bluuebunny/crossref_metadata_2025_split huggingface dataset:
Floodplain ‘murundus’ of Central Brazil: evidence for the termite-origin hypothesis
Authors: De Oliveira-Filho Ary Teixeira 
Published: July 2009

ABSTRACT‘Campos de murundus’ are a typical landscape of Central Brazil characterized by countless rounded earthmounds (the ‘murundus’), which are covered by woody ‘cerrado’ (savanna) vegetation and are found scattered over a grass-covered surface (the ‘campo’). A detailed study was carried out in the region of Cuiabá, state of Mato Grosso on a particular campo de murundus (area of 5.065 ha) lying in a sedimentary depression where the earthmounds are true islands during the annual floods, allowing the colonization both by cerrado plants and by termites. The mounds were mapped and measured for their size and shape. Mounds' diameters ranged from 0.2 to 22.0 m and heights ranged from 0.1 to 1.1m. The 445 smaller mounds (&lt; 0.8 m diameter) were found to have a clumped distribution, occupying 0.1% of the area. They are actually small termite nests built byArmitermes euamignathus. The 80 larger mounds (&gt; 0.8 m diameter) were uniformly distributed, occupying 6.3%, of the area. These mounds are colonized byCornitermes snyderiandCornitermes bequaertiwhich build big termite nests on the summit of the mounds. Soil analyses indicated a close similarity between the campo and the surrounding cerrado whose soils had coarser texture and were poor in nutrients. Soils of the earthmounds and termite nests showed finer texture, lower pH and higher amounts of mineral nutrients. It is suggested here that this particular type of campo de murundus is formed mainly from the localized activity of nest-building by termites, followed by nest degradation, during many generations of termite colonies.
Population structure, density and biomass of large herbivores in the tropical forests of Nagarahole, India
Authors: Karanth K. Ullas , Sunquist Melvin E. 
Published: July 2009

ABSTRACTWe studied the population structure, density and biomass of seven ungulate and two primate species in the tropical forests of Nagarahole, southern India, using line transect sampling and roadside/platform counts, during 1986–87. The estimated ecological densities of large herbivore species in the study area are: 4.2 muntjac km−2, 50.6 chital km−2, 5.5 sambar km−2, 0.8 four-horned antelope km−2, 9.6 gaur km−2, 4.2 wild pig km−2, 3.3 elephant km−2, 23.8 hanuman langur km−2and 0.6 bonnet macaque km−2. Most ungulates have female-biased adult sex ratios. Among common ungulate species, yearlings and young of the year comprise about a third of the population, suggesting relatively high turn-over rates. Three species (muntjac, sambar and four-horned antelope) are solitary, while others form groups. The study area supports a wild herbivore biomass density of 14,744 kg km−2. Among the three habitat types within the study area, biomass is lower in dry deciduous forests when compared with moist deciduous or teak plantation dominant forests. Using our results, we have examined the factors that may contribute towards maintenance of high ungulate biomass in tropical forests.
Hurricane Hugo: damage to a tropical rain forest in Puerto Rico
Authors: Basnet Khadga , Likens Gene E. , Scatena F. N. , Lugo Ariel E. 
Published: July 2009

ABSTRACTHurricane Hugo of September 1989 caused severe damage to the rain forest in the north-rust corner of Puerto Rico. We assessed the severity of damage distributed in space, species, and size-classes of trees in the Bisley Watersheds of the Luquillo Experimental Forest. We analyzed pie- and post-hurricane data for vegetation from transects established in 1987 and 1988. The severity of damage was significantly greater in valleys than on ridges and slopes. All the species exceptDacryodes excelsa, Sloanea berteriana, andGuarea guidoniashowed 100% severe damage. Large trees (&gt; 70 cm DBH) were highly susceptible to hurricane damage, but there was no clear pattern in the small size-classes.D. excelsa(tabonuco) was the most resistant to damage by the hurricane. Tabonuco which has extensive root-grafts and root anchorage to bedrock and subsurficial rocks, apparently can survive frequent hurricanes and continue as a dominant species in this montane tropical rain forest. The high frequency of hurricanes, which can override other ecological and topographic factors, may largely determine the overall spatial pattern of species in this rain forest.
Ant recolonisation of rehabilitated bauxite mines of Poços de Caldas, Brazil
Authors: Majer Jonathan D. 
Published: July 2009

