bluuebunny/crossref_metadata_2025_split huggingface dataset:
Growth, recruitment and mortality in the Gama gallery forest in central Brazil over a six-year period (1985–1991)
Authors: Felfili Jeanine Maria 
Published: July 2009

ABSTRACTDiameter increments, recruitment and mortality were studied over a six-year period in a 3.02 ha sample in an area of 64 ha of undisturbed gallery forest alongside the Gama stream. The study site is located in Fazenda Água Limpa in Brasília, Federal District, Brazil. Trees ≥ 31 cm gbh (10 cm dbh) were measured every three years from 1985 in 151 (10 m × 20 m) permanent plots in Gama forest.The mean annual diameter increment for trees ≥ 10 cm dbh was 0.25 cm y-1. Variability was high with coefficients of variationc.100% or more. Light-demanding and large upper storey species tended to grow faster than shade-tolerant and lower storey species. Mean increments for the community increased with increasing diameter classes.The mean annual mortality rate for the community was 3.5% y−1while the recruitment was 2.7%. The community was dynamic with 86% of all species either suffering mortality or gaining recruits or both during the six years. The net difference between recruitment and mortality was zero for 55 species. The recruitment compensated for the mortality of most of the abundant species.
Variation in propagule mass and its effect on carbon assimilation and seedling growth of red mangrove (Rhizophora mangle) in Florida, USA
Authors: Lin Guanghui , Sternberg Leonel Da S. L. 
Published: July 2009

ABSTRACTWe investigated the intraspecific variation in propagule mass within red mangrove (Rhizophora mangle) and its effect on carbon assimilation and seedling growth. Propagule sizes of red mangrove varied considerably at all three study sites along the south-eastern coast of Florida, with propagule fresh mass from 3.9 to 20.7 g for the scrub form and from 5.3 to 35.8 g for the tall form. Highly significant correlations were observed between propagule length and fresh weight at all three study sites and for two growth forms. The scrub form had significantly smaller propagules than the tall form. A greenhouse study showed that CO2 assimilation rates were not correlated with propagule mass, but total leaf area per plant increased significantly with increasing initial propagule mass in all three family lines of both the scrub and tall forms. Consequently, total carbon fixation rate by each seedling increased significantly with increasing propagule fresh weight in all cases, and the biomass increment significantly increased with increasing mass. Relative growth rate, however, was not correlated with propagule mass. The differences in leaf areas and biomass accumulation among seedlings from different sizes of propagules seem to have resulted from the differences in maternal reserve of hypocotyls. The considerable intraspecific variation in propagule size observed for red mangrove may have a significant effect on seedling growth and competitive ability.
Home-range size and territoriality inBolomys lasiurus(Rodentia: Muridae) in an Amazonian savanna
Authors: Magnusson William E. , De Lima Francisco Angelo , Sanaiotti Tania M. 
Published: July 2009

ABSTRACTBolomys lasiurusis the only species of rodent commonly found in the savanna of Alter do Chão, central Amazonia. Peak densities during 42 months were less than have been reported from the cerrado biome of central Brazil. However, the population at Alter do Chão appears to be more stable than those in other areas and we never recorded zero densities. Many animals were captured over periods greater than 7 months, indicating that either mortality or dispersal was less than in previous studies. Mean home-range size of females was inversely related to the proportion of females that were gravid or lactating. Female home ranges were mutually exclusive and averaged 35% (SD = 8.2%) of male home ranges. Male home ranges overlapped extensively. Indices of home-range size varied seasonally and among years.
Seedling survival and growth of four Shorea species in a Sri Lankan rainforest
Authors: Ashton P. Mark S. , Gunatilleke C. V. S. 
Published: July 2009

