Pond

, Netherlands , Ohio. image of a pond in Central City Park, Macon, GA, . A pond is a small, still, land-based body of water formed by pooling inside a depression, either naturally or artificially. A pond is smaller than a lake and there are no official criteria distinguishing the two, although defining a pond to be less than in area, less than in depth and with less than 30% of its area covered by emergent vegetation helps in distinguishing the ecology of ponds from those of lakes and wetlands. . View of the Chaudhary Pokhair at the premises of the Basuki Nath Mahadev Mandir in Basuki Bihari village of India. Ponds can be created by a wide variety of natural processes (e.g. on floodplains as cutoff river channels, by glacial processes, by peatland formation, in coastal dune systems, by beavers). They can simply be isolated depressions (such as a kettle hole, vernal pool, prairie pothole, or simply natural undulations in undrained land) filled by runoff, groundwater, or precipitation, or all three of these. They can be further divided into four zones: vegetation zone, open water, bottom mud and surface film. The size and depth of ponds often varies greatly with the time of year; many ponds are produced by spring flooding from rivers. Ponds are usually freshwater, but may be brackish in nature.…

, Netherlands , Ohio. image of a pond in Central City Park, Macon, GA, . A pond is a small, still, land-based body of water formed by pooling inside a depression, either naturally or artificially. A pond is smaller than a lake and there are no official criteria distinguishing the two, although defining a pond to be less than in area, less than in depth and with less than 30% of its area covered by emergent vegetation helps in distinguishing the ecology of ponds from those of lakes and wetlands. . View of the Chaudhary Pokhair at the premises of the Basuki Nath Mahadev Mandir in Basuki Bihari village of India. Ponds can be created by a wide variety of natural processes (e.g. on floodplains as cutoff river channels, by glacial processes, by peatland formation, in coastal dune systems, by beavers). They can simply be isolated depressions (such as a kettle hole, vernal pool, prairie pothole, or simply natural undulations in undrained land) filled by runoff, groundwater, or precipitation, or all three of these. They can be further divided into four zones: vegetation zone, open water, bottom mud and surface film. The size and depth of ponds often varies greatly with the time of year; many ponds are produced by spring flooding from rivers. Ponds are usually freshwater, but may be brackish in nature. Saltwater pools, with a direct connection to the sea to maintain full salinity, may sometimes be called 'ponds' but these are normally regarded as part of the marine environment. They do not support fresh or brackish water-based organisms, and are rather tidal pools or lagoons. Ponds are typically shallow water bodies with varying abundances of aquatic plants and animals. Depth, seasonal water level variations, nutrient fluxes, amount of light reaching the ponds, the shape, the presence of visiting large mammals, the composition of any fish communities and salinity can all affect the types of plant and animal communities present. Food webs are based both on free-floating algae and upon aquatic plants. There is usually a diverse array of aquatic life, with a few examples including algae, snails, fish, beetles, water bugs, frogs, turtles, otters, and muskrats. Top predators may include large fish, herons, or alligators. Since fish are a major predator upon amphibian larvae, ponds that dry up each year, thereby killing resident fish, provide important refugia for amphibian breeding. Ponds that dry up completely each year are often known as vernal pools. Some ponds are produced by animal activity, including alligator holes and beaver ponds, and these add important diversity to landscapes. Ponds are frequently man made or expanded beyond their original depths and bounds by anthropogenic causes. Apart from their role as highly biodiverse, fundamentally natural, freshwater ecosystems ponds have had, and still have, many uses, including providing water for agriculture, livestock and communities, aiding in habitat restoration, serving as breeding grounds for local and migrating species, decorative components of landscape architecture, flood control basins, general urbanization, interception basins for pollutants and sources and sinks of greenhouse gases.

