Reforestation and lianas

I read an interesting article on Mongabay.com about Lianas today.  The gist of the article is that Lianas have been thought to be tree killers (which they are) but could possibly be useful in restoring a forest if planted correctly.  The article argues that they could improve soil quality and create shade, two things desperately needed in tropical reforestation projects.

I worked on a reforestation project for a while, not where Lianas are native but in Madagascar.  One of the biggest problems in tropical rain forests is that the soil is actually quite poor; most nutrients and biological components being held in plant life.  So when a piece of rain forest is cleared, any residual soil nutrients wash out very quickly, leaving parched, dead soil.  In Madagascar we solved this problem in a manner I strongly disagreed with; by planting non-native Acacia trees.  These are fast growing, nitrogen-fixing trees, so they do the same theoretically as the Lianas, they create shade and healthier soils for further succession of forest plant life.  The problem is there is no long-term research on the effect of Acacia in Madagascar.  It’s my opinion that the trees are as likely to damage the ecosystem even more than deforestation in the long run.  The point being, if you can do the same thing with native plants (like Lianas in South America) I say it’s worth a good trial.

There is some evidence that Acacia has a potential to become highly invasive and spread un-checked, especially as deforestation occurs, creating environments where it can out compete native trees.  It might be harder to do reforestation with only native plants and certainly it would take longer and be more labor intensive.  The root of the problem is that our funding was based only on the number of trees planted and our goals reflected it.  As time went on the number of Acacia and other non-native pioneers being planted only increased as they were faster growing and easier to take care of.  The point of all this is to say, it may seem like you need to do as much as possible in a world that is increasingly affected by habitat loss and extinction but sometimes doing a small thing with deep consideration and care is best.  You can read my full Mongabay.com article about reforestation in Madagascar here.  In the end it is my opinion that when it comes to conservation, there are no quick fixes but hard work and diligence are needed to solve the problems facing our world.