Kyrksjön () is a small

lake A lake is often a naturally occurring, relatively large and fixed body of water on or near the Earth's surface. It is localized in a basin or interconnected basins surrounded by dry land. Lakes lie completely on land and are separate from ...

Bromma Bromma () is a Boroughs of Stockholm, borough (''stadsdelsområde'') in the western part of Stockholm, Sweden, forming part of the Stockholm Municipality. Bromma is primarily made up of Bromma Parish and Västerled Parish. The fourth largest airpo ...

, a western suburb in

Stockholm Stockholm (; ) is the Capital city, capital and List of urban areas in Sweden by population, most populous city of Sweden, as well as the List of urban areas in the Nordic countries, largest urban area in the Nordic countries. Approximately ...

Sweden Sweden, formally the Kingdom of Sweden, is a Nordic countries, Nordic country located on the Scandinavian Peninsula in Northern Europe. It borders Norway to the west and north, and Finland to the east. At , Sweden is the largest Nordic count ...

. Named after its vicinity to the old

Bromma Church Bromma Church is a round church in the borough Bromma in Stockholm, Sweden. It is the parish church of Bromma Parish in the Diocese of Stockholm. The oldest parts of the church were built in the late 12th century as a fortress church, and the ...

, the lake was made part of the nature reserve Kyrksjölöten in 1997. Three other lakes are located near Kyrksjön: Judarn, Lillsjön, and Råcksta Träsk.

Characteristics

With an area of 6,7

hectare The hectare (; SI symbol: ha) is a non-SI metric unit of area equal to a square with 100-metre sides (1 hm2), that is, square metres (), and is primarily used in the measurement of land. There are 100 hectares in one square kilometre. ...

s and average depth of 1,5 metres (maximum 2,5 metres), Kyrkosjön contains 80,000 cubic metres of water and is supplied by a drainage area of 48 hectares. The lake is thus small and shallow, with no feeder or

storm water Stormwater, also written storm water, is water that originates from precipitation (storm), including heavy rain and meltwater from hail and snow. Stormwater can soak into the soil ( infiltrate) and become groundwater, be stored on depressed lan ...

conduit connected to it. The lake is surrounded by one of the biggest

broadleaf forest A forest is an ecosystem characterized by a dense community of trees. Hundreds of definitions of forest are used throughout the world, incorporating factors such as tree density, tree height, land use, legal standing, and ecological functio ...

in Stockholm rich in various species of

bird Birds are a group of warm-blooded vertebrates constituting the class (biology), class Aves (), characterised by feathers, toothless beaked jaws, the Oviparity, laying of Eggshell, hard-shelled eggs, a high Metabolism, metabolic rate, a fou ...

s, batrachians, and

bat Bats are flying mammals of the order Chiroptera (). With their forelimbs adapted as wings, they are the only mammals capable of true and sustained flight. Bats are more agile in flight than most birds, flying with their very long spread-out ...

s. Levels of

phosphorus Phosphorus is a chemical element; it has Chemical symbol, symbol P and atomic number 15. All elemental forms of phosphorus are highly Reactivity (chemistry), reactive and are therefore never found in nature. They can nevertheless be prepared ar ...

and

nitrogen Nitrogen is a chemical element; it has Symbol (chemistry), symbol N and atomic number 7. Nitrogen is a Nonmetal (chemistry), nonmetal and the lightest member of pnictogen, group 15 of the periodic table, often called the Pnictogen, pnictogens. ...

have decreased since the 1980s. Metal levels are low and the waters are moderately clear. Two bathe are located at Kyrkosjön, which is considered to be of significant recreational and natural value. Sewers from a nearby allotment-garden and a traffic route produces some input flow, but normally not enough to even produce an outflow. Historically considerably larger, Kyrksjön used to extend well into the

Spånga Spånga is a community and parish in the borough of Spånga-Tensta in Stockholm County, Sweden. Background Spånga was an independent municipality until January 1, 1949, when most of it was merged with the City of Stockholm, with smaller ...

parish and its outflow used to discharge through a nine metres tall

white water Whitewater forms in the context of rapids, in particular, when a river's gradient changes enough to generate so much turbulence that air is trapped within the water. This forms an unstable current that froths, making the water appear opaque ...

. The lake was lowered to the present level in 1863 which resulted in today's stagnant lake, notwithstanding later attempts to reopen the outflow.

Flora and fauna

Moderate levels of algae are commons in late summer, principally

golden algae The Chrysophyceae, usually called chrysophytes, chrysomonads, golden-brown algae, or golden algae, are a large group of algae, found mostly in freshwater. Golden algae is also commonly used to refer to a single species, '' Prymnesium parvum'', wh ...

and carapace algae ('' Ceratium hirudinella''), while

zooplankton Zooplankton are the heterotrophic component of the planktonic community (the " zoo-" prefix comes from ), having to consume other organisms to thrive. Plankton are aquatic organisms that are unable to swim effectively against currents. Consequent ...

