Comparing Carapa guianensis Seed Production in 3 Amazonian Forests

This paper is the first part of a project that has the purpose of creating models that help us better understand variation in seed production in Carapa guianensis, a species in the mahogany family. The goal of this paper is to visualize seed production patterns to inform species management. When this study is completed, it will aid local communities harvesting Carapa in projecting revenue from the oil produced from the seeds. Carapa is a masting species, which means it has an intermittent synchronous production of large seed crops. The major suspected causes of variation in seed production are resource acquisition and allocation, while some trees may use masting as a defense mechanism against predators. We compiled data from 2005-2017 in three forests in Brazil, Acre, Amapá, and Roraima, and by using statistical computing language R, we found that Carapa did not have consistent seed production in these forests. In Acre, masting years 2005, 2008, 2011, and 2013 had medians of 73.15, 328.54, 134.80 and 235.90 kg seeds, respectively (Appendix A). In Amapá, the medians from 2012-2016 were 1,481.52, 276.62, 573.52, 1,467.67, and 1135.12 kg, respectively, and those years were the only recorded. In Roraima, masting years 2006, 2007, 2008, 2009, 2011, and 2012 had medians of 312.80, 1016.60, 1919.81, 164.22, 469.20, and 316.71 kg, respectively, with zero median production in 2010 and 2017. These data have variation between years, and in the future, we will work to see what causes this variation and how we can model seed production for revenue projections