The rate at which environmental factors change often varies overtime. Phenotypic plasticity is one solution organisms have adopted to cope with such variability. Since developmental plasticity takes time, mechanisms that assist plants to estimate future growth conditions should be selected for. Absolute values of environmental factors are good predictors for future conditions only when the rate of change is constant among growing seasons. But if this is not the case, sensitivity to gradients is expected. We tested whether plants can preempt future growth conditions by responding to both absolute values and the dynamics of resource availability. Pea plants were grown in a split-root choice experiment where different roots of the same plant experienced both constant and dynamic (increasing or decreasing) resource levels.

Results/Conclusions

Plants invested significantly more in roots growing in improving habitats rather than deteriorating ones. This was true regardless of absolute resource levels, implying that they developed according to future rather than prevailing conditions.