Vertical foodweb structure of freshwater zooplankton assemblages estimated by stable nitrogen isotopesResearches on Population Ecology - Tập 38 - Trang 283-287 - 1996
R. France, K. Westcott, P. del Giorgio, G. Klein, J. Kalff
Although theoretical foodweb models predict the presence of only three to four trophic categories, estimation of “potential” vertical foodweb structure from species lists and inferred feeding interactions suggest that as many as 7 trophic categories can occur in the pelagic foodwebs of North American glaciated lakes. A compilation of data on the nitrogen isotopic composition of zooplankton from 46...... hiện toàn bộ
Evolution of condition-dependent dispersal: A genetic-algorithm search for the ESS reaction normResearches on Population Ecology - Tập 39 - Trang 127-137 - 1997
Hideo Ezoe, Yoh Iwasa
Many insects produce two types (winged and wingless) of offspring that greatly differ in dispersal ability. The ratio of the two types often depends on the quality of the local habitat and the crowding experienced by the mother. Here we studied the condition-dependent dispersal that is evolutionarily stable. The model is also applicable to annual plants that produce two types of seeds differing in...... hiện toàn bộ
The evolution of dispersal polymorphisms in insects: The influence of habitats, host plants and matesResearches on Population Ecology - Tập 36 - Trang 127-135 - 1994
Robert F. Denno
Wing-dimorphic, delphacid planthoppers were used to test hypotheses concerning the effects of habitat persistence and architectural complexity on the occurrence of dispersal. For reasons concerning both the durational stability of the habitat and the reduced availability of mates, selection has favored high levels of dispersal in species occupying temporary habitats. Flightlessness predominates in...... hiện toàn bộ
Biology ofhyphantria cunea drury (lepidoptera : Arctiidae) in Japan. IX. population dynamicsResearches on Population Ecology - Tập 11 - Trang 211-228 - 1969
Yosiaki Itô, Atsuhiro Shibazaki, Osamu Iwahashi
Fluctuations in population density ofHyphantria cunea in Japan are characterized by a gradation-like pattern. Analysis of the life table data taken from two stations during eight successive generations showed that (1) mortality during egg and early larval stages was density-independent, (2) mortality during later larval stages wasinversely density-dependent, and (3) mortality during prepupal and p...... hiện toàn bộ
A simple model of host-parasitoid interaction with host-feedingResearches on Population Ecology - Tập 30 - Trang 353-369 - 1988
Norio Yamamura, Eizi Yano
A simple mathematical model of host-parasitoid interaction with host-feeding was presented with special reference to the system of the greenhouse whitefly and the parasitoidEncarsia formosa. In the model, when a parasitoid encounters a host, it has a choice between feeding the host and ovipositing one egg in the host. It was shown that an intermediate value of the feeding ratio of all attacks give...... hiện toàn bộ
Consequences of competition on the reproduction and mortality of three species of terrestrial slugsResearches on Population Ecology - Tập 25 - Trang 20-43 - 1983
C. David Rollo
The interaction of three species of terrestrial slugs was studied in six field cages containing monocultures and 2-way combinations.A. columbianus andA. ater were non-aggressive species andL. maximus was highly aggressive during the summer. All three species were similar in body design and resource utilization. Reproduction (egg size, eggs/batch, number of batches, wet-weight productivity) and mor...... hiện toàn bộ