ABSTRACTThe ant species were sampled in one campo (grassy shrubland), one mata (semideciduous rain forest) and 11 rehabilitated bauxite mine plots at Poços de Caldas, in the humid sub-tropical climatic region of Brazil. Rehabilitation was either by planting AustralianEucalyptusspp, the BrazilianMimosa scabrellatree, or by planting mixed mata trees. Sixty-eight ant species were recorded, of which 26 were exclusively found in the native vegetation and 16 were confined to the rehabilitated plots. Ant species richness built up most rapidly in areas rehabilitated with mixed mata species and least rapidly in areas withEucalyptus. Younger rehabilitated plots appeared to be developing a campo-type ant community, although evidence indicates that more mata ant species will colonise once tree canopy closure takes place. Rate of ant return in Australia is positively correlated with the quantity and distribution of rainfall – the rates in the current study concur with those from humid sub-tropical climatic zones within Australia, suggesting that similar constraints to the succession may be operating. If found to be the case, this would have practical implications for planning and evaluating the success of rehabilitation.
Forest ecology on Java: human impact and vegetation of montane forest
Authors: Smiet Alfred C 
Published: July 2009

ABSTRACTNatural forests on Java have been generally cleared and remnants are now confined to mountain areas Although legally protected, these forests are used by local people for products like firewood, timber and fodder Locally, such exploitation is carried out daily by hundreds of people, whose livelihood depends on forest products Using a landscape-guided approach, a 15,500 ha area of montane forest in East Java has been sampled and analysed at the sylvatic mosaic level Vegetation types, sociologic species groups and vegetation structure are described for landscape units The most accessible landscape units have the most degraded forest with basal area values < 15 m2 ha−1 and a canopy closure of < 20% The least accessible units have relatively undisturbed forest with basal area values of > 45 m2 ha−1 and a canopy closure of > 60% Human activities such as tree cutting have altered species composition and modified forest structure to such an extent that large stretches of forest have been replaced by woodland or shrubland Forest degradation is described as a human induced process in which basal area and canopy closure are ultimately reduced, in spite of regrowth Comparison with other forest areas on Java shows that degradation as a result of tree cutting is a widespread phenomenon
Aspects of rodent ecology in Lunyo Forest, Uganda
Authors: Okia Nathan O 
Published: July 2009

ABSTRACTA study of small rodents was conducted in a small lake-shore forest (Lunyo) in southern Uganda between April 1970 and December 1972 Using capture recapture methods, data on population changes and breeding of six murid species were obtained At the beginning of the study, populations of Lophuromys flavopunctatus and Praomys jacksoni were higher during the mid-annual dry season (June-September), but later fluctuated with rainfall Breeding coincided with rainfall in all species but in Praomys jacksoni and Oenomys hypoxanthus breeding occurred in both wet and dry months The growth rate of laboratory reared Praomys jacksoni and Lemniscomys striatus was comparable to that in the forest within the 20–60 g weight ranges The growth rate of Lophuromys flavopunctatus in the laboratory was lower than in the forest Nonsignificant differences in growth rates were observed between individuals of different litters of the same species Except in L striatus, testicular descent in males occurred at an earlier age than vaginal opening in females The average litter size ranged from a high of 4 5 for L striatus to a low of 2 7 for O hypoxanthus
Balanites wilsoniana: elephant dependent dispersal?
Authors: Chapman Lauren J. , Chapman Colin A. , Wrangham Richard W. 
Published: July 2009

ABSTRACTThis study demonstrates that forest elephants (Loxodonta africana) play a key role as seed dispersal agents for the upper canopy forest tree, Balanites wilsoniana. Seed that passed through elephants had a much greater probability of germinating (50.7%) than seeds from fruits eollected directly from the tree (3%). Of 515 seeds that were collected from under parent trees, 89.1% were rotten at the time of collection, 2.6% had been eaten by forest pigs, 2.8% had been killed by squirrels, and 0.7% had been killed by insect damage. The remaining 4.8% of the seeds were still alive. In 150 hours of focal observations on B. wilsoniana trees, two fruits were seen to be destroyed by squirrels, no fruits were seen to be consumed by potential dispersers, and no evidence of scatter hoarding was found. Experimental seedling stations placed out under parent trees and away from parent trees indicated no significant effect of dispersal on seedling survival. Although elephants are not essential for the successful germination of B. wilsoniana seeds, they do greatly increase probability of germination and play a vital role in their dispersal, suggesting that this is a highly interdependent plant-animal seed dispersal system.
The effects of tree canopy cover on soil fertility in a Nigerian savanna
Authors: Isichei Augustine Onwuegbukiwe , Muoghalu Joseph Ikechukwu 
Published: July 2009

