Counting Uvos

Elysa counts and maps "uvos" (Spondias mombin L.) seedlings under one of her sample trees in the Peruvian Amazon in 1985 (see Yield Studies, The Water Was Up To Here, and The Importance of Looking Down). There is so much that I like about this photo. The painted blue tips on the stakes used to grid the area under the crown of the tree. The metal clipboard. The clunky, heavy, yet locally-produced, rubber boots. Elysa's haircut. The huge machete (marked with red bandana) that she is carrying with such insouciance. [NOTE: I still have that clipboard].

The Water Was Up to Here

José Tuanama showing how high up the water came last year (1985) in this floodplain forest. The tree he's pointing to, Number 22, is one of the Spondias mombin trees that was measured for fruit production (see Yield Studies). Wonderful to be gliding through the mid-canopy of the forest in a boat when the Rio Ucayali floods. [NOTE: I can remember scooping up handfuls of Spondias mombin fruits out of the water (and eating them) as we paddled by. The sight of thousands of bright orange fruits bobbing up and down in the water was one of the best parts of studying the reproductive biology of this tree].      

Yield Studies

Knowing how much fruit a tree produces can be a very useful piece of information.  It can give you some idea of how much fruit you can expect to harvest (and sell) from the forest, and it can provide insight into how many fruits you need to leave in the forest so that the tree will continue to regenerate itself. Yield studies can also be used to estimate rates of pollination, fruit set, fruit predation, and a host of other demographic parameters.  Good estimates of fruit production provide the basis for sustainable forest use.  

Unfortunately, we know very little about fruit production by tropical trees, even for valuable species like Brazil nut, mahogany, or rubber. Goes a long way in explaining the currently dismal situation with a lot of wild-harvested tropical forest resources.  The image above shows sample traps in position under a large Spondias mombin ("uvos") tree in Peru to quantify fruit production.  The fruits fall into the traps, the traps represent a certain percentage of the crown area of the tree, you count the former and multiply it by the latter to estimate total fruit yield.  Really not that hard to collect these data, and yet they are so rare. If you want to know the size-specific rate of fruit production for natural populations of Spondias in the Peruvian Amazon, click here. [NOTE: That's José Tuanama shown in the foreground; Umberto (see Umberto Pacaya) is visible in the background to the left. Elysa conducted the yield study of Spondias as part of her M.S. thesis].