Why Needle Length Matters

Plants actively manage the water flowing through their limbs – and leaves of all shapes and sizes play a central role. Indeed, plants are known to tailor their leaves to optimize water use in different environments. For example, conifers produce shorter leaves in dry soils, higher elevation and at the tops of trees. Until now, most studies assumed that when pine trees grow shorter needles it's because the lack of water restricted leaf growth. But a new study published in Annals of Botany has...