Theory 56/Mountain & Alpine/Elevation gradients
Diversity Peaks Mid-Slope
The claim
Mountain diversity peaks at intermediate elevation because both area and climatic favourability are maximised there rather than at the base.
01Mechanism
Low elevations are hot and dry, high ones cold and small in area; the product of area and favourability peaks between.
02Prediction
Richness should peak mid-elevation.
03Refutation
Monotonic decline with elevation would remove the area term.