging Behavior of Two Neotropical Gleaning Bats, Tonatia silvicola and Trachops cirrhosus (Phyllostomidae)1
Authors: Kalko Elisabeth K. V. , Friemel Dorothea , Handley Charles O. , Schnitzler Hans‐Ulrich 
Published: March 2006

ABSTRACTWe studied roosting and foraging behavior of two Neotropical gleaning bats, ďOrbigny's round‐eared bat, Tonatia silvicola, and the fringe‐lipped bat, Trachops cirrhosus (Phyllostomidae). Techniques included radio‐tracking in a tropical lowland forest in Panama and analysis of data from long‐term studies in Panama and Venezuela. Day roosts of T. silvicola were in arboreal termite nests. T. cirrhosus roosted in a hollow tree. T. silvicola emerged late (ca 60 min after sunset), and foraged close to the roosts (maximum distance 200–500 m). T. cirrhosus emerged early (ca 30 min after local sunset), and foraged farther from its roost (>1.5 km). Both bats used small foraging areas (3–12 ha) in tall, open forest. They foraged in continuous flight (maximum 27–36 min) or in short sally flights (<1 minute) from perches (“hang‐and‐wait” strategy). The small foraging areas of these bats and their sedentary foraging mode most likely make them vulnerable to habitat fragmentation.
Short‐Term Disappearance of Foliar Litter in Three Species Before and After a Hurricane1
Authors: Sullivan Neal H. , Bowden William B. , McDowell William H. 
Published: March 2006

ABSTRACTLitter disappearance was examined before (1989) and after (1990) Hurricane Hugo in the Luquillo Experimental Forest, Puerto Rico using mesh litterbags containing abscisedCyrilla racemiflontorDacryodes excelsaleaves or freshPrestoea montanaleaves. Biomass and nitrogen dynamics were compared among: (i) species; (ii) mid‐ and high elevation forest types; (iii) riparian and upland sites; and (iv) pre‐ and post‐hurricane disturbed environments. Biomass disappearance was compared using multiple regression and negative exponential models in which the slopes were estimates of the decomposition rates subsequent to apparent leaching losses and the y‐intercepts were indices of initial mass losses (leaching).Cyrilla racemifloraleaves with low nitrogen (0.39%) and high lignin (22.1%) content decayed at a low rate and immobilized available nitrogen.Dacryodes excelsaleaves had moderate nitrogen (0.67%) and lignin (16.6%) content, decayed at moderate rates, and maintained the initial nitrogen mass.Prestoea montanafoliage had high nitrogen (1.76%) and moderate lignin (16.7%) content and rapidly lost both mass and nitrogen. There were no significant differences in litter disappearance and nitrogen dynamics among forest types and slope positions. Initial mass loss ofC. racemifloraleaves was lower in 1990 but the subsequent decomposition rate did not change. Initial mass losses and the overall decomposition rates were lower in 1990 than in 1989 forDacryodes excelsa. Dacryodes excelsaandC. racemifloralitter immobilized nitrogen in 1990 but released 10‐15 percent of their initial nitrogen in 1989, whereasP. montanareleased nitrogen in both years (25‐40%). Observed differences in litter disappearance rates between years may have been due to differences in the timing of precipitation. Foliar litter inputs during post‐hurricane recovery of vegetation in Puerto Rico may serve to immobilize and conserve site nitrogen.
Biomass Allocation in Cyperus papyrus in a Tropical Wetland, Lake Naivasha, Kenya1
Authors: Boar Rosalind R. , Harper David M. , Adams Christopher S. 
Published: March 2006

ABSTRACTThe nutrient status of Lake Naivasha, a freshwater lake in southeastern Kenya, has been rising since at least 1982. A potential effect of increases in nutrient supply to the lake's floating papyrus is increasing of the plants’ investment in above–water material and reduction of the amount of energy invested in uptake and storage. Biomass and its allocation between culms, panicles, roots, and rhizomes was measured in 17 sites around the 150–km2 lake. Although above–water biomass was greatest in sites closest to the lake's major nutrient inflow, the River Malewa, there was little evidence of corresponding decreases in the biomass of uptake and storage tissues. In August 1995, the average ± SD biomass of papyrus in the lake was 11,540 ± 3020 g/m2, with the papyrus containing about 4500 ± 1900 g total carbon/m2 and about 100 ± 70 g total nitrogen/m2. Plant nitrogen contents did not vary with distance from the main external nutrient supply. Together with low nitrogen concentrations in the plants (0.60 ± 0.26 in culms and 0.99 ± 0.50% in rhizomes), very high carbon to nitrogen ratios (49 ± 20:1) and nitrogen fixation in the rhizosphere explaining only about half of the plants’ nitrogen, papyrus is a likely net sink for nitrogen supplied from the lake's increasingly cultivated watershed. Despite this role, clearance of papyrus in favor of agriculture partly explains the reductions in the area of papyrus within the lake basin from 48 km2 in the late 1960s to 14 km2 in 1995.
Effects of Light Regime on Antioxidant Content of Foliage in a Tropical Forest Community1
Authors: Frankel Steven , Berenbaum May 
Published: March 2006

