bluuebunny/crossref_metadata_2025 huggingface dataset:
Allometry and life history of tropical trees
Authors: King David A.
Published: July 2009

The 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

A 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

Two 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

The 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

Fog 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

The 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

Five 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

The 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.
The water status of six woody species coexisting in the Sahel (Ferlo, Senegal)
Authors: Berger A. , Grouzis M. , Fournier C.
Published: July 2009

In the Sahel during recent decades, anthropogenic disturbance and periods of drought have caused changes in woody species frequency. The internal water status of six coexisting species was analysed to estimate the importance of water constraints in this process. Predawn and midday xylem pressure potential and stomatal conductance were monitored monthly for two years. The relations between xylem pressure potential and transpiration made it possible to determine the hydraulic conductivity of the soil—plant system. Two types of results were obtained. First, there was considerable diversity in water status of the different species. Minimum predawn xylem pressure potentials (dry season) ranged from – 1.5 MPa to – 5 MPa depending on species, with interseasonal variation from 0.08 MPa to 2 MPa. Response to rainfall was very rapid (a few days) or very slow (several months). The three functioning types defined using these results were compared with the phytogeographical status of the species. Second, more specific phenomena were observed, (a) Some species (Balanites aegyptiaca and Boscia senegalensis) showed an imbalance between the predawn xylem pressure potential and the soil water status during the rainy season; (b) a sharp increase in xylem pressure potential was observed in deciduous species in the middle of the dry season; probably related to bud break; and (c) the water status was always favourable for Combrelum glutinosum. The few remaining individuals seem to benefit from very favourable subsoil water supply conditions.
Elevational and latitudinal changes in tree associations and diversity in the Eastern Arc mountains of Tanzania
Authors: Lovett Jon C.
Published: July 2009

A total of 200 variable-area plots covering 20.3 ha containing 4000 trees with a basal area of 921.4 m2 were assessed over a combined elevational range of 410–2180 m in the moist forests of three Tanzanian Eastern Arc mountains: West Usambara, Nguru and Udzungwa. Plot data were ordinated on the basis of species presence/absence, frequency and basal area. Axis 1 of ordinations based on species presence/absence are correlated with elevation. Axis 1 of the frequency-weighted ordination was correlated with elevation in the Nguru and Udzungwa mountains, but plots from the West Usambara showed a rainfall-related discontinuity. Axis 1 of the West Usambara basal area-weighted ordination showed evidence of long-term dynamics of Ocotea usambarensis and in the Udzungwa mountains was determined by presence of Parinari excclsa. Plot diversity was not correlated with elevation or latitude, but was lower in disturbed, low rainfall or more seasonal forest. Stem density was positively correlated with elevation and was greater on ridge tops than valley sides and valley bottoms.
Hurricane damage and forest structure in Guadeloupe, French West Indies
Authors: Imbert Daniel , Labbé Patrick , Rousteau Alain
Published: July 2009

A comparative study of the damage caused by Hurricane Hugo on the three main types of forest in the lesser Antilles was carried out in the mangrove forest, the semi-evergreen forest and the rainforests of Guadeloupe. Hurricane impact on these forests showed at first that high canopy trees generally prevented understorey trees from heavy direct damage (shield effect). In the species-poor, structurally homogeneous stands, in the mangrove forest, species' susceptibility was the major determinant in both intensity and type of damage. Damage was heavy in places and showed a certain spatial uniformity. In the rainforest, the high structural complexity of the vegetation generally induced a great variability in the spatial distribution of damage even at a small scale. Due to the presence of tall trees, indirect damage was locally very heavy. Clumps of large trees formed resistant structures which diminished lethal damage below the main canopy (cluster effect). In such a highly structured, species-rich forest, species' susceptibility was concealed at the local scale by the prevailing influence of vertical structure. Because of its relatively rich flora but low stature, the semi-deciduous forest exhibited intermediate patterns of damage. It was concluded that floristic composition and forest structure help to explain, and to predict, hurricane damage to forest cover.
Successional age and forest structure in a Costa Rican upper montaneQuercusforest
Authors: Kappelle Maarten , Geuze Thorwald , Leal Miguel E. , Cleef Antoine M.
Published: July 2009

