Impact of adjacency and green-up constraints on wood supply in Georgia, USA

1. Impact of adjacency and green-up constraints on wood supply in Georgia,USA Michal Zasada, Chris J. Cieszewski, Roger C. Lowe, Don Reimer 2nd International Conference on Forest Measurements and Quantitative Methods and Management & the 2004 Southern Mensurationists Meeting Hot Springs, AR, June 15-18, 2004

2. Outline • Where are we? • What have we already done? • Project objectives and assumptions • Results we’ve got so far • Short discussion

3. Georgia • Located in the southeastern part of the United States • 3rd fastest growing state in the US • Total land area: ~150,000 km2 • Population: ~8.6 million

4. Georgia • ~ 9.7 million ha in commercial forests (almost as much as Germany or France) • 66% of the total area of the state • the highest area of commercial forests in the US • growing stock ~900 million m3 (1/3 of Germany or France) • Avg. volume ~100m3/ha & MAI 3.8 m3/ha • annual harvest over 40 million m3 (almost as this in Germany or France)

5. Georgia • Public forests: 7%; practically no commercial utilization • Timber industry: 21%; intensive management, planning, harvest scheduling, … • ~700,000 private owners: 72%; a whole variety of uses, no coordination nor optimization • Changes: more TIMOs

6. Current situation • rapid changes to the US Southeast • harvesting limitations in public forests, especially in the western part of the country • increasing demand on wood from southern region • fast population growth with associated urban and suburban development - shifts in land uses

7. Current situation • research on possibilities of increasing forest productivity from shrinking commercial forest areas • investments in silviculture and g&y research more than doubled growth rates of pine plantations and significantly shortened rotation ages • questions related to the forest resource sustainability

8. Sustainability project • “Long-term sustainability analysis of forest resources in Georgia and assessment of potential effects of riparian zones and other regulatory and business constraints” • Granted in 2001 by the Georgia TIP3 committee • Already in its final stage

9. Sustainability project • Proof of concept • Impact of: • SMZs and RBBs • Intensive management • The final stage: increased resolution, combined multi-source data, spatial analyses

10. Sustainability project • Data: Landsat TM5, Georgia GAP ecological data, Forest Inventory and Analysis (FIA) nationwide inventory from USDA Forest Service, proprietary industrial data, various GIS data available from state sources, published and unpublished research • Simulation tool: Options, a forest estate planning and modeling application

11. Adjacency/green-up constraints • spatial restrictions in harvesting stands bordering previously harvested areas • allow some length of time for establishing a new stand before the adjacent stand can be harvested • may introduce additional costs or loses caused by non-optimal harvest timings • impact on ecological and social functions of forests • help in preventing the forest from windthrows

12. Adjacency effects depend on… • allowable size of forest management blocks before an adjacency rule is activated • length of time an adjacency rule is in effect once it is activated • the parameter(s) used to determine when an adjacency rule has been satisfied (e.g., average height of dominant trees) • the range of silvicultural and harvesting treatments subject to adjacency rules

13. Adjacency effects depend on… • existence of additional constraints or regulations affecting the availability of forest stands for harvest (e.g., SMZs, RBBs, etc) • growth rates of newly regenerated or treated stands relative to the adjacency rule (note that if time is being used, then growth rates are immaterial) • size of the landbase

14. Assumptions Base (“no action”) scenario: • Constant landbase • Current management practices and trends in their transition • Constant harvesting of 42 million m3/year • Constant extent of intensive management (current 30% of all pine plantations)

15. Assumptions • Modifies base (“realistic”) scenario • Constant landbase • Current management practices and trends in their transition • Gradually increasing cut (+50%/50y, from 42 to 63 million m3/year in 2050) • Increasing extent of IMP (30% rate of conversion)

16. Assumptions • Rule 1: neighboring stand can be harvested when a newly established stand reaches the average height of 1.5 meters • Rule 2: regeneration has to be at least 2 meters high, but harvesting cannot take place earlier than 3 years after harvesting of the adjacent stand

17. Results Base scenario, Rule 1, Rule 2: • Volume available for harvesting (sum of volume of all stands that reached or passed their maturity age) • Volume cut • Extent of deferred area and volume

18. Base (“no action”) scenario

19. Base Rule 1 Rule 2

20. Deferred area

21. Deferred volume

22. Modifies base (“realistic”) scenario

23. Base Rule 1 Rule 2

24. Deferred area

25. Deferred volume

26. Discussion • harvesting and constraints pushed harder – more noticeable impact • small impact for large areas, especially when harvesting is way below the resource capacity, • large impact on smaller areas, especially if other spatial constraints are considered

27. Discussion • can affect wood availability in the future, however this depends on the assumed rules • effects can be significant especially with combination with other factors • impact on particular owners, their management and additional costs is can be significant in any case

28. Thank you!