bluuebunny/crossref_metadata_2025_split huggingface dataset:
Ecology of the Asian elephant in southern India. I. Movement and habitat utilization patterns
Authors: Sukumar R. 
Published: July 2009

ABSTRACTThe movement and habitat utilization patterns were studied in an Asian elephant population during 1981–83 within a 1130 km2 area in southern India (11° 30′ N to 12° 0′ N and 76° 50′ E to 77° 15′ E). The study area encompasses a diversity of vegetation types from dry thorn forest (250–400 m) through deciduous forest (400–1400 m) to stunted evergreen shola forest and grassland (1400–1800 m).Home range sizes of some identified elephants were between 105 and 320 km2. Based on the dry season distribution, five different elephant clans, each consisting of between 50 and 200 individuals and having overlapping home ranges, could be defined within the study area. Seasonal habitat preferences were related to the availability of water and the palatability of food plants. During the dry months (January-April) elephants congregated at high densities of up to five individuals km-2 in river valleys where browse plants had a much higher protein content than the coarse tall grasses on hill slopes. With the onset of rains of the first wet season (May-August) they dispersed over a wider area at lower densities, largely into the tall grass forests, to feed on the fresh grasses, which then had a high protein value. During the second wet season (September-December), when the tall grasses became fibrous, they moved into lower elevation short grass open forests.The normal movement pattern could be upset during years of adverse environmental conditions. However, the movement pattern of elephants in this region has not basically changed for over a century, as inferred from descriptions recorded during the nineteenth century.
Moth diversity of a tropical forest in Peninsular Malaysia
Authors: Barlow H. S. , Woiwod I. P. 
Published: July 2009

ABSTRACTA standard Rothamsted light trap was operated for slightly over 12 months from the end of September 1979 to October 1980 at Genting Sempah, Pahang in Malaysia. All specimens of macrolepidoptera families together with the Pyralidae were identified, counted and recorded. The numbers of species caught were compared with those obtained by a different method at a nearby site for over 10 years. Diversity, biomass and seasonality of the catch were compared with identically sampled populations in Great Britain and New Zealand. The Genting Sempah trap had very high diversity and biomass compared with the temperate samples and exhibited much less seasonality. The Pyralidae and other families (excluding Noctuidae and Geometridae) formed a much higher component of diversity in Genting than in Britain. The log-normal distribution fits the data better than the log-series. So the inter-quartile slope, Q, is the correct parameter for interfaunal comparisons.
Distribution and ecology of epiphytic bryophytes and lichens in dry evergreen forest of Guyana
Authors: Cornelissen J. H. C. , Steege H. Ter 
Published: July 2009

ABSTRACTA floristic and ecological study of epiphytic bryophytes and lichens on standing mature Eperua trees was carried out in dry evergreen (walaba) forest in Guyana, South America. The trees were sampled from their base up to the highest canopy twigs, using mountaineering techniques. Clear vertical distribution patterns of epiphytic species and life-forms were found. Many species, particularly foliose lichens, appear to be preferential or exclusive to either Eperua grandiflora or E. falcata (Leguminosae), which are the dominant trees in the walaba forest. Special attention is given to the species-rich epiphyte vegetation on the upper canopy twigs, which include two categories of species: the sun epiphytes and the pioneers (facultative epiphylls).
Estimation of arboreal arthropod density in a dry evergreen forest in Northeastern Thailand
Authors: Watanabe Hiroyuki , Ruaysoongnern Sawaeng 
Published: July 2009

ABSTRACTThe density of arboreal arthropods in a dry evergreen forest in Northeastern Thailand was investigated by the insecticide fogging (knockdown) method. Arthropod densities of 256.4 and 140.4 m-2 were recorded in the dry season and 195.2 and 123.1 m-2 in the rainy season. The main orders were Collembola, Thysanoptera, Hymenoptera (mainly Formicidae) and Hemiptera. Distinct differences were not found in the arthropod faunal structure and density between the dry and rainy seasons. However, this fauna is completely eliminated by the clearing and burning of forest for shifting cultivation.The results of an experiment investigating the rate of arthropod fall after application of insecticide are presented and problems concerning the efficiency of the estimation methods used in this study are discussed.
A survey of small mammals within a Sabah tree plantation in Malaysia
Authors: Stuebing Robert B. , Gasis Joseph 
Published: July 2009