ABSTRACTIn this study four species of the genus Shorea section Doom were investigated. All occur together as canopy trees in the Sinaraja rainforest of south-west Sri Lanka. Partitioning of the regeneration niche can be one explanation for the co-existence of ecologically similar canopy tree species within a forest. Seedlings were planted in plots located in five zones that represent a range of forest groundstorey microenvironments found adjacent to and across canopy openings of three sites – valley, midslope, ridgetop. Experiments were designed to monitor survíval and growth of planted seedlings for two years. At the end of two years percentage survival was calculated, height increment recorded and destructive samples taken to measure dry mass gain of root, stem and leaves. Comparisons were made of establishment and growth performance of seedlings planted in the different plots and sites. Results demonstrated clear differences in survival and growth among species. These differences appeared related to availability of soil moisture and groundstorey radiation regimes. Disturbance patterns that determine species co-existence are suggested.
Comparison of three fruit census methods in French Guiana
Authors: Zhang Shu-Yi , Wang Li-Xin 
Published: July 2009

ABSTRACTThree census methods for studying fruiting phenology and fruit production were compared: platform observation, fruit-trap collection and raked-ground survey. The estimation of fresh fruit mass varied greatly with the census method used. Moreover, the fruiting phenology recorded using the fruit-trap collection and raked-ground survey methods showed a delay of one to two months compared with the platform observation method. Any of the three methods can be used for the approximation of annual fruiting phenology, but that of fruit-trap collection is suited to measure the annual fruit production, and that of platform observation offers the best estimation of the quantity of fruit in tree crowns at a given time.
Litter decomposition and nutrient release in a tropical rainforest, Southern Bakundu Forest Reserve, Cameroon
Authors: Songwe Nicholas C. , Okali D. U. U. , Fasehun F. E. 
Published: July 2009

ABSTRACTDecomposition of litter on the forest floor and of leaves of five species,Celtis zenkeri, Cola lepidota, Desbordesia glaucescens, Ceiba pentandraandTerminalia superbain nylon mesh bags, as well as wood decay were studied in the tropical rainforest at Southern Bakundu Forest Reserve, Cameroon.The rate of loss of dry matter was fastest inCeltis zenkeriwhich was significantly different from the other species, while potassium was the most rapidly released element from all species with more than 50% being released in the first two months of the experiment. Nitrogen and phosphorus showed initial increases in bagged leaf litter independent of dry weight losses and while nitrogen was later released phosphorus continued to increase reaching 2–3 times the initial concentration. Decomposition constant (k) of litter on the forest floor was found to be 2.23 whereas the mean decomposition constants of the different species were as follows:Celtis zenkeri4.18,Cola lepidota2.18,Desbordesia glaucescens1.60 andCeiba pentandra2.16 for the two experiments.Termites were found to have a very great influence on the decay of the wood ofTerminalia superbawith decay due to micro-organisms being negligible.
Relationships between rainfall, nesting habitat and fecundity ofCaiman crocodilus yacarein the Pantanal, Brazil
Authors: Campos Zilca , Magnusson William 
Published: July 2009

ABSTRACTDifferences in rainfall between years influenced the proportions of different types of nesting habitats ofCaiman crocodilus yacareavailable near water bodies in a region of intermittent rivers (Campo Dora Ranch). In contrast, rainfall had little effect on the proximity of nesting habitat to water bodies in a region of isolated lakes (Nhumirim Ranch). There was a strong positive correlation between female body size and clutch size Snout-vent lengths of females on Campo Dora Ranch were significantly larger than those from Nhumirim Ranch which probably accounts for the larger mean clutch size than in the region of isolated lakes. Hatchling size was correlated with egg size, but there was no relationship between egg size and female size or egg size and clutch size.
Leaf-cutting ants and forest groves in a tropical parkland savanna of Venezuela: facilitated succession?
Authors: Farji Brener Alejandro G. , Silva Juan F. 
Published: July 2009

