"YOU DON'T EXPECT ME TO GROW THERE,
DO YOU ?"

In my last column, I considered physical and aesthetic changes that may occur in a species as a sequel to the involvement of man in their reproduction. Metabolic changes which may occur concurrently are less easily appreciated. By breeding and raising large populations of species plants under greenhouse conditions, we are automatically selecting for plants that grow well under precisely those conditions. Such conditions probably have little to do with the conditions under which the species will grow in nature. It is therefore likely that most first-generation, greenhouse-bred plants do not have the wherewithal to grow in nature, bearing in mind that they were not subject to the tremendous selection pressure that nature necessitates. Further, it is likely to be an an impossible task to find the correct position to place any particular clone in a natural environment. That is important, if you subscribe to my concept of a 'sacred relationship' (see Part 2).
Here, I am painting a gloomy picture regarding the possibility of restocking nature with its lost treasures. I, for one, do not find it surprising when I hear that orchids transplanted from a threatened environment to a safe one do not thrive and frequently such attempts turn out to be completely futile. Transplantation will work with some species, particularly those that have weedy tendencies, but unfortunately orchid weeds are few. Weeds, by my definition, are those plants which have pioneering tendencies and will grow in disturbed areas. Amongst the orchids, the South American reed-stemmed epidendrums and the zygopetalums are often weedy; other weedy plants include some of the cypripediums that grow along northern USA highways, Spiranthes spp., Oeceoclades maculata, originally from Africa and now spreading around the world, some African species of Polystachya, etc. But this class of plant is precisely that unlikely to be threatened and need not be of concern to us. At present we need to worry about the narrow endemics, a group which includes many of the choicest orchid species.
One article I have come across concerning the reintroduction of a narrow endemic, was published in Lindleyana 4(2): 68-73 (1989) and is titled: "In vitro seed-germination and re-introduction of Bletia urbana (Orchidaceae) in its natural Habitat" by Rubluo et al. This article dealt with the short-term results of the reintroduction of greenhouse-raised seedlings of this threatened species into its natural habitat in the Valley of Mexico. It was shown that after 90 days the survival-rate was 56% and by the following year only 15% of the seedlings could be located. I do not know the current status of this project, but my projections based on these original figures do not paint a rosy picture.
My basic premise is that we cannot afford to allow any species to lose its natural foothold, because rectifying such a situation will be fraught with difficulty.

© 2003-2009 Greig Russell

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