ABSTRACTA survey of small mammals was made in a tree plantation in Sabah, East Malaysia. Transects within pure plantings of Eucalyptus deglupta, Gmelina arborea, Albizia falcataria, and A. falcataria/Theobroma cacao were compared with a similar transect laid through seven-year-old logged forest near the plantation. A total of 16 small mammal species were trapped, with 11 found in the logged forest area, and 15 in the plantation. Values for the Shannon-Wiener Diversity Index (H') and for biomass were highest in logged forest, which also showed a low (<45%) Percent Similarity when compared with any of the plantation areas. Highest diversity and biomass values within the plantation were found in Albizia falcataria plantings, while the lowest were found in A. falcataria underplanted with Theobroma cacao. All plantation areas were dominated by Maxomys whiteheads, whereas A. falcataria plantings had the highest numbers of Tupaia glis and Tupaia tana.The study shows that although tropical plantations of exotic tree species can support a large number of species of scansorial small mammals, overall diversity and species biomass per hectare is much lower than that found in logged forest.
The influence of elephants and fire on a Brachystegia-Julbernardia woodland in Zimbabwe
Authors: Guy Peter R. 
Published: July 2009

ABSTRACTBrachystegia-Julbernardia (miombo) woodlands inside and outside the Sengwa Wildlife Research Area, Zimbabwe, show major differences in structure, biomass and species composition. The woodlands inside the research area have a lower stem area, tree density and biomass than those outside it. The shrubs inside the research area occur at a higher density than they do outside it, but the biomasses of shrubs in the two woodlands are similar. The woodlands inside the research area are affected by elephants and fire, whereas those outside it are affected mainly by fire. It is postulated that the policy of maintaining the elephant population at 250 in the research area is having a beneficial effect and, provided elephants and fire are kept in check, the woodlands inside the research area will eventually recover.
Litterfall, nutrient-fall and production in an Acacia albida woodland in Zimbabwe
Authors: Dunham Kevin M. 
Published: July 2009

ABSTRACTLitterfall was recorded for one year in Acacia albida woodland in Mana Pools National Park, Zimbabwe. Leaves fell throughout the year, but leaf-fall rate peaked in the wet season. Litterfall was 1.5 t ha−1 year−1, comprising 50% leaves, 20% fruits, 17% ‘fine’ material (mainly frass), 4% flowers and 9% wood and bark. Net above ground production by A. albida trees was 1.7 t ha−1 year−1, including leaf production of 1.0 t ha−1 year−1, twig production of 0.3 t ha-1 year−1 and fruit production of 0.3 t ha−1 year−1. Insects consumed about 26% of leaf production. Net above ground herbaceous production was estimated from rainfall data using regression equations: it was 6.8 t ha−1 year−1 for annual grasses and 2.8 t ha−1 year−1 for forbs. Net above ground primary production in A. albida woodland was 11.3 t ha−1 year−1. The seasonal variations in the nitrogen, phosphorus, potassium, magnesium and calcium concentrations of different A. albida litter components were recorded. The estimated falls of N, P, K, Ca and Mg were 31.1, 2.1, 9.8, 15.0 and 3.4 kg ha−1 year−1 respectively.
Avian attendance and foraging at army-ant swarms in the tropical rain forest of Los Tuxtlas, Veracruz, Mexico
Authors: Coates-Estrada Rosamond , Estrada Alejandro 
Published: July 2009

