Climate Change Causes Leaves to Shrink

Scientists from the University of Adelaide have discovered that climate change is causing some leaves to shrink in Australia. They discovered this while analysing some herbarium specimens of Narrow-leaf Hopbush from the 1880's and compared them with today's Narrow-leaf Hopbush leaves.

The study revealed that there was a 2mm decrease in leaf width over the past few years. Scientists claim that the major reason behind this decrease is climate change. They have found that there has been a 1.2ºC increase in maximum temperatures in South Australia over the past few decades.

"Climate change is often discussed in terms of future impacts, but changes in temperature over recent decades have already been ecologically significant," said Dr Greg Guerin, scientist at the University of Adelaide, in a statement.

Recently, researchers across the globe have found that climate change has led to a decline in many species such as turtles, pandas and tigers. It is one main reason for ice loss in the Antarctica. Now scientists have found it has also shrunk leaves by 2mm.

Dr Guerin says climate change is driving adaptive shifts within plant species and leaf shape has demonstrated adaptive significance in relation to climate. The results indicate that leaf width is closely linked to maximum temperatures, and plants from warmer latitudes typically have narrower leaves.

"Climate change is driving adaptive shifts within species, but research on plants has been focused on phenology. Leaf morphology has demonstrated links with climate and varies within species along climate gradients," says Dr Guerin in the Biology Letters journal.

Some Australian plant species have greater potential to respond to and cope with increasing temperatures than others. It is important to understand how plants cope with changing climates, because species that are more adaptive to change may be good candidates for environmental restoration efforts, say scientists.

"Other species in the region have less potential to adapt. These species may rely more heavily on migration - moving from location to location where the climate is favourable - but this can be problematic in a landscape fragmented by human activity," Dr Guerin concludes.