Talk:Stenocereus thurberi

Latest comment: 15 years ago by 70.171.209.148 in topic What does Organ Pipe Cactus "prefer"

I don't understand the ribs, what does it mean? edit

The article says: Each stem has 10 or more[2] 12 to 20 inch high ribs that bear dark brown to black spines that turn gray as it matures.

I don't get it. The stems are 6 inches thick so the "12 to 20 inch high" can't be the length they stand out from the center of the stems. The stems are many feet long so the 12 to 20 inches can't mean the length of the rib. The closeup picture shows a stem, the ribs clearly don't circle the stem.

This is my best guess of what the author meant to say: ... 12 to 20 cm high ribs ...

This is my next best guess: Each stem has many many ribs. The ribs run parallel to the stem, but any one rib only runs 12 to 20 inches along the length of the stem, implying that as you travel along a stem you will see ribs start and end. There are 10 or more at any cross section of the stem. Is either guess right? --Djfeldman 13:38, 3 August 2006 (UTC)Reply

You're right thank you. I messed up the wording. --Chroniclev 23:20, 3 August 2006 (UTC)Reply

What does Organ Pipe Cactus "prefer" edit

I find this article good; the only thing I was not quite happy with is the phrase

"The plant is slow growing, and prefers well-drained soil and full sun".

Now, well-drained and sunny sites in a desert environment mean more drought stress relative to generally already pretty dry conditions. Does any plant "prefer" this? I guess not... the issue is (probably) that Organ Pipe Cactus doesn't make it on other sites because there it is outcompeted by other desert plants. Hence the issue is not what it "prefers", but what it is able to tolerate.

Therefore, I would suggest that the phrase should be re-worded to something like

"The plant is slow growing, and is competitive against other desert plants on well-drained soil and in sunny sites only."

If this sounds too scientific (i.e., not understandable to "outsiders"), then perhaps something like this would do, although it is longer:

"The plant is slow growing, and therefore it cannot compete well with most other desert plants. On well-drained soil and in sunny sites, however, it is too dry for other large cacti, and this is where Organ Pipe Cactus dominates."

Thanks.

70.171.209.148 (talk) 06:20, 7 December 2008 (UTC)Harald Bugmann Professor of Forest Ecoogy, ETH Zurich (on sabbatical leave in summer/fall 08 in Tucson, AZ) harald.bugmann-at-env.ethz.chReply