1. CARBON SEQUESTRATION BY HYBRID POPLARS IN THE PACIFIC NORTHWEST Dr. Jon D. Johnson Hybrid Poplar Research Program Washington State University - Puyallup Research & Extension Center, Puyallup, Washington poplar@wsu.eduwww.puyallup.wsu.edu/poplar

2. Overview Funded by DOE SBIR through Broadacres Nursery, Hubbard, OR Objectives 1.Determine above- and below-ground carbon sequestration rates for commercial hybrids during an 8 year plantation cycle. 2.Quantify changes in soil carbon as related to plantation development and vegetation. 3.With carbon sequestration, biomass and morphometric data from 1. develop and validate a field method for estimating carbon sequestration rates for hybrid poplar.

3. Why Hybrid Poplar? Fast growing Fast growing Straight stems Straight stems Dioecious (male and female trees) Dioecious (male and female trees) Easily propagated Easily propagated

4. 18 month old tree in Central Valley of California

5. Methods 3 clones growing in eastern Oregon: 184-411, 52-225, OP-367 4 ages: 2, 4, (5), 6 and 8 years old 2 clones growing in western Oregon: 184-411, 52-225 3 ages: 5, 6, and years old 5 trees per clone-age class Above ground biomass & carbon Below ground biomass & carbon Soil carbon at 0-30 and 30-100 cm Fractionated soil C

6. Site Locations + + Dallas Hermiston West East Silty clay loam Sand

10. Above-ground Sampling Standing trees were measured for height and diameter; After felling, stems and branches were processed by whorl All tree parts were weighed in the field and subsamples taken for dry weight conversion and carbon content

11. Stumps were excavated and then roots were separated from stump; each weighed separately and subsamples were taken for dry weight conversion and carbon content Below-ground Sampling

12. Tree Carbon Distribution 6.4 28.1 95.4 7.4 24.3 33.9 77.9 6.4 24 53.3 103.7

13. Carbon Sequestration Rates Total C

14. Summary – Mean Annual Sequestration Rate Total C (Mg/ha/y) Total tree C (Kg/y) 11.2 11.5 20.0 14.9 18.3 7.3 7.5 13.0 9.7 11.9 89.6 92.0 160.0 119.2 146.4 Total C @ 8 y (Mg/ha) 52-225 W 15-29 W OP-367 E 184-411 E 52-225 E Clone/Location

15. 6 samples/tree (pooled); 5 trees /clone6 samples/tree (pooled); 5 trees /clone 2 depths: 0-30 and 30-100 cm2 depths: 0-30 and 30-100 cm Adjacent fields sampled: crop and native vegetation (E)Adjacent fields sampled: crop and native vegetation (E) Fine roots removed, dried and weighedFine roots removed, dried and weighed Boiling water extraction to estimate labile soil C (E)Boiling water extraction to estimate labile soil C (E) Soil Sampling

16. Soil Carbon

17. Labile Soil Carbon (E)

18. R 2 = 0.9763 R 2 = 0.9768 Volume Tree Carbon Predicting Tree Carbon Total C Aboveground C

19. Conclusions Hybrid poplars are capable of sequestering high amounts of C Hybrid poplars are capable of sequestering high amounts of C Soil C increased significantly in hybrid poplar plantations when compared to adjacent crop land (7-82% depending on soil texture) Soil C increased significantly in hybrid poplar plantations when compared to adjacent crop land (7-82% depending on soil texture) Over time, the proportion of labile soil C decreased Over time, the proportion of labile soil C decreased Standing tree C can be predicted with easy to measure parameters allowing for third party verification of C storage Standing tree C can be predicted with easy to measure parameters allowing for third party verification of C storage