Changes in structure of a Costa Rican upper montaneQuercusforest were studied in twelve 0.1 ha plots along a chronosequence including 8- to 20-year-old Early Secondary Forest (ESF), 25- to 32-year-old Late Secondary Forest (LSF) and mature Primary Forest (PF). In 1.2 ha 2854 stems ≥ 3.0 cm dbh belonging to 42 tree species were recorded. Tree species richness per 0.1 ha ranged from 15 to 30. Diversity indices did not change significantly during succession. Stem density did not differ significantly among successional phases, while basal area was significantly higher in PF than in ESF and LSF. Maximum canopy height and basal area increased linearly during the first three decades of recovery. Height and dbh showed a significant, logarithmic regression for all forest phases. A period of 84 y was estimated as the theoretically minimum time needed for structural recovery. The maximum canopy height and basal area recovered two to five times slower in upper montane than in lower montane or lowland Neotropical forests.
Removal of seeds ofCarapa procera(Meliaceae) by rodents and their fate in rainforest in French Guiana
Authors: Forget Pierre-Michel
Published: July 2009

Experiments were performed to investigate monthly variations in seed fate ofCarapa procera(Meliaceae), a rodent-dispersed subcanopy tree species in French Guiana. A total of 600 thread-marked seeds were placed on the ground in mature forest under 20 adult trees during different months (March, April and May 1991) of the species' fruiting season. In 1991 the seed crop reached 1536 seeds in the study area, with a majority of seeds being produced in March and May. On average, seed removal rate steadily increased from March (23%) to May (96%). Of the seeds removed, the proportion eached almost doubled between March (28%)-April (25%) and May (48%), whereas the proportion eaten (gnawed) steadily declined between March (43%) and May (9%). Approximately 75–100% seed removal was therefore associated with intense scatterhoarding and low seed predation, especially in May. Greater seed dispersal rates occurred during the late wet season when fruit diversity decreased but when overall fruit biomass peaked because of fruiting occurrence of large-seeded species. The seasonal hoarding behaviour of rodents is discussed.
Effects of canopy species dominance on understorey light availability in low-elevation secondary forest stands in Costa Rica
Authors: Kabakoff Randy P. , Chazdon Robin L.
Published: July 2009

The effect of canopy species dominance on understorey light availability in secondary forests was examined for Pentaclethra macroloba and Goethalsia meiantha, two common tree species with contrasting canopy architecture at La Selva Biological Station in the Atlantic lowlands of Costa Rica. In each of six 12- to 16-year-old successional stands dominated by one of these species, relative abundance and basal area of the focal species were determined within a 20 m × 50 m plot. Light availability at 1 m height was measured within each plot using a Licor-2000 Plant Canopy Analyzer at 27 locations and by analysing hemispherical photographs taken at 10 locations. Across stands, mean LAI values were significantly negatively correlated with canopy openness. Understorey microsites beneath Pentaclethra had significantly higher light availability than microsites beneath Goethalsia. Across stands, however, light availability was not correlated with either total basal area or stem density of trees ≥10 cm DBH. These results indicate that basal area and stem density of trees in the upper levels of the forest canopy are poor predictors of light penetration to the understorey. One hypothesis suggested here is that dense subcanopy and understorey vegetation in tropical secondary forests can strongly influence understorey light levels. Alternatively, light transmittance characteristics of the upper forest canopy may be influenced by species-specific differences in canopy architecture or foliage density that vary independently from tree diameter and density.
Resource availability, diet and reproduction in Glossophaga longirostris (Mammalia: Chiroptera) in an arid zone of the Venezuelan Andes
Authors: Sosa Maricela , Soriano Pascual J.
Published: July 2009

