Hovsgol GEF/WB: Hovsgol Lake Area
The Siberian larch (Larix sibirica) dominates the forest composing more than 90% of the trees. The lake is surrounded by continuous permafrost. Hovsgol National Park has many rare and endemic taxa. The level of endemism in the Lake is ca. 10% of the taxa of several phyla, but most taxonomic groups are poorly studied. Endemic taxa compose most of the animal biomass of the Lake. Based upon phytoplankton biomass and primary production measurements, Hovsgol is an ultra-oligotrophic lake. Because of the very low productivity, larch leaf detritus may be a primary source of food for aquatic invertebrates. Detritus can be carried deep into the lake by thermal density currents that mix the water in the spring from the shoreline areas.
The tributary streams have many endemic species of insects and are important spawning sites for the lake's fishes.
Meteorological and hydrological data are collected daily at the south and north ends of the Lake. The National Park has a chemistry laboratory and has monitored water chemistry of the Lake. In 1999 new equipment was purchased for analysis of water samples, and an improved water quality monitoring program was developed, which included study of the major tributary streams entering the Lake. Several long-term data sets will soon be available or are being obtained for the region and the Lake. Land cover maps from LandSat 4 satellite imagery are available, and new LandSat 7 imagery is now being used to develop more detailed land-cover maps for the region.
Grazing and fires
Grazing. The Hovsgol watershed primarily consists of taiga forest, but there are steppe grasslands bordering high alpine tundra in the west, and steppe on south-facing slopes of mountains. These areas have been grazed for centuries. Stream valleys are generally a combination of steppe vegetation and wetlands. Recently, the number of livestock in the valleys has increased because the loss of trade with Russia has limited the ability of the herdsman to sell their animals. This indirectly affects tributary streams of the Lake due to increased herd sizes. When grazing livestock move into grasslands they dramatically alter stream conditions. The erosion of stream banks is beginning to occur as grazing sheep, yaks, cows and goats move across streams more intensively.