Forcasting Shortleaf Pine Seed Crops in the Ouachita Mountains (2004)Shelton, M. G., & Wittwer, R. F. (2004). Forcasting Shortleaf Pine Seed Crops in the Ouachita Mountains. Southern Research Station, General Technical Report SRS-71. Retrieved from http://www.treesearch.fs.fed.us/pubs/6619 We field tested a cone-rating system to forecast seed crops from 1993 to 1996 in 28 shortleaf pine (Pinus echinata Mill.) stands, which represented a wide range of stand conditions. Sample trees were visually assigned to one of three cone-density classes based on cone spacing, occurrence of cones in clusters, and distribution of cones within the crown. Classification took < 1 minute per tree, permitting a large number of trees to be evaluated rather than making precise counts on a few trees. The stand’s mean cone rating and basal area explained 82 percent of the variation in sound seed production; however, the developed prediction equation had a large root mean square error (257,000 seeds per acre). Our cone-rating system did well in forecasting the poor and good seed crops. However, more precise determinations of both cone and seed density are probably warranted when seed crops are forecast to be marginal for stand regeneration http://www.treesearch.fs.fed.us/pubs/6619
|
