bluuebunny/crossref_metadata_2025_split huggingface dataset:
Small mammal community structure and composition in the Cerrado Province of central Brazil
Authors: Mares Michael A. , Ernest Kristina A. , Gettinger Donald D. 
Published: July 2009

ABSTRACTCommunity structure, macrohabitat selection, and patterns of species co-occurrence were examined during a 14-month study of small mammals in the Cerrado Province of central Brazil. Data were collected from mark-recapture grids in brejo and gallery forest, and from live-trapping and specimen collection in all habitat types within cerrado (campo limpo, campo sujo, cerrado [s.s.], cerradão, brejo, valley-side wet campo, and gallery forest). Gallery forest supported the highest species richness, most complex vertical distribution of species, highest level of trophic diversity, and highest macroniche diversity. Degree of habitat selection varied widely. All habitat types supported both rodents and marsupials, although marsupials tended to be much less common in the grasslands (campos) than in woodlands (cerrado) and forests (cerradão, gallery forest). Some species, such asDidelphis albiventris, occurred in all habitat types, while others were much more restricted.Oryzomys bicolor, for example, ocur-red only in gallery forest. No habitat type had a completely distinct fauna: overlap in species composition always occurred with at least one other habitat type. Because of the great variability of habitats, and the fact that subsets of the mammal fauna were frequently habitat specific, the overall species richness of any portion of mixed cerrado vegetation is remarkably high.
Fruiting and frugivores at a strangler fig in the tropical rain forest of Los Tuxtlas, Mexico
Authors: Coates-Estrada Rosamond , Estrada Alejandro 
Published: July 2009

ABSTRACTDiurnal and nocturnal censuses were conducted on animal visitors at a single strangler Ficus aff. cotinifolia (H.B.K.) tree during the entire period of ripe fruit availability. Fruit fall to the ground was measured with fruit traps, and chemical analyses were conducted on the figs. Fourteen species of birds, four species of nonvolant mammals and two species of bats consumed the figs. Of the total number of ripe figs accounted for during the sampling period (N= 1.9 X 105), 42% fell to the ground, 45% were removed by mammals and 13% by birds. Frugivores such as the howling monkey Alouatta palliata, the cacomistle Bassariscus sumichrasti, the keel-billed toucan Ramphastos sulphuratus and fruit-eating bats removed the largest amounts of figs from the tree and deposited seeds of 13 plant species other than figs below the tree crown.
Leaf production, growth rate, and age of the palm Prestoea montana in the Luquillo Experimental Forest, Puerto Rico
Authors: Lugo Ariel E. , Batlle Carmen T. Rivera 
Published: July 2009

ABSTRACTLong-term growth rates of 32 palms (Prestoea montana) were studied using height and diameter measurements taken four times between 1946 and 1982. All leaf scars were counted to estimate leaf production rate, and the distance between scars was measured to establish relationships between leaf production and height growth. Height and diameter growth and leaf production of these palms were not constant during this 36-year period. A greater distance between leaf scars was indicative of rapid height growth but not of high leaf production rate. Dominant palms always grew fast (> 20 cm/yr) in height when they were small, but height growth slowed down when they reached the canopy. Small palms with slow height growth remained suppressed and lost the capacity to grow rapidly in height as adults. Diameter growth decreased with age from 0.07 cm/yr (SE = 0.02) between 1946–51 to 0.01 cm/yr (SE = 0.003) between 1951–82. Annual leaf production averaged 4 leaves/yr over the 36 years of study, was significantly different (P = 0.001) between 1946–51 (5.6 leaves/yr) and 1951–82 (3.8 leaves/yr), and was 4.6 leaves/yr for palms that grew >5 m since 1946 and 3.7 leaves/yr for those that remained suppressed. The best estimate for the mean age of all palms was 61.1 yr (SE = 2.4), obtained from long-term population leaf production rates.
Site characteristics and the distribution of tree species in Mixed Dipterocarp Forest on Tertiary sediments in central Sarawak, Malaysia
Authors: Baillie I. C. , Ashton P. S. , Court M. N. , Anderson J. A. R. , Fitzpatrick E. A. , Tinsley J. 
Published: July 2009

