STRUTURE AND SPATIAL DISTRIBUTION PATTERNS OF MACROZOOBENTHOS IN QINGHAI LAKE AREA

To study macrozoobenthos community structures, distributions and key underlying drive forces of the Qing-hai Lake (QL), one of typical saline lakes in Tibetan Plateau, the samples of benthic animals were taken via four diffe-rent times during 2011-2012 from QL area, including main body (MB), 3 adjacent lakes (ALs) and 5 inflowing rivers (IRs). We identified 28 taxa: 9 in MB, 5 in 2 saline ALs, 9 in 1 freshwater AL, and 15 in IRs. The mean density of 4 types of water bodies were 455.8, 1562.7, 741.3, and 331.2 ind./m2, respectively. Biomass of these 4 different water bodies were 1.18, 3.70, 2.75, and 4.53 g/m2 respectively. Chiroinomus salinarius was the major species (83.32% of the total abundance) in MB. The general spatial distribution pattern was supported by the Surfer Model, indicating that the highest value of macrozoobenthos abundance and biomass occurred in the southeast littoral zone of MB, especially in the sites near estuaries of IRs (e.g., Buha, Caiji and Quanji Rivers), and that the lowest value was in the profundal zone of MB. The CCA analysis showed that pH, water depth, total nitrogen, and salinity were the key environmental factors to affect macrozoobenthos community variance.