(such as

Rotifer The rotifers (, from Latin 'wheel' and 'bearing'), sometimes called wheel animals or wheel animalcules, make up a phylum (Rotifera ) of microscopic and near-microscopic Coelom#Pseudocoelomates, pseudocoelomate animals. They were first describ ...

and

Copepod Copepods (; meaning 'oar-feet') are a group of small crustaceans found in nearly every freshwater and saltwater habitat (ecology), habitat. Some species are planktonic (living in the water column), some are benthos, benthic (living on the sedimen ...

) are relatively rare).

Aquatic plant Aquatic plants, also referred to as hydrophytes, are vascular plants and Non-vascular plant, non-vascular plants that have adapted to live in aquatic ecosystem, aquatic environments (marine ecosystem, saltwater or freshwater ecosystem, freshwater ...

s are relatively few, the lake floor is mostly covered by

Charales Charales is an order of freshwater green algae in the division Charophyta, class Charophyceae, commonly known as stoneworts. Depending on the treatment of the genus '' Nitellopsis'', living (extant) species are placed into either one family ( ...

such as '' Chara tomentosa'' (present since the mid 19th century), accompanied by

bladderwort ''Utricularia'', commonly and collectively called the bladderworts, is a genus of carnivorous plants consisting of approximately 233 species (precise counts differ based on classification opinions; a 2001 publication lists 215 species).Salmon, Br ...

, milfoils, and others. Along the shores are found ''

Carex pseudocyperus ''Carex pseudocyperus'' is a species of flowering plant in the sedge family known by the common name cyperus sedge or hop sedge. It grows in marshes, swamps, and the margins of ponds, rivers and canals. The stems can be up to with one male spik ...

'',

purple loosestrife ''Lythrum salicaria'' or purple loosestrifeFlora of NW Europe''Lythrum salicaria'' is a flowering plant belonging to the family Lythraceae. It should not be confused with other plants sharing the name loosestrife that are members of the family Pr ...

, milk parsley, and lesser bulrush. Trees around the lake include black alder and

grey willow Grey willow or gray willow may refer to: *''Salix atrocinerea'', a species of willow native to Europe commonly called grey willow *''Salix cinerea'', a species of willow native to Europe and western Asia, also occasionally called grey sallow *''Sal ...

. Bottom specimens taken in July 1996 mostly unveiled larvae of

chironomids Chironomidae , commonly known as non-biting midges or chironomids , are a family of Nematoceran flies with a global distribution. They are closely related to the families Ceratopogonidae, Simuliidae, and Thaumaleidae. Although many chironomid s ...

Oligochaeta Oligochaeta () is a subclass of soft-bodied animals in the phylum Annelida, which is made up of many types of aquatic and terrestrial worms, including all of the various earthworms. Specifically, oligochaetes comprise the terrestrial megadril ...

, and empty shells - typical for lakes rich in nutrients but poor in oxygen. Specimens taken along the shores the same year resulted in reports of

mayflies Mayflies (also known as shadflies or fishflies in Canada and the upper Midwestern United States, as Canadian soldiers in the American Great Lakes region, and as up-winged flies in the United Kingdom) are aquatic insects belonging to the order ...

caddisflies The caddisflies (order Trichoptera) are a group of insects with aquatic larvae and terrestrial adults. There are approximately 14,500 described species, most of which can be divided into the suborders Integripalpia and Annulipalpia on the basis ...

, and

dragonflies A dragonfly is a flying insect belonging to the infraorder Anisoptera below the order Odonata. About 3,000 extant species of dragonflies are known. Most are tropical, with fewer species in temperate regions. Loss of wetland habitat threate ...

. Fish population has been decimated by low levels of oxygen and is now reduced to

Crucian carp The crucian carp (''Carassius carassius'') is a medium-sized member of the common carp family Cyprinidae. It occurs widely in northern European regions. Its name derives from the Low German ''karusse'' or ''karutze'', possibly from Medieval Lat ...

. Birds reported include

Eurasian coot The Eurasian coot (''Fulica atra''), also known as the common coot, or Australian coot, is a member of the rail and crake bird family, the Rallidae. It is found in Europe, Asia, Australia, New Zealand and parts of North Africa. It has a slaty-bla ...

great crested grebe The great crested grebe (''Podiceps cristatus'') is a member of the grebe family of water birds. The bird is characterised by its distinctive appearance, featuring striking black, orange-brown, and white plumage, and elaborate courtship displa ...

tufted duck The tufted duck (or tufted pochard) (''Aythya fuligula'') is a small diving duck with a population of nearly one million birds, found in northern Eurasia. They are partially migratory. The scientific name is derived from Ancient Greek , an unide ...

common moorhen The common moorhen (''Gallinula chloropus''), also known as the waterhen, is a bird species in the Rail (bird), rail family (Rallidae). It is distributed across many parts of the Old World, across Africa, Europe, and Asia. It lives around well-ve ...

pochard Pochard is a common name used for several species of diving ducks: *Four species in the genus ''Aythya'': ** Common pochard, ''Aythya ferina'' ** Baer's pochard, ''Aythya baeri'' ** Ferruginous pochard, ''Aythya nyroca'' ** Madagascar pochard, ' ...

