Survivorship, attained diameter, height and volume of three Paulownia species after 9 years in the southern Appalachians, USA

Little is known of the tree and stand dynamics of varied species of planted Paulownia left unmanaged until harvest in the southeastern United States. We sought to remedy this lack of information needed by land managers to make informed decisions by investigating differences in survivorship, attained diameter breast height (DBH), diameter at ground level, total height, tree volume and stand-level volume yields of planted P. elongata, P. fortunei, and P. tomentosa in the cool-moist environment of the southern Appalachian Mountains. After 9 years, combined-species survivorship was only 27.3%. Low survivorship was likely related to several inclement weather events. P. fortunei was significantly smaller in DBH and total height. Three combined-species stem (bole) volume models were developed as functions of (1) DBH squared, (2) the product DBH squared and total height, and (3) the product diameter ground line squared and total height. Mean total volume production of unmanaged stands was greatest for P. elongata and P. fortunei 4 years after planting; by the 9th year, total volume of P. elongata was greater than the other two species. Results of our study provide managers information on productivity of three species of Paulownia that can be used for estimating plantation yields.