Humusjärviin

Humusjärviin, also known as brown-water lakes or blackwater lakes, are a specific type of lake characterized by high concentrations of dissolved organic matter, primarily humic and fulvic acids. These organic compounds originate from the decomposition of plant material in surrounding bogs, wetlands, and forests. The presence of these substances gives the water a distinct dark, tea-like color, and often a slightly acidic pH.

The rich organic content of humusjärviin significantly influences their ecological characteristics. Light penetration is limited due to the dark water, which affects the distribution of aquatic plants. Photosynthesis is primarily confined to shallower areas. Consequently, the food web often relies less on phytoplankton and more on detritus and dissolved organic matter. Organisms living in these lakes are adapted to low light conditions and often acidic water.

Humusjärviin are common in regions with extensive peatlands and coniferous forests, such as Scandinavia, Canada, and parts of Russia. Their water chemistry and biological communities differ notably from clear-water lakes. These differences can impact their suitability for various uses, including fishing and recreation, and are important considerations in environmental management and conservation efforts. The specific composition and concentration of humic substances can vary, leading to a spectrum of brown-water lake types.