ABSTRACTForaging and attendance of birds at army-ant swarm raids were studied in the tropical rain forest of Los Tuxtlas, Mexico. Sixty-eight raiding swarms were intercepted over a four-year period of which 57% were Eciton burchelli and 43% Labidus praedator. A total of 461 birds (37 species/12 families) were recorded at swarms of E. burchelli and 208 birds (34 species/10 families) were recorded at L. praedator swarms. The mean number of bird species detected per swarm was 7.2 at E. burchelli raids and 5.6 at L. praedator raids. Red-throated ant-tanagers (Habia fuscicauda) were most frequently seen at the swarms of both army-ant species. Other important species were the golden-crowned warbler (Basileuterus culicivorus), the white-breasted wood wren (Henicorhina leucosticta) and the Kentucky warbler (Oporornis formosus). Swarms of both army-ant species were active year-round. Birds weighing between 20 and 40 g dominated perches closest to the ground and the central zone of the swarms, richest in animal prey. Birds weighing less than 20 g occupied higher perches and tended to forage in more peripheral zones. At Los Tuxtlas raiding swarms of army ants are important in the foraging ecology of 44 bird species, including 12 North American migrants.
Mist and fog interception in elfin cloud forests in Colombia and Venezuela
Authors: Cavelier Jaime , Goldstein Guillermo 
Published: July 2009

ABSTRACTFog interception and rainfall were measured during one year in three elfin cloud forests on small mountains along the Caribbean coast of South America and one in the Venezuelan Andes. (1) While rainfall increases from west to east in the small mountains along the coast, fog interception decreases. In 1985, the total annual rainfall and fog interception were 853 mm and 796 mm in the cloud forest of Serrania de Macuira, 1630 mm and 518 mm in Cerro Santa Ana and, 4461 mm and 480 mm in Cerro Copey. In the Andean forest of El Zum-bador, the 1985 rainfall was 1983 mm and the annual fog interception was only 72 mm. (2) Fog interception seems to be an important source of water to the elfin cloud forests of the small mountains which are surrounded by dry vegetation types and where the rainfall regime is highly seasonal. (3) Fog interception increases with altitude (in the same mountain), exposure (windward slopes) and leaf inclination. These variations of fog interception could partially explain the observed distribution of epiphytic flora in some of these cloud forests.
Short term nitrogen dynamics in a small Brazilian wetland (Lago Infernão, São Paulo)
Authors: Howard-Williams Clive , de Esteves F. , Santos J. E. , Downes M. T. 
Published: July 2009

ABSTRACTWe have studied a number of related processes of the nitrogen cycle in a Brazilian floodplain lake to identify the major pools and pathways over a short time period. The study was centred on the littoral zone dominated by the floating plantEichhornia azurea, which has a large epiphyte algal community of which heterocystous cyanobacteria were the major components. The water column was continuously undersaturated with oxygen although some elevated values (to 60% saturation) were recorded in the macrophyte beds in the afternoon. Marked diel temperature changes were documented. NH4-N dominated the dissolved N component in the water with maximal values (60 mg m−3) at lowest O2, concentrations early in the morning. Nitrogen fixation (acetylene reduction) of the epiphyte community showed marked diel changes with daily values of 5 mg N fixed m−2day−1(based on 3:1 C2H4:N2ratio). Macrophyte NH4-N uptake rates (in situincubations) were 93 mg N m−2day−1. The activities of nitrifying bacteria could not be detected with the nitrapyrin block on dark CO2fixation but denitrification (acetylene block technique) was recorded in the sediments when enhanced with NO-3. The major pathways of aquatic nitrogen involved macrophyte uptake and sediment release of NH4-N.
Red crabs in rain forest, Christmas Island: removal and relocation of leaf-fall
Authors: O'Dowd Dennis J. , Lake P. S. 
Published: July 2009

ABSTRACTField experiments comparing leaf-fall in the presence and absence of the red land crab, Gecarcoidea natalis, in rain forest on Christmas Island, Indian Ocean showed that, by eating and returning leaves to their burrows, they significantly reduced accumulation of leaf-fall on the forest floor. Red crabs removed 30–50% of the leaf-fall at the experimental sites during the study. Differences in leaf-fall mass between crab-access and exclusion quadrats were positively correlated with the density of foraging red crabs. Red crabs also generated spatial heterogeneity in the distribution of litter on the forest floor by returning litter to their burrows. Leaves lined chambers of 64% of excavated burrows and litter biomass around the entrances was significantly greater than that on off-burrow locations. This was reflected in the significantly higher concentrations of organic matter and nutrients (N, P, K, Ca, Na, and Mg) associated with soils near burrow entrances. These results suggest that a single species, G. natalis, is the major processor of leaf-fall in rain forest on Christmas Island and may affect (1) the temporal and spatial patterns of nutrient availability and (2) the diversity and biomass of the litter fauna.
Fig-eating by birds in a Malaysian lowland rain forest
Authors: Lambert Frank 
Published: July 2009