Seasonal variation in the consumption of cactus fruit by the bat Glossophaga longirostris was related to the availability of this resource in the arid pocket of Lagunillas in the Venezuelan Andes. When fruits were scarce, G. longirostris ate items not preferred in other seasons. The intraspecific flowering periods of the most common cactus species, Stenocereus griseus and Subpilocereus repandus, were synchronized but the number of flowers open per night was low. S. griseus and S. repandus had separate flowering and fruiting periods, possibly to reduce competition for dispersers and pollinators while providing food resources for bats throughout the year. G. longirostris is bimodally polyestrous with extended reproductive periods, probably as a response to the continual availability of cactus flowers and fruits. A strong interdependence between columnar cacti and G. longirostris was demonstrated. Sexual reproduction of the cacti would be greatly reduced without the bats, which in turn could not live in the arid study area without the food sources provided by these cacti.
Characteristics of vertebrate-dispersed fruits in Hong Kong
Authors: Corlett Richard T.
Published: July 2009

Hong Kong has a native angiosperm flora of approximately 1800 species, of which 27% (482 spp.) bear fleshy, presumably vertebrate-dispersed fruits, including 76% of the 337 tree and shrub species and 70% of the 103 climber species. Morphological characteristics were determined for 255 species and nutritional characteristics of the fruit pulp for 153 species. Most fruit species were black (45.1%) or red (24.3%) and 85.9% had a mean diameter <13 mm. Nutritional characteristics varied widely between species with ranges and median values as follows: pulp percentage (range 10.0–99.2%, median 69.2%), water content of pulp (11.1–94.0%, 78%), lipid (0–84.0%, 2.0%), soluble carbohydrate (4–88%, 53%), nitrogen (0.2–3.4%, 0.86%), neutral detergent fibre (1–44%, 14.3%). Fruit development time (50–360 d, 156 d) showed a negative correlation with lipid content, but no significant correlation with fruit or seed size. Principal components analysis of fruit characteristics was dominated by a trend from single-seeded fruits with a thin, lipid-rich pulp layer to multiple-seeded fruits with much, watery, carbohydrate-rich pulp. Birddispersed species cover the full range of fruit characteristics except those too large to swallow and too hard to peck bits from. Mammals (bats, civets and/or macaques) are known or suspected to consume most of the fruits too large for birds as well as many bird fruits but none with high-lipid content. Summer fruits (May—September) were significantly larger and had significantly higher seed size and carbohydrate content than winter fruits (November-March). Winter fruits took more than twice as long to develop as summer fruits.
Sepal and nut size ratio of fruits of Asian Dipterocarpaceae and its implications for dispersal
Authors: Suzuki Eizi , Ashton Peter S.
Published: July 2009

The relationship between sepal and nut size of fruits was studied in fruit of 394 species of Dipterocarpaceae in Malesia and Sri Lanka. The fruits of many dipterocarps have long twisted sepals which have a role as blades for dispersal by gyration. But long sepals decrease resource allocation to other parts, and increase the chance of fruit being trapped in the canopy. The frequency distribution of the ratio of sepal length to nut length was bimodal. The gyrationdispersed group with longer sepals comprised 74% of Dipterocarpaceae studied. The group with short sepal mainly comprised understorey trees, but there were a few emergents. In both groups, sepal areas were expressed as a power function of nut volumes'. Because fruit weight per sepal area increases with fruit size, larger fruits fall more quickly than smaller fruits, and sepals of the former can not serve so effectively as propeller blades. This is consistent with the fact that a few emergent trees with large nuts have short sepals and are not dispersed by gyration. Therefore, the re-evolution of short fruit sepals appears to have been mainly due to two reasons: reduction of tree height and enlargement of nut size.
Comparison of root and mycorrhizal characteristics in primary and secondary rainforest on a metamorphic soil in North Queensland, Australia
Authors: Hopkins Michael S. , Reddell Paul , Hewett Robert K. , Graham Andrew W.
Published: July 2009

