William Burkman Christopher M. Oswalt Analysis completed with contributions from:

1. Combining historic and contemporary fia data to assess long-term trends: The longleaf pine footprint in the south William Burkman Christopher M. Oswalt Analysis completed with contributions from: Christopher W. Woodall Horace W. Brooks

2. Outline • Brief background • Methods of Investigation • Results • Latitudinal/Longitudinal shifts • Central range thinning • Highlights from FIA assessment • Comments on outlook Longleaf Pine in the Southern United States Photo – Stephen F. Austin

3. Background • Longleaf pine forests were once – one of the most extensive ecosystems in North America (Landers and others 1995), occupying about 92 million acres in the southeastern United States (Frost 2006). • Only a fraction of this longleaf pine remains today. • The remaining longleaf pines are scarce, compared to their historical extent, and are spread among eight southern states in largely fragmented stands (longleaf pine is known to historically and currently occur in southeastern Virginia, however does not currently occur in the Forest Inventory and Analysis sample). • Numerous studies recording the decline of Longleaf pine • FIA Assessment of Longleaf Pine in the South (Oswalt et al. 2012) • Use of historical data was needed for comprehensive assessment of changes Longleaf Pine in the Southern United States Increase to 8.0 million acres

4. Change in longleaf dominated stands – 1970’s to 2010 Longleaf Pine in the Southern United States 1970’s 2010 15 percent 7 percent Longleaf pine = 3,300,717 LLP – Oak = 984,637 Oswalt et al. In Press

5. Longleaf Pine in the Southern United States

6. Longleaf Pine in the Southern United States

7. Methods • 1970’s vs. 2010 • Periodic, asynchronous inventories vs. Annual, continuous inventories • Total Plots Longleaf Pine in the Southern United States

8. Methods – Forest type definitions • Longleaf pine - 141 • Longleaf pine occurs as a pure type comprises a majority of trees in the overstory • Associates – Slash, loblolly and shortleaf pine, southern red oak, blackjack oak, water oak, persimmon, and sweetgum • Sites – those areas that can and do burn on a periodic basis – usually occurs on middle and upper slopes with low severity brush or hardwood competition • Longleaf pine – Oak - 403 • Associates – Longleaf pine and scrub oaks – primarily turkey oak, bluejack oak, blackjack oak, and dwarf post oak • Sites – Common on sandhills where soils are dry, infertile, and coarse-textured Longleaf Pine in the Southern United States

9. Graphical descriptions of forest types Longleaf Pine in the Southern United States Longleaf pine forest type Longleaf pine – Oak forest type

10. Combine Outer Range analysis techniques from Woodall et al. (2009) with longitudinal band analysis techniques from Kai et al. (2012). • Woodall et al. (2008 and 2009) describes the inherent difficulty in comparing historical and contemporary FIA Inventories. • Here we overcome those difficulties by: • Greater electronic availability of historical data • Not examining seedlings • Greater similarity in periodic inventories within a single region • No attempt made at linking causality to long-term phenomenon (changing climate) that would require a large span of time between inventories Longleaf Pine in the Southern United States

11. Methods Longleaf Pine in the Southern United States Defining the “Outer Range” (sensu Woodall et al. 2009 - also see Zhu et al. 2012) 90th & 10th percentiles calculated based on 1970’s presence Eastern, Western, Southern, & Northern Outer Ranges (EOR, WOR, NOR, & SOR, respectively). Primary focus was on “Outer Ranges” – The “heart” of the LLP range was investigated further for changes in area et al.

12. Methods • Comparison between decades of: • Mean latitude by 1 degree longitude classes • Mean longitude by 1 degree latitude classes • Welch’s two-sample t-test • Comparison across decades of: • Mean area • Mean biomass • Welch’s two-sample t-test • Transformations • Presentation of back-transformed metrics Longleaf Pine in the Southern United States

13. Mean Latitude – Longitude for 1970 & 2010 Longleaf Pine in the Southern United States

14. Changes in Latitude Longleaf Pine in the Southern United States Northern Outer Range Southern Outer Range

15. Changes in Longitude Longleaf Pine in the Southern United States Western Outer Range Eastern Outer Range

16. Longleaf Pine in the Southern United States

17. Longleaf Pine in the Southern United States

18. Potential “Thinning” Longleaf Pine in the Southern United States

19. Potential “Bright side” of the story Longleaf Pine in the Southern United States LLP forest type across the South (excluding VA)

20. From the FIA Assessment – Change in Diameter Distribution Longleaf Pine in the Southern United States

21. Challenges to Using Historical Data • Electronic Availability • Regional differences in temporal richness of available data • SRS – 1970’s • NRS – 1980’s • RMRS – 1980’s • PNWRS – 1990’s • Temporal Consistency of Variables • Great example – collection of seedling data • Many others • Temporal Consistency of Inventory Design • Multiple designs • Changes, Changes, Changes • None of these challenges are insurmountable. • However, all of these challenges impact the strength of inferences that can be made and the confidence in those inferences. Longleaf Pine in the Southern United States SC 1968 also available electronically VA 1984 renamed 1985

22. CONCLUSION • Combination of Woodall’s “Outer Range” and Zhu’s “Longitudinal Bands” • Longleaf pine “footprint” has contracted since 1970 • Most significant contraction in Northeast of range • “Rebounding” from low may be occurring • FIA data and analyses good at helping identify large-scale conservation issues – not so good (in many cases) at identifying cause and effect Longleaf Pine in the Southern United States

23. William Burkman Christopher M. Oswalt bburkman@fs.fed.us coswalt@fs.fed.us • 865-862-2073 865-862-2068 • Knoxville, TN Knoxville, TN