A diffusion phenomenon in the interaction of two communities is discussed through mathematical methods and it is pointed out that the kind of phenomenon is decided by the intrinsic growth rate.

The interaction of two communities is studied in the technique spreads phenomena. Two thresholds R 0 and R 1 are identified. If R 0<1, the technique spreads phenomena globally exponentially disappear.

On the basis of calculation of diversity and similarity index between every two communities,the results show that the highest index of diversity is community A_(2)(2.7423) and community C_(1)(0.3953) is the lowest.

The main results are reported as follows: (1) The seasonal changes in soil respirationin the two communities had similar dynamic patterns (both being of two peaks), ranging from 312.8 to1 738.9 mg C穖-2穝-1 and from 354.6 to 2 235.6 mg C穖-2穝-1 in the growing season for the steppe plotand the meadow plot respectively.

RESULTS:Through investigation to the 1 018 the elderly people aged over 60 years old in two communities of Xi'an city,the total incidence rate of depression was 26.7%,that of mild depression was 16.50%,that of middle to severe depression was 9.14%and that of severe depression was only 1.08%.

The results were as follows:1.The transpiration from the meadow community was the highest(9.2 mm·d￣(-1)),being the 2-3 times of the other two communities;

Results (1 ) In this two communities based population the prevalences of metabolic syndrome and its components were as follow: hyperglycemia 21. 63% ( diabetes 9. 21% , impaired glucose regulation 12. 41% ) , hypertesion 32. 95% , high triglyceride (TG) / low high-density lipoprotein cholesterol (HDL- C) 46.04%, central obesity 40.68% and metabolic syndrome 13.98% .

In this study, the occurrence of ataxic polyneuropathy was compared in two communities in Nigeria, one located in the endemic area and the other located outside the endemic area.

The study explores the ways in which ideologies of motherhood and femininity operate differently in the two communities and within groups of women with different migration and marital statuses.

This attempt, too, is best understood in the light of the difference between the two communities.

While the conversion generated considerable ill feeling at the time relations between the two communities were not radically affected.

Despite tensions and inequalities between the two communities inter-ethnic relations were shaped by a long-established structure of extensive social and political cooperation between Poles and Jews.

The correlation and association between dominant species of the Dinghushan forest communities have been analysed by means of a 2×2 contingency table and calculation of X~2,and the t-test of correlation coefficients.These characters of community structure have also been showed evidently by the diagrams of species correlativity.Analysis of varance can be applied to compare the quantitative difference of the dominant species between two communities. The research showed that the correlativity between species...

The correlation and association between dominant species of the Dinghushan forest communities have been analysed by means of a 2×2 contingency table and calculation of X~2,and the t-test of correlation coefficients.These characters of community structure have also been showed evidently by the diagrams of species correlativity.Analysis of varance can be applied to compare the quantitative difference of the dominant species between two communities. The research showed that the correlativity between species depends on their age structures,life forms,densities,and succession stages of the communities they live in.Variant species showed the different correlativity characteristics in different community environments.The quadrat size effects the results of the meansurment. The methods used in this paper are suitable to the research of correlation and association between tree species in the evergreen broadlead forest of lweor sub-tropical.

Jiaozhou Wan is situtated on the south side of the Shangdong peninsula, There are more than ten rivers entering the bay and large quantities of organic matters are brought by them into the littoral zone.Many marine invertebretes and algae live in the bay and its littoral zone.The area of Jiaozhou Wan is 423M2,the area of littoral zone is about 1/4 of the area of Jiaozhou Wan,and most is sand-mud and mud beach.The Congkou littoral zone is typical sand-mud beach of Jiaozhou Wan.We have colleted 141 species invertebretest...

Jiaozhou Wan is situtated on the south side of the Shangdong peninsula, There are more than ten rivers entering the bay and large quantities of organic matters are brought by them into the littoral zone.Many marine invertebretes and algae live in the bay and its littoral zone.The area of Jiaozhou Wan is 423M2,the area of littoral zone is about 1/4 of the area of Jiaozhou Wan,and most is sand-mud and mud beach.The Congkou littoral zone is typical sand-mud beach of Jiaozhou Wan.We have colleted 141 species invertebretest in Congkou littoral zone.This is second part on the ecological study of the Intertidal zone of Jiaozhou Wan.In this paper,the communical structure and numbercal dlstrabution of domi-nantal species are described in deatial. There are two communites at the night zone: (1)Scopimera globosa community and (2)Glaucomya chimnsis Perinereis aibuhitensls community. There are three communites at mldzone:(1)Aloides sp.Hacrophthalmus japonicus community, (2)Ruditayes philippinarum Aloides sp.community and(3)Ruditapes philippinamm Musculus senhousei community.There are two communities at low-zone:(1)Rudi-tapes philippinarum Amphiura vadicola community and (2)Ruditapes philippinarum community.We have mathematical tretmented for the diversity of the communities by Fishers' index number of the diversity of the community and by Sanders' Rarefaction methodology in this paper.

In this paper, the log-series model for studying species-abundance distrib-tions of pest-natural enemy communities in paddy fields is discussed. Ecological efficiencies of several diversity indices are compared too.The log-series model is the ideal one which describes the species abundance distributions in the pest-natural enemy community in paddy fields. Analyzed data show that those two communities which follow a single log-series distribution respectively could be enlarged or mixed into a community...

In this paper, the log-series model for studying species-abundance distrib-tions of pest-natural enemy communities in paddy fields is discussed. Ecological efficiencies of several diversity indices are compared too.The log-series model is the ideal one which describes the species abundance distributions in the pest-natural enemy community in paddy fields. Analyzed data show that those two communities which follow a single log-series distribution respectively could be enlarged or mixed into a community which follows still a log-series model.The Shannon-Wiener index has stronger discriminant ability than others among different sites. But it appears insensitive for community compositingchanges in a large sample. The parameter a in the log-series model is more appropriate for the statistic describing community.