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1,041 records · Page 58Linked to original sources
PubMed2003

[Ecological distribution of mycorrihizal fungi associated with oak in Dandong district of Liaoning Province].

With plot cruising and rout investigation methods, 36 species of ectomycorrhizal fungi associated with oaks were found in natural secondary oak forest in Dandong district of Liaoning Province. They were subordinated to 7 familyies, 13 genera. Studies on the relationship of the ecological distribution of mycorrhizal fungi with tree species, tree age and seasons showed that 29 species mycorrhizal fugi preferred to grow with Q. mongolica, The species of Russulla were associated with a wider tree ages of oak, and the species of Amanita were most likely to grow with old tree. July and August were the occurrence peak of mycorrhizal fungi. 75% species occurred in July, and 100% species occurred in August. The relative density of the occurrence number was the highest in mid-August (19.5%) and last-August (18.4%).

Ecology↗
PubMed2003

The sex attractant pheromone of the oak processionary, Thaumetopoea processionea a field evaluation.

The sex pheromone of Thaumetopoea processionea has recently been described as a mixture of different isomers with (Z,Z)-11,13-hexadecadien-1-yl acetate as the major active compound. First trials have shown that traps baited with this compound attract male moths in the field. In the present paper we evaluate the use of pheromone traps under practical aspects. The traps can be very well applied to monitor the pest, but the devices have to be installed in the upper crown of the oak trees. It is possible to determine the seasonal flight pattern of the moths. Results of field trials in Germany suggest that the traps can be used to roughly estimate the degree of infestation.

Animals↗
PubMedDate not supplied

Serum total IgE and specific IgE to Dermatophagoides pteronyssinus, but not eosinophil cationic protein, are more likely to be elevated in elderly asthmatic patients.

Serum IgE (total and five specific) and eosinophil cationic protein (ECP) levels were compared in elderly physician-diagnosed patients with asthma with non-asthmatic controls matched by age and gender to ascertain whether elevated levels are indicators of asthma in the elderly. All subjects and controls were non-smokers. The subjects were participants in the Florida Geriatric Research Program (FGRP), a longitudinal aging study that tracks the health status of people 65 years and older. Frozen sera from 33 randomly selected asthmatic patients and 21 controls, none of whom had any other chronic respiratory disease, such as chronic obstructive pulmonary disease (COPD), all between the ages of 65 and 90, were assessed for total IgE; five specific IgE concentrations (for cat, ragweed, German cockroach, Dermatophagoides pteronyssinus (Dp) and live oak); and ECP levels using the Pharmacia Unicap System. The odds of an elderly asthmatic patient having a total IgE of > 100 KU/L were higher than that for a non-asthmatic patient (odds ratio (OR) = 13.0; Mantel-Haenszel (MH) p = 0.005). The odds of elderly asthmatic patients having at least one positive serum specific IgE compared to elderly age-matched non-asthmatic patients were higher (OR = 21.2; MH p = 0.001). Among the five specific IgE concentrations, only IgE for Dp was higher in asthmatic than in non-asthmatic patients (OR = 13.00; MH p = 0.005). The ECP level was not significantly different between elderly asthmatic and non-asthmatic patients (asthmatic mean = 20.7 microg/L, SE = 0.48; control mean = 19.5 microg/L. SE = 0.76) (mean for younger adults 4.4 microg/L, Pharmacia Diagnostics). The serum of elderly asthmatic patients is more likely to have elevated total IgE and a positive specific IgE to Dp. ECP is elevated in elderly subjects but is not an indicator of asthma.

Aged↗
PubMed2004

[Dynamics of soil fauna communities during succession process of secondary forests in Changbai Mountain].

The secondary succession of forest communities in Changbai Mountain might be divided into three stages, i.e., aggradation, transition, and steady states. The last stage will be arrived after about 100 years. At same time, the succession dynamics of various soil fauna groups were shown as: Saprophagous group was more abundant than other fauna groups, and its change trend was similar to the development of forest vegetation after disturbing; Phytophagous group had a higher amount during the prophase of forest succession, which was decreased with forest succession; the quantity of Carnivorous increased obviously after about 100-years-succession; and the composition of insect groups was that the unstable groups was more abundant when the forest was younger, but less abundant when the forest was older.

Animals↗
PubMed2005

[Relationship between plant community succession and fertility variation of mountain yellow soil in east Chongqing].

Based on the analyses of soil physical and chemical properties, this paper studied the relationship between plant community succession and fertility variation of mountain yellow soil in east Chongqing. The results showed that the values of integrated soil fertility index of Pinus massoniana, Cunninghamia lanceolata, deciduous oak, Camellia sinensis and evergreen broad-leaved forest soils were 0.1256, 0.2085, 0.3514, 0.2479 and 0.9329, respectively, implying that soil development had a close relation to plant community succession.

Cunninghamia↗
PubMedDate not supplied

[The recent trend of the biodiversity dynamic of biotic communities in forest-steppe oak forests].