ABSTRACTSome savanna areas in the Orinoco Llanos region in Venezuela are characterized by the abundance of small forest groves, resulting in a parkland landscape. We hypothesized that forest groves are the result of colonization of the open savanna by forest species, facilitated by the activity of leaf-cutting ants. In this paper we present results from a field study conducted on an ecotonal belt between a deciduous gallery forest and an open savanna in the western Llanos of Venezuela. In seven transects, trees, groves and leaf-cutting ant nests were counted, size parameters evaluated and distance from grove to forest measured. Soil chemical analysis and microclimatic measurements were performed in the forest, grassland and groves. Floristic composition of the woodland component of the savanna (scattered trees) was very dissimilar from that of the forest, but the composition of the groves was essentially a mixture of both woodland and forest species. Woodland trees were present in all groves, whereas forest trees were present only in larger groves. The size structures of populations of the two types of trees differed significandy according to the size of the grove; also, woodland tree population structure differed significantly between open savanna and groves. The frequency of groves withAtta laevigatanests increased with the size of the grove, and groves with forest trees were positively associated with the presence of nests.A. laevigatanests improved the soil of groves, increasing N, Mg, Ca and organic carbon, but other soil properties were not modified. Temperatures at ground level in the dry season were ameliorated in the groves compared with the grassland, and this effect increased with the size of the grove. We concluded that a dynamic process of grove formation is facilitated by the aggregation of a few woodland trees, followed by the successful invasion of forest trees and a leaf-cutting ant nest. The results did not show any clear sequence of arrival of the ants or the forest trees, but it seems clear that these two would act synergistically, improving conditions for each other.
Movement patterns of five species of small mammals in a Brazilian restinga
Authors: Gentile Rosana , Cerqueira Rui 
Published: July 2009

ABSTRACTDuring the course of a population study of small mammals in a Brazilian coastal shrubland we calculated the movements between successive captures, the residence time, the indices of aggregation and the kinds of movements of the five most common species of small mammal. A capture-mark-recapture study was undertaken over two years, quarterly.Philander opossum, Akodon cursorandProechimys iheringipresented low mobility, with a high proportion of restricted movements, long residence time and larger coefficients of aggregation.Didelphis auritaandMetachirus nudicaudatuspresented higher mobility and exploratory movements, short residence time and small coefficients of aggregation. The species with lower mobility had permanent populations within our sampling grid, while the species with higher mobility used areas outside the grid, presenting no local populations but occupying portions of regional metapopulations.
Allometry and life history of tropical trees
Authors: King David A. 
Published: July 2009

ABSTRACTThe scaling of crown size and trunk diameter with tree height (allometry) was determined for 14 common species of the tropical wet lowland forest at La Selva, Costa Rica. The study showed that allometric differences between species are related to adult size, regeneration niche (gap vs. non-gap) and longevity, as follows: (1) adults of understorey species are larger crowned than similar statured (6–15 m) saplings of canopy trees; (2) species commonly found in gaps as saplings are somewhat larger crowned than shade-tolerant species over the 1–6 m height range; and (3) long-lived canopy species show greater increases in crown breadth with increasing height thandoshort-livedspecies.Trunkallometryisrelated to mechanical requirements for support, including the need to withstand greater wind forces in the upper canopy. The common canopy species,Pentaclethra macroloba, which comprises 40% of the basal area at La Selva, is particularly wide-crowned and thick-trunked at its maximum height. On the other hand, the comparatively narrower crowns and trunks of the other canopy species allow them to reach a given height with less biomass. These differences in allometry may influence tree density and forest structure at La Selva.
Behavioural ecology ofTropidurus hispiduson isolated rock outcrops in Amazonia
Authors: Vitt Laurie J. , Zani Peter A. , Caldwell Janalee P. 
Published: July 2009

ABSTRACTA population of the tropical lizardTropidurus hispidus, isolated on a granitic rock outcrop in tropical forest of northern Brazil, was studied during the 1993 wet season. Four types of observational studies revealed that lizards are active throughout most of the day. During 10-minute intervals, individual lizards moved five times for an average of 240 cm and tongue-flicked once. Habitat temperatures vary considerably during the day, with rock and air temperatures in sun exceeding body temperatures of lizards during much of the activity period. During most of the day, lizards thermoregulate by moving among shady, filtered sun, and sunny microhabitats maintaining body temperatures near 35°C. Temperatures of lizards active during cloudy periods were significantly lower than temperatures of lizards during sunny periods, indicating that clouds decrease the ability of lizards to effectively thermoregulate. Most feeding occurs in the afternoon at edges of rock outcrops with ants, insect larvae, termites and beetles dominating the diet. Comparisons with a near-by savanna population revealed differences in body size (males only), activity period (longer on rocks), body temperatures (higher on rocks), number of prey categories consumed (lower on rocks), mean size of prey (larger on rocks), number of prey eaten (fewer on rocks) and microhabitat use (more restricted on rocks).
Structure, dynamics, home range and activity pattern of mixed-species bird flocks in a montane alder-dominated secondary forest in Ecuador
Authors: Poulsen Bent Otto 
Published: July 2009