ABSTRACTSite data from 291 forest inventory plots in Mixed Dipterocarp Forest in central Sarawak were simplified by factor analysis. The distribution of the 33 commonest canopy tree species was related to site factor scores by ‘t’ tests. There appears to be a degree of edaphic influence on the distribution of many species. Fairly constant soil characteristics related to the lithology of the parent material appear to be more important than ephemerally variable pro perties such as organic matter or exchangeable cations. Magnesium appears to be particularly important, possibly because of an effect on the capacity of mycorrhizal root systems to absorb phosphorus.
Tree population dynamics at Kade, Ghana (1968-1982)
Authors: Swaine M. D. , Hall J. B. , Alexander I. J. 
Published: July 2009

ABSTRACTChanges in two 1-ha samples of Moist Semi-deciduous forest at Kade, Ghana are described for 14 years from 1968 to 1982. Density of trees ≥10 cm dbh was 552 ± 13 ha−1and the basal area was 30.85 ± 1.38 m2 ha−1, and showed little variation over the study period: diameter class distributions did not change significantly. There were 120 species of tree ≥10 cm dbh, including seven immigrants and seven emigrants.Mortality did not differ significantly between diameter classes, but was significantly greater amongst trees showing negative diameter increment. Total mortality for the 2 ha over the 12-year period 1970–1982 was 216 trees (1.77% yr−l) and was balanced by a recruitment of 212 trees to the measured population.Growth rates were highly variable within species populations. Overall, bigger trees tended to have higher growth rates. Successive diameter increments in individual trees were strongly correlated, and were still significant after 10 years. These results support the idea that the faster-growing individuals are the more likely to reach the canopy.Estimates of the age of trees by summing mean passage times for successive diameter classes is shown to be misleading because similar calculations using only the fastest-growing trees gives substantially lower estimated ages.Although overall forest composition showed little change, a few species showed small but significant imbalance between recruitment and mortality. Recruitment and mortality differed significantly from overall rates for some species, but only markedly for the megaphanerophyte Celtis mildbraedii which had lower than average rates for both mortality and recruitment.
Relict mangrove stand on Last Interglacial terrace, Christmas Island, Indian Ocean
Authors: Woodroffe Colin D. 
Published: July 2009

ABSTRACTA unique stand of mangroves of the genus Bruguiera occurs on the shore terrace at Hosnies Spring, Christmas Island, Indian Ocean. The mangrove stand, of about 0.33 ha, occurs 120 m inland and over an elevational range of 13 m, from 24 to 37 m above sea level. It is flooded by freshwater from a spring which trickles over a partially-cemented calcsinter concretion gravel with mud. Trees reach 30–40 m high, and 80 cm diameter breast height. The size structure is bimodal with few trees in the 10–25 cm dbh size classes, but abundant propagules, seedlings and saplings. The shore terrace contains corals, some in their position of growth, and has been shown by Uranium-series dating to be Last Interglacial in age. Several alternative explanations of how the mangroves reached this site are examined. One explanation is that this stand of mangroves has persisted at the site for approximately 120,000 years since the Last Interglacial. While this cannot be proved it does appear that the stand is relict and is actively regenerating in this unusual location.
Frugivory and seed dispersal in Cymbopetalum baillonii (Annonaceae) at Los Tuxtlas, Mexico
Authors: Coates-Estrada Rosamond , Estrada Alejandro 
Published: July 2009

ABSTRACTFruit production, frugivore foraging activity and seed dispersal was studied at 10 Cymbopetalum baillonii (Annonaceae) trees during an entire fruiting season. Fruits dehisced during the first six months of the year offer to potential dispersal agents a package of 8–24 arillate seeds. Insects and fungi, however, killed up to 14% of the seeds potentially available for dispersal before fruit dehiscence. Visitation by 24 species of birds and one mammal to the trees closely followed the availability of arillate seeds. The foraging activity of Peromyscus and Heteromys rodents accounted for ≥ 80% mortality of the seeds deposited under the crown of the parent tree. Among those seedlings that became established under the crown mortality was ≥ 90% after 12 months. Seeds dispersed under conspecific fruiting trees experienced intense predation by vertebrates. Field experiments showed that seeds and seedlings planted ≥ 30 m away from adult trees survived significantly longer than those planted under the crown and at distances ≤ 30 m. An unequivocal advantage to dispersal away from the tree and under allospecific trees was evident from the data. A very narrow range of frugivores (N = 8 species) accounted for the quality component of dispersal services to the trees. The tree with the lowest animal visitation and fruit crop was the most efficient in the dispersal of its seeds.
Water potential gradients for gaps and slopes in a Panamanian tropical moist forest's dry season
Authors: Becker Peter , Rabenold Peter E. , Idol Jacquelyn R. , Smith Alan P. 
Published: July 2009