Root biomass, root lengths, and mycorrhizal associations were compared in a series of primary and Acacia-dominated secondary rainforest stands on nutrient-poor, red podzolic soils developed from low grade Palaeozoic metasediments. Five soil cores to 200 mm depth were collected at random locations from each of 20 sites. Ten of these sites were in 20–25 m high closed secondary forest (30–40 y old) dominated by Acacia aulacocarpa and ten sites were located in primary, selectively-logged, rainforest (28–32 m tall). Arbuscular mycorrhizas were the only form of association found in the primary forest sites. Ectomycorrhizas dominated the secondary forest sites although arbuscular mycorrhizas were also present. The primary forest sites had significantly higher root biomass (34.4 ± 17.8 t ha-1) and root length (33,400 ± 3,200 km ha-1) than the secondary forests (11.6 ± 4.6 t ha-1 and 25,200 ± 4,800 km ha-1 respectively), and this was interpreted as a reflection of the greater allocation of biomass to roots necessary to support the greater above ground biomass. The specific root length in the secondary forest (340 ± 119 cm g-1) was twice that of the primary forest (154 ± 65 cm g-1) indicating that the trees in the secondary forests achieved a degree of soil exploration which was comparable to that in the primary forest with less than half the biomass allocation to roots. The dominance of ectomycorrhizas in the secondary forest was associated with the prevalence of Acacia aulacocarpa, and the results cannot be extended to other secondary forests in the region. The implications that the dominant ectomycorrhizal associations have for the patterns of successional development and the patterns of species colonization in these Acaria-dominated secondary forests are discussed.
Dispersion and abundance of Macrotermes michaelseni colonies: a limited role for intraspecific competition
Authors: Schuurman Gregor , Dangerfield J. Mark
Published: July 2009

The position of Macrotermes michaelseni mounds were mapped in six areas of 1.5 to 31.0 ha in a range of habitats on the fringes of the Okavango delta. Abundance varied significantly between and within habitats with highest densities in relatively stable floodplain woodland. In all sites apparent overdispersion of active mounds was not statistically significant when edge effects were taken into account. When active and inactive mounds were combined some overdispersion was seen but due to the disturbance regime the probability of all mounds being active simultaneously was small. Intraspecific competition was, therefore, not considered likely. Our results and reanalyses of dispersion patterns in published accounts for Macrotermes species suggest that although mound dispersion can appear to be regular this is probably a result of historical precedence and chance events rather than any current density-dependent process.
Ecological correlates of trap response of a Neotropical forest rodent, Proechimys semispinosus
Authors: Adler Gregory H. , Lambert Thomas D.
Published: July 2009

Patterns of trap response in the Central American spiny rat (Proechimys semispinosus), a frugivorous forest rodent, were examined in relation to age, sex, density and resource abundance. Populations on four small islands (designated numbers 4, 8, 14, and 52) in Gatun Lake (central Panama) were sampled by live-trapping for four nights every month for four years. Trappability was calculated as the proportion of all individuals known to be alive that were actually captured. Mean body mass at first capture was within the range of subadult body masses and differed among islands but not between sexes. Trappabilities summed over the entire study were generally low and differed among islands and age classes (juveniles, subadults and adults) and between sexes. In general, adults were more trappable than juveniles and subadults, and females (particularly adults) were more trappable than males. Trappability and the number of captures per individual varied seasonally and were generally greatest during December and January. Monthly estimates of these two variables were examined for autocorrelation, and the order of the autoregressive error model was determined separately for each island population. The arcsine of trappability and the number of captures per individual were regressed on log10 densities of spiny rats and of fruiting trees and lianas after controlling for autocorrelation. Both trappability indices were negatively related to the density of fruiting trees and lianas on islands 8 and 14, indicating that spiny rats may be seasonally food-stressed. The number of captures per individual was related positively to the density of spiny rats on island 52 and negatively on island 8. Results indicate that spiny rat populations must be sampled with greater intensity and duration than temperate forest rodents.
Bird communities in Panamanian black mangroves: potential effects of physical and biotic factors
Authors: Lefebvre Gaëtan , Poulin Brigitte
Published: July 2009

