拉萨河中下游河段原生动物功能群分布和水环境质量评价

Distribution of Functional Groups of Protozoa and Assessment of Water Environment Quality in the Middle and Lower Reaches of the Lhasa River

2015年5月1日至3日、8月1日至3日和2016年11月1日至3日,在拉萨河中下游干流和支流河段的17个采样点,采集了原生动物定性和定量样品以及河水样品;在实验室中,鉴定了采集到的原生动物物种,测试了水样的理化指标;根据计算出的原生动物群落的Pielou均匀度指数、地表水环境质量标准和功能群分布特征,评价了拉萨河中下游河段的水环境质量。研究结果显示,2015年5月至2016年11月,拉萨河中下游河段水体中有2门5纲24目48科75属197种原生动物物种;197种原生动物物种被划分为食藻者(45种)、食细菌-碎屑者(119种)、腐食者(7种)、光合自养者(6种)、无选择性的杂食者(3种)和捕食者(17种)共6种功能群;食细菌-碎屑者和食藻者为拉萨河中下游河段水体中原生动物的优势功能群;拉萨河中下游河段水体中原生动物功能群的结构存在明显的时空变化;拉萨河中下游河段的大部分水域总体上为清洁或轻度污染水域。

Qualitative and quantitative samples of protozoa and river water samples were collected at 17 sampling sites in the middle and lower reaches of the Lhasa River from May 1 to 3, August 1 to 3, 2015 and November 1 to 3, 2016;in the laboratory, the collected protozoa species were identified and the physicochemical indicators of the water samples were tested;based on the calculated Pielou evenness index of protozoa community, surface water environmental quality standards and functional group distribution characteristics,the water environmental quality of the middle and lower reaches of the Lhasa River was evaluated. The results of the study showed that from May 2015 to November 2016, there were 197 species of protozoa in the water bodies of the middle and lower reaches of the Lhasa River, which belong to 2 phyla, 5 orders, 24 families, 48 families, and 75 genera;the 197 species of protozoa were classified as algae eaters(45 species), bacterial-debris eaters(119 species), carrion feeders(7 species), photosynthetic autotrophs(6 species), non-selective omnivores(3 species), and predators(17 species);bacterial-debris eaters and algae eaters were the dominant functional groups of protozoa in the water bodies of the middle and lower reaches of the Lhasa River;there were obvious spatial and temporal variations in the structure of protozoa functional groups in the water bodies of the middle and lower reaches of the Lhasa River;most of the water bodies in the middle and lower reaches of the Lhasa River were generally clean or lightly polluted.