lake ecosystem.pptx000000000000000000000

It gives the detail ppt of lake eco system

1. LAKE ECOSYSTEM

2. LAKES Range in size from just a few square meters to thousands of square kilometers. Lakes may exist for hundreds of years or more.

3. LAKES May have limited species diversity They are often isolated from one another and from other water sources like rivers and oceans. Most lakes have outlet streams and they are generally temporary features on the landscape

4. FORMATION OF LAKES : Some of the oldest lakes (more than three hundred thousand years old) were formed by tectonic activity related to movement of Earth's crust. EXAMPLE: Lake Baikal in Siberia formed from the movement of tectonic plates and is the largest freshwater lake by volume in the world.

5. FORMATION OF LAKES: Lakes are formed through a variety of events, including glacial, tectonic, and volcanic activity. Most lakes form as a result of glacial processes. As a glacier retreats, it may leave behind an uneven surface containing hollows that fill with water.

6. FORMATION OF LAKES : Volcanic activity can also lead to lake and pond formation. EXAMPLE: the collapse of a volcanic cone of Mount Mazama in Oregon led to the formation of Crater Lake, the seventh deepest lake in the world.

7. Lake Baikal Crater Lake , Oregon

8. Lakes Temperature varies seasonally. During summer the temp. is from 4°C near the bottom to 22°C at the top. During winter the temp. is from 4° C while the top is 0° C (ice). during the spring and fall seasons is a mixing of the top and bottom layers resulting in a uniform water temperature of around 4° C.

9. Lakes divided into four different “zones” determined by depth and distance from the shoreline littoral zone limnetic zone profundal zone Photic zone Benthic zone

10. Littoral Zone Limnetic Zone Profundal (aphotic) zone Photic Zone Benthic Zone

11. Littoral Zone warmest since it is shallow and can absorb more of the Sun’s heat sustains a fairly diverse community several species of algae (like diatoms) rooted and floating aquatic plants grazing snails Clams Insects Crustaceans Fishes amphibians

12. Littoral Zone the egg and larvae stages of some insects are found in this zone vegetation and animals living in the littoral zone are food for other creatures such as turtles, snakes, and ducks

13. Limnetic Zone near-surface open water surrounded by the littoral zone well-lighted (like the littoral zone) and is dominated by plankton, both phytoplankton and zooplankton plankton are small organisms that play a crucial role in the food chain – most life would not be possible without them variety of freshwater fish also occupy this zone

14. Profundal Zone much colder and denser little light penetrates all the way through the limnetic zone into the profundal zone Plankton have short life spans—when they die, they fall into the deep-water part of the lake/pond Animals found are decomposers

15. Benthic Zone The area of the bottom.  Many groups and varieties of animals live here, a few are worms, crustaceans, and protozoa.   The life in this zone is mostly made up of bottom dwellers which get most of their food from dead and decaying organisms.   most of the organisms in the benthic zone are scavengers because they depend on dead flesh as their main food source.

16. LAKES ECOSYSTEM

17. Clasification of Lake Oligotrophic lakes - deep, nutrient-poor lakes in which the phytoplankton is not very productive. The water is usually clear Eutrophic lakes -shallow, nutrient-rich lakes with very productive phytoplankton. The waters are usually murky due to large phytoplankton populations the large amounts of matter being decomposed may result in oxygen depletion.

18. Lakes Ecosystem A lake is bigger than a pond, and is too deep to support rooted plants except near the shore. Some lakes are big enough for waves to be produced. Lakes may exist for hundreds of years or more. Lakes are often classified as oligotrophic or eutrophic, depending on the amount of organic matter produced.

19. Oligotrophic lake Eutrophic Lake

20. Examples of lakes Taal volcano lake Mitchigan lake Grasmere lake Silver lake Lake lamonia

21. BLUE LAKE

22. Dal Lake Mono Lake Okanagan Lake Lake Titicaca  

23. Lac Pavin in France is a meromictic crater lake

24. Freshwater: biological communities of lakes

25. THANKING YOU DONE BY A.KIRANRAJ CSE 2