Isolated in forest patches, mangrove stands often experience different physical conditions (rainfall, tide, salinity) despite similar floristic composition and structure. These abiotic factors are known to influence mangrove phenology but their potential effect on the local invertebrate and bird fauna have not been investigated. This study contrasts two sites of black mangrove (Avicennia germinans) located on the Caribbean and Pacific coasts of Panama. The two mangrove sites are characterized by different rainfall and tide patterns, and consequently ground inundation and salinity. These mangrove sites also differed in their plant phenology as well as invertebrate and bird composition. Although 95% of the bird species sampled occur on both coasts, the two mangrove sites shared only 34%. Moreover, each bird community was composed of a particular feeding guild assemblage consistent with the abundance distribution of their invertebrate-prey. Because floristically similar mangrove stands can support different invertebrate and bird faunas, conservation efforts should target mangrove patches submitted to different physical factors in order to preserve biodiversity.
Mound structure of the fungus-growing termite Macrotermes gilvus in Thailand
Authors: Inoue Tetsushi , Vijarnsorn Pisoot , Abe Takuya
Published: July 2009

The change of mound structure of the fungus growing termite, Macrotermes gilvus, which has no clear air passage system in the mound, was examined in relation to the mound growth in a rubber plantation of southern Thailand. The nest proper consisted of the hive with a royal chamber and nursery, and diffused chambers with fungus combs. The location of the hive became higher with the growth of the mound. Therefore, colonies with a very large mound utilize only the upper mound part and this may be due to the lack of air passage systems in this species. A colony with a very large mound is not in reality commensurately large in colony size and this may be the reason why the density of huge mounds of M. gilvus in Thailand is much higher than that of Macrotermes in Africa.
Seed and seedling survival of the palmAstrocaryum murumuruand the legume treeDipteryx micranthain gaps in Amazonian forest
Authors: Cintra Renato , Horna Viviana
Published: July 2009

The role of regeneration strategies in structuring tropical tree communities has been a recent focus of attention of tropical ecologists. Canopy discontinuities created by tree-falls are considered to be critical to many rain forest trees for establishing and completing their life cycles. It was investigated whether it is advantageous for two common large-seeded and shadetolerant Amazonian tree species, the palmAstrocaryum murumuruand the legume,Dipteryx micrantha, to have their seeds dispersed to gaps. The dispersal process was simulated by placing experimental seeds and seedlings in gaps and in the shaded understorey, and then following their performance. Seeds and seedlings from the two species were used. The Cox proportional hazard model was used to estimate the survival functions and compare survivorship curves. Survival ofAstrocaryumseeds, and ofDipteryxseeds and seedlings, was higher in two gap zones (crown and bole) than in the shaded understorey (both near and far away from a conspecific adult). A higher proportion of seedlings of both plant species survived within gaps than in the shaded understorey over an 18-wk period. One year after the seedlings had been transplanted into gaps these patterns still held. Naturally occurringAstrocaryumseeds survived better beneath conspecific adult trees located within 30 m of gaps than beneath trees located 100 m from gaps. Variation in gap size was significant forDipteryxseeds, but not forDipteryxseedlings andAstrocaryumseeds and seedlings.Dipteryxseeds survived longer in smaller than in larger gaps. By colonizing tree-fall gaps, these two species improved their chances of completing their life cycles.
The effects of cutting and burning on grass quality and axis deer (Axis axis) use of grassland in lowland Nepal
Authors: Moe Stein R. , Wegge Per
Published: July 2009