ABSTRACTSoil water potentials were measured weekly by psychrometers at 20 cm depth during the dry season in a tropical moist forest on Barro Colorado Island, Panama. There was a persistent gradient of decreasing soil moisture from gap centre to gap edge to adjacent understorey at both a large and a small gap. On both a north-south and an east-west transect, the soil was drier (water potentials were more negative) on an upland surface than on moderate slopes. This trend was reflected in the predawn, total water potentials of shallow-rootedPsychotria horizontalisand deep-rootedTrichilia tuberculatameasured in the understorey during the last two months of the dry season.P. horizontalisfrom the wettest sites on the transects had higher osmotic potentials at full hydration and at zero turgor, indicating less drought resistance than for conspecifics from the driest sites.
Growth and photosynthesis of Aechmea magdalenae, a terrestrial CAM plant in a tropical moist forest, Panama
Authors: Pfitsch William A. , Smith Alan P. 
Published: July 2009

ABSTRACTAechmea magdalenae is a terrestrial bromeliad that dominates areas of forest understorey on Barro Colorado Island, Panama. Nocturnal CO2 uptake via crassulacean acid metabolism was the primary means of carbon gain under well-watered conditions and all light regimes. The ability to maintain a positive carbon balance under conditions of very low light was demonstrated by laboratory measurements of photosynthesis and forest measurements of growth. Low-light-grown juvenile rosettes had the same daily net assimilation whether tested at photon flux densities of 15 or 300 μmol m−2 s−1 Growth rates of rosettes in treefall gaps were similar to those of plants in closed canopy forest. Growth rates of forest plants were increasingly correlated with canopy openness as the wet season progressed due to increased growth by gap plants, suggesting that water availability rather than light may limit growth during the annual dry season.
Studies on Acacia mangium in Kemasul Forest, Malaysia. I. Biomass and productivity
Authors: Tsai Lim Meng 
Published: July 2009

ABSTRACTMalaysia is establishing large-scale plantations for reforestation and the production of wood for pulp and paper as well as for light construction. The main species used currently is the exotic legume Acacia mangium. The above-ground biomass, litter production and litter accumulation in a four-year-old stand in Peninsular Malaysia were studied. The mean diameter at breast height (dbh) was 12 cm. The mean annual increment (MAI) in dbh of individual trees ranged from 0.9 to 5.1 cm while MAI in height of sample trees ranged from 2.9 to 5.5 m. The total above-ground biomass of the stand was 90.4 t ha−1, consisting of 57.6 t stem, 14.1 t branch and 5.4 t leaf. Litter production averaged 10.23 t ha−1 yr−1 with leaf litter making up 87.4% of the total. Leaf litter accumulation amounted to 6.64 t ha−1 and the turnover constant of leaf litter was estimated at 1.35. The high productivity is discussed in relation to the high turnover of foliage and the low turnover of litter.
Litterfall and litter nutrient content in primary and secondary Amazonian ‘terra firme’ rain forest
Authors: Dantas Mario , Phillipson John 
Published: July 2009

ABSTRACTLitterfall in primary and secondary forests (‘capoeira’) in eastern Brazilian Amazonia was measured fortnightly from August 1979 to October 1980. The nutrient contents of the litter (N, P, K, Ca and Mg) were determined.Litterfall differed between the two forest types (primary forest − 8.04 t ha−1yr−1; secondary forest − 5.04 t ha−1yr−1). The value obtained for primary forest was similar to those reported elsewhere in Brazil (mean = 8 t ha−1yr−1) and from other regions of S. America (mean = 7.20 t ha−1yr−1).Prediction of net primary production from litterfall at the primary forest site gave rise to values of 14.47 and 26.53 t ha−1yr−1. Estimates of net primary production in ‘capoeira’ ranged from 9.07 to 16.63 t ha−1yr−1.Seasonality of litterfall was more marked in ‘capoeira’ than primary forest but in both cases was less pronounced than elsewhere in Brazil.Nutrient concentrations were highest in ‘capoeira’ litter, a finding which accords with results from other tropical sites; nevertheless input of nutrients per unit area of forest floor was greatest in the primary forest.
Population demography and sex ratio in a Neotropical damselfly (Odonata: Coenagrionidae) in Costa Rica
Authors: Hamilton Linda D. , Montgomerie Robert D. 
Published: July 2009

