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Results 401 - 450 of 685
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van der Straten K M - - 2006
As a first step towards the development of a method for the cryopreservation of black marlin spermatozoa, this study investigated the effect of dimethylsulfoxide (DMSO) concentration and pellet size on post-thaw spermatozoal motility. Spermatozoa were recovered from the spermatic duct of testes retrieved post-mortem from four adult black marlin caught ...
Janmaat Karline R L - - 2006
Temperature and solar radiation are known to influence maturation of fruits and insect larvae inside them . We investigated whether gray-cheeked mangabeys (Lophocebus albigena johnstonii) of Kibale Forest, Uganda, take these weather variables into account when searching for ripe figs or unripe figs containing insect larvae. We predicted that monkeys ...
Ward Tony J - - 2006
Tree bark and core samples were collected from areas surrounding the asbestos-contaminated vermiculite mine in Libby, MT. These samples were collected to provide preliminary data in support of a proposed study to determine if trees can serve as reservoirs for amphibole fibers and to determine if there is a potential ...
Swan Christopher M - - 2006
Forest soils and streams receive substantial inputs of detritus from deciduous vegetation. Decay of this material is a critical ecosystem process, recycling nutrients and supporting detrital-based food webs, and has been attributed, in part, to leaf litter species composition. However, research on why speciose leaf litter should degrade differently has ...
Young J A - - 2006
In 2002, Tennis Australia commissioned a report into the experiences of elite female past players on leaving the professional tennis circuit. Australian players who were in the top 800 of the Women's Tennis Association (WTA) end of year rankings and who had left the professional circuit within the previous 15 ...
Lovelock Catherine E - - 2006
Spatial gradients in mangrove tree height in barrier islands of Belize are associated with nutrient deficiency and sustained flooding in the absence of a salinity gradient. While nutrient deficiency is likely to affect many parameters, here we show that addition of phosphorus (P) to dwarf mangroves stimulated increases in diameters ...
Galantino-Homer Hannah L - - 2006
Porcine sperm are extremely sensitive to the damaging effects of cold shock. It has been shown that cholesterol-binding molecules, such as 2-hydroxypropyl-beta-cyclodextrin (HBCD), improve post-cooling porcine sperm viability when added to an egg yolk-based extender, but also enhance sperm capacitation in other species. The objective of this study was to ...
Moldan F - - 2006
Beginning in 1991, we have added nitrogen (N) to the 0.5-ha, N-poor, coniferous-forested catchment G2 NITREX at Gårdsjön, Sweden, to investigate the consequences of chronic elevated N deposition. We have added 40 kg N ha-1 yr-1 in fortnightly doses of NH4NO3 to the ambient 15 kg N ha-1 yr-1 by ...
Sala Anna - - 2006
As trees grow tall and the resistance of the hydraulic pathway increases, water supply to foliage may decrease forcing stomata to close and CO2 uptake to decline. Several structural (e.g. biomass allocation) and physiological adjustments, however, may partially or fully compensate for such hydraulic constraints and prevent limitations on CO2 ...
Gibb A R - - 2006
Gas chromatography-electroantennographic detection analysis of sex pheromone gland extracts of the common forest looper Pseudocoremia suavis (Lepidoptera: Geometridae), a polyphagous defoliator of introduced Pinaceae and many New Zealand trees, revealed four compounds that elicited antennal responses. The two major active compounds (6Z)-cis-9,10-epoxynonadec-6-ene and (3Z,6Z)-cis-9,10-epoxynonadeca-3,6-diene were identified by comparison with known ...
Raghuvansi S K S - - 2007
The effect of inclusion of tree leaves in mustard (Brassica campestris) straw (MS) based complete feed blocks (CFB) on nutrient utilization and rumen fermentation was studied in adult male sheep. Four types of CFB diets (Roughage:Concentrate:Molasses, 70:25:5) were prepared. The compaction process increased bulk density (g/cm(3)) of MSB, MSNL, MSSL ...
Norghauer Julian M - - 2006
According to the Janzen-Connell model, high mortality of seeds and seedlings in proximity to conspecific adults can help maintain species diversity in tropical forests. Using a natural population of big-leaf mahogany (Swietenia macrophylla King), we tested the model's mechanism by examining seed predation and juvenile recruitment in the forest understory ...
