Community composition of phytoplankton in Fujian-Guangdong coastal upwelling region in summer and related affecting factors

Based on the investigation data of 133 samples from 30 grid stations in the Fujian-Guangdong coastal upwelling region (21.6 degrees - 24.3 degrees N,115.7 degrees -118.7 degrees E) in 11-16 June 2009, this paper studied the phytoplankton species composition and cell abundance in the region in three dimensions (vertical, horizontal, and sectional), and approached their relations with major environmental factors. A total of 159 taxa belonging to 85 genera of 4 phyla were identified, among which, diatom was predominant, followed by dinoflagellate. Cyanophyceae mainly composed of Trichodesmium also occupied a greater proportion, but Chrysophyceae was only checked out in the upper 10 m water layer at coastal stations. The dominant species were Rhizosolenia alata f. gracillma, Thalassionema nitzschioides, Pseudonitzschia pungens, Skeletonema costatum, Thalassionema frauenfeldii, Paralia sulcata, Guinadia striata, Trichodesmium thiebautii, Ceratium fusus, and Gyrodinium spirale. Most of the phytoplankton taxa were cosmopolitan species, followed by warm-water species, while tropic high-salinity or oceanic eurythermal species were lesser. The cell abundance of the phytoplankton was average of 67.59 x10(2) ind x L(-1). In vertical profile, the cell abundance of the phytoplankton was the highest in surface water, and decreased with water depth. In horizontal and sectional profiles, the cell abundance had no definite patterns, but the high abundance region was in Nanao Island water area, being anastomosed with the center of upwelling region, which indicated that the weak and small intensity of deep-sea water upwelling caused lesser phytoplankton cell abundance and superposition. The comparatively high phytoplankton cell abundance in the four sections (B, C, D, E) along Nanao-Zhangpu was resulted from the upwelling from Taiwan Bank. The phytoplankton cell abundance had a significant positive correlation with the PO4(3-) concentration in the upper 10 m water layer, but no correlation with the dissolved inorganic nitrogen (DIN) concentration. Thereby, to study the eco-physiological responses of phytoplankton species to nutrient stress would be helpful to reveal the formation mechanism of algal bloom in upwelling region.

[1]  A. Watkinson,et al.  Yield-density Relationships: the Influence of Resource Availability on Growth and Self-thinning in Populations of Vulpia fasciculata , 1984 .

[2]  C.J.T. Spitters,et al.  An alternative approach to the analysis of mixed cropping experiments. II. Marketable yield , 1983 .

[3]  C.J.T. Spitters,et al.  An alternative approach to the analysis of mixed cropping experiments. I. Estimation of competition effects , 1983 .

[4]  A. Watkinson,et al.  INTERFERENCE IN PURE AND MIXED POPULATIONS OF AGROSTEMMA GITHAGO , 1981 .

[5]  T. Bellows.  The Descriptive Properties of Some Models for Density Dependence , 1981 .

[6]  Andrew R. Watkinson,et al.  Density-dependence in single-species populations of plants , 1980 .

[7]  J. Harper.  Population Biology of Plants , 1979 .

[8]  G. E. Hutchinson,et al.  An Introduction to Population Ecology , 1978 .

[9]  M. Hassell,et al.  Discrete time models for two-species competition. , 1976, Theoretical population biology.

[10]  P. Putwain,et al.  Population interrelationships , 1975, Heredity.

[11]  P. Lovell,et al.  Interference in Populations of Some Dune Annuals , 1974 .

[12]  P. Thompson.  The effects of geographical dispersal by man on the evolution of physiological races of the Corncockle(Agrostemma githago L.) , 1973 .

[13]  John L. Harper,et al.  OCCUPATION OF BIOLOGICAL SPACE DURING SEEDLING ESTABLISHMENT , 1972 .

[14]  S. Jain,et al.  Interference in Pure and Mixed Populations of Avena Fatua and A. Barbata , 1969 .

[15]  P. D. Putwain,et al.  The management of grass weeds in cereal crops, a population biology approach. , 1984 .

[16]  R. Cousens,et al.  Models of yield loss-weed density relationships , 1984 .

[17]  P. DeBenedictis.  The Meaning and Measurement of Frequency‐Dependent Competition , 1977 .

[18]  R. Hall.  Analysis of the nature of interference between plants of different species. I. Concepts and extension of the de Wit analysis to examine effects , 1974 .

[19]  R. Hall.  Analysis of the nature of interference between plants of different species. II.* Nutrient relations in a Nandi Setaria and Greenleaf Desmodium association with particular reference to potassium , 1974 .

[20]  K. Yoda,et al.  Self-thinning in overcrowded pure stands under cultivated and natural conditions (Intraspecific competition among higher plants. XI) , 1963 .