ABSTRACTThroughout the latter part of the dry season (January-April) of 1985 and 1986, we studied the demography of mature adults in a small population of Argia chelata along a stream at Monteverde, Costa Rica. Males defended sunlit spots along the stream between 1030 h and 1400 h central standard time each day and females visiting these sunlit spots were soon mated. By individually marking all mature adults in the population we found that there was no significant difference between the sexes in daily survival rates (0.85 for males and 0.86 for females). Lifetime mating success was positively correlated with longevitiy in both males and females but the ability of males to obtain a mate appeared to be independent of age.Although the sex ratio at emergence was 1:1, that of mature adults at the stream was strongly male-biased (87% male), perhaps as a result of a longer or more risky prereproductive period in females related to the costs of egg formation. We argue that the strongly male-biased sex ratio has important effects on the mating system of this species in that the male contact-guards the female for the entire oviposition period each day. Although this limits each male to mating with one female per day, it probably ensures that the male will fertilize most of the eggs laid by the female that day.
Red coloration of tropical young leaves: a possible antifungal defence?
Authors: Coley Phyllis D. , Aide T. Mitchell 
Published: July 2009

ABSTRACTMany woody species in humid tropical forests synchronously flush entire canopies of young red leaves. Numerous unsuccessful attempts have been made to explain the adaptive value of this visually striking phenomenon. In the humid tropics, fungal attack is a potentially important source of mortality for expanding young leaves. We propose that the anthocyanins responsible for the red coloration of young leaves may play a protective role against invasions by leaf-attacking fungal pathogens.Fungus-growing leaf cutting ants (Atta columbica Guerin) were used in choice tests because they are known to select against leaves or chemicals containing fungicidal properties. In feeding trials with leaf discs from 20 common species, ant preference decreased significantly with increasing anthocyanin content. In feeding trials with pure anthocyanin (3,3',4',5,7-pentahydroxyflavylium chloride) presented on oat flakes, ants again showed a significant dosage dependent preference. This suggests that even low concentrations of anthocyanins may be harmful to the fungal colonies of ants. Additional work on the effects of anthocyanin on leafattacking fungi is encouraged.
The breeding season and diet of Arvicanthis in northern Nigeria
Authors: Rabiu Safianu , Fisher Martin 
Published: July 2009

ABSTRACTThe breeding season and diet of the rat Arvicanthis was monitored from December 1983 to November 1985 in the semi-arid Sudan savanna at Kano, Nigeria, West Africa. Breeding began 1–2 months before the start of the rainy season and ceased at the beginning of the dry season. The diet of Arvicanthis was omnivorous, but with seasonal differences. Monocotyledons and dicotyledons predominated in the diet in the dry season, with seeds and insects increasing in the diet in the rainy season. The major differences between the ecology of Arvicanthis at Kano and on the East African savanna were that in East Africa the breeding season is longer and begins after the start of the rainy season. These and other dissimilarities between the biology of Arvicanthis in the two areas could be due to the effect of climatic differences on food supply and to the possible existence of different taxonomic groupings of Arvicanthis in the two regions.
Phenology and diversity of necrophagous Diptera in a Hong Kong forest
Authors: So Ping-Man , Dudgeon David 
Published: July 2009

ABSTRACTNecrophagous Diptera were sampled in a seasonal tropical mixed forest in Hong Kong from February 1985 to May 1986 using carrion-baited traps. Six families of flies were caught but only Calliphoridae, Muscidae and Sarcophagidae were considered. They made up a total of 14,669 flies of 21 species in the sample. Total species abundance followed Fisher's log-series distribution. The commonest five species were calliphorids, constituting 79.44% of the total combined catch. Temperature was apparently the main factor affecting seasonality of necrophagous Diptera in Hong Kong. Fluctuations in total abundance, species richness and H' followed seasonal changes in weekly mean air temperatures.
An elephant (Loxodonta africana) survey using dung counts in the forests of the Central African Republic
Authors: Fay J. Michael 
Published: July 2009

