Highway to the canopy

Stefan Schnitzer has noticed that lianas (woody vines) are all over the place in tropical forests!  And he is not the only one.  Many ants, mammals, and birds have noticed them and are making good use of them.  Stefan has been monitoring the growth of lianas in the forest for the past few years and has been able to compare his data to observations made by other scientists. Stefan has found that the amount of lianas in tropical rain forests has increased.  You may wonder, why does this matter? (We did).

Well it might matter if lianas win the getting-to-the-sunlight competition that they have with trees. They take up space in the forest but store less carbon. Why is carbon important?  To put it simply, extra carbon in the air (instead of in plants) is leading to Global Climate Change.

One of the experiments Stefan and his research team have recently set up is to compare what happens when you cut all of the lianas in one plot and compare it to a plot that has been left alone. His team has prepared 16 60 x 60 meter plots.  They labeled, measured and plotted every tree and liana growing in the plots – there were thousands of them!  Eight of the plots have been left untouched.  This is the control plot. The other eight had the lianas cut out of them in a 80 x 80 meter area (since lianas have such a long-distance growth pattern they cut 10 extra meters on each side of the square so that they could get all of the lianas that were growing into the plot). Of course when you cut the lianas, they still have energy and life in the roots, and so they try to grow again.  Every two months someone goes through the plot and cuts the new shoots.  They also walk through the control plot so that the only difference in the two plots is that the lianas have been cut (not that someone is walking through one plot, but not the other.)

Maybe this study will show the effect lianas have on tree growth.  Other people are interested in what happens to the ecosystem when lianas are removed. For example, there is a research groups that is using Stefan’s plots to trap mammals, and photograph mammals that walk by at any time of the day or night.  These two groups want to see if animals use the forest differently if there are no lianas. Other groups are studying how changing the trees and vines that grow will affect bird communities, ant communities and invertebrate communities.

I am sure that a good deal of exciting results will come from this work – much of it will probably lead to even more questions then they started with!

Do you think that taking lianas out of the forest help save the forest or harm the forest, or something else altogether? Could it change the air we breathe?

What would you like to find out about these plots? Have you seen lianas where you live?