, and

Slavonian grebe The horned grebe or Slavonian grebe (''Podiceps auritus'') is a relatively small and threatened species of waterbird in the family Podicipedidae. There are two subspecies, ''P. a. auritus'' (Slavonian grebe), which breeds in Eurasia, and ' ...

. The dense vegetation surrounding the lake contains

nightingale The common nightingale, rufous nightingale or simply nightingale (''Luscinia megarhynchos''), is a small passerine bird which is best known for its powerful and beautiful song. It was formerly classed as a member of the thrush family Turdidae, ...

blackcap The Eurasian blackcap (''Sylvia atricapilla'') is a bird usually known simply as the blackcap. It is a common and widespread typical warbler. It has mainly olive-grey upperparts and pale grey underparts, and differences across the five subspec ...

s and

marsh warbler The marsh warbler (''Acrocephalus palustris'') is an Old World warbler currently classified in the family Acrocephalidae. It breeds in temperate Europe and the western Palearctic and winters mainly in southeast Africa. It is notable for incorpor ...

s hiding from

sparrowhawk Sparrowhawk (sometimes sparrow hawk) may refer to several species of small hawk in the subfamily Accipitrinae The Accipitrinae are the Family (biology), subfamily of the Accipitridae often known as the "true" hawks. The subfamily contains 73 s ...

goshawk Goshawk may refer to several species of birds of prey in the family Accipitridae: Palearctic * Eurasian goshawk, ''Astur gentilis'', often referred to simply as the goshawk, since it is the only goshawk found in much of its range (in Europe and ...

s, and

tawny owl The tawny owl (''Strix aluco''), also called the brown owl, is a stocky, medium-sized owl in the family Strigidae. It is commonly found in woodlands across Europe, as well as western Siberia, and has seven recognized subspecies. The tawny owl' ...

s. The lake is also an important breeding ground for

frog A frog is any member of a diverse and largely semiaquatic group of short-bodied, tailless amphibian vertebrates composing the order (biology), order Anura (coming from the Ancient Greek , literally 'without tail'). Frog species with rough ski ...

s, including

common frog The common frog or grass frog (''Rana temporaria''), also known as the European common frog, European common brown frog, European grass frog, European Holarctic true frog, European pond frog or European brown frog or simply the frog, is a semi ...

moor frog The moor frog (''Rana arvalis'') is a slim, reddish-brown, semiaquatic amphibian native to Europe and Asia. Moor frogs are known for their ability to freeze solid and survive thawing. The frog makes use of various cryoprotectants i.e. Antifreeze ...

, and

common toad The common toad, European toad, or in Anglophone parts of Europe, simply the toad (''Bufo bufo'', from Latin ''bufo'' "toad"), is a toad found throughout most of Europe (with the exception of Ireland, Iceland, parts of Scandinavia, and some List ...

. The presence of

great crested newt The northern crested newt, great crested newt or warty newt (''Triturus cristatus'') is a newt species native to Great Britain, northern and central continental Europe and parts of Western Siberia. It is a large newt, with females growing up to ...

is threatened and all frog species are protected by law.

Grass snake The grass snake (''Natrix natrix''), sometimes called the ringed snake or water snake, is a Eurasian semi-aquatic non- venomous colubrid snake. It is often found near water and feeds almost exclusively on amphibians. Subspecies Many subspecie ...

was observed in 1996. Surrounding buildings and

deciduous forest In the fields of horticulture and botany, the term deciduous () means "falling off at maturity" and "tending to fall off", in reference to trees and shrubs that seasonally shed leaves, usually in the autumn; to the shedding of petals, after flo ...

forms a great habitat for

s such as

northern bat The northern bat (''Eptesicus nilssonii'') is the most abundant species of bat in northern Eurasia occurring from France to Hokkaidō and south to Kazakhstan. Description The northern bat is dark brown or black with some gold touched at the tip ...

soprano pipistrelle The soprano pipistrelle (''Pipistrellus pygmaeus'') is a small species of bat. It is found in Europe and often roosts on buildings. Taxonomy Until 1999, the soprano pipistrelle was considered as conspecific Biological specificity is the tendenc ...

Daubenton's bat Daubenton's bat or Daubenton's myotis (''Myotis daubentonii'') is a Eurasian bat with rather short ears. It occurs across Eurasia, from Ireland in the west to Hokkaido in the east, and is believed to be increasing its numbers in many areas of it ...

, and ''

Nyctalus ''Nyctalus'' is a genus of vespertilionid bats commonly known as the noctule bats. They are distributed in the temperate and subtropical areas of Europe, Asia and North Africa. There are eight species within this genus: * Birdlike noctule, ''N ...

''.

References

{{DEFAULTSORT:Kyrksjon Geography of Stockholm Norrström basin Lakes of Stockholm County

Characteristics

Flora and fauna

See also

References