A research world under glass: plants, survival, and a changing climate. PART 1 of 3 - Rainforest and desert plant traits

A walk through Biosphere 2 offers an insight into important differences between plants found in rainforests and those that grow in deserts. These differences reflect adaptations to extremely different environmental conditions. How these differences will affect the survivability of plants under changing conditions with climate change is not fully understood. 

One of the most obvious differences between rainforest and desert plants can be seen in their leaves. The banana plant, for example, a native from Southeast Asia’s rainforests, has leaves that can measure more than ten feet in length. Not all rainforest plants have leaves that large, of course, but the banana plant is reflective of the larger leaves that are commonly found on rainforest plants. Larger leaves suggest that many plants in rainforests are not adapted to conserving water but rather to using copious amounts of it. In addition, many plants in rainforests (including bananas) are often found in the understory and may need additional light. Their large leaves allow them to collect the more of the light that trickles down through the upper canopy. 

Conversely, desert plants employ quite different tactics aimed at avoiding water loss. Here, leaves tend to be small, which reduces the surface area to a minimum. Desert plants may also have leaves with thick, waxy cuticles or that are leathery in texture while others have leaves that are hairy. Some have even gone so far as to modify their leaves into spines, reducing water loss even further. These different strategies suggest that desert plants receive sufficient, if not too much, light, but need to reduce water loss due to lower precipitation and humidity levels.