Man-made grasslands dominated byImperata cylindrica(L.) Beauv. in forested areas of lowland Nepal are commonly cut and/or burned annually. Changes in grass forage quality following different treatments of cutting and burning and axis deer (Axis axis) response to such habitat manipulations were investigated. Samples of matured grass were collected in December 1990, February and April 1991 from three experimental sites: cut, burned, cut-and-burned. Four locations on cut-and-burned grassland were repeatedly sampled at 12-d intervals from January to April 1992. Numbers of axis deer were recorded during the dry season of 1991/1992 on grassland plots receiving the following treatments: cut, cut-and-burned, and uncut/unburned (controls). Based on grass quality differences between December and February and between December and April, cut-and-burned treatments gave the greater increase in forage quality. N was significantly higher on cut-and-burned plots than on cut plots both in February and in April, while Na, K and P was significantly higher in February. On plots cut-and-burned in January, Ca concentrations were relatively low while the P content fell below required levels for domestic stock towards the end of the dry season in April. Na concentrations were below the minimum required levels for both domestic and wild ruminants during the whole period. When an entire grassland was cut, deer density increased gradually. When the same area was subsequently burned, the daily deer density increased much more rapidly. Axis deer preferred burned plots compared to plots neither cut nor burned and to cut plots. Plots burned in late February had higher densities of axis deer than plots burned 1.5 mo earlier. When nearby recently burned plots were available, deer density was reduced on plots burned earlier.
Geographical distribution and aspects of the ecology of the hemiparasitic angiospermStriga asiatica(L.) Kuntze: a herbarium study
Authors: Cochrane Valerie , Press Malcolm C.
Published: July 2009

Striga asiatica(Scrophulariaceae) is an obligate root hemiparasite of mainly C4grasses (including cereals). It is the most widespread of the 42Strigaspecies occurring in many semi-tropical, semi-arid regions of mainly the Old World. Examination of herbaria specimens revealed thatS. asiaticahas a wider geographical distribution, is present at higher altitudes and occurs in a more diverse range of habitats than previously reported. The host range is also larger than previously reported and is likely to include a large number of C3plants. Morphology of examined specimens revealed variation in size and corolla colour suggesting the existence of ecotypes. Climate may exert a significant influence on the distribution ofS. asiaticagiven the diversity of potential host plants and their distribution beyond the current recorded range ofS. asiatica.
Primate community structure at twenty western Amazonian flooded and unflooded forests
Authors: Peres Carlos A.
Published: July 2009

This paper presents data from a standardized series of line-transect censuses on the species and subspecies composition, population density, and crude biomass of western Amazonian primate communities occurring at eight flooded (= vázea) and 12 unflooded (= terra firme) forests. These were located primarily along one of the largest white-water tributaries of the Amazon (= Solimōes), the Juruá river. On average, terra firme forests contained twice as many primate species, lower population densities, and less than half of the total community biomass than did adjacent várzea forests. There was a clear habitat-dependent positive association among primate species, particularly within várzea forests, as well as marked shifts in guild structure between forest types. Species turnover between these two forest types involved primarily understorey insectivores (e.g.Saguinussp.), which do not occur in seasonally inundated forest. These were consistently replaced by squirrel monkeys (Saimirisp.), which are extremely abundant in annually flooded várzea forests. Similarly, large-bodied folivores such as red howler monkeys (Alouatta seniculus) were uncommon or rare in terra firme forests, but very abundant in várzea forests, even though they are hunted less intensively in the former than in the latter. This can be largely explained by the nutrient-rich alluvial soils of young floodplains, compared to the heavily weathered terra firme soils occurring even within short distances of major white-water rivers. This study clearly shows a reversed diversity/density pattern resulting from the lower species richness, but high overall community biomass of seasonally flooded Amazonian forests, which can now be generalized for a wide range of terrestrial vertebrate taxa, including amphibians, birds, and several other orders of mammals.
Estimating species richness in tropical forest: the missing species extrapolation technique
Authors: Tackaberry Rosanne , Brokaw Nicholas , Kellman Martin , Mallory Elizabeth
Published: July 2009

A new technique for estimation of tree species richness in tropical forests was developed and tested in this study. The missing species extrapolation technique is based on the assumption that the rate of accumulation of new species with increasing area is the same within sampled and unsampled areas of similar habitat within a region. This new technique was tested on four 1-ha sites of subtropical moist forest in Rio Bravo, Belize for which complete species counts of trees ≥10cm dbh are available. Estimates given by the technique are 115, 98, 93 and 106% of the actual species counts within the four sites. The accuracy of these estimates was found to be equal to or better than most others obtained by using existing methods of extrapolation. The missing species extrapolation technique was also applied to a 21-ha riparian forest patch in the Mountain Pine Ridge, Belize, where it was used to obtain an estimate of the number of tree species ≥10cm dbh in the entire patch.
Decomposition and potential nitrogen fixation inDicranopteris linearislitter on Mauna Loa, Hawai'i
Authors: Russell Ann E. , Vitousek Peter M.
Published: July 2009

