Mother Tree – a large tree within a forest that acts as a centralized hub supporting mycorrhizal fungi that facilitate connection, communication and resource exchange with neighboring trees.
Mycorrhizae – literally means “fungus-root” and is the symbiotic relationship between a fungus and a tree’s roots.
Mycorrhizal network – a vast underground network of mycorrhizal fungal linkages that connect trees to one another.
Mycelium – branching fungal threads (hyphae) that grow from the mycorrhizal root.
Wood Wide Web – a colloquial term for the mycorrhizal network, which was coined for Dr. Simard’s 1997 paper by the scientific journal Nature.
Climate gradient – the change in regional climate across a geographic area (e.g., latitude or elevation).
Source-sink gradient – the mechanism by which solution moves in a mycorrhizal network. Water is absorbed by source cells with high solute concentration, and this increases pressure inside those cells. The solution then moves by mass flow from the source cells under high pressure toward sink cells that have low solute concentration and low pressure. Thus, the movement of solution from source to sink equalizes concentration in the network of cells.
Space for time – this is a colloquial term that represents the scientific approach we are using to understand how climate change may affect our interior Douglas-fir ecosystems. Using this approach, we are examining a range of current forest ecosystem conditions across several regional climates, from dry to wet, and from cool to hot, in order to predict how climate change will affect the forests over time. An example of how we are examining this climate gradient is that we are planting trees that come from and are adapted to hot, dry climates to areas that are cool and wet in anticipation that the cool, wet regions will become warmer and drier in the future.
Forest Resilience – the ability of a forest ecosystem to recover following a disturbance.