Kyrksjön is a small lake

Lake

A lake is a body of relatively still fresh or salt water of considerable size, localized in a basin, that is surrounded by land. Lakes are inland and not part of the ocean and therefore are distinct from lagoons, and are larger and deeper than ponds. Lakes can be contrasted with rivers or streams,...

 in Bromma, a western suburb in Stockholm

Stockholm

Stockholm is the capital and the largest city of Sweden and constitutes the most populated urban area in Scandinavia. Stockholm is the most populous city in Sweden, with a population of 851,155 in the municipality , 1.37 million in the urban area , and around 2.1 million in the metropolitan area...

, Sweden

Sweden

Sweden , officially the Kingdom of Sweden , is a Nordic country on the Scandinavian Peninsula in Northern Europe. Sweden borders with Norway and Finland and is connected to Denmark by a bridge-tunnel across the Öresund....

. Named after its vicinity to the old church Bromma kyrka, the lake was made part of the nature reserve Kyrksjölöten in 1997. Three other lakes are located near Kyrksjön: Judarn

Judarn

Judarn is the name of a small lake in Bromma, a western suburb in Stockholm, Sweden. Surrounded by the forest and nature reserve Judarskogen, it stretches between Åkeshov and Södra Ängby. Three other lakes are found nearby: Kyrksjön, Lillsjön, and Råcksta Träsk...

, Lillsjön, and Råcksta Träsk

Råcksta Träsk

Råcksta Träsk is a small lake in the western suburbs of Stockholm, Sweden. Notwithstanding its location in the vicinity of the Swedish capital and high levels of lead and copper, the lake is considered as an important breeding ground for frogs, of moderate interest to pleasure fishing, and of...

.

Characteristics

With an area of 6,7 hectare

Hectare

The hectare is a metric unit of area defined as 10,000 square metres , and primarily used in the measurement of land. In 1795, when the metric system was introduced, the are was defined as being 100 square metres and the hectare was thus 100 ares or 1/100 km2...

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

Stormwater is water that originates during precipitation events. It may also be used to apply to water that originates with snowmelt that enters the stormwater system...

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

Broadleaf forest

Broadleaf forest can refer to:* Temperate broadleaf and mixed forests* Tropical and subtropical dry broadleaf forests* Tropical and subtropical moist broadleaf forests...

 in Stockholm rich in various species of bird

Bird

Birds are feathered, winged, bipedal, endothermic , egg-laying, vertebrate animals. Around 10,000 living species and 188 families makes them the most speciose class of tetrapod vertebrates. They inhabit ecosystems across the globe, from the Arctic to the Antarctic. Extant birds range in size from...

s, batrachians, and bat

Bat

Bats are mammals of the order Chiroptera "hand" and pteron "wing") whose forelimbs form webbed wings, making them the only mammals naturally capable of true and sustained flight. By contrast, other mammals said to fly, such as flying squirrels, gliding possums, and colugos, glide rather than fly,...

s. Levels of phosphorus

Phosphorus

Phosphorus is the chemical element that has the symbol P and atomic number 15. A multivalent nonmetal of the nitrogen group, phosphorus as a mineral is almost always present in its maximally oxidized state, as inorganic phosphate rocks...

 and nitrogen

Nitrogen

Nitrogen is a chemical element that has the symbol N, atomic number of 7 and atomic mass 14.00674 u. Elemental nitrogen is a colorless, odorless, tasteless, and mostly inert diatomic gas at standard conditions, constituting 78.08% by volume of Earth's atmosphere...

 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

Allotment (gardening)

An allotment garden, often called simply an allotment, is a plot of land made available for individual, non-professional gardening. Such plots are formed by subdividing a piece of land into a few or up to several hundreds of land parcels that are assigned to individuals or families...

 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

Spånga is a community and parish 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 portions of the area merging with Solna, Sundbyberg, and Sollentuna municipalities.Spånga was...

 parish and its outflow use to discharge through a nine metres tall white water. 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

Golden algae

The golden algae or chrysophytes are a large group of algae, found mostly in freshwater.The term "chrysophyceae" should not be confused with the term Chrysophyta, which is more ambiguous.-Members:...

 and Carapace

Carapace

A carapace is a dorsal section of the exoskeleton or shell in a number of animal groups, including arthropods such as crustaceans and arachnids, as well as vertebrates such as turtles and tortoises. In turtles and tortoises, the underside is called the plastron.-Crustaceans:In crustaceans, the...

 algae

Algae

Algae are a large and diverse group of simple, typically autotrophic organisms, ranging from unicellular to multicellular forms, such as the giant kelps that grow to 65 meters in length. They are photosynthetic like plants, and "simple" because their tissues are not organized into the many...