As a consequence of its relatively high productivity in primary successional sites on Mauna Loa, Hawai'i, the mat-forming fernDicranopteris lineariscan influence attributes of soil detrital pools. Decomposition, nutrient release and rates of asymbiotic N fixation inDicranopterislitter were determined over an elevational range of oligotrophic sites. ‘Hot spots’ of nitrogen fixation occurred inDicranopterislitter, as evidenced by acetylene reduction rates as high as 22 nmol g−1h−1. However, potential N fixation rates for the entire litter mass were 0–0.1 g m−2y−1, less than other N inputs such as rainfall.Dicranopteris' decomposition rates were low compared to other tropical species, even under high temperature and rainfall conditions, with ≥50% of the original leaf and >77%of the stem mass remaining after 2 y of decomposition. Slow decomposition was related to high ligninrnitrogen ratios (56–129) in litter and above-ground positioning of unabscised, decomposing litter. As a result of its slow decomposition rates,Dicranopterisis an major contributor to soil detrital pools. Aggradation of the detrital pool is an important process whereby nutrients are accrued within these ecosystems. Consequently,Dicranopterisexerts an important influence on soil genesis and ecosystem development during primary succession on pahoehoe lava.
Forest and forest succession in Hong Kong, China
Authors: Zhuang Xue Ying , Gorlett Richard T.
Published: July 2009

Hong Kong is on the northern margin of the Asian tropics. The original forest cover was cleared centuries ago but secondary forest has developed since 1945 at many sites protected from fire and cutting. There are also older forest patches maintained behind villages for reasons of ‘feng shui’, the Chinese system of geomancy. All plants >2 cm dbh were identified and measured in forty-four 400-m2plots. Detrended correspondence analysis showed a floristic continuum, with the montane sites (>500 m) most distinct and some overlap between lowland post-1945 secondary forest and the feng shui woods. The 30–40 year-old secondary forest is dominated byPerseaspp. Montane forest is similar but lacks several common lowland taxa of tropical genera and includes more subtropical taxa. The feng shui woods have the most complex structure and contain some tree species not found in other forest types. Their origin and history is obscure but we suggest that both planting and selective harvesting have had a role in their current species composition
One people – many names: on different designations for the Sami population in the Norwegian county of Nordland through the centuries
Authors: EVJEN BJØRG , HANSEN LARS IVAR
Published: July 2009

During the eighteenth, nineteenth and twentieth centuries, the Sami and the Kvens were classified and categorized in different ways by the Norwegian state authorities in their official censuses. The process whereby various categorization principles were applied was heavily imbued with ideological and political considerations. During the eighteenth century, when main concern was establishing and consolidating the borders of the state, a kind of geographical enclosure and delimitation took place. During the nineteenth century and through to the Second World War, however, the overriding ambition was to depict all the inhabitants within these established borders as being as culturally homogeneous as possible. Today, it has once more become desirable to acknowledge the presence of both the Sami and the Kvens.
Money supply and credit in rural Cheshire, c.1600–c.1680
Authors: MATTHEWS STEPHEN
Published: July 2009

This article examines the incidence of moneylending and the supply of cash in four rural communities and one small urban centre in Cheshire through the seventeenth century. The evidence on which it is based is drawn from wills and inventories, supplemented by such probate accounts and depositions as are available. It considers the questions of who lent money and to whom, for what purposes and in what amounts. It also examines the incidence of cash holdings in inventories and the effect that the Civil War and its aftermath had upon the availability of cash.
Lives in the balance? Gender, age and assets in late-nineteenth-century England and Wales
Authors: GREEN DAVID R. , OWENS ALASTAIR , MALTBY JOSEPHINE , RUTTERFORD JANETTE
Published: July 2009

