Theory 18/Boreal Forest/Treeline advance
Advance Needs Survivors
The claim
Treeline advance is set by the ratio of seedling establishment to herbivory, so a warmer climate without reduced browsing produces no advance.
01Mechanism
Establishment above the treeline requires seedlings to survive; herbivores remove them before they can form a cohort.
02Prediction
Advance should track the ratio.
03Refutation
Advance tracking warming would remove herbivory.