ABSTRACTA basic tenet of plant ecology is that under high light and limiting nutrient levels, carbon becomes relatively more available for investment in anti‐herbivore defense. Rarely considered in discussions of such defense investments, however, is the necessity for plants to defend themselves against oxidative damage caused by light exposure itself. To determine if the ability to respond to elevated levels of light exposure by increasing production of antioxidant compounds is a general characteristic of foliage in tropical plants, we conducted a broad survey of antioxidant content in foliage of 55 species in a tropical forest community by comparing individuals within forest gaps to conspecifics in the closed canopy forest. To do so, we devised a rapid assay to use under field conditions. Of the 41 species of shrubs, trees, and lianas demonstrating a discernible difference in antioxidant content under the two light regimes, 34 (68%) showed higher antioxidant content under high light conditions. In a quantitative laboratory‐based study using four of these species, light was associated with a 15 to 45 percent increase in water‐soluble antioxidants in three species; one species displayed a 118 percent increase in fat‐soluble antioxidants as well. Thus, changes in the chemistry of plant foliage in response to light may reflect plant investments in defense against abiotic stress factors as well as investments in defense against biotic stress factors.
Patterns of Clonal Diversity in Dicranopteris linearis on Mauna Loa, Hawaii1
Authors: Russell Ann E. , Ranker Tom A. , Gemmill Chrissen E. C. , Farrar Donald R. 
Published: March 2006

ABSTRACTThe clonal mat‐forming fern, Dicranopteris linearis (N. L. Burm.) Underw., dominates vast areas of rainforests on the windward slopes of Mauna Loa Volcano on the island of Hawai'i. Because clone size has important ecological and evolutionary consequences in such a dominant species, we used isozyme analysis to investigate clone size and other aspects of genetic diversity and reproduction over a broad range of environmental conditions on primary successional sites (pahoehoe lava substrates).Isozyme analysis provided a measure of the upper limit of clonal size in this interdigitating clonal species. Each 0.5‐ha primary successional site on Mauna Loa was comprised of a minimum of two to four clones. Genetic diversity in Dicranopteris was low; of 32 putative loci investigated, only 4 were polymorphic, with 2 or 3 alleles/locus. Over the 17 study locations on Mauna Loa and Kilauea Volcanoes, we identified nine multilocus genotypes based on unique combinations of allozymes. Seven of the nine genotypes were heterozygous for at least one locus, evidence of an intergametophytic mating system. Highly dispersible spores, coupled with intergametophytic mating should promote higher genetic diversity. We propose that the following factors contributed to low genetic diversity: founder effects; extreme isolation from mainland gene pools; high potential for mating among different gametophytes produced from the same sporophyte; relatively low numbers of safe sites for gametophyte establishment over space and time; and long‐term reliance on vegetative growth. Leaf phenotypes were associated with genotype, but also with environmental conditions. Enough variability within a genotype existed to support the current treatment of Hawaiian Dicranopteris as one species.Vegetative growth was the primary means by which Dicranopteris covered the landscape. Nevertheless, spore production, gametophyte establishment, and sexual reproduction were absolutely essential for colonization of the few favorable microsites available on pahoehoe lava substrates of Mauna Loa following lava eruptions, dieback, and similar landscape‐level disturbances.
Inflorescence Height Affects Visitation Behavior of Bees–A Case Study of an Aquatic Plant Community in Bolivia1
Authors: Gumbert Andreas , Kunze Jan 
Published: March 2006

ABSTRACTWe studied the bee fauna visiting a plant community of 10 species of flowering aquatic plants in an inundated savanna region in Bolivia. In total we observed 36 bee species in 17 genera at the flowers. Cluster analysis of the similarities among the plant species in terms of their visitor spectra showed a division into two groups: plants with inflorescence heights shorter than the grass height and plants with inflorescences projecting out of the surrounding vegetation. Larger bees of the genera Apis, Melipona, Bombus, and Xylocopa were observed only at flowers above the surrounding vegetation. Smaller, mainly solitary bees (e.g., Augochlorella, Ancyloscelis) visited flowers in the dense vegetation near the water surface. Analyses of the pollen loads revealed that most individuals were highly flower constant. When bees carried different pollen types, it was generally pollen from flowers within a single stratum. We discuss specialization, flower constancy, competition, and different foraging strategies as possible reasons for stratum fidelity.
Use of Vocal Signatures for the Inventory of Free‐flying Neotropical Bats1
Authors: O'Farrell Michael J. , Miller Bruce W. 
Published: March 2006