ABSTRACTTwo mixed-species bird flocks were studied in a high-altitude humid secondary forest in the Andes of Ecuador. Birds were mist-netted and colour-ringed for individual identification. The flocks (A and B) were followed to record structure, dynamics, home range and activity pattern. All observations of the two flocks studied included members from all vertical levels, which is different from flocks of Amazonia. In two nucleus species, some individuals alternated between the flocks, a feature not previously reported. Various tanagers were loosely associated, joining and leaving flocks. Minimum home-range sizes of flocks A and B were 4.2 ha and 7.8 ha, respectively. Some individuals of two species used an area encompassing the home ranges of both flocks. Mean flock sizes in A and B were 21.7 and 44.7 individuals, whereas the mean numbers of species were 13.7 and 21.7, respectively. Number of species and individuals were high compared to even most lowland flocks. Altogether, mixed-species flocks in different habitats and at various latitudinal and altitudinal sites appear to have some features in common, but others are highly distinct. Compared to the great stability of Amazonian flocks, some high-altitude flocks of secondary forest in the Andes appear to be more dynamic and unstable.
Dispersal ofAcaciaseeds by ungulates and ostriches in an African savanna
Authors: Miller Maxine F. 
Published: July 2009

ABSTRACTThe dispersal of AfricanAcaciaseeds in the presence and absence of large mammalian herbivores and ostriches was assessed in a savanna ecosystem in South Africa. In the absence of large herbivores,A. tortilisandA. niloticapods were mainly dispersed in the shade, directly beneath the tree crown and seeds remained in pods for over 18 months. In the presence of large herbivores,A. tortilis, A. niloticaandA. karrooseeds were freed from pods and were dispersed into open, non-shaded habitats. Impala dispersed mostA. tortilisseeds (18,900 ha−1), giraffe mostA. niloticaseeds (1060 ha−1) and giraffe and kudu mostA. karrooseeds (452 and 448 ha−1, respectively). Seedling survival in dung in open environments may exceed that of seedlings in soil shaded beneath the tree crown. It appears that seed dispersal by large herbivores may be advantageous to future seedling recruitment.
Fog interception in montane forests across the Central Cordillera of Panamá
Authors: Cavelier Jaime , Solis Daniel , Jaramillo Maria A. 
Published: July 2009

ABSTRACTFog interception and rainfall were measured at 14 stations across the Central Cordillera in western Panamá. Fog interception and rainfall were measured monthly during 1988–1989 with artificial fog catchers and rain gauges, respectively. Fog interception was highest on ridges and increased with increasing altitude. Fog interception contributed between 2.4 and 60.6% of the total water input, depending on altitude and exposure to the prevailing winds. Absolute amounts of annual fog interception ranged from 142 to 2295 mm. Although low clouds were more frequent in montane forests, clouds close to the ground also occurred in the lowlands. During the study period, there was a gradient of increasing total rainfall from the Caribbean (3355 mm) to the Pacific side (5759 mm) of the Central Cordillera. Nevertheless, rainfall was more seasonal on the leeward side of the mountain range. Seasonal variation in fog intereption was different from rainfall patterns and no correlation was found between monthly (or annual) rainfall and fog interception. The results of this study showed the importance of montane forests for the preservation of water sources, particularly along ridges of the Fortuna drainage basin that provides more than 50% of the electricity of the Republic of Panamá.
The phytoplankton periodicities of two warm-climate lakes subject to marked seasonal variability
Authors: Khan M. A. 
Published: July 2009

