• Marine

• Freshwater

Freshwater is defined as having a low salt concentration—usually less than 1%. Plants and animals in freshwater regions are adjusted to the low salt content and would not be able to survive in areas of high salt concentration (ocean).

Types of Freshwater Regions:• Ponds

• Lakes• Rivers

• Streams• Wetlands

These regions range in size from just a few square meters to thousands of square kilometers.Many ponds are seasonal, lasting just a couple of months • Vernal Pools

while some lakes may exist for hundreds, to thousands of years.

Ponds and lakes may have limited species diversity since they are often isolated from one another and from other water sources like rivers and oceans. Lakes and ponds are divided into different “zones” which are usually determined by distance from shore, and depth

• Littoral• Limnetic

• Profundal• Euphotic

• Aphotic• Benthic

The topmost zone near the shore of a lake or pond is the littoral zone.

This zone is the warmest since it is shallow and can absorb more of the Sun’s heat.

It sustains a fairly diverse community, which can include several species of algae (like diatoms), rooted and floating aquatic plants, grazing snails, clams, insects, crustaceans, fishes like the bluegill sunfish, and amphibians.

The near-surface open water surrounded by the littoral zone is the limnetic zone.

The limnetic zone is well-lighted (like the littoral zone) and is dominated by plankton, both phytoplankton and zooplankton.

A variety of freshwater fish also occupy this zone.

Plankton have short life spans—when they die, they fall into the deep-water part of the lake/pond, the profundal zone.

The bottom sediment, known as the benthic zone has a surface layer abundant with organisms.

Profundal Zone

Vertically, there are also other zones within lakes.• Euphotic

• Aphotic• Benthic

• Colder• Denser• Less light• ONLY heterotrophs

What two zones are measured by distance from shore?

What types of organisms might you find in the littoral freshwater zone?

What types of organisms might you find in the limnetic freshwater zone?

What is the difference between phytoplankton and zooplankton?

What zones in a body of freshwater are measured by depth?

These are bodies of flowing water moving in one direction.

• Headwaters

• Mouths The characteristics of a river or stream change during the journey from the source to the mouth.

• Source: Water is colder, and highly oxygenated (usually)Freshwater fish such as trout

and other heterotrophs that rely upon high dissolved oxygen can be found there.

Source of Colorado River

Towards the middle part of the stream/river, the width increases, as does species diversity—numerous aquatic green plants and algae can be found.

Mid-Hudson River Valley

Toward the mouth the water slows down, and the channel widens, resulting in

Increasing turbidity

Resulting in

•Decreasing light

Resulting in…?

The water generally moves at such a slow pace as it nears the ocean, and the sediments begin to “fall out”, producing a delta.

Muddy Mississippi

Because of the lower oxygen levels, only species who can survive in those conditions do well, like catfish and carp.

Where do rivers begin?

Where do rivers end?

How do the conditions of the river change throughout its long journey?

HeadwatersMiddleMouth

How do organisms that live at the headwaters and the mouth of a river differ? Give examples

Wetlands are areas of standing water that support aquatic plants. • Marshes

• Swamps

• Bogs

Wetland soil is special because it is often soaked with water. The water fills up the spaces between the soil so no oxygen can fit.

This is called anaerobic soil. Anaerobic bacteria live in wetland soil to decompose plants without the use of oxygen.  This process causes the “swamp gas” smell that is characteristic of wetlands.

Plant species adapted to the very moist and humid conditions are called hydrophytes.

Wetlands have the highest species diversity of all aquatic ecosystems.

Many species of amphibians, reptiles, birds (such as ducks and waders), and mammals can be found in the wetlands.

Wetlands are among the most endangered of all biomes.Why do you suppose that’s true?

Marshes predominantly contain plants without strong woody stems and branches, called herbaceous plants. •Plants that flourish in marshes can grow in the varying water levels of the marsh, with their stems partly immersed in the water and partly above it. •Marshes may be either freshwater or saltwater, depending on the type of water they contain. •Freshwater marshes constitute 90 percent of America's wetlands.

Freshwater Marshes: cattails, water lilies, and arrowheads, ducks, geese, waterfowl including snowy egrets and great blue herons, raptors such as hawks and bald eagles, and mammals including raccoons, minks, and beavers.

Swamps start out as lakes, ponds or other shallow bodies of water. Over time, trees and shrubs begin to fill in the land. Plants die and decay and the level of the water gets lower and lower.

Eventually, the original body of water becomes a swamp.

Succession

Swamps are wetlands whose dominant vegetation is comprised of woody plants such as trees and shrubs. The water may be anywhere from a few inches to over a foot deep. Though swamps are usually saturated with water during the growing season, they may dry out in the heat of a long summer. The soil saturation and diversity of vegetation in swamps lures a wide variety of animal life into their murky environments. Alligators and cottonmouths are the more famous swamp inhabitants. Because of the ever present water, insects abound in the swamp. Pneumatophore

s

Bogs are freshwater wetlands found in cold regions. In North America, many bogs were formed over 10,000 years ago when the last of the glaciers departed, leaving lakes called kettle holes. In some instances, the retreating ice left shallow basins where rain collected and formed the wetland.

A variety of wildlife including moose, bear, and deer often find food, water, and shelter in bogs throughout the year. The bottom layer of a bog consists of peat. Peat is an organically rich material that forms when plants die, fall into the water, and are compressed over time, forming a thick layer.

Among the more interesting and unique plants of bogs are bladderworts, pitcher plants, and sundews that trap and digest insects and tiny animals.

This layer of peat can be up to forty feet deep. Bogs are sometimes called "peatlands."

___Wetlands_________ as ____________________ Aquatic biomes Terrestrial biomes

Wetlands include…

What are plants adapted to wetlands known as?

Why are wetlands so endangered?

How do plants from marshes differ from plants in swamps?

What ecological process helps to form swamps?

What plant root type is well adapted to a water-logged existence?

What is peat, and why are bogs sometimes called “peatlands”?

While carnivorous plants are autotrophs...They are also:

•“facultative heterotrophs”

They are able to gather some of their nutrients (primarily nitrogen) through digesting organisms.

Nepenthes

Dionaea muscipula

What other biomes with notoriously poor soil (low in nitrogen) might you also find facultative heterotrophs in?