ABSTRACTAn ongoing study is being conducted to test the efficacy of the Anabat II detector and analysis system in obtaining reliable vocal signatures for the identification of non–phyllostomid species of bats. We sampled a wide range of elevations and associated habitat types throughout Belize. Anabat provides an instantaneous output of echolocation call structure with a laptop computer. Select sequences can be saved directly to the hard drive, avoiding extraneous noise and sound distortion commonly associated with tape recorders. To date, 18 of the 37 species known or expected to occur in the study region were identified by recognizable differences in the time–frequency characteristics of echolocation calls. In general, each family is recognizable by call structure patterns and species readily separated by frequency range parameters. Species that commute or forage at high altitudes are not susceptible to capture but are conspicuous by acoustic sampling. Further work is needed to determine limitations of the equipment, establish better sampling procedures, and develop a comprehensive library of vocal signatures incorporating the range of variation inherent in each species. As this work progresses, we predict the addition of hitherto unknown species occurring within the study region.
Long‐term Persistence of Raphia taedigera Mart. Swamps in Nicaragua1
Authors: Urquhart Gerald R. 
Published: March 2006

ABSTRACTThe palm Raphia taedigera Mart, forms vast, monodominant swamps in Central and South America, but very little is known about the ecology and natural history of these ecosystems. Debate surrounds the issue whether R. taedigera swamps are early successional stages or mature “climax” communities. This paleoecological analysis of a 1.46‐m sediment core from swamps on the Caribbean coast of Nicaragua establishes the abundant presence of R. taedigera swamps for at least 2800 ± 90 years. R. taedigera swamps must be considered persistent communities, warranting further study because of their great extension into Central and South America.
Vagility and the Monsoon Rain Forest Archipelago of Northern Australia: Patterns of Genetic Diversity in Syzygium nervosum (Myrtaceae)1
Authors: Shapcott Alison 
Published: March 2006

ABSTRACT Syzygium nervosum is a common monsoon rain forest tree. Its habitat in Australia consists of small rain forest patches that are scattered through a savanna matrix. It is a mast flowering canopy species that produces large quantities of fruits fed on by mobile frugivores such as birds and fruit bats. The genetic diversity of this species was investigated, especially in relation to rain forest patch size, geographic isolation, and geographic distribution. Syzygium nervosum was found to have high levels of genetic diversity within populations (He= 0.307). Diversity among populations, however, was relatively low (Fsr = 0.118), and was not spatially structured across its geographic range in Australia. This is thought to have been caused by relatively frequent gene flow among populations (Nm= 1.67), mediated primarily by mobile frugivores. Genetic diversity was not correlated with patch size or isolation. It is thought that seed dispersal by frugivores has acted to expand the effective population size of this species beyond the individual rain forest patch, and thus has prevented the substantial loss of genetic diversity that otherwise would have been observed. Thus this species is dependent upon these frugivores for the maintenance of its genetic diversity and hence its long‐term viability. These results lend support to theories of post‐Holocene expansion of rain forest by vagile species in northern Australia.
Small Gap Creation in Belizean Mangrove Forests by a Wood–Boring Insect1
Authors: Feller IIka C. , McKee Karen L. 
Published: March 2006

ABSTRACTWe investigated the role of wood‐boring insects in the creation of light gaps within mangrove forests. We compared the frequency of gaps caused by wood borers to other gap‐forming processes and characterized the physical attributes of light gaps in mangrove forests on small islands in Belize. Methods of quantifying light gaps included aerial photography, ground surveys, and experimental plots. Small light gaps (≤12 m2) were very common in Rhizophom mangle fringe, comprising almost 22 percent of these forests. Rhizophora mangle gaps were smaller than gaps in Avicennia germinans forests. In R. mangle forests, gaps were caused by branch death, and in A. germinans forests, gaps were caused primarily by downed trees. More than 91 percent of the gap‐forming branches and boles in the R. mangle fringe were killed by a wood‐boring cerambycid beetle, Elaphidion mimeticum, indicating that it is the major cause of small‐scale disturbances in these forests. No trees or branches in the A. germinans forest were attacked by this beetle. In R. mangle forests, small gaps had significantly higher light levels and soil temperatures than areas under the closed canopy; however, soil conditions for sulfide concentrations, porewater salinity, and redox potentials were similar in small gaps and under the closed canopy. Survival of R. mangle, A. germinans, and Laguncularia racemosa seedlings was also higher inside these small gaps, indicating their importance in regeneration of mangrove forests. Feeding by wood borers is thus an important type of indirect herbivory in mangrove forests, with a critical role in ecological processes such as gap dynamics.
Reproductive Ecology of Understory Species in a Tropical Montane Forest in Costa Rica1
Authors: Wesselingh Renate A. , Witteveldt Martin , Morissette Julienne , den Nijs Hans C. M. 
Published: March 2006

