Rainforest Restoration of an Abandoned Orchard

Posted: October 24, 2013

We have just welcomed our students back from the mid-semester break. Hopefully, after snorkeling on the Great Barrier Reef, visiting Magnetic Island, or sampling the pastries in the best cake shops in Melbourne (actually, rumour has it that these may be the best cake shops and cafes in Australia—no, I’m not jealous at all…), the students are now re-energised and ready to study rainforest restoration!

We made a start on this topic before the break with a field exercise on rainforest restoration in an abandoned lychee orchard at the Centre for Rainforest Studies in Australia. I’m not sure who planted the lychee orchard, but old aerial photographs indicate that it went in somewhere between 1986 and 1992 and was abandoned some time before 2002—without producing a single lychee fruit (the explanation I was given for this was that the winters here are too wet for the lychee trees to successfully set fruit). We spent Week 7 of the semester wandering through the old plantation to see how many native trees and seedlings had recruited since the plantation was abandoned.

Overall, the students found more native trees and seedlings on the side of the abandoned orchard that was closest to the boundary of the Wet Tropics World Heritage Area and the old-growth (though previously-logged) rainforest. The students also found that many of the native trees in the abandoned orchard were growing beneath the canopies of the lychee trees—possibly because the lychee trees provide a convenient place for frugivorous birds to perch and “disperse” the seeds they’ve eaten.

The next step will be to set up some long-term experiments to see whether different restoration techniques might help speed rainforest recovery in the abandoned orchard—and for future students to build on the data set collected by our students this semester!