Ju Lihua, Yang Jun, Liu Lemian, Wilkinson David M
Aquatic EcoHealth Group, Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen, 361021, People's Republic of China.
Microb Ecol. 2014 Nov;68(4):657-70. doi: 10.1007/s00248-014-0442-1. Epub 2014 Jun 10.
Freshwater microbial diversity is subject to multiple stressors in the Anthropocene epoch. However, the effects of climate changes and human activities on freshwater protozoa remain poorly understood. In this study, the diversity and distribution of testate amoebae from the surface sediments were investigated in 51 Chinese lakes and reservoirs along two gradients, latitude and trophic status. A total of 169 taxa belonging to 24 genera were identified, and the most diverse and dominant genera were Difflugia (78 taxa), Centropyxis (26 taxa) and Arcella (12 taxa). Our analysis revealed that biomass of testate amoebae decreased significantly along the latitudinal gradient, while Shannon-Wiener indices and species richness presented an opposite trend (P < 0.05). The relationship of diversity and latitude is, we suspect, an artifact of the altitudinal distribution of our sites. Furthermore, biomass-based Shannon-Wiener index and species richness of testate amoebae were significantly unimodally related to trophic status (P < 0.05). This is the first large-scale study showing the effects of latitude and trophic status on diversity and distribution of testate amoebae in China. Therefore, our results provide valuable baseline data on testate amoebae and contribute to lake management and our understanding of the large-scale global patterns in microorganism diversity.
在人类世，淡水微生物多样性受到多种压力因素的影响。然而，气候变化和人类活动对淡水原生动物的影响仍知之甚少。在本研究中，沿着纬度和营养状态两个梯度，对中国51个湖泊和水库表层沉积物中的有壳变形虫的多样性和分布进行了调查。共鉴定出属于24个属的169个分类单元，其中种类最多、占主导地位的属为鳞壳虫属（78个分类单元）、砂壳虫属（26个分类单元）和表壳虫属（12个分类单元）。我们的分析表明，有壳变形虫的生物量沿纬度梯度显著下降，而香农-威纳指数和物种丰富度则呈现相反趋势（P < 0.05）。我们怀疑多样性与纬度的关系是我们研究地点海拔分布的一个人为产物。此外，基于生物量的有壳变形虫香农-威纳指数和物种丰富度与营养状态呈显著单峰关系（P < 0.05）。这是第一项展示纬度和营养状态对中国有壳变形虫多样性和分布影响的大规模研究。因此，我们的研究结果提供了关于有壳变形虫的宝贵基线数据，并有助于湖泊管理以及我们对微生物多样性全球大规模格局的理解。