ABSTRACTThe reproductive ecology of nine hermaphroditic understory species in a tropical montane Quercus forest was studied at two sites (2300 and 2600 m elev.) in the Cordillera de Talamanca, Costa Rica. Flower life span, studied in six species, averaged 4.4 d. This is longer than flower life spans found in the Monteverde cloud forest (2.7 d) and comparable to flower life spans found for arctic and alpine species. We studied the breeding system in five species and found no self‐incompatible species. Four species proved self‐compatible, and three of these showed autogamy. The main diurnal insect pollinator was the bumblebee Bombus ephippiatus. Natural fruit set was low (8‐32%) in six species with few seeds per fruit, while two many‐seeded species showed a high rate of fruit set (90 and 96%). The incidence of pre–dispersal seed predation was high; the percentage of seeds infested in four species ranged from 8 to 56 percent.
Rareza y Diversidad de Hormigas en Fragmentos de Bosque Seco Colombianos y sus Matrices1
Authors: Armbrecht Inge , Ulloa‐Chacón Patricia 
Published: March 2006

RESUMENLos bosques secos del valle medio del Rio Cauca (suroeste de Colombia) ban sido casi eliminados de la región y los últimos remanentes corren peligro de desaparecer. Este estudio registra el valor boilógico de siete fragmentos de bosque comparando la diversidad y rareza de hormigas dentro de ellos con la de las matrices (alrededores antropogénicos del bosque). Entre agosto de 1994 y febrero de 1995 se hicieron dos muestreos intensivos de hormigas en cada fragmento boscoso y su matriz. El esfuerzo de muestreo fue similar en cada uno de los siete sitios. Todos los fragmentos boscosos fucron más ricos y más diversos que sus matrices respectivas. Los bosques preservan un número mayor de especies raras de hormigas que las matrices. A medida que el bosque se hace más rico en hormigas, mayor es el número dc especies de hormigas exclusivas que preserva. Estos bosques deben ser preservados para mantener la biodiversidad regional.
Seed Dispersal by Salvin's Curassow, Mitu salvini (Cracidae), in a Tropical Forest of Colombia: Direct Measurements of Dispersal Distance1
Authors: Yumoto Takakazu 
Published: March 2006

ABSTRACTSeed dispersal by Salvin's curassows (Mitu salvini) was studied in a lowland tropical forest at La Macarena on the border of the Macarena and Tinigua National Parks, the Department of Meta, Colombia. Continuous observations were made on the feeding and ranging behavior of a well‐habituated pair of birds from 0600 to 1800 h for 19 days. Ibtal observation time was 222 h. The daily distance traveled by the birds ranged from 630 to 3750 m, with a mean of 1959 m (± 776 m). The total home range was ca 34.4 ha. Although curassows were observed consuming fruits of 13 species belonging to the families Rubiaceae, Meliaceae, Moraceae, Burseraceae, Leguminosae, and Lecythidaceae, only seeds of Geophila re fens (Rubiaceae) and Picas spbenophylla (Moraceae) were found in their feces. For G. repens, the mean and maximum retention times were 1 h 52 min (± 1 h 20 min) and 6 h 08 min, and the mean and maximum direct dispersal distances were 245 m (± 164 m) and 633 m. More than half the seeds were dispersed in canopy gaps. For F. sphenophylla, the mean and maximum retention times were 3 h 1 5 mm (± .37 min) and 7 h 08 min, and the mean and maximum direct dispersal distances were 329 m (± 46 m) and 451 m. Nearly 60 percent of the estimated seed intake of G. repens and 92‐94 percent of F. sphenophylla were digested or damaged. The retention times and the dispersal distances for Streptogyna americana, which has adhesive burrs, were also measured. The mean and maximum retention times were 1 h 55 min (± 1 h 56 min) and 9 h 11 min, and the mean and maximum direct dispersal distances were 128 m (± 68 m) and 280 m. This is the first study in which direct measurements were made for retention times and dispersal distances of the epizoochory and endozoochory for birds in the field.