Formation

Any depression in the ground which collects and retains a sufficient amount of water can be considered a pond, and such, can be formed by a variety of geological, ecological, and human terraforming events. in Niagara Falls Rock Garden Natural ponds are those caused by environmental occurrences. These can vary from glacial, volcanic, fluvial, or even tectonic events. Since the Pleistocene epoch, glacial processes have created most of the Northern hemispheric ponds; an example is the Prairie Pothole Region of North America. When glaciers retreat, they may leave behind uneven ground due to bedrock elastic rebound and sediment outwash plains. These areas may develop depressions that can fill up with excess precipitation or seeping ground water, forming a small pond. Kettle lakes and ponds are formed when ice breaks off from a larger glacier, is eventually buried by the surrounding glacial till, and over time melts. Orogenies and other tectonic uplifting events have created some of the oldest lakes and ponds on the globe. These indentions have the tendency to quickly fill with groundwater if they occur below the local water table. Other tectonic rifts or depressions can fill with precipitation, local mountain runoff, or be fed by mountain streams. Volcanic activity can also lead to lake and pond formation through collapsed lava tubes or volcanic cones. Natural floodplains along rivers, as well as landscapes that contain many depressions, may experience spring/rainy season flooding and snow melt. Temporary or vernal ponds are created this way and are important for breeding fish, insects, and amphibians, particularly in large river systems like the Amazon. Some ponds are created by beavers, bison, alligators, and other crocodilians through damming and nest excavation respectively. In landscapes with organic soils, local fires can create depressions during periods of drought. These may fill up with small amounts of precipitation until normal water levels return, turning these isolated ponds into open water. Manmade ponds are created by human intervention for the sake of the local environment, industrial settings, or for recreational/ornamental use.

Uses

Many ecosystems are linked by water and ponds have been found to hold a greater biodiversity of species than larger freshwater lakes or river systems. As such, ponds are habitats for many varieties of organisms including plants, amphibians, fish, reptiles, waterfowl, insects, and even some mammals. Ponds are used for breeding grounds for these species but also as shelter and even drinking/feeding locations for other wildlife. Aquaculture practices lean heavily on artificial ponds in order to grow and care for many different type of fish either for human consumption, research, species conservation or recreational sport. in Swarzynice, Poland In agriculture practices, treatment ponds can be created to reduce nutrient runoff from reaching local streams or groundwater storages. Pollutants that enter ponds can often be mitigated by natural sedimentation and other biological and chemical activities within the water. As such, waste stabilization ponds are becoming popular low-cost methods for general wastewater treatment. They may also provide irrigation reservoirs for struggling farms during times of drought. in an urban area As urbanization continues to spread, retention ponds are becoming more common in new housing developments. These ponds reduce the risk of flooding and erosion damage from excess storm water runoff in local communities. , Nepal Experimental ponds are used to test hypotheses in the fields of environmental science, chemistry, aquatic biology, and limnology. Some ponds are the life blood of many small villages in arid countries such as those in sub-Saharan Africa where bathing, sanitation, fishing, socialization, and rituals are held. In the Indian subcontinent, Hindu temple monks care for sacred ponds used for religious practices and bathing pilgrims alike. In Europe during medieval times, it was typical for many monasteries and castles (small, partly self-sufficient communities) to have fish ponds. These are still common in Europe and in East Asia (notably Japan), where koi may be kept or raised. In Nepal artificial ponds were essential elements of the ancient drinking water supply system. These ponds were fed with rainwater, water coming in through canals, their own springs, or a combination of these sources. They were designed to retain the water, while at the same time letting some water seep away to feed the local aquifers.

Examples

Some notable ponds are: Rani Pokhari, 17th-century artificial pond in Kathmandu, Nepal Gangasagar, Janakpur, Mithila region, Nepal Big Pond, Nova Scotia, Canada Christian Pond, Wyoming, United States Walden Pond, Massachusetts, United States, associated with Henry David Thoreau Hampstead Ponds, London Kuttam Pokuna, Medieval artificial pond in Anuradhapura, Sri Lanka Rožmberk Pond, Czech Republic

References

Text derived from https://en.wikipedia.org/w/index.php?oldid=1376556855 under CC BY-SA 4.0; modifications have been made.