| 摘要： |
Virio- and picoplankton mediate important biogeochemical processes and the environmental factors that regulate their dynamics, and the virus-host interactions are incompletely known, especially in the deep sea. Here we report on their distributions and relationships with environmental factors at 21 stations covering a latitudinal range (2-23 degrees N) in the Western Pacific Ocean. This region is characterized by a complex western boundary current system. Synechococcus, autotrophic picoeukaryotes, heterotrophic prokaryotes and virus-like particles (VLPs) were high (< 2.4 Chi 10(2)-6.3 Chi 10(4), < 34-2.8 Chi 10(3), 3.9 Chi 10(4)-1.3 Chi 10(6) cellsmL(-1) and 5.1 Chi 10(5)-2.7 Chi 10(7) mL(-1), respectively), and Prochlorococcus were low (< 2.3 Chi 10(2)-1.0 Chi 10(5) cellsmL(-1)) in the Luzon Strait and the four most southerly stations, where upwelling occurs. Covariations in the abundances of VLPs with heterotrophic and autotrophic picoplankton, and their correlation (i.e. r(2) = 0.63 and 0.52, respectively) suggested a strong host dependence in the epi-and mesopelagic zones. In the bathypelagic zone, only abiotic factors significantly influenced VLPs abundance variation ( r(2) = 0.12). This study shows that the dynamics of virio- and picoplankton in this Western Pacific are controlled by suite of complex and depth-dependent relationship among physical and biological factors that in turn link the physical hydrography of the western boundary current system with microbial-mediated biogeochemical processes. |