ABSTRACTThe effect of tree canopy cover on soil properties was studied over three periods: middry season (January), mid-growth period (August) and peak-growth period (October) in three 1 ha plots in savanna of north-west Nigeria. The objective was to find out whether tree canopies change the nutrient status of the soil under them relative to adjacent grasslands. Soils under tree canopies were found to have significantly higher levels of organic matter, calcium, magnesium, potassium, total exchangeable bases, cation exchange capacity and pH than those in open grasslands. Nitrogen and phosphorus were slightly higher in soils under tree canopies than those in the open grasslands. Trees 7 m and above had more influence on soil properties than smaller trees. Differences in soil properties among the study plots were due to differences in their soil texture. Seasonal trends were observed in organic matter, carbon: nitrogen ratio, cation exchange capacity, phosphorus, calcium, sodium, total exchangeable cations and percentage base saturation.
Grasses of the Precambrian Shield region in eastern lowland Bolivia. II. Life-form and C3–C4 photosynthetic types
Authors: Killeen Timothy J. , Hinz Paul N. 
Published: July 2009

ABSTRACTA life-form classification from Neotropical Gramineae is proposed for 113 native species from eastern lowland Bolivia. A factor analysis was performed on a correlation matrix of 51 vegetative attributes to identify ‘character suites,’ which were then used as the basis for the classification. The principal types are arboreal, liana, shrub-like, forb-like, bunch grass with basal foliage, bunch grass with basal and caulescent foliage, caespitose annuals, elongate rhizomes, turf grass, stoloniferous, and decumbent (the last category is further divided into subgroups: -perennial, -indefinite, -floating aquatic, and -vine-like). A key component of the life-form classification is the morphology of leaf blades, with five major patterns recognized: elongate and inrolled, elongate and conduplicate, elongate and flat with an attenuate base, short and broad with an amplexicaule base, and short and broad with a pseudopetiole.The distribution and relative abundance of three major photosynthetic categories were compared with life-form and habitat preference. Photosynthetic type of individual species was identified based on leaf anatomy. C4-(XyMS −) species predominated in cerradao, cerrado, campo rupestre, valleyside campos, and seasonally inundated savanna, as well as on granite outcrops. C4-(XyMS + ) species were relatively rare in all habitats, but were significantly more abundant in the xeric microenvironments of granite outcrops. C3 species predominated in semi-deciduous forest and increased in relative abundance in wetland habitats. Caespitose annuals and bunch grass species were predominantly C4 type, while arboreal and liana species were uniformly C3 type. Grasses classified as decumbent or shrub-like were predominantly C3 type, while rhizomatous, stoloniferous, and forblike grasses were a mixture of C3 and C4 type.The intent of the study was to group morphological characteristics objectively in order to derive a life-form classification specific for the Gramineae. Comparisons of the relative abundance of the various life-forms in a broad range of habitat types provide a descriptive assessment of the adaptive value of these characteristics.
Dung beetles attracted to mammalian herbivore (Alouatta palliata) and omnivore (Nasua narica) dung in the tropical rain forest of Los Tuxtlas, Mexico
Authors: Estrada Alejandro , Halffter Gonzalo , Coates-Estrada Rosamond , Meritt Dennis A. 
Published: July 2009

