Meteorological signals in primary productivity at two mountain lakes

Fluctuations in primary productivity at two subalpine lakes reveal both meteorological and biological influences. At Castle Lake, California, large-scale climate events such as the El Niño/Southern Oscillation affect total annual production and, combined with human fishing activity, modify the seasonal pattern of productivity. At Lake Tahoe, California-Nevada, local spring weather conditions modulate annual production and its seasonality by determining the depth of mixing and resulting internal nutrient load. Climatic conditions also contribute to deviations from the long-term trend in productivity by increasing the incidence of forest fires and through anomalous external nutrient loads during precipitation extremes. A 3-year cycle in productivity of as yet unknown origin has also been detected at Lake Tahoe.

Results of the Austrian-Ceylonese hydrobiological mission 1970 of the 1st Zoological Institute of the University of Vienna (Austria) and the Department of Zoology of the Vidyalankara University of Ceylon, Kelaniya. Pt. 2. Hydrochemical studies on mountain rivers in Ceylon

The morphology, climate, geology and geochemistry of Sri Lanka is briefly described. The separation into a wet zone (the south-west and greater part of the central highland) and a dry zone with two very dry parts in the south-east and in the north-west, is obvious and has great influence on the hydrochemistry of the island. Geology is very homogenous (Precambrian crystalline series) and some Jurassic and Miocene limestones (only in the north).

Results of the Austrian-Ceylonese hydrobiological mission 1970 of the 1st Zoological Institute of the University of Vienna (Austria) and the Department of Zoology of the University of Ceylon, Vidyalankara Campus, Kelaniya. Pt. 14. The freshwater crabs of the Ceylonese mountain rivers

The report deals with the material on freshwater crabs, collected by the Austrian-Ceylonese hydrobiological mission 1970 from the running waters of the mountains in south-west Ceylon. The locality records for Paratelphusa (Oziotelphusa) senex (Fabricius 1798) Paratelphusa (Ceylontelphusa) sorror (Zehntner 1894) and Paratelphusa (Ceylontelphusa) rugosa (Kingsley 1880), are described.