ABSTRACTSixty bird species ate the figs of 29Ficustaxa at a lowland forest site in Peninsular Malaysia. Although most bird-eaten figs were brightly coloured, fourFicusspecies produced dull-coloured ripe fruits. Whilst there was tremendous overlap in the sizes of figs eaten by different bird species, data presented show that the fig resource was partitioned by birds. Large birds were commoner visitors to large-fruitedFicus, but small birds tended to eat small figs. Within two avian genera, theTreronpigeons andMegalaimabarbets, there was distinct partitioning of figs consumed according to fig size.
Metabolism and distribution of grasses in tropical flooded savannas in Venezuela
Authors: Medina Ernesto , Motta Norma 
Published: July 2009

ABSTRACTFlooded savannas in south-west Venezuela consist of seasonal, marshy and flooded grassland communities, the distribution of which depends on soil level. Seasonal grasslands are dominated by tuft-forming, rhizomatous C4-grasses (exemplified byPaspalum chaffanjoniiin this study), while flooded grasslands are dominated by stoloniferous grasses which develop rooted, floating culms during the rainy season(Leersia hexandraandHymenachne amplexi-caulis).The interface between these two communities is a marshy grassland dominated by stoloniferous grass species which tolerate flooding to a depth of 10 to 25 cm(Panicum laxumandLeersia hexandra).All perennial grass species in flooded grasslands behave as typical C3 plants, while marshy grasslands are dominated byPanicum laxum,a species with reduced photo-respiration, low RuBP/PEP-carboxylase ratios, and low absolute RuBP-carboxylase activity compared to C3 grasses. It also has lower photosynthetic rates than the other grass species.Hymenachne amplexicaulisappears to be the least drought tolerant from the species selected, in accordance with its distribution in the wettest side of the flooding gradient studied. The other species showed marked reduction in relative water content and pronounced increase in leaf proline content in drought experiments lasting 6 to 30 days. Alcohol dehydrogenase increased markedly in response to anaerobiosis in the root environment in the tuft forming grasses, while the stoloniferous species with ascending culms were least affected by this treatment, probably as a result of better aeration inside the culms and also to the production of adventitious roots in upper nodes. Nitrate reductase activity increased as a result of anaerobiosis in the roots but not in the leaves, of all species exceptLeersia hexandra.No difference among the species was found in malate accumulation, or the activity of malic enzyme.
Wetland herpetofauna of Kakadu National Park, Australia: seasonal richness trends, habitat preferences and the effects of feral ungulates
Authors: Friend Gordon R. , Cellier Kevyn M. 
Published: July 2009

ABSTRACTThe abundance and distribution of reptiles and amphibians inhabiting tropical monsoonal wetlands in Kakadu National Park, northern Australia, were monitored between late 1979 and 1982. Seasonal trends in species richness, and the influence of various environmental attributes (including those caused by feral ungulates) on species distribution patterns were also examined.These wetlands support a high proportion of the amphibian species known from the Park, but are of less importance to reptiles. Within the wetlands, the structurally more complex forested ‘margins’ support many more species than the treeless floodplains. Amphibian species distributions seem to be influenced primarily by elevation, through its effects on soil moisture and flooding levels, while reptile distribution patterns reflect a more complex set of environmental factors, with structural attributes (e.g. vegetation height structure and cover, refuge abundance, leaf litter cover and depth, extent of flooding) being of prime importance.Feral buffalo and pigs, through their grazing, trampling and wallowing, may considerably influence such structural attributes and change the duration and extent of water lie, and thus indirectly affect species distribution patterns. Current buffalo culling programmes provide an opportunity to monitor vegetation and faunal changes, and quantify feral animal impactpost facto.
Ecology of the small mammals in the riverine forests of the Jubba Valley, Southern Somalia
Authors: Varty Nigel 
Published: July 2009

