Fitting a dendrometer band around a Manilkara tree.
Reading the band with a caliper to see how much the tree has grown.
The forest management systems used by communities in the Selva Maya are very good - but there is always room for improvement. The growth data used to calculate harvest volumes and rotation lengths, for example, are based on government estimates. This could cause big problems. If the growth estimates are too high, you'd cut more wood than you should. If the growth estimates are too low, you'd be leaving valuable timber in the forest. Better to actually measure how fast the trees are growing.
In 2005, with support from the Overbrook Foundation, we started an extensive study of tree growth in the Selva Maya using stainless-steel dendrometer bands. The research included 21 timber species (in addition to mahogany) and invoved 7 forestry ejidos. The communities banded almost 3,000 sample trees. As far as I can tell, this is the largest community-based study of tree growth ever initiated in the tropics.