青藏高原陆相介形类的分布特征及其对生态环境的响应

统计分析了青藏高原不同区域水体环境表层沉积物陆相介形类的属种分布特征，探讨了介形类在不同水环境下（盐度、pH值及水深）对生态环境的响应.结果显示，青藏高原现生介形类共计21属67种，其中Candona candida、Ilyocypris bradyi、Eucypris inflata、Limnocythere dubiosa、Limnocythere inopinata、Paracypricerus angulata、Leucocytherella sinensis和Leucocythere mirabilis为青藏高原地区的常见种.湖泊、河流、洼地和湿地4类水体环境中，湖泊中介形类最为丰富，达19属62种；青藏高原东北部（祁连山和柴达木盆地）、北部（昆仑山）、西部和南部不同区域的介形类常见种存在较大差异，可能是区域海拔、pH值和盐度综合作用的结果.淡水和微咸水环境介形类属种数量较咸水及盐湖中丰富，分别有17属41种和13属42种，Limnocythere dubiosa （0.52~90.6 g/L）和Leucocythere mirabilis（0.51~174.63 g/L）在淡水、咸水及盐湖中均有出现，适应盐度范围较广；pH值在8.0~10.0范围内介形类属种多样性最丰富，表明大部分介形类具有嗜碱性的特征；青藏高原陆相介形类属种多样性随水深的增加而降低，浅湖（0~15 m）中介形类属种最为丰富，达到17属52种，其中Candona candida（0.2~80 m）和Leucocythere dorsotuberosa（0.3~110 m）从滨湖至深湖区均有分布，二者均具有较大的水深适应范围.

Distribution characteristics and responding to ecological environment of terrestrial ostracod on the Qinghai-Tibetan Plateau

Terrestrial ostracods can adapt to fresh waters, brackish waters, salt waters and hypersaline waters, and most of them in shallow waters (river, springs, ditches and swamps) and lakes. It is very sensitive to the physical and chemical changes of the host water. The Qinghai-Tibetan Plateau (QTP) not only directly influences the formation and evolution of monsoon climate in China, but also is a sensitive area of climate change in China and the world. Distribution characteristics of terrestrial ostracod in surface sediments of different regions on the QTP were analyzed statistically, and the response of ostracods to ecological environment in different water environments (salinity, pH and water depth) was discussed. The results show that total of 21 genus and 67 species are discovered on the QTP, among which Candona candida, Ilyocypris bradyi, Eucypris inflata, Limnocythere dubiosa, Limnocythere inopinata, Paracypricerus angulata, Leucocytherella sinensis and Leucocythere mirabilis are common species. The four types of water environment including lakes, rivers, depressions and wetlands, among which the number of ostracods is the most abundant in lakes, accounting for 19 genus and 62 species. The common ostracod species in the northeastern (Qilian Mountains and Qaidam Basin), the northern (Kunlun Mountains), the western and the southern part of the QTP are different greatly, which may be closely related to the altitude, pH value and salinity of regional water bodies. The abundance of ostracods in fresh water and brackish water is higher than that in saline waters and salt lakes, with 41 species in 17 genera and 42 species in 13 genera, respectively. Limnocythere dubiosa (0.52-90.6 g/L) and Leucocythere mirabilis(0.51-174.63 g/L) can be discovered in fresh water, brackish water and salt lake, which have the wider range of adaptation salinity. Ostracods have the maximum species diversity in water bodies with pH values of 8.0-10.0, indicating that most of which are basophilic. Genus''s diversity of terrestrial Ostracods on the QTP decreases with increasing water depth. In shallow lakes (0-15 m), ostracods are the most abundant with 52 species in 17 genera, and Candona candida(0.2-80 m) and Leucocythere dorsotuberosa(0.3-110 m) are distributed from lakeside to deep lake, and both of them have deeper depth adaptability range.