Comparative studies of the structure and diversity of model biotic communities (grass cover, soil macrofauna, xylotrophic fungi and xylophilous coleopterans) were carried out in oak forests of the core and buffer zones of the Voronezh biosphere reserve. The functional structure of the communities in the buffer zone had clearly expressed nemorose features characteristic of the broad-leaved zonal forests, while that in the core zone demonstrated more xerophilous patterns with a wide participation of meadow-steppe elements. The restricted anthropogenic activity in the buffer zone enhances the mesophytization of the oak forest habitats. Complete elimination of anthropogenic pressure in the core zone for two last decades results in the formation of a peculiar, dynamic pattern of forest ecosystems, which corresponds to the zonal climatic conditions.

Biodiversity↗
PubMed2005

[Research advances on BVOCs emission from forest].

BVOCs play an important role in atmospheric environmental quality, global tropospheric chemistry, and global carbon balance, while forest is the main sources of them. This paper summarized the seasonal and diurnal variations of BVOCs emission from forest and its affecting factors including habitat variation, environmental change, forest development phase and its physiological status, and exotic interference. The ecological significance of forest BVOCs emission was further discussed, and some suggestions were proposed on ecological healthcare forest resources exploitation and urban forest construction.

Air↗
PubMedDate not supplied

[First isolation of the yeast Saccharomyces paradoxus in Western Siberia].

Two ascomycetous yeast strains have been isolated near Novosibirsk from oak exudate. The strains have been identified as Saccharomyces paradoxus Bachinskaya based on the results of biochemical tests. The conspecificity of the isolates with S. paradoxus was confirmed by electrophoretic karyotyping and restriction analysis of the ITS region of its rDNA. This first isolation of S. paradoxus in Siberia provides evidence for the continuity of its natural habitats.

DNA, Fungal↗
PubMedDate not supplied

[Ecological-genetic aspects of trophic preference partitioning in a micro-assemblage of oak herbivores].

Trophic niche partitioning among five most common herbivore species was described in respect to the stiffness of the leaves consumed on two trees of pubescent oak. Using discelectrophoresis procedure, genotypes at nonspecific protein loci were detected in two herbivore species, Tortrix viridana (Lepidoptera, Tortricidae) (Pt-2 locus) and Neuroterus quercusbaccarum (Hymenoptera; Cynipidae) (Pt-1 locus). Each locus was represented in studied samples by two alleles, F and S. Significant intra-species partitioning occurred among corresponding genotype classes in these two species. The mean niche overlap measured by Czechanowski index was the lowest (0.324 +/- 0.046) between genotype classes from different species. The intermediate values of this index (0.420 +/- 0.029) characterize niche overlap between genotype classes of given species and other species The highest values correspond to niche overlap between different species (0.578 +/- 0.049) or between genotype classes in the same species (0.585 +/- 0.078). The distribution of gypsy moth (Lymantria dispar) specimens along the leaf stiffness gradient significantly differed from that of T. viridana (FS-genotype class) and coincided with distribution of two other genotypes of the same species. The distribution of T. viridana (SS-genotype class) along the leaf stiffness gradient significantly differed from analogous distribution of heterozygote FS-genotype class of N. quercusbaccarum but was similar with distribution of homozygote FF and SS of the same species. These results means that different genotype classes in the same species interact differently with other species and even with different genotype classes of other species in the micro-community. Different genotypes of one species show different response to leaf stiffness and therefore unequally interact with each other as well as with different species.

Adaptation, Physiological↗
PubMed2006

Differences in the spatial distribution of airborne pollen concentrations at different urban locations within a city.

BACKGROUND: The objective of the present work was to compare pollen counts at three different urban locations within a city to each other and to the counts from a fixed trap. This information could be useful to delimit zones in the urbanized part of the city according to the risk of allergic affections. METHODS: Aerobiological sampling using portable traps was carried out at three points in urban zones of the city of Badajoz (SW Spain) over one year at the same time as continuous sampling using a fixed trap at a point in the nonurban outskirts of the city. The sources of airborne pollen were studied by counting the trees in the streets and squares of the selected zones. A statistical analysis was performed of the differences between the portable and fixed traps and of the temporal and spatial variation in the city as a function of the distribution of the most important pollen sources. RESULTS: Forty-eight pollen types were identified with the fixed trap, and 28 with the portable traps. The grass, olive, and oak pollens come from almost exclusively external sources, there being no spatial differences in their concentrations in the city. Cypress pollen concentrations were much higher at the urban locations than at the fixed trap site. Plane tree pollen levels could be locally very high, reflecting the proximity of the source. Except for ornamental plants, pollen levels were lower at the urban locations than at the site on the outskirts of the city. CONCLUSIONS: (1) Using portable traps at different urban zones in a city could provide information about the spatial variation of atmospheric pollen levels. (2) A knowledge of the often widely variable distribution of ornamental plants with potentially allergenic pollen could be useful in indicating city zones with a greater or lesser incidence of potential pollinosis.

Air Pollutants↗
PubMedDate not supplied

[Hemicelluloses of oak wood extracted with aqueous-alcoholic media].

Hemicellulose fractions were isolated from ethanol extracts (40-90%) of oak wood. To determine the composition of these fractions, they were hydrolyzed, and the hydrolysis products in the form of trimethylsilyl derivatives were analyzed by GLC-MS. Depending on the content of ethanol, hemicelluloses of different composition were extracted from wood. In alcohols stored in a contact with oak wood and intended for manufacturing brandy and whisky, the content of hemicelluloses increased depending on storage duration. It is assumed that this makes drinks more full-bodied and imparts softness to them.

Alcoholic Beverages↗