Mother Trees: What Science Really Says About Forest Networks
For more than a quarter of a century, researchers have explored how trees and fungi interact within underground networks. One influential idea to emerge from this work is the concept of “mother trees”—large, old trees that may occupy highly connected positions within forest networks. The idea is fascinating, but some of the claims surrounding it remain actively debated.
Understanding the idea of mother trees
In 1997, forest ecologist Suzanne Simard published influential research on carbon transfer between paper birch and Douglas-fir associated with mycorrhizal fungi. This work helped popularise the idea that trees can exchange resources through shared fungal associations—the phenomenon later nicknamed the “Wood Wide Web”, which I explore in more detail in another article on this blog. Mycorrhizal fungi form associations with tree roots and can connect multiple plants. Studies have documented transfers of carbon and nutrients, although the scale, direction and ecological significance of these transfers in natural forests vary and remain areas of active research.
Simard later used the term “mother trees” for some of the largest and oldest trees in a forest, especially when they are highly connected within mycorrhizal networks. Experiments have suggested that such trees may influence the establishment and resource environment of nearby seedlings. However, describing them as literal “nurturing mothers” that intentionally care for younger trees goes beyond what the evidence can demonstrate. The biological relationships are real; the human metaphor should remain a metaphor.
In her book Finding the Mother Tree: Discovering the Wisdom of the Forest, Suzanne Simard presents a vision of forests as complex systems shaped by competition, cooperation and fungal connections rather than as simple collections of isolated trees. Her “mother tree” metaphor has helped many readers see forests as networks, while also prompting vigorous scientific discussion about how far the metaphor can be taken.
Why this research matters for forest protection and management
In a 2020 report by ICI Radio-Canada, Suzanne Simard discussed long-term work in British Columbia examining how different levels of tree retention affect regenerating forests. The broader research programme has compared different intensities of harvesting and tree retention to better understand how leaving large trees on site may influence forest recovery.
Simard’s research has focused particularly on Douglas-fir (Pseudotsuga menziesii). Some experiments suggest patterns of resource transfer and seedling response may differ with relatedness, leading to discussion of possible kin recognition or preferential interactions. These results are intriguing, but the mechanisms and their importance at whole-forest scale are still being studied. It is therefore safer to say that retaining large old trees may support structural complexity and regeneration in several ways than to describe a universal nurturing behaviour.
Understanding the role of large, old trees can still be extremely useful. It supports efforts to protect and manage forests with greater ecological continuity and encourages reforestation strategies that consider climate change, local species and genetic diversity rather than simply maximising the number of planted trees. Choosing species and genetic sources suited to future conditions
A lively scientific debate
Suzanne Simard is not the only public figure associated with ideas of tree communication. German forester Peter Wohlleben, author of The Hidden Life of Trees has also popularised the idea of socially connected forests and has argued for less damaging forestry practices, including reducing heavy machinery where it compacts soils and damages roots.
Scientific ideas become stronger when they survive testing, replication and criticism. In recent years, several papers have challenged broad popular claims about common mycorrhizal networks and “mother trees”, a debate also covered by the Canadian newspaper La Presse.
The main points of disagreement concern how confidently we can identify what moves through shared fungal networks and what those transfers mean ecologically. Tree roots can also interact directly, and field studies are difficult to interpret. Researchers continue to debate how strongly network connection predicts seedling survival, growth or support of old stumps.
In short, critics question anthropomorphic language about cooperation, communication and care when the evidence supports physiological exchange but not human-like intention.
So the most accurate position is neither “trees secretly behave like people” nor “forest networks are a myth”. Mycorrhizal associations and resource transfers are well documented; the strength and ecological meaning of broader network-level claims remain under active investigation.
Beyond biology: the felt presence of ancient trees
Science is not the only language people use when they encounter very old trees. Some people describe mature trees as powerful presences—silent guardians shaped by seasons, storms and centuries of change. This is a subjective, spiritual or symbolic experience rather than a biological measurement, but it can still be deeply meaningful.
A broad trunk can give a profound sense of stability; a high crown can open our gaze towards the sky. Around an old tree, some people experience calm, spaciousness, abundance or safety.
Environmental psychology research—including work by Bratman, Hamilton and colleagues (2015)—has found psychological benefits from time spent in natural settings compared with urban environments. Such studies do not demonstrate an effect specific to “mother trees”, but they do support the wider idea that contact with nature can influence stress, attention and rumination.
Beyond measurable effects, some people describe an “energetic signature” around certain trees: a stable softness, a sense of light or support. I hold this as an experiential and spiritual language, not as a scientific claim. For those who feel it, these trees can become living symbols of connection, continuity and belonging.
This meeting point between science, sensitivity and spiritual experience is one of the dimensions we explore during my spiritual forest therapy training 🌿
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