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Takaya Ikemoto 《Researches on Population Ecology》1978,19(2):237-249
Summary The spatial distribution patterns of the population ofAnopheles sinensis larvae were studied in the rice field area in the suburb of Urawa city in Japan, during the summer seasons in 1973 and 1974.
The distribution pattern of the larval population within the field, analysed by the m−m regression method, indicated that
the basic component of larval distribution was not a group of individuals but a single individual and such components were
distributed contagiously over the field. This basic pattern did not change significantly according to developmental stage,
census date or field. Therefore, we could describe the distribution pattern of the population in a rice field by the single
linear regression, x=0.021+1.339x(r2−0.912).
Also, the relation for the whole population in the field area including the five fields could be shown by the linear regression,
x=0.049+1.749x(r2−0.959). The value of α remained to be nearly equal to zero, but the value of β became larger than the value for the single-field
relation. Such a change in distribution pattern seemed to reflect the greater heterogeneity in conditions among the fields
than within individual field.
Using the information on the distribution patterns mentioned above, some considerations were given on the sampling plans for
mosquito larvae, including samplesize determination and application of sequential methods to estimate population size as well
as to classify population level. 相似文献
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M. Kato Akihiro Shibata Takaya Yasui Hidetoshi Nagamasu 《Researches on Population Ecology》1999,41(2):217-228
The Bonin (Ogasawara) Islands are oceanic islands located in the northwest Pacific, and have ten native (nine endemic) bee
species, all of which are nonsocial. The European honeybee (Apis mellifera), which was introduced to the islands for apiculture in the 1880s, became naturalized in a few islands shortly after introduction.
To detect the impact of the honeybees upon native bee diversity, we analyzed pollen harvest by honeybees and surveyed the
relative abundance of honeybees and native bees on flowers on several islands. Both hived and feral honeybee colonies were
active throughout the year, harvesting pollen of both native and alien flowers and from both entomophilous and anemophilous
flowers. Honeybees strongly depended on the alien plants, especially during winter to spring when native melittophilous flowers
were rare. From June to November, honeybees exhaustively utilized native flowers, which had originally been utilized and pollinated
by native bees. On Chichi and Haha Islands, where human disturbance of forests has been severe, both native and alien flowers
were dominated by honeybees, and native bees were rare or extinct even in well-conserved forests. In contrast, on Ani Island
and Haha's satellite islands where primary forests were well conserved and honeybees were still uncommon or absent, native
bees remained dominant. These results suggest that competition for nectar and pollen of the native flowers between honeybees
and native bees favors honeybees on the disturbed islands, which are thoroughly invaded by alien nectariferous, sometimes
aggressive, weedy plants.
Received: May 8, 1998 / Accepted: May 6, 1999 相似文献
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