 (Ceratium hirudinella), while zooplankton

Zooplankton

Zooplankton are heterotrophic plankton. Plankton are organisms drifting in oceans, seas, and bodies of fresh water. The word "zooplankton" is derived from the Greek zoon , meaning "animal", and , meaning "wanderer" or "drifter"...

 (such as Rotifer

Rotifer

The rotifers make up a phylum of microscopic and near-microscopic pseudocoelomate animals. They were first described by Rev. John Harris in 1696, and other forms were described by Anton van Leeuwenhoek in 1703...

 and Copepod

Copepod

Copepods are a group of small crustaceans found in the sea and nearly every freshwater habitat. Some species are planktonic , some are benthic , and some continental species may live in limno-terrestrial habitats and other wet terrestrial places, such as swamps, under leaf fall in wet forests,...

) are relatively rare). Aquatic plant

Aquatic plant

Aquatic plants are plants that have adapted to living in aquatic environments. They are also referred to as hydrophytes or aquatic macrophytes. These plants require special adaptations for living submerged in water, or at the water's surface. Aquatic plants can only grow in water or in soil that is...

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

Charales

Charales is an order of pondweeds, freshwater algae in the division Charophyta. They are green plants believed to be the closest relatives of the green land plants. Linnaeus established the genus Chara in 1753.-Description:...

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

Utricularia vulgaris

Utricularia vulgaris is an aquatic species of bladderwort found in Asia and Europe. The plant is a free-floating and does not put down roots. Stems can attain lengths of over one metre in a single growing season, but die back and form turions in winter...

, milfoil

Myriophyllum

Myriophyllum is a genus of about 69 species of freshwater aquatic plants, with a cosmopolitan distribution. The center of diversity for Myriophyllum is Australia with 43 recognized species...

s, and others. Along the shores are found Carex

Carex

Carex is a genus of plants in the family Cyperaceae, commonly known as sedges. Other members of the Cyperaceae family are also called sedges, however those of genus Carex may be called "true" sedges, and it is the most species-rich genus in the family. The study of Carex is known as...

, Purple loosestrife

Purple loosestrife

Lythrum salicaria is a flowering plant belonging to the family Lythraceae, native to Europe, Asia, northwest Africa, and southeastern Australia. It should not be confused with other plants sharing the name loosestrife that are members of the family Primulaceae...

, Milk Parsley

Milk Parsley

Milk Parsley is a plant in the family Apiaceae. Also known as Marsh Hog's Fennel.It resides on wetlands, mires etc., shallow riverbanks, occasionally on ditches and other smaller water features. It's relatively shadow-tolerant. It requires seasonal submerging of the site to compete with other...

, and Lesser Bulrush. Trees around the lake include Black Alder

Black Alder

Alnus glutinosa is an alder native to most of Europe, including all of the British Isles and Fennoscandia and locally in southwest Asia....

 and Grey Willow. Bottom specimens taken in July 1996 mostly unveiled larvae of chironomids

Chironomidae

Chironomidae are a family of nematoceran flies with a global distribution. They are closely related to the Ceratopogonidae, Simuliidae, and Thaumaleidae...

, Oligochaeta

Oligochaeta

Oligochaeta is a subclass of animals in the biological phylum Annelida, which is made up of many types of aquatic and terrestrial worms, and this includes all of the various earthworms...

, 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

Mayfly

Mayflies are insects which belong to the Order Ephemeroptera . They have been placed into an ancient group of insects termed the Palaeoptera, which also contains dragonflies and damselflies...

, Caddisflies

Trichoptera

The caddisflies are an order, Trichoptera, of insects with approximately 12,000 described species. Also called sedge-flies or rail-flies, they are small moth-like insects having two pairs of hairy membranous wings...

, and Dragonflies

Odonata

Odonata is an order of insects, encompassing dragonflies and damselflies . The word dragonfly is also sometimes used to refer to all Odonata, but the back-formation odonate is a more correct English name for the group as a whole...

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

Crucian carp

The crucian carp is a member of the family Cyprinidae, which includes many other fish, such as the common carp, or the smaller minnows. They inhabit lakes, ponds, and slow-moving rivers throughout Europe and Asia. The crucian is a medium-sized cyprinid, which rarely exceeds a weight of over 3.3...

.

Birds reported include Eurasian Coot

Eurasian Coot

The Eurasian Coot, Fulica atra, also known as Coot, is a member of the rail and crake bird family, the Rallidae. The Australian subspecies is known as the Australian Coot.-Distribution:...

, Great Crested Grebe

Great Crested Grebe

The Great Crested Grebe is a member of the grebe family of water birds.- Description :The Great Crested Grebe is long with a wingspan. It is an excellent swimmer and diver, and pursues its fish prey underwater. The adults are unmistakable in summer with head and neck decorations...

