More recently, the assumption of tree growth being limited by
a single nutrient species was challenged by the ‘non-Liebig’ concept
of nutrient limitation postulating that different growth processes
should be limited by the shortage of different nutrients resulting in
a simultaneous multi-element limitation of plant growth
In fact, there is evidence that K, Mg, Ca or other
elements may also limit the growth of tropical trees under certain
circumstances, but it is unclear how important these factors are in
tropical mountain forests