Effect of environmental factors on distribution of stream macroalgae in Niangziguan Spring in Shanxi Province, North China
A survey of the spatial and temporal distribution of macroalgae in a stream system in Shanxi Province, North China, was undertaken from March, 2006 to January, 2007. The percent cover, biomass of macroalgae and several environmental factors were monitored along a 20 m stretch at each of seven sites, every 2 months during 1 year. All the measured environmental factors had seasonal fluctuations in different extent, but only air temperature and P3+ showed significant seasonality. In terms of temporal characterization of environmental factors, they also showed some differences among different sampling sites. Seventy-nine (79) species of macroalgae were found, with a predominance of Chlorophyta (38 species, 48.10%). Bacillariophyta and Charophyta represented the smallest proportion (3 species, 3.80% and 2 species, 2.53%, respectively). Three macoralgae species were the most widespread, occurring in all seven sampling sites. Thirty-five (35) species were found at only one site each. In terms of seasonality, 17 species occurred throughout the year, whereas 27 species were found in only one season each. The most key factor that affected the stream macroalgae was current velocity. We calculated Sorensen similarity indices to compare our study with other continent-wide surveys of stream macroalgae, but the similarity indices were all very low. This study also showed that macroalgae in different locations had significant reproductive isolation.
Key words: China, distribution, environmental factors, spatial, temporal, stream macroalgae.