Lake Tanganyika is a large Rift Valley lake (on average 670 km long, 50 km wide, 570 m deep) situated in East Africa between 3° to 9°S. It plays a vital role in the economy and food source of the surrounding riparian nations. It is a meromictic tropical lake: complete overturning of the water never takes place and mixing occurs only partially. Thermal stratification in the lake is well marked and varies seasonally above the permanent hypolimnion. The upper layer undergoes seasonal temperature change annually, while the hypolimnion is anoxic with an invariant temperature. The latter is a vast reservoir of nutrients largely isolated from surface influences. The main seasons around the lake are a four-month long 'dry season', characterised by cooler dry weather and fairly constant southeasterly (trade) winds from around May to September, and a 'wet season' during the rest of the year, during which the winds are weaker and mainly northeasterly. Wind speed during the dry season reaches 7-9 m/sec with gusts of 10-12 m/sec. The wind stress pushes the warmer surface water away from the southern end of the lake towards the northern end and an upwelling occurs to replace the loss of water at the south. Southern upwelling leads to the high productivity and the standing stock of the Lake.

In recent years Lake Tanganyika, like many other large lakes of the world, has begun to feel the effects of a variety of human impacts, including fishing pressures, an increased rate of sediment accumulation along rocky coasts caused by deforestation and soil erosion in the lake's watersheds, and climate change. The great volume of Tanganyika together with its relatively arid climate limits the direct effect that river inflows can have on the pelagic system as the water turnover time based on river inflows is about 1000 years. This reduces the immediate influence of the watershed just as the pelagic ocean is little affected by annual riverine inputs. This talk will present the annual primary productivity of the Lake under actual circulation and solar radiation using a simple ecological model coupled to a hydrodynamic model and compare model generated regional patterns to observations, and study the climatic influences on lake ecosystem since the year 1970. The simulated primary production will be compared to the available fish production (catch) data.

1. Université catholique de Louvain, Institut d'astronomie et de géophysique Georges Lemaître (ASTR), Chemin du Cyclotron 2, B-1348 Louvain-La-Neuve, Belgium. naithani@astr.ucl.ac.be

2. Royal Museum for Central Africa, Leuvensesteenweg, 13, B-3080 Tervuren, Belgium

3. Université catholique de Louvain , Institut d'astronomie et de géophysique Georges Lemaître (ASTR) and Centre for systems engineering and applied mechanics (CESAME), 4 Avenue Georges Lemaître, B-1348 Louvain-La-Neuve, Belgium

The kodachadri is one of the highest mountains peaks of Shimoga district. The study area covers a 15 Km radius from the temple complex which is located almost at the top of the mountain. The area harbours different types of vegetation which is classified into wet evergreen forest, semi evergreen forest, shoal forest and the grass lands. The shoal forests and the grasslands which are situated at the top of the mountain are least effected and the wet evergreen and the semi evergreen forest which are found at the foot hills of the mountain have been damaged by human interferences. The flora has been grouped into medicinal plants, timber yielding plants, gum land resin yielding plants and bee flora. The fauna includes lion tailed macaque (Macaca silenus),which is an endangered primate. The impact of construction of roads, buildings and temple complexes, introduction of exotic species. encroachment of vegetation and tourism have been discussed. The conservation methods to be taken has been briefed.

Key words:- bee flora, conservation, endangered, gum and resins, medicinal plants, vegetation, tourism.

1. Department of Applied Botany

2. Department of Enviromnental Science

Kuvempu University, Shankaraghatta: 577451, Karnataka, India .