期刊
HYDROBIOLOGIA
卷 452, 期 1-3, 页码 129-137出版社
SPRINGER
DOI: 10.1023/A:1011984212798
关键词
acidic; volcanic lake; trophic status; water chemistry; Patagonia
The acidic caldera lake Caviahue (Patagonia, Argentina) and its main tributaries were studied on two dates during September 1998. The main results are: The acidity of the Lake Caviahue (pH: 2.56, acidity: >5 mmol H+ l(-1)) is controlled by the extremely acidic Upper Rio Agrio (pH: 1.78, acidity: > 20 mmol H+ l(-1)). The high sulphate contents of both the river and the lake can be attributed to sulphuric acid generated by the uptake of sulphurous gases in the crater lake of Copahue Volcano at approximately 2800 m a.s.l. The high concentrations of both Fe and trace metals (e.g. Cr, Ni, Zn) in Lake Caviahue originate from sulphur-acid interactions with the predominantly volcanic geology of the catchment area. The P-rich andesitic geology influences both the Upper and Lower Rio Agrio and Lake Caviahue. Both were found to have high phosphorus concentrations (300-500 mug P l(-1)) indicative of a high potential for eutrophication. The plankton community consisted of bacterioplankton, phytoplankton and rotifers. The phytoplankton was dominated by one green alga, Keratococcus raphidioides (> 90% of total abundance) followed by a green sphaerical and Chlamydomonas sp. The total phytoplankton density was about 15 000 cells ml(-)1 in the upper 10 m of the water column. Rotifers were represented by one bdelloid species and their abundance was highly variable (360-4040 ind l(-1)) in the water columm. In the Upper and Lower Rio Agrio, the epilithic community was dominated by one chloroccocal species and two species of Ulothricales. According to trophic categories based on phytoplankton density and TP concentration, Lake Caviahue can be classified as mesotrophic/eutrophic. However, chlorophyll a concentrations observed were not in agreement with this state.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据