The effect of nutrient stress on developmental instability in leaves of Acer platanoides (Aceraceae) and Betula pendula (Betulaceae)

Studies of developmental stability can provide insights into the amount of genetic or environmental stress experienced by individuals or populations. In the present study, we used young plants of Acer platanoides (Norway maple) and Betula pendula (silver birch), two distantly related tree species with widely different leaf morphologies, to compare the expression of developmental instability in two contrasting environments: one with free access to nutrients and the other with a severely limited supply of nutrients. Using the difference in size between the right and left side of each leaf as a measure of developmental instability, we found no effect of nutrient deficiency on leaf asymmetry, despite large sample sizes (370-380 plants per species and treatment) and evidence for stress-related changes in overall leaf size and plant biomass. Moreover, there was no consistent relationship between individual leaf asymmetry and plant biomass within each nutrient treatment. In view of these observations, leaf asymmetry appears to be a poor indicator of nutrient stress in young plants of Acer platanoides and Betula pendula.