Lehman Shawn M - - 2006
Forest edges are dynamic zones characterized by the penetration (to varying depths and intensities) of conditions from the surrounding environment (matrix) into the forest interior. Although edge effects influence many tropical organisms, they have not been studied directly in primates. Edge effects are particularly relevant to lemurs because of the ...
Lehman Shawn M - - 2006
Edge effects are caused by the penetration of abiotic and biotic conditions from the matrix into forest interiors. Although edge effects influence the biogeography of many tropical organisms, they have not been studied directly in primates. Edge effects are particularly relevant to lemurs due to the loss of 80-90% of ...
Twedt Daniel J - - 2006
The historical area of bottomland hardwood forest in the Mississippi Alluvial Valley has been reduced by >75%. Agricultural production was the primary motivator for deforestation; hence, clearing deliberately targeted higher and drier sites. Remaining forests are highly fragmented and hydrologically altered, with larger forest fragments subject to greater inundation, which ...
Corlett Richard T - - 2006
Ecologists have tended to overemphasize the common features of tropical rainforests on different continents. In reality, the five major tropical rainforest regions (tropical America, Africa, Southeast Asia, Madagascar and New Guinea) are distinct ecological and biogeographical entities. Although it is easy to find examples of at least superficial convergence between ...
Wantzen, Karl M.
Leaf litter is a major component in the organic matter budgets of streams worldwide. Shredding invertebrates are widely considered to be of central importance for the breakdown of allochthonous organic material in temperate-zone streams. However, various authors report an absence of this group in tropical streams. Various phenomena, including hydraulic ...
Verheyden, H.
1. The literature on bark-stripping by red deer Cervus elaphus in Europe is reviewed to reveal quantitative variation in this behaviour and relate it to deer density and local characteristics such as dominant tree species, occurrence of artificial feeding, altitude, region and size of the study site. We also review ...
Wright S J - - 2006
It has recently been reported that humid tropical forests are changing rapidly in response to global anthropogenic change and that these forests experience greater tree mortality and even fire during droughts associated with El Niño events. The former reports are controversial largely because a single method has been used - ...
Solari Luis I - - 2006
It is well known that rootstocks can have an effect on the vegetative growth and development of the tree; however, there has been no clear explanation about the physiological mechanism involved in this phenomenon. Evidence indicates that the rootstock effects on tree vegetative growth may be related to hydraulic limitations ...
Teaford M F - - 2006
Primate species often eat foods of different physical properties. This may have implications for tooth structure and wear in those species. The purpose of this study was to examine the mechanical defenses of leaves eaten by Alouatta palliata from different social groups at Hacienda La Pacifica in Costa Rica. Leaves ...
Shi Guanglu - - 2006
An investigation on the insects in the jujube ecosystem in Taigu District of Shanxi Province, Northern China showed that more species and individual numbers of pest, predatory and neutral insects were found on the tree than on the ground. The ratio of the species and individual numbers of predatory and ...
Larl I - - 2006
Morphogenesis of floral structures, dynamics of reproductive development from floral initiation until fruit maturation, and leaf turnover in vegetative short-stem shoots of Saxifraga oppositifolia were studied in three consecutive years at an alpine site (2300 m) and at an early- and late-thawing subnival site (2650 m) in the Austrian Alps. ...
Pandjaitan N - - 2005
Spinach leaves harvested at three maturity stages from eight commercial cultivars (CC) and eight advanced breeding lines (ABL) were evaluated for oxygen radical absorbing capacity (ORAC), total phenolics, and flavonoid composition and content. ABL had higher levels of total phenolics, total flavonoids, and ORAC than CC. Midmaturity spinach leaves had ...
Nissinen Anne - - 2005
The effect of carrot psyllid (Trioza apicalis Förster) feeding and limonene and methyl jasmonate (MeJA) treatments on the essential oil composition and headspace volatiles of carrot (Daucus carota ssp. sativus), cvs. Parano and Splendid, leaves was studied. Carrot psyllid feeding significantly increased the concentrations of sabinene, beta-pinene, and limonene, whereas ...
