In a message dated 7/1/02 3:37:03 PM Eastern Daylight Time, NJPharris@aol.com writes:
<< I can think of rainforests that do not show this physiognomy (and I'm sure Ben, as a Seattleite, can too...).
Or maybe I'm missing the point. >>
Unless you have a "a high-diversity tropical rainforest" in Seattle you are missing the point. DV
Well, then so am I. I've just lend away my tree books, so the following statement is subject to the vagarities of my memory, but my recollections of walking through rainforests on the Australian East Coast - from tropical ones in North Queensland to sub-tropical around Brisbane, and warm temperate near Sydney, is that the major trees often don't show the classic 'jungle' physiognomies. In Mt Lammington National Park, for example (sub tropical, near Brisbane), where I've spent many hours walking, the vegetation is a patchwork of wet schlerophyll (dominated by eucalypt trees) and rainforest-proper (still with lots of eucalypts, but also including others, especially figs). The leaves on the rainforest growing eucalypts are smooth edged (as are all gum leaves), but you wouldn't call them large, and as for drip tips?
When you walk from a patch of wet schlerophyll into rainforest, the feel of the forest changes. There is more shade, and the temperature is much cooler. But I've always felt that it is the composition of the understory, especially the large number of ferns (e.g. tree ferns, Dickensonia) that is the most noticable difference between the two physiognamies. You have to look real hard to see any differences in the composition of the canopy.
Is this something unique to Australian rainforests, or is it more generally true that the 'classic' rainforest look is not really representative of the vegetation types that are termed rainforest? Are there any botanists who can help out there?
Anyway, the notion of rainforests as diversity hotspots seems to me to be a bit of a myth, especially if you are (as we all are on this list) interested in larger creatures. Yes, they are full of lots of different kinds of insects, and even though many of the plants look the same there is an enormous diversity in them if you know what you're looking at. And there can be a few birds (if you can see them). But as far as herps or even mammals go? Give me a semi-arid zone or a river bank any day. Even in rainforest zones the areas with most animals are usually where (surprise, surprise) there is a high degree of structural heterogeniety - patches of rainforests interspersed with dry woodland, open grasslands, and swamps. Classic place to see this - national parks which used to be logged, but are now protected. Lots of re-generating vegetation, at different phases of growth. Lots and lots of birds and big mammals.
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