Longleaf pine regional cone production study

The number of green cones per tree produced by mature longleaf pines, at selected sites across the Southern Region, has been recorded during the spring of each year since 1958, beginning first at the Escambia Experimental Forest in Alabama for 8 years and then expanded to include several more sites during subsequent years in Louisiana, Florida, Georgia, South Carolina, and North Carolina. These spring cone counts (during April and May) are used to forecast longleaf pine tree cone production for fall (late October). Annual average cone production is provided for 11 sites ranging from 1958 to 2024 (data collection at most sites began in the late 1960s). Also included are annual diameter at breast height (DBH) measurements collected for 10-50 longleaf pine trees in each of 25 different stands (amongst the 11 different sites), as well as green cone production counts for individual longleaf pine trees in 35 stands from 1989-2024. Data from the 1957-2013 Escambia Experimental Forest Pollen Production Study are also provided, which includes measurements such as annual pollen grain counts, date of highest pollen count, and quality of next year's cone crop based on number of green cones found per tree. Study plans for the longleaf pine seed production study at the Escambia Experimental Forest and the establishment report are provided, in addition to the 2023 and 2024 annual reports for this study, which encompasses several other locations in the Southern Region. Photographs taken at a few of the study site locations are also included.
These data were originally collected to further understanding of the reproductive biology of longleaf pine and to provide useful information to forest managers and nursery managers about current cone crop quality. More recently, these data have been used by researchers who are analyzing the influence of climate change on the reproductive biology of longleaf pine and, thus, factors that may impair the long-term sustainability of this important tree species. These data can also be helpful to forest managers in their decision-making concerning whether or not to implement site preparation via prescribed burning during the period prior to seed fall. Forest tree nursery managers can also use it in planning their longleaf pine cone and seed collection activities. This ongoing study effort will continue generating new data that will be used to annually prepare a technical report, which forecasts longleaf pine cone production for each year, that is widely distributed to interested constituent groups and individuals.
There are many publications containing detailed information about this study, which are provided as cross-references below.