ABSTRACTIn May and June of 1989 data on elephant (Loxodonta africana) dung density were collected in the main forested areas of the Central African Republic. A total of 147.0 km of line transects (N = 14 transects,= 10.50 km, SD = 3.79) was completed. Dung was recorded in 37.4% of the 294 sectors of 0.5 km each. The overall dung density was estimated to be 266 piles km-2(= 382, SD = 383.7). The highest dung density was found in the proposed Dzanga-Sangha Reserve in the extreme south-west with 1166 piles km-2(N = 12 sectors of 0.5 km). The south-eastern forests were found to have an intermediate dung density of 336 piles km-2(N = 215 sectors of 0.5 km,= 419, SD = 308). In the eastern section of the south-western forests no dung was recorded along survey transects (N = 67 sectors of 0.5 km). These data indicate that elephant populations are still relatively high in the forests of south-western and south-eastern Central African Republic, while the population in the eastern section of the south-western forests has diminished to a very low level.
The carnivore community in a dry tropical forest mosaic in Huai Kha Khaeng Wildlife Sanctuary, Thailand
Authors: Rabinowitz Alan R. , Walker Susan R. 
Published: July 2009

ABSTRACTAn assessment of carnivore species richness and food habits was carried out in a 100 km2 area of dry tropical forest in Huai Kha Khaeng Wildlife Sanctuary, Thailand. Twenty-one carnivore species of five families were found to be feeding on at least 34 mammal species, as well as birds, lizards, snakes, crabs, fish, insects, and fruits. Forty-four percent of the prey identified in faeces of larger carnivores, primarily leopards, consisted of barking deer, Muntiacus muntjak. Sambar deer, macaques, wild boar, porcupine, and hog badger were important secondary prey items. In faeces from small carnivores (< 10kg), murid rodents accounted for 33% of identified food items. The two most frequently encountered mammalian prey species were the yellow rajah rat, Maxomys surifer, and the bay bamboo rat, Cannomys badius. Non-mammal prey accounted for 21.3%, and fruit seeds for 12.4%, of all food items found in small carnivore faeces.
Distribution and abundance of a tropical rodent, the spiny rat, on islands in Panama
Authors: Adler Gregory H. , Seamon Joshua O. 
Published: July 2009

ABSTRACTThe insular distribution and abundance of the spiny rat (Proechimys semispinosus) were studied by live-trapping rats on 50 small forested islands in Gatun Lake, Republic of Panama. Rats were found on 29 of these islands. Rat abundance was not correlated with island size or isolation, in contrast to temperate rodents, and may be due to the highly patchy nature of tropical forests and the differing floristic compositions of the study islands. Rat occurrence on islands was related positively to island size and negatively to island isolation. All islands greater than 2.1 ha contained spiny rats, whereas most islands less than 0.9 ha did not contain rats. The relationship between occurrence, size, and isolation are illustrated by a three-dimensional response surface. Results suggest that colonization and extinction regularly occur on these islands and that (1) larger islands with year-round fruit production, regardless of isolation, will have persistent populations of rats, (2) small isolated islands will never or only very rarely have rats owing to a lack of a year-round food source and the difficulty of immigration, and (3) small near islands frequently will have rats when fruits arc present. No other species of mouse-or rat-like rodents were captured on the islands. We suggest that P. semispinosus is a better colonist than other sympatric forest species, is more of a habitat generalist, and has a more flexible demographic structure allowing persistence in heterogeneous and changing environments.
A plot study of forest floor litter frogs, Central Amazon, Brazil
Authors: Allmon Warren D. 
Published: July 2009

ABSTRACTAbundance and distribution of frogs inhabiting the litter layer of an area of primary lowland rain forest in Central Amazonia were studied over a period of 15 months by sampling 498 plots each 5m × 5m. The litter frog fauna of the area consists of 23 species, but only 12 of these were encountered in the plots, and 84% of the frogs encountered belonged to only six species. Total abundance and diversity within the plot data are strongly seasonal and peak in the late wet season. Both are positively correlated with litter volume and moisture. Most of this variation is due to seasonality of reproduction, as indicated by patterns of occurrence of juveniles of the most abundant species.These results indicate that the plot sampling method docs not sample the entire fauna adequately. Since this technique has been used to study other tropical forest litter herpetofaunas, however, comparison with other studies may be useful. Species diversity of litter frogs appears to be approximately the same in lowland primary forest sites studied, averaging around 20 ‘regular’ species. Abundances, however, vary widely. Central American communities contain 14–15 frogs (100m)-2, African 9–10, South American 4–6, and South-east Asian 1–2. These differences may be due to differential nutrient availability in forests of different ages and/or on different soils.