Nurse log

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Avatar Grove, British Columbia, Canada

A nurse log is a fallen

mycorrhizae, disease protection, nutrients, and sunlight. Recent research into soil pathogens suggests that in some forest communities, pathogens hostile to a particular tree species appear to gather in the vicinity of that species, and to a degree inhibit seedling growth.[1]
Nurse logs may therefore provide some measure of protection from these pathogens, thus promoting greater seedling survivorship.

Occurrence

western hemlock

Various mechanical and biological processes contribute to the breakdown of lignin in fallen trees, resulting in the formation of niches of increasing size, which tend to fill with forest litter such as soil from spring floods, needles, moss, mushrooms and other flora. Mosses also can cover the outside of a log, hastening its decay and supporting other species as rooting media and by retaining water. Small animals such as various squirrels often perch or roost on nurse logs, adding to the litter by food debris and scat. The decay of this detritus contributes to the formation of a rich humus that provides a seedbed and adequate conditions for germination.

Nurse logs often provide a seedbed to conifers in a

temperate rain forest
ecosystem.

The oldest nurse log fossils date to the earliest Permian, approximately 300 million years ago.[2]

References

Books

External links