A 50-Year Retrospective of the Forest Productivity Cooperative in the Southeastern United States: Regionwide Trials
Abstract In 2019, the Forest Productivity Cooperative (FPC) celebrated its 50th anniversary. The mission of the FPC is and has been creating innovative solutions to enhance forest productivity and value through the sustainable management of site resources. This industry-government-university partnership has generated seminal research with sweeping implications for increasing productivity throughout the southeastern United States and Latin America. To commemorate this semicentennial, we highlighted some of the pivotal findings in the southeastern United States from the past 50 years derived from our large, regional experiments: regionwide trials. Study Implications: Fifty years of research have yielded substantial management implications for intensively managed loblolly pine in the southeastern United States. Some of our most impactful findings are the following: our generalized fertilization rate of 200 lb ac−1 elemental N and 25 lb ac−1 elemental P has been found to increase growth on most plantations in the region when applied at or before midrotation, whereas the addition of K and micronutrients was found to be important on the Pleistocene Terraces. Stands with a leaf area index (LAI) less than 3.5 will respond to fertilization, increasingly, so the lower the initial LAI. Our long-term site preparation studies demonstrated the importance of pairing optimal site preparation with fertilization and that subsoiling and tillage typically yielded lesser gains than fertilization and vegetation control at establishment. Fertilization tends to be more important to growth responses at midrotation than onetime vegetation control treatments, but an additive response when the two treatments are applied together is generally experienced. When fertilization is paired with thinning, the rate of postthinning diameter growth is accelerated.