Millett J - - 2005
Deciduous trees recycle nitrogen within their tissues. The aim of this study was to test the hypothesis that reductions in plant growth, caused by competition and herbivory, reduce the sink strength for N during autumn nutrient withdrawal, and reduce the storage capacity and hence the amount of N remobilized in ...
Salm Rodolfo - - 2005
This study examines how the seed morphology of two large arborescent palms, Attalea maripa (Aubl.) Mart. and Astrocaryum aculeatum G. Mey, may affect their seed shadow in a seasonally dry Amazonian forest. In addition to being smaller and produced in larger numbers than those of A. aculeatum, A. maripa seeds ...
Pretzsch Hans - - 2006
Experimental plots covering a 120 years' observation period in unthinned, even-aged pure stands of common beech (Fagus sylvatica), Norway spruce (Picea abies), Scots pine (Pinus sylvestris), and common oak (Quercus Petraea) are used to scrutinize Reineke's (1933) empirically derived stand density rule [see text], N=tree number per unit area, [see ...
Langhans Simone D - - 2006
Despite growing recognition of the importance of a natural flow regime in river-floodplain systems, researchers struggle to quantify ecosystem responses to altered hydrological regimes. How do frequency, timing, and duration of inundation affect fundamental ecosystem processes such as leaf litter decomposition? Along the semi-natural Tagliamento River corridor, located in northeastern ...
Cristóbal-Azkarate Jurgi - - 2005
This research focuses on identifying the principal habitat characteristics that influence the presence and abundance of mantled howlers in forest fragments. We provide information on the demography of several fragmented Alouatta palliata mexicana subpopulations at Los Tuxtlas, Mexico, and relate this to the biogeographical and floristic characteristics of the forest ...
Kato-Noguchi Hisashi - - 2005
The release levels of a growth inhibitor, momilactone B, from rice (Oryza sativa L.) seedlings of eight cultivars were compared with the endogenous concentrations of momilactone B in their seedlings. All rice cultivars contained momilactone B in the seedlings, and their concentrations differed between the cultivars. Momilactone B was also ...
Plumptre Andrew J - - 2006
Primate census techniques have been developed over the past 35-40 years yet there is still some confusion and great variation in the methods used. This precludes comparisons between sites where different techniques have been used. This paper discusses the variations between the methods that seem to be practiced currently and ...
Terakado Junko - - 2006
In legumes, the number of root nodules is controlled by a mechanism called autoregulation. Recently, we found that the foliar brassinosteroid (BR), a plant growth-regulating hormone, systemically regulates the nodule number in soybean plants. In the present study we report that such down-regulation of root nodule formation by a BR ...
Zimmer Martin - - 2005
To investigate species-specific decomposition rates of litter from native (Quercus faginea) and introduced (Eucalyptus globulus) tree species in Portugal, we monitored changes in the phenolic signature of leaf litter during decomposition as mediated by an aquatic, Proasellus coxalis (Isopoda: Asellota), and two terrestrial, Porcellio dispar and Eluma caelatum (Isopoda: Oniscidea), ...
Hubbard J L - - 2005
Seasonal phenology of calico scale, Eulecanium cerasorum (Cockerell), was monitored for 3 yr on various deciduous tree species in central Kentucky. Infestations were found on 16 host species in six plant families. Calico scale is a univoltine parthenogenic species that overwinters as second instars on bark. Nymphs molted to adult ...
Hanya Goro - - 2005
We compared food availability and group density of Japanese macaques in Yakushima, southern Japan, among primary forest and two habitats that had been disturbed by logging and had different regeneration histories. The study was conducted in an undisturbed national park, forest that was logged 7-18 years ago and later naturally ...
Goulart Maíra Figueiredo - - 2005
BACKGROUND AND AIMS: Plathymenia reticulata (Leguminosae) is a Brazilian tree that occurs in two biomes: Cerrado, a woody savanna vegetation, and the Atlantic Forest, a tropical forest. In this study, phenological patterns and their variability within and among populations located in these biomes and in transitional zones between them were ...
Fustec Joelle - - 2005
BACKGROUND AND AIMS: To improve the management of grass communities, early plant development was compared in three species with contrasting growth forms, a caespitose (Lolium perenne), a rhizomatous (Poa pratensis) and a caespitose-stoloniferous species (Agrostis stolonifera). METHODS: Isolated seedlings were grown in a glasshouse without trophic constraints for 37 d ...
