Science to assist the restoration of American chestnut to Vermont. Paul G. Schaberg Kendra M. Gurney Gary J. Hawley John B. Shane

Transcription

1 Science to assist the restoration of American chestnut to Vermont Paul G. Schaberg Kendra M. Gurney Gary J. Hawley John B. Shane

2 Past: American chestnut ruled! Major component of eastern forest Fast growth, large, extremely rot resistant High-value timber species Nuts valuable to wildlife/livestock/people Tannins used in tanning leather Culturally significant

3 Past: Historic Range

4 Past: Chestnut Blight Blight first identified in New York in 1904 Fungus (Cryphonectria parasitica) girdling canker Spread quickly, functionally wiped out chestnut as overstory tree by 1950 s

5 Past: Restoration Attempts Cultural methods - tree surgery, fungicide, forest gap barriers Identifying natural resistance among American chestnuts Hypovirulence Breeding

6 Past: Breeding Methods Hybrid breeding American chestnut x Chinese chestnut Hybrid/backcross breeding American American chestnut x chestnut Chinese chestnut Offspring backcrossed with American chestnut Intercross resistant Chinese offspring chestnut

7 Present: TACF Backcross Breeding VT

8 Present: Restoration in VT Tailor restoration to VT conditions Most breeding material from heart of range Very few mother trees from VT Genetic diversity, capture local genetics/adaptation, and potentially augment cold hardiness

9 Present: Filling the VT Gap Locate new VT mother trees Include in breeding program Identify potential future restoration sites Conduct controlled pollinations in VT Cold tolerance trials Look at American chestnut, hybrid/backcross chestnut, and native competitors Point person: Kendra Gurney!

10 Present: Locating Vermont Chestnut Contact state and private foresters, ecologists, and researchers Field visits Location, ID, pollination potential, blight status, basic measurements Spatial database for future pollination and eventual restoration

11 Present: Locating Vermont Chestnut Current inventory: ~30 trees inventoried ~14 sites ~5 sprout sites (lesser priority)

12 Present: Controlled Pollination

13 Present: Harvest Results Controlled Pollination Results Tree Berlin, Jr Colchester 1 Berlin, Sr Colchester 1 Colchester 2 Year Hybrid/Backcross Nuts Harvested Goal: 100 seedlings per source Non-viable vs. viable seed

14 Present: Cold Tolerance Tests - Shoots Valley View Farm, Shelburne GMNF Planting, Sunderland American & Hybrid/Backcross American & Hybrid/Backcross Compared to native sugar maple and red oak beside Valley View planting

15 Present: Cold Tolerance Tests

16 Dialy Air Temperatures from Fall Spring 2007 Temperature Data from NOAA National Climate Data Center, collected at Burlington International Airport Winter Sampling 2/12/2007 Temperature (C) Fall Sampling 11/13/2006 Spring Sampling 4/30/ /1/06 10/1/06 10/31/06 11/30/06 12/30/06 1/29/07 2/28/07 3/30/07 Date Maximum Temperature (C) Minimum Temperature (C) 4/29/07 5/29/07

17 Mean Shoot Cold Tolerance (Tm) Measured in Shelburne, VT Species/Seed Source -45 B -40 A A -35 B A Mean Tm Fall Winter Spring 0 American chestnut A and B are signaficantly different at p < Shaftsbury Dummerston Maple Oak

18 Mean Winter Shoot Cold Tolerance (Tm) for Three Chestnut Sources in Shelburne, VT Seed Source -37 A -36 B Mean Tm -35 B American chestnut Shaftsbury Dummerston A and B are signaficantly different at P =

19 Mean Terminal Shoot Winter Injury in Shelburne, VT by Species/Seed Source, % 90% Percent (%) Damage 80% 70% Van der Waerden P < % 50% 40% 30% 20% 10% * * Maple Oak 0% American Shaftsbury Dummerston Species/Seed Source American Shaftsbury Dummerston * No damage observed on these sources near chestnut

20 Present: Winter Injury Assessment Terminal shoot dieback Shrub-like growth habit

21 Mean Shoot Cold Tolerance (Tm) in Shelburne and Sunderland, VT Site Location by Season Temperature (C) * Fall * = significant difference in Tm at p Winter Shelburne Sunderland Spring

22 Minimum Daily Temperatures Fall 2006 Temperature Data from NOAA National Climate Data Center, collected at Burlington International Airport in Burlington, VT and at W. H. Morse State Airport in Bennington, VT Fall Sampling 11/13/2006 Temperature (C) /1 9/8 9/15 9/22 9/29 10/6 10/13 10/20 10/27 Date Burlington Bennington 11/3 11/10 11/17 11/24

23 Present: Seed Cold Tolerance Pure Chestnut C ) -7 Tm ( Pure American, backrossed, red oak No significant differences All intolerant to ambient air temperatures Oak Species Hybrid Chestnut

24 Present: Seed Cold Tolerance 0 Maine New York Pennsylvania Maryland Virginia Kentucky Tennessee C ) Tm ( Source Different sources of American chestnut Significant differences among sources (P = 0.043) Potential for increased tolerance through breeding

25 Future: Cold Tolerance Implications Limited cold tolerance complicates restoration Augment seedling shoot cold tolerance Cultural practices - winter protection and fertilization options Genetic selection for increased cold hardiness

26 Future: Climate Change Implications Warmer climate predicted northeastern US: Winter warming of 2-3 ºC, with nighttime temperatures warming more than daytime Future VT climate like Maryland Georgia? Decreased snow pack and days with snow on the ground Potential Consequences of Climate Variability and Change for the Northeastern United States, National Assessment Synthesis Team, USGCRP 2004 and Climate Change in the US Northeast, NECIA 2006

27 Future: Climate Change Implications Warming beneficial to seedling/seed winter survival? Species shift from beech-birch-maple to oakhickory (and chestnut?) Decreased snow pack potentially problematic Less insulation for shoots of snow-buried seedlings More soil freezing and damage to buried seed

28 Future: Climate Change Implications Wildlife benefits annual mast Timber and biomass Carbon sequestration Fast growth, large size/volume, rot resistance

29 Acknowledgements Kendra Gurney, Gary Hawley, John Shane, Mark Starrett, Chris Hansen, Josh Halman, Kelly Baggett, Paula Murakami, Homer Eliot, Sam Nijensohn, John Bennink, Michelle Turner, Brian Keel, Aubrey Choquette, Paul and Eileen Growald, Leila Pinchot, Fred Hebard, Marshal Case, Russ Barrett, Art and Dot Lavigne, Don Tobi, Martha Head and WVPD, Brett Huggett, TACF, and everyone who reported American chestnut in VT!! USDA Forest Service, USDA CSREES McIntire-Stennis Forest Research Program

30 Questions? Got chestnuts? Contact