1. Center for Advanced Forestry Systems 2014 Meeting Do Below Ground Processes Explain Differences in Growth, Productivity and Carrying Capacity of Loblolly Pine? FPC RW20 CAFS 14.49 Thomas Fox – Virginia Tech Jose Stape – North Carolina State University

2. RW20: Silviculture x Density x Genetics Center for Advanced Forestry Systems 2014 Meeting Sites in Virginia, North Carolina and Brazil

3. Coastal Plain Site Bladen Lakes State Forest, NC Wood NPP = 10 Mg ha -1 yr -1 Piedmont Site Reynolds Homestead Center, VA Wood NPP = 5 Mg ha -1 yr -1 Santa Catarina Site Renova Forest, Brazil Wood NPP = 20 Mg ha -1 yr -1

4. Silviculture: Operational vs Intensive Piedmont VA

5. Genotype Differences in Crown Dimensions and Leaf Area Center for Advanced Forestry Systems 2014 Meeting Variety #3 Variety #2

6. Stem Volume Growth and Leaf Area Center for Advanced Forestry Systems 2014 Meeting

7. Differences in Leaf Level Physiology Do Not Explain Observed Differences in Growth Center for Advanced Forestry Systems 2014 Meeting Rates of Photosynthesis, Respiration and Water Use Efficiency are Similar in these two stands

8. Hypothesis: Center for Advanced Forestry Systems 2014 Meeting 1. Below ground differences in soil nutrient availability, root nutrient uptake and belowground carbon allocation may explain differences in productivity - Among silvicultural treatments - Among genotypes - Among different regions 2. Seasonal-related growing conditions may also affect total C fixation and partitioning 3. Ultimately may affect carrying capacity of sites for pine.

9. Light Interception Growth Efficiency Partitioning Silviculture - Site Resources - Leaf Area Silviculture Harvest Slash disposal Cultivation Tree breeding Vegetation control Fertilization Thinning Resources Light Nutrients Water Temperature CO 2 O 2 Leaf Area Site Climate Geology Soils Forest Productivity

10. Root Growth – Coarse Roots Center for Advanced Forestry Systems 2014 Meeting

11. Root Growth – Coarse Roots Brazil Center for Advanced Forestry Systems 2014 Meeting

12. Root Growth – Fine Roots Center for Advanced Forestry Systems 2014 Meeting

14. Carbon Allocation – Soil Respiration Center for Advanced Forestry Systems 2014 Meeting Measure of CO2 from the soil determines the amount of carbon allocated below ground. Must Separate Heterotrophic Respiration (Rh) due to soil microbes and Autotrophic Respiraiton (Ra) due to roots.

15. Carbon Allocation – Root Exudates Center for Advanced Forestry Systems 2014 Meeting

16. Soil Nutrient Dynamics and Nutrient Uptake Center for Advanced Forestry Systems 2014 Meeting 300N 200N 100N 0N

17. Ecosystem 15 N Recovery – VA Center for Advanced Forestry Systems 2014 Meeting (fine roots, litter, etc.)

18. Center for Advanced Forestry Systems 2014 Meeting SiteUniversity USUniversity BrazilGraduate Students VirginiaVT, NCSU-PhD – Fall 2014 North CarolinaNCSU, VT-MS – Fall 2014 BrazilNCSU, VTUSP, UDECMS – Spring 2015 Loblolly Pine Total C Budget and C Allocation

19. Proposed Research Influence of Site, Silviculture and Genetics on:  Root Growth  Carbon Allocation Patterns  Soil Nutrient Dynamics  Nutrient Availability and Root Uptake  Fertilizer Uptake and Ecosystem Recovery Ultimately Will Lead to Understanding of Factors Determining Differences Productivity and Carrying Capacity in Forest Ecosystems in Different Regions Center for Advanced Forestry Systems 2014 Meeting

20. Why Does Carrying Capacity Change in Other Parts of the Word ? Center for Advanced Forestry Systems 2014 Meeting US South Argentina Hawaii (and Brazil?)

21. Loblolly Pine in South America Increased Carrying Capacity Argentina Brazil