At the Brink of Extinction
The Apalachicola River in Florida's Torreya State Park (January) |
In the 1950s, Torreya taxifolia
suffered a catastrophic decline, the ultimate cause of which is still unexplained. By the mid-1960s, no large adult specimens — which once measured more than a meter in circumference and perhaps 20 meters tall — remained in the wild, felled by what seemed to be a variety of fungal pathogens.
Today, the wild population persists as mere stump sprouts, along the Apalachicola River of the Florida panhandle, cyclically dying back at the sapling stage, such that seeds are rarely, if ever, produced. T. tax thus joins American chestnut in maintaining only a juvenile and diminishing presence in its current range. |
Torreya expert Mark Schwartz observes:
In June 2009, a paper published in the Proceedings of the National Academy of Sciences contained supplementary information that detailed the plight of Florida Torreya. Richardson et al. 10.1073/pnas.0902327106 wrote:
Reclining Specimen #1 at Torreya State Park
Specimen #2 near creek (with bald cypress knees visible), amid American holly tree, beech, evergreen magnolia), January.
Learn about efforts to SAVE Torreya taxifolia from extinction.
"There are probably fewer than 1000 individuals extant in the current distribution and the numbers are dwindling. At last count, there is a single known individual that is producing seeds in the wild (personal observation). Aside from this one individual and the approximately 8 seeds it has produced, there has been no observed seedling recruitment for at least 20, and probably 40 years."
Torreya taxifolia (Cephalotaxaceae) is a dioecious coniferous
tree that is endemic to the bluffs that extend 5Ð10 km eastward
from the Apalachicola River for approximately 35 km in northern
Florida, extending less than a kilometer into Georgia.
During the late 1950s and early 1960s, all adult trees throughout
its range were killed as a consequence of a pathogen outbreak. The current population is likely not 1,500 individuals, likely seeds and seedlings that were viable at the time of the
decline. During the past 40 years, there has been a single
tree that has been observed to have matured into a seed-bearing
adult. It produced 2 seeds. This individual is now dead, and the
seeds produced are presumed dead as well. The agent of the
decline is unknown but is thought to be a fungal pathogen. The current rate of decline is slow. Estimates of growth
and mortality data suggest that it will be at least a century before
the population goes extinct in the wild. Cuttings from 150
trees are currently grown in botanic gardens.
More recently, 2 efforts have begun for the conservation of
this species. Torreya taxifolia has been planted in North Carolina
in an attempt to establish populations in that region (http://
www.torreyaguardians.org/). This effort was done as an indirect
response to climate change. The species is in declining in its
native range with no sign of recovery. Proponents felt that this
species 'belongs' in the region where they relocated it. They also
feel that this intervention is the best chance for the species to
survive, given its condition in its native range.
Specimen No. 1
Bark damage near base of Specimen No. 1. (Notice browsed suckers to right.)
Specimen No. 2
Evidence of pathogens on foliage (left) and stem (right) on Specimen No. 2
Glenn Rilke with wild T. taxifolia in Torreya State Park, autumn 2007.
Notice bark problem below his left hand. (Leigh Brooks, 2009, suggests it is probably deer rub, not disease.)
Barlow and Martin 2004 proposed that Torreya taxifolia might have gotten trapped in its peak-glacial pocket reserve (in northern Florida) for lack of its coevolved seed disperser, and thus was unable to geographically respond to the warming interglacial climate. The above paper suggests that another taxon of gymnosperm that thrived (along with genus Torreya) in the Jurassic period might have suffered from an inability to easily track climate change when the seed-dispersing dinosaurs died out.
Download in PDF two articles, for and against assisted
migration of Torreya taxifolia, published as the featured
Forum in the Winter 2005 issue of Wild Earth. Download
the pro and con articles separately for printing on standard
size paper. Or, for viewing the 2-article Forum as it
appeared in publication (wide-screen, with all illustrations),
download the "Forum."
FOR assisted migration, by Connie Barlow & Paul Martin
ANTI assisted migration by Mark Schwartz
FORUM (both articles for wide screen)
"Rewilding North America" — The 18 August 2005 issue
of the prestigious science journal, Nature contains an advocacy
article that proposes "rewilding" close-kin of some of the
large mammals that went extinct in North America at the
end of the Pleistocene, 13 thousand years ago. By comparison,
the proposal to "Rewilding Torreya taxifolia" looks mild! To access
this amazing article, you can view or download it at
http://rewilding.org/pdf/Pleistocene-Re-wildingNorthAmerica1.pdf.
Explore a photo-essay of Torreya Guardians REWILDING ACTION in Waynesville, NC in July 2008.