ABSTRACTThe phytoplankton periodicity of a tropical upland reservoir in Nigeria (Liberty Dam, Jos Plateau) and a temperate-type lake (L. Naranbagh) from the Kashmir Himalaya were compared. Variations in the phytoplankton communities in the water-bodies were both quantitative and qualitative. Liberty Dam conformed to the oligotrophic-desmid plankton type whilst in L.Naranbagh, phytoplankton resembled the eutrophic chlorococcales-diatom plankton type. Contrary to the general belief of muted (or lack of) seasonal changes in tropical regions, phytoplankton succession in the Jos reservoir was pronounced with dense persistence of some species for relatively short periods. The most striking fluctuations, typical of many temperate waters, were characteristic of L. Naranbagh with a build-up of plankton during summer and autumn. Variability in photosynthetic productivity was related to shifts in the climate-dependent population densities. The seasonal growth of the Jos phytoplankton reflected the alteration from the dry ‘Harmattan’ (December–February) to wetter (May–September) periods. These are analogous to the winter (December–February) and summer (June–August) seasons of the Kashmir Himalayan Valley. Phytoplankton associations and periodicities in each of the two warm-belt lakes were strongly driven by their respective local environments, including especially the marked seasonality of the climatic variables (rain, wind and solar radiation). Detailed comparisons of adequate long-term data from tropical and temperate waters are still required.
Ecology of small mammals in tropical forest habitats of southern India
Authors: Chandrasekar-Rao Anjali , Sunquist Melvin E. 
Published: July 2009

ABSTRACTFive species of rodent (Rattus rattus wroughtoni, Mus platythrix, Funambulus tristriatus, Cremnomys blanfordiandGolunda ellioti) were live-trapped over a period of eight months in three different habitat types (moist evergreen forest, moist deciduous forest and teak plantation) in Anaimalais Wildlife Sanctuary, Tamil Nadu, India. Small mammal densities ranged between 16.3 individuals ha−1and 20.7 ha−1for the natural forest sites and were 10.4 ha−1in the teak plantation. Moist deciduous forest had the highest species richness and diversity scores. Although the teak plantation site had the same mammal species richness as the moist evergreen forest, numbers of individuals and overall small mammal biomass in the plantation was far lower than on the natural forest sites. Compared to moist deciduous forest, species richness and diversity were significantly lower on the teak plantation.R. r. wroughtoniandM. platythrixwere the two most common species captured on all three sites.R. r. wroughtoniwas the most common small mammal species captured, reaching densities of 14.5 ha−1in moist evergreen forest.G. elliotiwas the least common species, present only in moist deciduous forest. Demographic patterns and microhabitat selection were examined forR. r. wroughtoni, M. platythrix, andF. tristriatus. OnlyM. platythrixappeared to show any distinct seasonality in reproduction, with an increase in capture of breeding individuals towards the end of the wet season. Discriminant analysis did not reveal any distinct microhabitat preferences for any of the species. However,R. r. wroughtonishowed a significant association with bamboo, andF. tristriatuswas associated with areas of higher canopy height and density in moist deciduous forest.
The life history of a tropical dragonfly:Cora marina(Odonata: Polythoridae) in Guanacaste, Costa Rica
Authors: Pritchard Gordon 
Published: July 2009

ABSTRACTThe life history ofCora marinawas followed for one year in two permanent streams at 600 m elevation in Guanacaste National Park; Costa Rica. The water temperature wasc.21°C year-round, but there was a distinct wet-dry seasonality, very little rain falling from January to May. In both streams,C. marinawas univoltine. Adults first appeared at the beginning of May and the flight period coincided with the wet season. The availability of water-soaked logs as oviposition sites probably restricts reproduction to the wet season. Eggs hatched from mid-July to December. Recruitment to subsequent larval instars was slow during the wet season but increased at the start of the dry season. Final-instar larvae were collected from March to October. Oviposition in logs above the stream and the ability to live in the low oxygen conditions of the hyporheic zone probably allow eggs and small larvae to survive wet season spates.El ciclo biológico de una libelula tropical:Cora marina(Odonata: Polythoridae) en Guanacaste, Costa Rica.