, Tufted Duck

Tufted Duck

The Tufted Duck, Aythya fuligula, is a medium-sized diving duck with a population of close to one million birds.- Description :The adult male is all black except for white flanks and a blue-grey bill. It has an obvious head tuft that gives the species its name.The adult female is brown with paler...

, Common Moorhen

Common Moorhen

The Common Moorhen is a bird in the Rallidae family with an almost worldwide distribution. The North and South American Committees of the AOU and the IOC have voted on or before July 2011 to split the American forms into a new species Common Gallinule, however, no other committee has voted to...

, Pochard, and Slavonian Grebe

Slavonian Grebe

The Horned Grebe or Slavonian Grebe, Podiceps auritus, is a member of the grebe family of water birds. The Slavonian Grebe is an excellent swimmer and diver, and pursues its fish prey underwater...

. The dense vegetation surrounding the lake contains Nightingale

Thrush Nightingale

The Thrush Nightingale, Luscinia luscinia , is a small passerine bird that was formerly classed as a member of the thrush family Turdidae, but is now more generally considered to be an Old World flycatcher, Muscicapidae...

s, Blackcap

Blackcap

The Blackcap is a common and widespread sylviid warbler which breeds throughout temperate Europe, western Asia and northwestern Africa, and winters from northwestern Europe south to tropical Africa...

s and Marsh Warbler

Marsh Warbler

The Marsh Warbler, Acrocephalus palustris, is an Old World warbler currently classified in the family Acrocephalidae. It breeds in temperate Europe and western Asia and winters mainly in south east Africa...

s hiding from Sparrowhawks, Goshawks, and Tawny Owl

Tawny Owl

The Tawny Owl or Brown Owl is a stocky, medium-sized owl commonly found in woodlands across much of Eurasia. Its underparts are pale with dark streaks, and the upperparts are either brown or grey. Several of the eleven recognised subspecies have both variants...

s. The lake is also an important breeding ground for frog

Frog

Frogs are amphibians in the order Anura , formerly referred to as Salientia . Most frogs are characterized by a short body, webbed digits , protruding eyes and the absence of a tail...

s, including Common Frog

Common Frog

The Common Frog, Rana temporaria also known as the European Common Frog or European Common Brown Frog is found throughout much of Europe as far north as well north of the Arctic Circle in Scandinavia and as far east as the Urals, except for most of Iberia, southern Italy, and the southern Balkans...

, Moor Frog

Moor Frog

The Moor Frog is a slim, reddish-brown, semi-aquatic amphibian native to Europe and Asia. It is a member of the family Ranidae, or "true frogs".-Taxonomy:...

, and Common Toad

Common Toad

The common toad or European toad is an amphibian widespread throughout Europe, with the exception of Iceland, Ireland and some Mediterranean islands...

. The presence of Great Crested Newt

Great Crested Newt

The Great Crested Newt, also called Northern Crested Newt or Warty Newt is a newt in the family Salamandridae, found across Europe and parts of Asia.-Distribution:...

 is threatened and all frog species are protected by law. Grass Snake

Grass Snake

The grass snake , sometimes called the ringed snake or water snake is a European non-venomous snake. It is often found near water and feeds almost exclusively on amphibians.-Etymology:...

 was observed in 1996. Surrounding buildings and deciduous forest forms a great habitat for bat

Bat

Bats are mammals of the order Chiroptera "hand" and pteron "wing") whose forelimbs form webbed wings, making them the only mammals naturally capable of true and sustained flight. By contrast, other mammals said to fly, such as flying squirrels, gliding possums, and colugos, glide rather than fly,...

s such as Northern Bat

Northern Bat

The Northern Bat is a species of bat. An adult Northern Bat has a body length of 4.9-6.6 cm, a tail of 3.2-5.1 cm, and a wing length of 4.1-5.1 cm. The species is found across Europe and Asia, from England to Hokkaidō and south to northern India.-References: 2006 IUCN Red List of Threatened...

, Soprano Pipistrelle

Soprano Pipistrelle

The Soprano Pipistrelle is a small bat that was only formally separated from the Common Pipistrelle Pipistrellus pipistrellus in 1999....

, Daubenton's bat

Daubenton's bat

Daubenton's Bat, Myotis daubentonii, is a Eurasian bat with quite short ears. It ranges from Britain to Japan and is considered to be increasing its numbers in many areas.The name commemorates the French naturalist Louis-Jean-Marie Daubenton....

, and Nyctalus

Nyctalus

The bat genus Nyctalus are members of the family Vespertilionidae or sometimes Evening bats. They are distributed in the temperate and subtropical areas of Europe, Asia and North Africa.There are eight species within this genus:...

.