ABSTRACTDung beetles attracted to howler monkey (Alouatta palliata) and coati (Nasua narica) dung were studied for an annual cycle in the tropical rain forest of Los Tuxtlas, Mexico. Pitfall traps set for 24 h month−1captured 1567 dung beetles of 21 species. The speciesCanlhidium martinto, Deltochilum pseudoparile and Canthon femoralisaccounted for 62% of all individuals captured. While species overlap was high (> 80%) between diurnal and nocturnal samples and between howler monkey and coati dung baits, coati dung attracted species such asC. martinezi, D. pseudoparileandOnthophagus rhinolophuswhile species such asC. femoralisandCopris laevicepswere numerically dominant at howler monkey dung. Thirteen non-ball rolling dung beetle species and eight ball-rolling species accounted for 43% and for 57% of all beetles captured respectively. Dung beetles were present and active in all months of the year, but occurred in higher numbers between the months of March and October, when temperatures were higher. Relative abundance of howler monkey and coati dung in the rain forest of Los Tuxtlas was estimated at 11.2 g (fresh weight) ha−1day−1and at 13.0 g ha−1day−1respectively, a seemingly low amount for the large number of scarabs attracted to the dung.
Orchid—phorophyte relationships in a forest watershed in Puerto Rico
Authors: Migenis Luis E. , Ackerman James D. 
Published: July 2009

ABSTRACTOrchid diversity, distribution and host specificity were examined in a tropical watershed in the Luquillo Experimental Forest of Puerto Rico. Eleven orchid species occur in the area. The low diversity is attributed to island isolation and large-scale hurricane disturbances. Pleurothallis ruscifolia and Maxillaria coccinea were by far the most abundant species in the area and occurred on the largest number of host species and host zones. None of the orchids were host specific or host zone specialists although preferences for hosts and vertical host zones were encountered.Only 8.2% of the 426 trees and shrubs and 24.4% of the 45 species surveyed were orchid phorophytes (= hosts). Examination of host distribution by diameter at breast height (DBH) showed that 80.5% were greater than 16 cm DBH. Orchid species in the area tend to occur on rough bark hosts, but their preferences are not statistically significant. Guarea guidonia (Meliaceae) and Dacryodes excelsa (Burseraceae) are the two most important orchid hosts in our study site comprising 62.9% of all host trees. Careful management of these two tree species is suggested, since these species may be crucial to the maintenance of orchid abundance and diversity in the area.
A model of litterfall, litter layer losses and mass transfer in a humid tropical forest at Pernambuco, Brazil
Authors: de Sá Barretto Sampaio Everardo Valadares , Dall'Olio Attilio , Nunes Katia Smera , de Lemos Eurico Eduardo Pinto 
Published: July 2009

ABSTRACTData on litterfall, litter layers accumulated on top of the mineral soil and layer mineralization collected for three years in a tropical rain forest at Pernambuco, Brazil, were implemented on a simulation model. Litterfall was collected biweekly using 11 collectors 1 × 1 m. Every three months, 20 litter mat samples, 0.5 × 0.5 m, were collected, divided into the L, F and H layers and the CO2 evolution from each litter layer was determined in the laboratory. Litterfall, in the three years, averaged 7.8, 8.3 and 8.2 Mg ha-1 y-1, most of it leaves. Litter mat masses varied widely from place to place (15–90 Mg ha-1) and the overall averages were 5.6, 7.6 and 26.1 Mg ha-1 for the L, F and H layers, with CO2 evolution averages of 2.27, 0.507 and 0.123 mgC g litter C-1 day-1. According to the model, the L layer had a high turnover rate, losing 4.7 Mg ha-1 y-1 through mineralization and 3.4 Mg ha-1 y-1 transferred to the F layer. Values for the F and H layers were 1.4 and 1.2 mineralized and 2.0 and 0.8 Mg ha-1 y-1 transferred. Thus, it would take 2.1, 6.7 and 39 years for newly fallen leaves to be mostly fragments, to be transformed to humus and to be incorporated to the soil organic matter, respectively. Variations of litterfall throughout the three years would have little effect on the system which was not very sensitive to litterfall changes, except for the top layer.
Ecosystem dynamics of disturbed and undisturbed sites in north Queensland wet tropical rain forest. I. Floristic composition, climate and soil chemistry
Authors: Congdon Robert A. , Herbohn John L. 
Published: July 2009

ABSTRACTThis paper introduces studies of nutrient cycling in disturbed and undisturbed rain forest plots in the upper catchment of Birthday Creek, near Paluma, North Queensland. The catchment is underlain by granite and has soils of comparatively low fertility. Differences between unlogged plots and plots disturbed 25 years previously by selective logging are still apparent. Disturbed plots have soils with higher bulk densities and pH, lower CEC, kjeldahl nitrogen and available phosphorus concentrations, and changed species composition. The data suggest that recovery from selective logging is dependent on soil fertility and intensity of disturbance.
Ecological relationships between lianas and trees in lowland rain forest in Sabah, East Malaysia
Authors: Campbell E. J. F. , Newbery D. McC. 
Published: July 2009