Hardman John Michael - - 2005
In a 2-yr study of causes of mite outbreaks in apple (Malus spp.) orchards in Nova Scotia, we monitored immigration of Tetranychus urticae Koch from orchard ground cover into trees populated by the generalist phytoseiid predator Typhlodromus pyri Scheuten. In both years, T. urticae-days in the tree canopy increased with ...
Kortekamp Andreas - - 2005
Although Plasmopara viticola causes grape downy mildew in most, if not all, wine producing countries, many basic biological or chemical aspects are still unknown and thus the histopathological changes during development of this oomycete pathogen were studied. The fluorochromes Aniline blue and Uvitex 2B were successfully used in whole leaf ...
Balko Elizabeth A - - 2005
We present a summary of a long-term field study that examined the effects of forest disturbance on the availability of palatable fruit and its utilization by V. variegata. Forest structure and tree species composition were measured in three adjacent study areas, with different histories of disturbance, in Ranomafana National Park ...
Ishida Atsushi - - 2005
In a field study, we compared anatomy and diurnal gas exchange and chlorophyll fluorescence in sunlit mature leaves of Macaranga gigantea (Reichb. f. and Zoll.) Muell. seedlings, saplings, an adult tree and suckers originating from stumps. We tested the hypothesis that the pattern of resource use shifts across various life ...
Chen Gen-Yun - - 2005
Net photosynthetic rates (Pns) in leaves were compared between rice plants grown in ambient air control and free-air CO2 enrichment (FACE, about 200 micromol mol(-1) above ambient) treatment rings. When measured at the same CO2 concentration, the Pn of FACE leaves decreased significantly, indicating that photosynthetic acclimation to high CO2 ...
Borchert Rolf - - 2005
Several North American broad-leaved tree species range from the northern United States at approximately 47 degrees N to moist tropical montane forests in Mexico and Central America at 15-20 degrees N. Along this gradient the average minimum temperatures of the coldest month (T (Jan)), which characterize annual variation in temperature, ...
DeMason Darleen A - - 2005
A number of mutations that alter the form of the compound leaf in pea (Pisum sativum) has proven useful in elucidating the role that auxin might play in pea leaf development. The goals of this study were to determine if auxin application can rescue any of the pea leaf mutants ...
Zhu You-Yong - - 2005
ABSTRACT Glutinous rice cultivars were sown after every fourth row of a nonglutinous, hybrid cultivar in an additive design. The glutinous cultivars were 35 to 40 cm taller and substantially more susceptible to blast than was the nonglutinous cultivar. Interplanting of glutinous and nonglutinous rice reduced the incidence and severity ...
Katz Ehud - - 2005
Although leaves and other vegetative tissues are generally considered as non-climacteric, citrus leaves show a climacteric system II behaviour after detachment. Upon harvest, young, fully expanded 'Valencia' orange (Citrus sinensis) leaves ( approximately 60-d-old) exhibited two phases of ethylene production. The first phase, up to 6 d after detachment, was ...
Rita S. W. Yam
Caridina spp. (Atyidae) are widespread and abundant omnivorous shrimps in tropical Asian streams. Spatial and seasonal variation in C and N stable isotope signatures of 2 species (Caridina cantonensis and C. serrata) and their potential food sources (leaf litter, fine particulate organic matter [FPOM], and periphyton) were investigated in 2 ...
Miyazawa Yoshiyuki - - 2005
* Here we investigated photosynthetic traits of evergreen species under a deciduous canopy in a temperate forest and revealed the importance of CO2 assimilation during winter for annual CO2 assimilation. * Saplings were shaded by the canopy trees from spring through to autumn, but were less shaded during the winter ...
Jasper André - - 2005
A new taxon of conifers (Coricladus quiteriensis) is described based on megafloristic remains from the roofshale level at the Quiteria Outcrop (Rio Bonito Formation-Lower Permian-Southern Parana Basin-Rio Grande do Sul-Brazil). This megafloristic community is included in the Botrychiopsis Zone--Botrychiopsis valida Sub-Zone (Kungurian/Roadian). The assemblage, preserved as impressions, do not present ...
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