Welwitschia (Gnetales), Queen of the Weird.
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So What?
A lot of people are apt to wonder, why a database on gymnosperms? The average person doesn't know what a gymnosperm is, although they probably know something about conifers. Botanists are well aware of the gymnosperms, but "serious" botanists (with a few notable exceptions) tend to pay them little attention, dismissing them as a primitive and taxonomically simple group. This attitude is clearly shown in elementary botany textbooks, which typically present the gymnosperms as little more than a stepping-stone to the more "advanced" flowering plants. (I should note in passing that this attitude was never very well supported by data, instead reflecting an old philosophical belief that all life can be seen as a continuum from the "primitive" to the "advanced", with Homo sapiens as king of the hill. In fact, recent work summarized by White (1994) suggests that all major extant groups of vascular plants may be of roughly similar antiquity.) To be sure, there are only about 800 species of gymnosperms, fewer than some individual genera of vascular plants (Eucalyptus, Acacia and Senecio, for example). However, there is more to biological importance than species diversity.
Nature does not keep museums. The gymnosperms may often be called "living fossils," but let's step back for a moment and look at them from an objective ecological point of view. They dominate the world's temperate and boreal forest ecosystems. For example, the globe is ringed by a nearly continuous conifer forest (the taiga or boreal forest) at a latitude of about 40° to 65° north. Conifers also consitute the dominant forest type throughout western North America and most of Mexico, the montane forests of the Alps, and eastward along the entire Eurasian cordillera through central Asia and the Himalaya to China, Korea and Japan. They are abundant (or at least conspicuous) in mountain ranges nearly everywhere else in the world as well, including South America, Australasia and Africa. By nearly every ecological value -- total living biomass, total carbon fixation, total area inhabited, diversity of habitats -- the gymnosperms are approximately as successful as the angiosperms when we consider forest and woodland ecosystems. Only in nonforest systems do the angiosperms show an unambiguous competitive advantage. Allowing for uncertainties in the fossil record, the gymnosperms are approximately as successful now as they were in the Cretaceous when the angiosperm radiation really began in earnest. Is this what we expect of a small group of "living fossils?"
This, then, is the real root and focus of my interest in the gymnosperms. Certainly, I think they are beautiful. There are few things I enjoy more than wandering though a forest of giant conifers, or of ancient desert pines, or of gnarled krummholz at timberline. And, I admit to a fascination with the unique ways that they have adapted to their sundry environments. But I love them root, leaf, and branch for this: to understand how and why such a simple, primitive group of plants has retained mastery of about half the world's forests despite a hundred million years of root-to-root competition with the angiosperms, an enormously diverse group that by conventional wisdom should have driven the conifers to extinction sometime during the age of dinosaurs.
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