ABSTRACTNumbers of lianas ≥2 cm gbh were recorded on trees ≥30 cm gbh in two 4 ha plots of dipterocarp forest. Associations between lianas and trees of the 12 commonest families and 16 commonest species were analysed. Liana density was 882 ha-1. Fifty-seven per cent of trees supported lianas and the mean number lianas per tree was 2.1. Lianas were highly aggregated on individual trees in most families; numbers of lianas per tree followed the negative binomial distribution for the Dipterocarpaceae but not Euphorbiaceae. Dipterocarpaceae and Euphorbiaceae differed in susceptibility, with 41 and 64% of their trees respectively supporting lianas. The proportions of trees with lianas (i.e. % trees laden) were correlated between plots at the species, but not the family, level. They were not related to tree girth; differences in proportions between families and species were maintained for trees in the 30–40 cm gbh class. At the species level, proportions of trees with lianas and the mean number of lianas per tree were significantly inversely correlated with mean branch-free bole height of trees in the 30–40 cm gbh class. Increased branch-free bole height and associated branch shedding may therefore decrease the susceptibility of trees to lianas and explain the lower susceptibility in the Dipterocarpaceae than the Euphorbiaceae.
Growth history of a Neotropical tree inferred from the spacing of leaf scars
Authors: King David A. 
Published: July 2009

ABSTRACTThe Neotropical tree,Pourouma aspera(Cecropiaceae), supports large lobed leaves on an erect stem which seldom branches below a height of 5 m. The prominent leaf scars are visible on trunks of mature trees and the distance between scars is highly correlated with the height growth rate when the leaves were produced. Relationships between height growth rate, internode length and light environment were determined from markedP. asperasaplings in a tropical wet lowland forest and used to infer the past growth histories of larger saplings and trees. Inferred growth rates were quite variable, both within and between individuals. Estimated passage times to grow from 0.7 to 2.2 m tall ranged from 0.6–23 y, with a mean of 4.4 y (N = 61). The study illustrates the importance of examining the distribution of growth rate over the length of the stem in addition to the more usual distribution of numbers of individuals per growth rate class. Species such asPourouma, which respond strongly to light, complete much of their total juvenile growth during intervals of high light, even though most saplings are growing slowly in shade at any given time.
Factors influencing tree growth in tropical savanna: studies of an abrupt Eucalyptus boundary at Yapilika, Melville Island, northern Australia
Authors: Wilson B. A. , Bowman D. M. J. S. 
Published: July 2009

ABSTRACTMost of the land surface of Melville Island, Australia's second largest island, is covered in Eucalyptus savanna. One exception is an area at Yapilika where a large tract of savanna is dominated by Acacia shrubs. An ordination analysis of 122 quadrats revealed that the boundary of Eucalyptus dominance did not correspond to a major change in floristic composition. Detailed transect studies at one site on the boundary showed that Eucalyptus trees were abruptly replaced by a band of Grevillea trees which gradually gave way to Acacia shrub dominance. There was a gradual change in the floristic composition of the savanna across the boundary. The distributional limit of Eucalyptus was found to be independent of any hydrological discontinuity. There was a slight decrease (<2.5 m) in altitude from Eucalyptus to Acacia savanna. The Acacia savanna soils were sandier and their surface soil had significantly lower concentrations of Ca and Mg and significantly greater concentration of Al compared with the Eucalyptus savanna soils. Eucalyptus seedlings planted in the three savanna communities were not found to be under drought stress (pre-dawn leaf xylem potentials of > – 0.9 MPa) during the dry season. Over a 12 month period Eucalyptus tetrodonta and E. miniata seedling growth was not significantly different on the Acacia or Eucalyptus savanna, although this result may be due to the counteracting effects of greater soil fertility and tree competition in the Eucalyptus savanna and lower soil fertility in the treeless, and hence competition-free, Acacia savanna. This hypothesis is supported by the significantly greater growth of Eucalyptus seedlings on fertilized Acacia savanna soils. The limited production, dispersal and establishment of Eucalyptus seeds and the greater frequency of fires in the Acacia savanna probably explains the abrupt limit to Eucalyptus dominance along the edaphic gradient.