Studies of wealth-holding in nineteenth-century Britain focus either on establishing aggregate measures or on individual case studies. These do not allow for a comparative analysis of the way that the composition of wealth was influenced by age and gender. This article explores the importance of these factors using both a case-study approach and a more comprehensive analysis of wealth left at death for a sample of 1,444 individuals. By establishing the age at death for 1,274 of these individuals, together with evidence from a series of death duty records, it is possible to determine the composition of assets by age and gender. For both men and women, shares became more important over the life course. Real estate was more important for men of all ages compared to women, for whom safe investments in government securities assumed greater significance with age. These findings confirm that both age and gender influenced the amount and composition of wealth and demonstrate that these factors need to be taken into account in any model that seeks to make generalizations about the pattern of wealth-holding in the population at large. Emphasizing these demand-side factors provides a different perspective on the rise of Britain as a ‘nation of investors’.
Geschützte Werte Skala (GWS)
Authors: Tanner Carmen , Ryf Bettina , Hanselmann Martin
Published: July 2009

Zusammenfassung. Geschützte Werte (GW) sind Werte, die von Individuen oder einer Gemeinschaft als absolut, unantastbar und nicht substituierbar angesehen werden. Da es bislang noch kein Messinstrument zur Erfassung von GW gibt, besteht das Ziel der vorliegenden Arbeit in der Entwicklung und ersten Validierung einer Geschützten Werte Skala (GWS). Die in Studie 1 durchgeführten Analysen zur Überprüfung der Skalen und der Modellgüte fallen zufrieden stellend aus. Im Sinne der diskriminativen Validität kann gezeigt werden, dass sich GW von wichtigen Einstellungen abgrenzen. Für die Validität spricht auch die Bestätigung mehrerer postulierter Gruppenunterschiede. Der in Studie 2 vorgenommene Vergleich zwischen zwei Extremgruppen (Befürworter und Gegner der Gentechnologie) ergibt zusätzliche Anhaltspunkte zur Validität und konzeptuellen Differenzierung zwischen GW und Einstellungswichtigkeit.
Zur Erklärungskraft der „Regulatory Focus” Theorie im Sport
Authors: Memmert Daniel , Plessner Henning , Maaßmann Jürgen
Published: July 2009

Zusammenfassung. Die „Regulatory Focus” Theorie (RFT) von Higgins (1997, 2000 ) unterscheidet zwei Arten der Selbstregulation beim Anstreben eines erwünschten Endzustands, den Promotion-Fokus (z. B. liegt der Fokus auf Erfüllung und Hoffnung) und den Prevention-Fokus (z. B. liegt der Fokus auf Sicherheit und Verantwortung). Des Weiteren postuliert sie einen Leistungsvorteil, wenn eine Person in eine Situation kommt, die ihrem chronisch bevorzugten Fokus entspricht („Regulatory Fit”). Entsprechend konnten Plessner, et al. (2009) in einer Studie zum Elfmeterschießen im Fußball – einer vermeintlichen Prevention-Aufgabe – zeigen, dass Spieler von einem „Regulatory Fit” profitieren. In der vorliegenden Arbeit wurde die Gültigkeit dieses Effekts für weitere Anforderungen im Sport untersucht. In Studie 1 konnte gezeigt werden, dass sich Aufgaben im Sport tatsächlich per se danach unterscheiden lassen, ob sie eher einen Prevention-Fokus (z. B. Elfmeter im Fußball) oder einen Promotion-Fokus (z. B. 3-Punkte-Wurf im Basketball) anfordern. In Studie 2 wurde der „Regulatory Fit” Effekt in einer Promotion-Aufgabe (3-Punkte-Wurf) mit Basketballspielern der 1./2. Bundesliga (n = 17) und der Bezirksliga (n = 23) untersucht. Zwar konnte der „Regulatory Fit” Effekt für die Spieler der unteren Leistungsklasse repliziert werden, nicht aber für die Spitzenspieler. Auf dieser Grundlage wird die RFT hinsichtlich ihrer Gültigkeit für den Bereich sportlicher Leistungen kritisch diskutiert.