skogbunnen

Skogbunnen is the uppermost part of the forest soil system, lying directly on the mineral soil and consisting mainly of organic material in various stages of decomposition as well as the surface mineral horizon enriched by organic matter. In practice the term covers both the litter layer and the organic-rich layer beneath, sometimes extending to the very top of the mineral soil that is influenced by organic inputs.

Components and processes

The forest floor contains litter from trees and understory vegetation, such as leaves, needles, bark, twigs, and bryophytes, as well as decomposed material in different stages. Microbial activity, fungi and invertebrates drive decomposition, releasing nutrients that plant roots can uptake. The balance between litter input and decomposition shapes humus formation, soil structure, moisture retention and nutrient availability. The depth and composition of the skogbunnen vary with tree species, climate, site productivity and disturbance history.

Ecological role

Skogbunnen is a key zone for biodiversity, providing habitat for fungi, bacteria, micro-arthropods, insects and detritivores. It functions as a nutrient reservoir and plays a significant part in carbon storage and the regulation of soil moisture. The seedling establishment and early root growth of many forest species are influenced by the condition of the forest floor.

Human impact and management

Forestry practices, drainage, litter removal, fire, and long-term soil compaction can alter the structure and function of the skogbunnen. Sustainable management often aims to preserve a supply of coarse woody debris, maintain litter layers, and minimize soil disturbance to protect nutrient cycling, biodiversity and soil health.