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The water used in the picture was partly derived from a photo by Randy Everette and is used under a CC 3.0 Unported license

We tend to think of land and water forms, of bogs and swamps and ponds, as established states. But the pictures above and below demonstrate that they are not. They're just stages in an ecological evolution. The evolution may take hundreds of years and may vary depending on environment, but it is a recognized process called pond succession.

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Each week, Hive account@shaka offers one of his beautiful pictures and invites us to make from that a unique collage. The second picture, with grass, trees and mountains in the background is Hive account@shaka's photo for this week. My idea for this blog and for the collage evolved together.

The top picture, with a lake and a forest backdrop, originally represented my entry into Hive account@shaka's #letsmakeacollage contest.

I've had to change my entry because of copyright considerations. The actual entry, which is not my preferred picture, is this:

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There are no copyright restrictions at all on this picture. The list of Pixabay credits is given at the end of the blog.

Lakes, Ponds, Wetlands and Forests

Is It a Pond, or Is It a Lake?

In everyday terms, it seems there is little difference between a lake and a pond. These words are used interchangeably, with most people considering lakes to be larger and deeper than ponds. However, limnologists, those who study inland bodies of water, are more precise in their terminology. A major distinction between a pond and lake is water flow. Water that flows in a "continuous and definite direction" makes up a lake, and water that does not makes up a pond.

By definition, a lake or pond is a body of water that is surrounded by land. This body of water may be huge, like the Caspian Sea, or it may be small, like the local neighborhood skating pond.

Open Lakes and Closed Lakes

The Great Salt Lake

Ever wonder how the Great Salt Lake (North America) or the Dead Sea (Asia) became so salty? Both bodies of water are "closed lakes", which means water only drains from them through evaporation. Lakes that drain through streams are called open lakes. Over time, a closed lake becomes increasingly saline. The salt flats around the Great Salt Lake are areas where the water has completely evaporated and left only salt. And at its deepest, the Dead Sea is so saline that the water can hold no more and the salt collects on the bottom of the lake.

The Caspian Sea, The Beach of Astara in the Morning

The Caspian Sea is the largest salt lake in the world. Although it is now landlocked, there was a time when the Caspian Sea had outlets to other bodies of water. Significant fresh-water rivers, such as the Volga, feed into the Caspian and this infusion tends to moderate its salinity.

Creation of a Lake/Pond

A lake, or pond, begins with a depression in the earth. This depression may be created by a variety of events--perhaps a crater was formed by a falling meteor, or a gash was carved out by a receding glacier. However it came to be, the depression fills with water. This water may be from rain, melting ice or underground streams. Some inland bodies of water are derived from other sources, such as damming and flooding.

Pond Succession

It may take hundreds of years for a primitive pond to go through successive stages until it eventually becomes terrestrial. A great YouTube video shows the different stages of succession.

The earliest life forms to populate a primitive pond are called pioneers. According to environmental scientist Paul Conti, the environment in the pond at this stage is "nutrient poor". As early life forms die and fall to the bottom, however, nutrients are introduced and greater life forms may be supported. These also mature and fall to the bottom. Over the years larger plants and soil are deposited so that the pond fills up, until soil forms. At this stage, the pond may look like the second picture on this page, Hive account@shaka's picture.

This process of pond succession may be sped up by human activity. It also may be sped up by other factors, such as beavers. Beavers have been called ecological engineers, because of their role in transforming land.

The Eurasian Beaver

The intermediate stage between a pond and a forest or grassland, is a wetland. There are various types of wetland. I believe the picture offered by Hive account@shaka most closely resembles a bog, a highly acidic wetland. Bogs may be home to life that tolerates acidic conditions, such as evergreens, shrubs and certain kinds of berries and flowers. Some mammals, such as beaver and moose, may also find a hospitable home in a bog.

A Bog in Iron County, Michigan, USA

One curious aspect of bogs is their ability to preserve fossils. Because the environment is so oxygen poor, decomposing bacteria do not thrive. Even soft tissue from dinosaurs and prehistoric hominids has been discovered in bogs.

Swamp: A Wetland Between Pond and a Terrestrial Community

This picture was taken in Keningau District, Sabah State, Malaysia. A swamp, as contrasted with a bog, is a wetland that is permanently saturated and has trees. There are saltwater and freshwater swamps. Because these are transitional (from pond to land), they are neither all water nor all soil. Both fresh and saltwater swamps are very bio diverse. As a matter of fact, saltwater swamps, which are generally found in coastal areas, are sometimes called the nurseries of the ocean.

Climax Community

There is a point in ecological succession in which a certain stability is achieved, in which no significant changes will occur, unless there is interference. This is called a climax community. Old growth forests are climax communities. A significant change in an old growth forest would be logging.

Old Growth Forest

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My Collage, and This Blog

When I first saw Hive account@shaka's picture I thought of my childhood and the days I spent wandering around the forest, which was behind my home. The swamp I remember was more sinister--more mud, more water, denser overgrowth. So I began to read about swamps and wetlands. I discovered a bit about how swamps and wetlands came to be. That's when the idea for my collage came to me.

Top Picture Genesis:

Part 1: Find the water