Trylen is a small lake 17 km (10 mi) south of central 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....

. Shared by Huddinge Municipality

Huddinge Municipality

Huddinge Municipality is a municipality in Stockholm County in east central Sweden. Its seat is located in Huddinge, which is a part of Stockholm urban area.The municipality is the second most populated in Stockholm County....

 and Haninge Municipality

Haninge Municipality

Haninge Municipality is a municipality in Stockholm County in east central Sweden. Its seat is located in Handen.Haninge Municipality was formed in 1971 when Västerhaninge and Österhaninge were united....

, it forms part of the Tyresån Lake System

Tyresån Lake System

Tyresån Lake System is a number of lakes in Sweden with a common basin of 251.5 km2....

.

Catchment area

With its catchment area characterized by morass

Morass

Morass may refer to:*Marsh, a wetland*Morass...

 and pine covered rock faces, Trylen is a popular spot for walks and bathing. Motorboats are not permitted on the lake. Fishing permits do not apply in the lake.

Environmental influence

Nutrients only reaches the lake from the air, which makes water quality high.

nutrition levels

PTOT 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...	NTOT 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...	N/P-quota	Chlor Chlorophyll Chlorophyll is a green pigment found in almost all plants, algae, and cyanobacteria. Its name is derived from the Greek words χλωρος, chloros and φύλλον, phyllon . Chlorophyll is an extremely important biomolecule, critical in photosynthesis, which allows plants to obtain energy from light...	Sight depth	Colour	TOC Total organic carbon Total organic carbon is the amount of carbon bound in an organic compound and is often used as a non-specific indicator of water quality or cleanliness of pharmaceutical manufacturing equipment....	pH PH In chemistry, pH is a measure of the acidity or basicity of an aqueous solution. Pure water is said to be neutral, with a pH close to 7.0 at . Solutions with a pH less than 7 are said to be acidic and solutions with a pH greater than 7 are basic or alkaline...	Alk Alkalinity Alkalinity or AT measures the ability of a solution to neutralize acids to the equivalence point of carbonate or bicarbonate. The alkalinity is equal to the stoichiometric sum of the bases in solution...
10 ug/l	640 ug/l	64	5 a ug/l	0,7 m (max)	150 mg/l	20 mg/l	6,2	0,09 mekv/l

Flora and fauna

An inventory in 1998 documented Common Reed

Phragmites

Phragmites, the Common reed, is a large perennial grass found in wetlands throughout temperate and tropical regions of the world. Phragmites australis is sometimes regarded as the sole species of the genus Phragmites, though some botanists divide Phragmites australis into three or four species...

, Water Horsetail

Water Horsetail

The water horsetail , also known as the Swamp Horsetail, is a perennial horsetail that commonly grows in dense colonies along freshwater shorelines or in shallow water, growing in ponds, swamps, ditches, and other sluggish or still waters with mud bottoms...

, Menyanthes

Menyanthes

Menyanthes is a monotypic genus of flowering plant in the family Menyanthaceae containing the single species Menyanthes trifoliata...

, Yellow Water-lily

Nuphar lutea

Nuphar lutea is an aquatic plant of the family Nymphaeaceae, native to temperate regions of Europe, northwest Africa, and western Asia.-Growth:...

, White Water-lily

Nymphaea alba

Nymphaea alba, also known as the European White Waterlily, White Lotus, or Nenuphar, is an aquatic flowering plant of the family Nymphaeaceae....

, Floating-leaf Pondweed

Potamogeton natans

Potamogeton natans L. is an aquatic species in the genus Potamogeton native to quiet or slow-flowing freshwater habitats throughout the Holarctic Kingdom....

, and Flatleaf Bladderwort

Utricularia intermedia

Utricularia intermedia, the flatleaf bladderwort, is a small, perennial carnivorous plant that belongs to the genus Utricularia. It is usually found affixed to the substrate but it can also survive suspended in a body of water. U. intermedia is a circumboreal species and is found in North America,...

. Additionally, there are red algae

Red algae

The red algae are one of the oldest groups of eukaryotic algae, and also one of the largest, with about 5,000–6,000 species  of mostly multicellular, marine algae, including many notable seaweeds...

 and moss

Moss

Mosses are small, soft plants that are typically 1–10 cm tall, though some species are much larger. They commonly grow close together in clumps or mats in damp or shady locations. They do not have flowers or seeds, and their simple leaves cover the thin wiry stems...

es such as Fontinalis dalecarlica.

Birds by the lake includes Mallard

Mallard

The Mallard , or Wild Duck , is a dabbling duck which breeds throughout the temperate and subtropical Americas, Europe, Asia, and North Africa, and has been introduced to New Zealand and Australia....

 and Common Goldeneye

Common Goldeneye

The Common Goldeneye is a medium-sized sea duck of the genus Bucephala, the goldeneyes. Their closest relative is the similar Barrow's Goldeneye....

. Toad

True toad

Bufonidae is the family of the true toads, members of the order Anura . They are the only family of anurans all members of which are known as "toads." The bufonids now comprise more than 35 genera, Bufo being the most widespread and well known.-Characteristics:True toads are widespread and occur...

s were reported in the lake in 2004, as were 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...

 such as brown hawkers

Aeshnidae

The hawkers include the largest dragonflies found in North America and Europe, and are among the largest of the dragonflies on the planet...

 and Brilliant Emerald. No reports are available concerning bats, fishes, and crayfish.