摘要:

The principle of attachment of pollen grains to flower-visiting insects is quite different in entomophilous angiosperms depending whether pollenkitt or viscin threads are the pollen adhesives. Pollenkitt is to be found in all angiosperm families investigated up to now, but viscin threads occur only in a small number. Moreover, the two pollen cementing principles do not correspond in their respective origin, structure, sculpture, and chemical and physical characters. Even the mechanical aspect of pollen cementing differs. Thus pollenkitt and viscin threads are analogous vehicles in pollination ecology.

ISSN:0017-3134    

DOI:10.1080/00173138109427656

出版商:Taylor & Francis Group    

年代:1981

数据来源: Taylor

ISSN:0017-3134    

DOI:10.1080/00173138109427657

出版商:Taylor & Francis Group    

年代:1981

数据来源: Taylor

摘要:

In this study several air samplers have been compared in more than one environment, in contrast to most environmental studies of airborne microorganisms in which only one type of sampler has usually been used. Very few comparative studies have been made on the efficiency of different apparatus and methods of cultivation, and therefore in most cases published results are difficult to compare and evaluate. In this study we have compared some samplers in common use, and found that many different factors must be taken into account when sampling viable microorganisms. The results will depend on type of apparatus, the environment, the conditions of cultivation, and the number of measurements. The efficiency ratio of an Andersen and a cyclone sampler varied depending on which type of environment was sampled.

ISSN:0017-3134    

DOI:10.1080/00173138109427658

出版商:Taylor & Francis Group    

年代:1981

数据来源: Taylor

摘要:

Soot, dust, occasionally industrial pollution and even dust from the Sahara are sometimes or often found as inorganic floating particles in the ‘Burkard’ pollen-and-spore trap. The time of their occurrence can be determined fairly accurately, as 2 mm of the exposed tape corresponds to one hour. It is possible to evaluate this kind of aerial pollution semiquantitatively with photometric equipment for electropherograms found at every modern hospital. In addition the flowering calendars of two places with very differing climate are shown (Basle and Davos). Therefore, several years of pollen collection can be compared. In the mountains there are fewer pollen grains and also grains of not so many species. But there are also fewer inorganic particles in the air of Davos than in a city such as Basle.

ISSN:0017-3134    

DOI:10.1080/00173138109427659

出版商:Taylor & Francis Group    

年代:1981

数据来源: Taylor

摘要:

Based on monthly means of climatic variables during the period 1937–65, the climate at two Norwegian meteorological stations in January and July was classified by principal component analysis. The new variables were interpreted as pairs of alternating weather types, or airmasses. Four airmasses were identified, covering 20–30% of the transported air at each station. The significance, properties and amounts of air transported by each airmass was calculated and distributed according to wind direction. Differences between air circulation pattern and airmass distribution and properties during the summer and winter season were pointed out. One of the major differences is the tendency to form high pressure over inland areas in winter vs. low pressure in the summer season.

ISSN:0017-3134    

DOI:10.1080/00173138109427660

出版商:Taylor & Francis Group    

年代:1981

数据来源: Taylor

摘要:

By means of a Burkard Seven Day Recording Volumetric Spore Trap located in central Stockhom, about 20 m above ground level, pollen was sampled between March and August for eight consecutive years (1973–1980). The pollen spectra with special reference to trees, in particularBetulaandPinus, were compared as to amount and distribution of taxa. No co-variation between the two latter genera was noted.Betulashowed a ± distinct biennial periodicity. The main pollen season is defined.BetulaandPinusshowed slightly different patterns regarding beginning and duration of the pollen season; mean intensity is compared.

ISSN:0017-3134    

DOI:10.1080/00173138109427661

出版商:Taylor & Francis Group    

年代:1981

数据来源: Taylor

摘要:

Measurements of atmospheric pollen concentration were made during winter conditions in Stockholm in 1977–78 and 1978–79. Filters were fixed vertically and at right angle to the wind by means of a wind vane, and it was possible to convert the data to be expressed as pollen/m3air. The filters were exposed for a period of fourteen days. The results of the analyses show, that pollen grains of various types are present in the winter atmosphere, i.e. November-February/March. The most abundant taxa wereBetula, Pinusand Poaceae, and sometimes more than 25 taxa were counted during one fourteen day period. The amount of pollen/m3air varied between about 0.1 and 15. This is probably the first study of atmospheric pollen during winter conditions.

ISSN:0017-3134    

DOI:10.1080/00173138109427662

出版商:Taylor & Francis Group    

年代:1981

数据来源: Taylor

摘要:

For the past five years pollen frequencies have been registered in Copenhagen and Malmö by using a Burkard spore trap in each city. The distance between the traps is about 31 kilometers. Since the last year the Danish samples have been analysed daily for the radio- and press-reports. By comparing the pollen counts from the two cities, the frequencies seem to follow each other so closely that the use of the Danish figures for radio bulletins in Malmö is justifiable. The quantitative and qualitative analyses forming the basis for this decision are presented.

ISSN:0017-3134    

DOI:10.1080/00173138109427663

出版商:Taylor & Francis Group    

年代:1981

数据来源: Taylor

摘要:

Variation patterns in the qualitative and quantitative composition of airborne pollen of Delhi are assessed. Habitat pressures have been considered as the probable causative factors for the year-to-year and site-to-site variations encountered in the present study.

ISSN:0017-3134    

DOI:10.1080/00173138109427664

出版商:Taylor & Francis Group    

年代:1981

数据来源: Taylor

摘要:

During the years 1977–1979 a total of 32 different fungal genera were observed. Species ofCladosporium, Alternaria, PenicilliumandAspergillusaccounted for 87% of the results.CladosporiumandAlternariadominated in summer, whereasPenicilliumandAspergillusoccurred throughout the year.

ISSN:0017-3134    

DOI:10.1080/00173138109427665

出版商:Taylor & Francis Group    

年代:1981

数据来源: Taylor