Why is a banana leaf a million times bigger than a common heather leaf? Why are leaves generally much larger in tropical jungles than in temperate forests and deserts? The textbooks say it’s a balance between water availability and overheating.
But it’s not that simple.
Research published today as a cover story in the journal Science, led by Associate Professor Ian Wright from Macquarie University in Australia, reveals that in much of the world the key limiting factor for leaf size is night temperature and the risk of frost damage to leaves.