Factor analysis was used to investigate the changes of dry-wet climate in the dry season in Yunnan during 1961-2007 based on observed data from 15 stations.Three common factors were extracted from the 9 climatic facto...Factor analysis was used to investigate the changes of dry-wet climate in the dry season in Yunnan during 1961-2007 based on observed data from 15 stations.Three common factors were extracted from the 9 climatic factors.The results showed that the dry-wet climate has evidently changed since the early 1960s.The general trends in the changes of drywet climate were described as slight decrease in humidity and gradual enhancement in drought intensity.The climate during 1960s-1980s was under weak-medium drought.But since early 1990s,dry conditions have markedly strengthened and continued due to uneven temporal distribution of rainfall and climate warming.展开更多
Keibul Lamjao National Park （KLNP）, a floating park in Loktak Lake, Manipur （India） was studied from Winter （WIN） to Post Monsoon （POM） for its zooplankton composition and some selected water parameters. The r...Keibul Lamjao National Park （KLNP）, a floating park in Loktak Lake, Manipur （India） was studied from Winter （WIN） to Post Monsoon （POM） for its zooplankton composition and some selected water parameters. The resultant data were subjected to multivariate techniques---Principal Component Analysis （PCA） and Canonical Correspondence Analysis （CCA）. Analyses of water parameters with PCA revealed that the first PC axis （PC 1） accounts for maximum variance in the seasonal data, explaining a variability of 91%. The PCA revealed that the seasonal variability in water parameters was due to the wet and dry cycle of seasons and the stations were distinguished on the basis of transparency and turbidity. Zooplankton abundance was dominated by copepods followed by cladocerans. Temporally, abundance of copepods reached a maximum during Post-monsoon （POM） （3 880 ind./L）. Spatially, $6 was found to be most abundant of the other stations in zooplankton. Copepodites and nauplii larvae were the major components of zooplankton. The Rotifera were the least abundant among the three zooplankton groups. Brachionus formed the major component of Rotifera zooplankton at all the stations during the study period. In the Cladocera, Macrothrix was present during all the four seasons, while Pleuroxus, Oxyurella, Kurzia and, Diaphanosoma were rare. The CCA shows that maximal temporal variability in zooplankton abundance was explained by temperature and rainfall. ANOVA revealed no significant difference in mean zooplankton abundance among the seasons, but there was a statistically significant difference among the sites.展开更多
基金supported by the program(40675045) from the National Natural Science Foundation of China
文摘Factor analysis was used to investigate the changes of dry-wet climate in the dry season in Yunnan during 1961-2007 based on observed data from 15 stations.Three common factors were extracted from the 9 climatic factors.The results showed that the dry-wet climate has evidently changed since the early 1960s.The general trends in the changes of drywet climate were described as slight decrease in humidity and gradual enhancement in drought intensity.The climate during 1960s-1980s was under weak-medium drought.But since early 1990s,dry conditions have markedly strengthened and continued due to uneven temporal distribution of rainfall and climate warming.
基金Supported by the University Grant Commission(UGC),New Delhi,India,under the Junior Research Fellowship(JRF-NET)scheme
文摘Keibul Lamjao National Park （KLNP）, a floating park in Loktak Lake, Manipur （India） was studied from Winter （WIN） to Post Monsoon （POM） for its zooplankton composition and some selected water parameters. The resultant data were subjected to multivariate techniques---Principal Component Analysis （PCA） and Canonical Correspondence Analysis （CCA）. Analyses of water parameters with PCA revealed that the first PC axis （PC 1） accounts for maximum variance in the seasonal data, explaining a variability of 91%. The PCA revealed that the seasonal variability in water parameters was due to the wet and dry cycle of seasons and the stations were distinguished on the basis of transparency and turbidity. Zooplankton abundance was dominated by copepods followed by cladocerans. Temporally, abundance of copepods reached a maximum during Post-monsoon （POM） （3 880 ind./L）. Spatially, $6 was found to be most abundant of the other stations in zooplankton. Copepodites and nauplii larvae were the major components of zooplankton. The Rotifera were the least abundant among the three zooplankton groups. Brachionus formed the major component of Rotifera zooplankton at all the stations during the study period. In the Cladocera, Macrothrix was present during all the four seasons, while Pleuroxus, Oxyurella, Kurzia and, Diaphanosoma were rare. The CCA shows that maximal temporal variability in zooplankton abundance was explained by temperature and rainfall. ANOVA revealed no significant difference in mean zooplankton abundance among the seasons, but there was a statistically significant difference among the sites.
