Field Testing of Climate Endangered Florida Torreya
"Assisted migration" to Michigan
How far north can this conifer survive in advance of rapid climate change?

   BACKGROUND: At least since the last glaciation of the Pleistocene, the two U.S. species of genus Torreya have been found only in California and along the Apalachicola River of the Florida panhandle. Nonetheless it is postulated that the Apalachicola species of Torreya (T. taxifolia) would have been native to the southern Appalachians and possibly further north during previous interglacials and warm epochs of the Cenozoic.

Torreya Guardians began moving Torreya taxifolia into regrowth forests on private land in NORTH CAROLINA in 2008. Soon thereafter, the effort expanded into field tests in OHIO. In 2014, seeds were planted in two regrowth forests in MICHIGAN. The aim is to ascertain just how far north Torreya can survive (possibly thrive) in today's climate, in expectation that conditions will continue to warm in the decades ahead. There is value in establishing "left-behind" tree species as far north as possible to ensure viability later in this century.

Note how the MAP LEFT shows the Great Lakes creating a diverse patterning of "plant zones" for testing Torreya in the state of Michigan (USDA 2012). Green zones are the warmest places in Michigan.


Free-Planting Successes of Seeds Directly into Forests

Editor's note: A number of volunteers have had success with out-planting potted seedlings into Michigan landscapes and reporting thrival through the winter. Featured first are those who are testing whether all phases of the Torreya lifecycle, beginning with germination, can occur in Michigan with little or no human assistance. The first successes were reported by planters who free-planted in April of 2017. The key to their success was the discovery gleaned from a dozen previous planters, who learned the hard way that the only way to deter rodents from harvesting the seeds is to bury each seed at least 4 inches deep.

LEELAUNAW PENINSULA (Empire, MI)

   Spring of 2017, Liana May contacted Torreya Guardians regarding possible planting of Torreya seeds on 40 acres of forested land (sugar maple, beech, ash) on upper slopes of a large end moraine. The land has a conservation easement and is nearby thousands of acres of private and national park forested lands. The Leelanau Conservancy approved the planting of seeds in March 2017.

April 2017 Connie Barlow mailed 240 seeds from the 2016 Medford Oregon ex situ harvest. Liana reported by email 15 April 2017: "Planted most of the seeds out today in a warm thunderstorm, eight groups across three locations with different aspects and slightly different wetnesses. I planted 25 in pots as well. Since there were so many mole tunnels even on the steepest slopes, I planted all seeds 4 to 6 inches in depth. I'm going to raise the potted ones at my house and see how they germinate, and if they do well I'll plant them out with tree tubes."

During a site visit Connie Barlow made 26 July 2018, 3 tiny seedlings were documented by video:

Go to Leelanau Peninsula torreya webapge for the site visit information and video, as well as future reports.


CAPAC, MI (in thumb): In April 2017, Torreya Guardians sent Paul Camire 200 Florida Torreya seeds from the autumn 2016 Medford OR ex situ harvest. Paul has "a 45-acre forest, and with the loss of the ash trees to the emerald ash borer I am looking to replant with conifers. The woods has white oak, beech, linden, red oak, swamp white oak, witch hazel, etc." Paul has also been experimenting with Giant Sequoia, Franklinia, and American Chestnut.
     July 2018 Paul reported the first tiny seedlings: just three at that time. See photos and ongoing documentation at Capac MI torreya webapge. Crucially, he planted all of them 4-6 inches deep, which seems to be the key to success.


Miscellaneous Plantings in Michigan

Editor's note: Any seeds planted prior to 2017 would have been shallow planted, which we later learned was a guarantee of seed-predation by rodents. As in science, "negative results" are crucial to report, so these 100% losses are among the examples listed below.

ALPENA, MI: In spring of 2014 Halsey Barlow planted 40 seeds on the property of her parents (Bill and Peggy Barlow) along the Lake Huron shore (barely zone 5b). Provenance of seeds: 4 from 2012 harvest, 34 from 2013 harvest, 2 from Mt Olive NC tree 2013, 2 from Clinton NC tree 2013, 2 (underripe/sticky) from Spencer NC. OUTCOME: No seedlings visible in subsequent years.

LUDINGTON (Wallhalla), MI: July 2015 Connie Barlow delivered 1 potted eedling from the 2014 harvest to the property of Julia Chambers. This was followed in November 2015 by 40 seeds mailed from our 2015 harvest. Small forest acreage on the property, but it is next to national forest land. Dominant canopy species are maple and oak. OUTCOME: No seeds germinated, but the seedling is still alive.

LUDINGTON, MI: In September 2014, Connie Barlow free-planted 30 T. taxifolia seeds from the 2013 harvest directly into the soil of regrowth forest (oak-maple-beech canopy, with some intermixed hemlock) near the Lake Michigan shore of the lower peninsula (property of Dave and Chrissy Hall). She posted a VIDEO of her planting. OUTCOME: No seedlings visible as of 2018.

MUSKEGON (Montague), MI: Property of Peter Bane and Keith Johnson (permaculturalists in Montague, north of Muskegon). Sept 2014 Connie delivered 40 seeds from the 2013 harvest. In March 2017 Peter Bane reported, "We have successfully sprouted at least half a dozen Torreya trees in our unheated hoophouse, where they went through a minimum temperature of 8F this winter and seem not to have suffered at all. We'll be looking to plant them out later in the year, after weather is a little more settled." June 2018 Peter reported that all their outplanted seedlings had thrived through their first winter.

TRAVERSE CITY, MI: In June 2015, property owner Andrew Hogarth and Connie Barlow free-planted 100 T. taxifolia seeds from the 2014 harvest directly into the soil of regrowth forest southwest of Traverse City (barely plant zone 6a). All seeds were shallow planted. The canopy was largely red oak and sugar maple, with some hop hornbeam as subcanopy. OUTCOME: Andrew and Connie joined for a site visit again in July 2018; no seedlings were visible.




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