An environmental scientist wants to compare the rate of decomposition of fallen Scots pine needles and silver birch leaves. They place 45 g of Scots pine needles in an incubator maintained at 28∘C28^\circ\text{C}28∘C with a low relative humidity of 30%. Simultaneously, they place 95 g of silver birch leaves in an identical incubator maintained at 14∘C14^\circ\text{C}14∘C with a high relative humidity of 80%.
Explain how this investigation could be improved to allow a valid comparison of the rate of decomposition.
