FRESHWATER- RIVERS, LAKES, AND PONDS. By: Alyssa Slater

Ecosystems ◦ Ponds and lakes are called lentic ecosystems. Meaning, they have still waters, not moving like rivers or streams. ◦ Rivers and streams are called lotic ecosystems. Unlike the still waters of ponds and lakes, their water moves.

Limnetic Zone ◦ The limnetic zone is shallower in turbid water than in clear and is a more prominent feature of lakes than of ponds.

Profoundal Zone ◦ Many lakes and few ponds are so deep that not enough light reaches here to support primary productivity. This zone depends for its calories on the drifting down of matter from the littoral and limnetic zones. ◦ Chiefly inhabited by primary consumers that crawl along the sediments at the bottom of the lake.

Profoundal Zone {Cont.} ◦ Bottom dwelling animals are called the benthos. ◦ The sediments underlying this zone also support a large population of bacteria and fungi. They break down the matter reaching them, releasing inorganic nutrients for recycling

Littoral zone ◦ This is the zone close to the shore. Here, light reaches all the way to the bottom. The producers are plants rooted to the bottom and algae attached to the plants and to any other matter.

Temperatures

World Map

Abiotic affects on the Ecosystem ◦ Light: ◦ 1. the time of day and the season ◦ 2. the depth ◦ 3. the clearness of the water ◦ 4. amount of cloud cover ◦ 5. altitude of the lake.

Abiotic affects on the Ecosystem ◦ Temperature ◦ 1. Distribution of organisms both seasonally and vertically through the water ◦ 2. Behavior and reproduction of organisms ◦ The reason that organisms are affected by temperature is because of the fact that they are cold blooded. The external environment will determine their internal temperature and therefore metabolic activity.

Aquatic Food Web

Adaptations ◦A◦Animals and plants in this environment survive because they are able to adapt to the changes in things such as sunlight, pH levels, temperature changes, seasonal changes, etc….

Values ◦P◦People value this ecosystem because they offer things like freshwater, which we use to drink with, bathe with, and cook with, plus, it offers part our food source, like fish. Their also dammed up for electrical reasons.

Human Impact ◦ Humans today don’t realize the negative impact they put on our freshwater biomes, we pollute them, we use them without any consideration; according to scientist, we will go from 97% of freshwater to only 10% if we don’t begin to consider the usage of it.

Credits ◦ eley.edu/glossary/glos s5/biome/aquatic.html

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