Dam

For alternative betydninger, se Dam (flertydig). (Se også artikler, som begynder med Dam)

En dam er et lille vandhul, der er så lavvandet at lyset normalt kan trænge ned til bunden. Damme adskiller sig fra de større søer, ved at de ikke udvikler springlag, og fra vandpytterne, ved at de indeholder vand hele året rundt. Man skelner mellem naturlige og kunstige damme. En kunstig dam kan f.eks. være en mølledam, branddam, fiskedam (f.eks. ørreddam, karpedam) og regnvandsdam (regnvandsreservoir).

Damme er ofte næringsrige (andedamme endog ekstremt næringsrige). Planterne består af rørskovsplanter, flydebladsplanter, bundplanter (rankegrøde) og planteplankton. Dyrelivet svarer til søernes dyreliv, dog ofte repræsenteret af arter, der er mere tolerante over for dårlige iltforhold. Man kan groft inddele dyrene i bunddyr, dyr der lever på planterne og dyreplankton (f.eks. dafnier), samt større dyr, herunder bl.a. fisk og padder.

Datadreven amerikansk forskerdefinition

En samling forskere har lavet en undersøgelse, hvor de definerer en dam som: Citat: "Ponds are small and shallow waterbodies, with a maximum surface area of five hectares, a maximum depth of 5 meters and less than 30% emergent vegetation." Det kan oversættes til: "Damme er små lavvandede vandmasser, med et maksimalt overfladeareal på 5 hektar, en maksimal dybde på 5 meter og mindre end 30% fremvoksende vegetation."^[1]

Se også

Litteratur

Hans Scherfig: Dammen, illustreret af Elisabeth Karlinsky, 1958, 3. udg. 1993, ISBN 87-00-15148-3, en fin naturbeskrivelse.

Referencer

^ Cornell University. (2022, July 5). What is a pond? Study provides first data-driven definition. ScienceDaily Citat: "...Their conclusion: Ponds are small and shallow waterbodies, with a maximum surface area of five hectares, a maximum depth of 5 meters and less than 30% emergent vegetation...The researchers found that ponds are not the same as lakes or wetlands, however. Further examination of the literature revealed that ponds have distinct ecological structures and function that make their categorization with either lakes or wetlands problematic..."

Eksterne henvisninger

Iowa State University (2008, May 8). Ponds Found To Take Up Carbon Like World's Oceans. ScienceDaily. Retrieved May 8, 2008 Citat: "..."Aquatic ecosystems play a disproportionately large role in the global carbon budget," Downing said...The combined effect is that farm ponds could be burying as much carbon as the world's oceans, each year...It may be that ponds will be the modern equivalent of the swamps that formed coal in the past. But before we all rush into making ponds to trap carbon we need to do some basic research here in the UK..."

Søsterprojekter med yderligere information:

[1] Cornell University. (2022, July 5). What is a pond? Study provides first data-driven definition. ScienceDaily Citat: "...Their conclusion: Ponds are small and shallow waterbodies, with a maximum surface area of five hectares, a maximum depth of 5 meters and less than 30% emergent vegetation...The researchers found that ponds are not the same as lakes or wetlands, however. Further examination of the literature revealed that ponds have distinct ecological structures and function that make their categorization with either lakes or wetlands problematic..."

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