ABSTRACTSeven species of rodent, Paraxerus ochraceus, Tatera robusta, Saccostomus meamsi, Praomys (Mastomys) natalensis, Acomys dimidiatus, Thamnomys (Grammomys) dolichurus and Hystrix cristata were recorded in the riverine forests of the Jubba Valley, southern Somalia, in the dry season of 1986. Acomys dimidiatus was the most common of the five species trapped. Overall trap success was low, but increased over successive days. Saccostomus mearnsi, Praomys natalensis, Acomys dimidiatus and Thamnomys dolichurus all showed signs of breeding, and pregnant females of A. dimidiatus and T. dolichurus were trapped until the end of the dry season. Analysis of stomach contents revealed that all five trapped species relied heavily on seeds and, where comparisons could be made, the degree of overlap in diets was high. The findings are discussed in relation to the environmental conditions in the forest and neighbouring habitats.
Responses of ungulates to seasonal inundations in the Amazon floodplain
Authors: Bodmer Richard E. 
Published: July 2009

ABSTRACTTerrestrial ungulates use different strategies to cope with widespread annual flooding of the Amazon basin. Red brocket deer (Mazama americana) and collared peccary (Tayassu tajacu) retreat to floodplain islands and shift from a frugivorous to a woody browse diet. However, both white-lipped peccary (Tayassu pecari) and lowland tapir (Tapirus terrestris) diets are unaffected by inundations; in the case of white-lipped peccary because they migrate into and out of flooded areas and in the case of lowland tapir because of their semi-aquatic nature. These-strategies of white-lipped peccary and lowland tapir enable them to exploit the greater fruit production of flooded forests more frequently than brocket deer and collared peccary.
Effects of canopy openings on tree seed germination in a Malaysian dipterocarp forest
Authors: Raich James W. , Khoon Gong Wooi 
Published: July 2009

ABSTRACTThe germination of 43 tree species native to the lowland forests of Malaysia was monitored on forest soil in trays placed in closed-canopy forest, an artificial forest gap, and a large clearing. Germination varied significantly among habitats, with only seven species germinating well in all three sites. Seed germination of most species demonstrated clear patterns of shade tolerance or intolerance identical to those long recognized for tree seedlings. Favoured locations for germination were similar to known distributional patterns of adult individuals in mature and secondary forests. Most forest canopy species germinated in the gap, but germination in the large clearing was dramatically reduced or nil; the regeneration of these species in large clearings will be severely retarded even when seeds are present. Canopy-induced inhibition of germination was apparent in several pioneer species; seeds moved from the forest into the gap or clearing germinated rapidly. Results indicate that natural treefall gaps do not inhibit the germination of most species, but do allow pioneer species to germinate, and therefore regenerate. Although germination occurred in all three locations, the level of germination for particular species varied greatly among habitats. We conclude that germination requirements play a very important role in controlling the species composition of regeneration in forest understorey, gap, and large clearing habitats.
Preliminary studies on forest structure and floristics on Volcán Barva, Costa Rica
Authors: Heaney Angela , Proctor John 
Published: July 2009

ABSTRACTVolcán Barva, Costa Rica, has on its northern slope an unbroken sequence of rain forest on volcanic parent materials from near sea level at La Selva Field Station up to its summit at 2906 m. It provides a good area to study forest changes with altitude and their causes. In the present paper we describe the forests as a background for soil and litterfall studies from 1 ha plots at each of the following altitudes: 100 m, 500 m, 1000 m, 1500 m, 2000 m and 2600 m. The canopy heights (with height of the highest emergent in parentheses) ranged from 35–40 m (45 m) at 100 m to 20–23 m (32 m) at 2600 m; basal area was least (22.7 m2) at 100 m and highest (51.2 m2) at 2600 m; the tree (≥10 cm dbh) density ranged from 391 ha–1at 500 m to 617 ha–1at 2600 m. Most trees were identified and on samples of them we recorded presence of buttresses, lianes, skiophytic climbers, vascular epiphytes and bryophytes; and drew profile diagrams. In the classification of Whitmore (1984) the two lower plots are evergreen lowland rain forests; the other four are lower montane rain forest. Species richness was highest in the plot at 500 m, with at least 135 species of tree, and least at 2600 m, with at least 35 species. The Volcán Barva forest altitudinal sequence is briefly compared with those elsewhere.