It's something that we learn to notice, speculate on, and eventually learn to ignore-- the hordes and hordes of eucalyptus trees found on the UCSD campus. They're everywhere and in every college. We pass by them every day, make wisecracks about their uniform dispersal, and bemuse ourselves with the Talking, Singing, and Silent individuals. These more artificially-preserved trees aside, the groves of trees on our campus have become living walls of greys and greens that we have come to chalk up as all one genus of plant. Of the thousands of trees currently growing on the UCSD campus, more than 220,000 are of the genus eucalyptus. However, how many distinct species of eucalyptus can be identified in their midst?
Photo courtesy of Dr. Heather Henter
No less than 18 different species of eucalyptus sprout around us. If you look closely, you might be able to spot the more obvious differences-- some have smooth bark while some are rough; some are white-grey while some are ashen and almost black. Which ever way you spin it, the eucalyptus are more diverse than we give them credit-- in Australia, where the trees are native, there are over 700 different species that have evolved over centuries of geographical isolation. But why in the world would our campus in sunny San Diego be covered by some smelly, invasive tree from across the ocean?
Back when UCSD was even conceived as an idea, the grounds where our campus currently stands was a eucalyptus tree farm. In the 19th century, eucalyptus was prized for its quick growth time and ability to thrive in San Diego's weather conditions. It was used both medicinally and for construction during a time of "timber famine" (however, the construction plans were later realized to be lacking in long-term strength). Consequently, this eucalyptus farm was also a place for alcoholics and county prison inmates to "sober up" and contribute back to society during their incarceration. After the interest and enthusiasm for eucalyptus died down, the trees remained in the area until the construction of UCSD in the mid 1900s. 95% of the original trees from the farm have been deforested or chopped at least once, save for a few exceptions-- the trees next to the Main Gym and Urey Hall have survived the last century without ever once being pruned or cropped.
Next time you see a eucalyptus tree on campus (which I can assure you will be quite soon), take a look around and see if the trees around it are similar or not. You'd be surprised as to how different things are once you start to pay attention. :)