 Torreya taxifolia cleaned seed |
Bibliography
Copyright July 1998 |
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| Schwartz produced an estimate of population levels
prior to the species' collapse based on population density data from 1914 that showed 30 Torreya per acre. Given the size of the potential habitat, he extrapolated a maximum population of between 300,000 to
600,000 plants, meaning, sadly, that 99.3 to 99.9 percent of the earlier population is dead. This means that the scope of any reintroduction is of a scale that will require collaborative efforts. To build up numbers of plants approaching these levels from the current estimates of 500 individuals is daunting to a botanist,
horticulturist, or ecologist, but would probably be considered a manageable project to forestry professionals. The ravines inhabited by
Torreya are unique ecosystems and contain many endemic species. The ravine slopes are often steep-sided, and large armies of volunteers planting Torreya could possibly destroy much of the understory layer
if planting is not correctly planned. Thought has to be given to the eventual product of an ex situ program with an eye toward re-introduction. Germplasm is always the product but in what package? Will it be large b&b plants, one-gallon size, racks of seedlings or rooted cuttings in tube pots, or seed? This is tied to many factors: cost of production, space and labor limitations, cost of transport to the ravines, impact of transport into the ravines and |
survivability once planted. We do not know if 10 large plants or 1,000 seeds offer a better chance of success in terms of long-term survival and regeneration. Germination of Torreya seed, like many primitive gymnosperms such as Taxus and Podocarpus, can involve a long after-ripening of the embryo once the fruit senesces from the tree. If seed were used it would have to be preconditioned and planted at the cusp of germination, thus avoiding a long period of dormancy in the ground when it would be subject to predation. Seed pretreated and ready to sprout would be the most cost-effective to produce, the easiest to transport and plant, and least environmentally damaging method of restocking the native range of Torreya taxifolia. New data by Chien, Kuo-Huang and Lin offer some crucial clues for successful pretreatmant of Torreya seed, and this line of research needs further exploration with Torreya species. Given the scale and scope of this project, it boggles the mind to assume that mankind is capable of repeating this process with every endangered species of plant. Ex situ conservation projects, such as the work with Torreya, may in fact become the best kind of advocacy for in situ conservation and the maintenance of where the wild things are. |
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