Absence Of Flowers Research Articles

Landscape Dynamics of Bird Communities in Relation to Mass Flowering in Some Eucalypt Forests of Central Victoria, Australia

The large-scale dynamics of bird communities in central Victoria, Australia, were studied in relation to eucalypt flowering by recording community changes throughout the annual cycle in sites north and south of the Great Dividing Range (GDR). Two kinds of forest habitat were considered, one of which flowers profusely in winter ('ironbark') while the other flowers little but over the warmer months ('stringybark'). There were eight sites, two of each habitat in both the northern and southern regions. In the absence of flowering in ironbark sites during summer, the avian communities of both kinds of habitat are virtually the same in each region. However, the sets of communities in each region differ significantly from one another at this time. With the onset of winter flowering, avian community composition in ironbark habitats in each region diverges greatly from the non-flowering ironbark and stringybark communities, but converges back to those communities as flowering declines. Most of these changes are due to the influx of high densities of nectarivores, especially honeyeaters and lorikeets. Such influxes in stringybark habitats did not occur, probably because the flowering intensity was at most an order of magnitude less than that in ironbark sites. The results show the dramatic impact that eucalypt flowering has on avian communities in south-eastern Australia, and the influence of habitat differences. Thus, although nectarivores move into the northern region of the study area to capitalize on winter flowering, they show high habitat specificity and virtually avoid the non-flowering stringybark habitats. The results are discussed in terms of landscape and regional dynamics of birds and the possible interactions among avian sub-communities (the 'nectarivores' and 'non-nectarivores').

REVIEWS

Book Reviewed in this article: Fungi and Environmental Change. Ed. by J. C. FRANKLAND, N. MAGANandG. M. GADD. Population Genetics and Genetic Conservation of Forest Trees. Ed. by PH. BARADAT, W. T. ADAMS AND G. MÜLLER‐STARCK. The Siol Seed Banks of North West Europe: Methodology, Density and Longevity. By K. THOMPSON, J. P. BAKKER AND R. M. BEKKER. Identification of Tropical Woody Plants in the Absence of Flowers and Fruits. By R. KELLER. Biology of Citrus. By P. SPIEGEL‐ROY and E. E. GOLDSCHMIDT. Mechanisms of Plant Growth and Improved Productivity. Modern Approaches. Ed. by A. S. BASRA.

Distribution of invertebrates on foliage in forests of south‐eastern Australia

AbstractNearly 1500 foliage samples were collected from a total of 156 plant species, distributed at 16 study sites representing a wide range of forests and woodlands in south‐eastern Australia. Samples were collected in all months. Invertebrates present in samples were counted, sorted into 13 categories, and the number present (> 3 mm in length) converted into density estimates. Densities of all invertebrates combined and invertebrate diversity were also calculated.Despite high variability there were some obvious distributional patterns for most categories. Three major dichotomies affected abundance and distribution of invertebrates: these were presence or absence of flowers, whether the plant species was Eucalyptus or other, and if Eucalyptus, whether the plant species was Symphyomyrtus or Monocalyptus. The presence of flowers in foliage samples increased the abundance of most invertebrate taxa. Compared to foliage of non‐Eucalyptus species, Eucalyptus foliage had more lerp‐forming psyllids and miscellaneous larvae, but fewer Arachnida, Coleoptera, Psocoptera, Hemiptera (other), Thysanoptera, Diptera, and total arthropods. Foliage of Symphyomyrtus species had higher densities of most categories (and particularly lerp‐forming psyllids) than that of Monocalyptus.There were seasonal variations in abundance in most invertebrate taxa, but these patterns were different for Eucalyptus and non‐Eucalyptus species. For most sites abundance of all arthropods combined was lowest in winter, but this decline was not especially pronounced, and was reversed at more xeric sites.For most categories there were significant differences between study sites in abundance and for some this was related to position of sites on a moisture gradient. In general total arthropod densities were highest at intermediate and xeric sites. There were some significant differences in arthropod communities for the same plant species at different study sites.Sample height, plant height, and the ratio of these were relatively unimportant variables. Likewise, the ratio of leaf width: leaf length was not significantly correlated with abundance for any invertebrate category across 128 plant species, but mean leaf size was negatively correlated with densities of Arachnida and total invertebrates. The distributions of some invertebrate categories were inter‐correlated.

Alkane distribution in epicuticular wax of epacridaceae

Alkane distribution pattern was determined in the epicuticular wax of leaves of 39 species and in the flower wax of three species of Epacridaceae. Uniform patterns were observed within some genera ( Monotoca, Styphelia) whereas in others no common pattern was apparent. There was no difference between the alkane patterns of the two subfamilies Epacrideae and Styphelieae. The pattern was not affected by the presence of new growth, and there was no correlation with the season, habitat, climate, nature of soil, or the presence or absence of flowers.

Ethnoecology of natural environment in trans-himalayan region of west Nepal

The present study was conducted during a period of two years from 2001 to 2003 in trans-Himalayan region from Mustang to Dolpa region of west Nepal. The indigenous people were found to be rich in ethnoecological knowledge regarding environment and plant resources. The locals catagorised six types of ecological land patterns such as Nakri (forest land), Penhri or pangri or Thakri or dakri (land pattern), Sim (marshy place or wetland), Lung (agricultural land) and Khangri (Snowy land). The people also had the knowledge of plants in population level and species level and had their own way of classifying them on the basis of different criteria like presence or absence of flower, habit, habitat, morphology, etc. 
 
 Key Words: Ethnobotany; Indigenous knowledge; Folk nomenclature; Folk classification 
 
 Banko Janakari Vol.15(2) 2005 pp13-18

AN INVESTIGATION OF FLOWER FORMATION IN ADULT AND JUVENILE CITRUS TREES

AN INVESTIGATION OF FLOWER FORMATION IN ADULT AND JUVENILE CITRUS TREES