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Höhenpotential: MB, Douglasie und andere Arten

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Tuff:
stimme dir zu bernt. ist auch eine gute idee ! nur leider findet man nie komplette Stämme. kenne beispiele wo stehender bestand verschüttet wurde, aber auch dann nur 30m oder so erhalten. wie du bereits sagst kann man aus dem D nicht auf die höhe schließen, jedenfalls nicht ohne vergleichswerte. die gibt's fossil aber einfach nicht.

vergleiche: (habe die quelle leider damals nicht notiert)

Fossil Sequoia is known best from tertiary floodplains, river valleys, and foothills of mountain ranges. The fossils are very often embedded in layers of mud flow or volcanic tephra. The most impressive example are trunks that were suddenly buried, and fossilized upstanding. Such en environment would not normally allow for any plant to get huge or old. Fast growing pioneer trees with resprouting capabilities, annual species re-immigrating from nearby undisturbed local patches, and generally lightweight flying seeds would be standard.

(...)

In this respect, the extraordinary height growth of Sequoia has still to be seen as a consequence of intraspecific competition for light; there's no reason to assume it would be a specific adaption to destructive mechanical forces. To the contrary, moderate to low height usually supports resistance under such circumstances. For example well known is the typically dwarfed adaption of trees under strong wind conditions, like on top of high ridges or in unprotected windy plains. Similar the dwarfed trees near the tree limit of high mountains, which to great extend can be credited to snow mass movement.

So, to be precise, it's rather the trunk mass as a result of huge diameter, than the great height, which establishes the adaption to erosive forces. It is for example plausible that Sequoia trees of less height but equal mass would be quite as resistant. This is perfectly demonstrated by another member of the Taxodiacea family, Sequoiadendron, which enormous trunk size make sit not only resistant to huge deep scarring but presumably also against any kind of mechanical force.

Kiefernspezi:
Es ist aber auch schön,  dass Raum für Spekulationen bleiben. Da darf die Phantasie noch schalten und walten. Deshalb möchte ich gerne glauben, dass es vor der Eiszeit noch Bäume gab, die an die 150 m hoch waren.
 ;D

Tuff:
Dunarobba Fossil Forest (Italien) -> Taxodioxylon gypsaceum:

According to Biondi & Brugiapaglia (1991), all the trunks so far examined appear to belong to one species only, identified as Taxodioxylon gypsaceum (Göppert) Kräusel, which became extinct during the Pliocene and had anatomical features similar to the present-day Sequoia sempervirens (Lamb.) Endl. (...) In conclusion, stratigraphic, palynological and paleomalacologic data indicate that the Dunarobba Fossil Forest can be attributed to a time span in the Pliocene with climatic conditions which were warmer and more oceanic than the present ones.

Von T.g. gibt es im ganzen Mittelmeergebiet etliche aber nicht außergewöhnlich große fossile Stümpfe. Aber Höhen ? Fehlanzeige.

Aber man muss ja gar nicht in die Ferne schweifen:

In Monterey, in Höhen von rund  1000 - 2000 ft gibt es auf eher trockenen Standorten die Sequoia sempervirens - Lithocarpus densiflorus / Carex globosa-Iris douglasiana / Gamboa - Gesellschaft.

[] Borchert, Mark. & Segotta, Daniel. & Purser, Michael D. & Pacific Southwest Forest and Range Experiment Station (Berkeley, Calif.)  1988. Coast redwood ecological types of southern Monterey County, California. U.S. Dept. of Agriculture, Forest Service, Pacific Southwest Forest and Range Experiment Station, Berkeley, Calif. http://www.treesearch.fs.fed.us/pubs/27278

"The most widespread redwood forest in the study area is the coast redwood-tanoak/round-fruited carex-Douglas's iris / Gamboa ecological type. It occupies middle and lower convex slopes of the main canyons and smaller draws above 800 ft elevation. On steep (>60 percent) colluvial slopes, stands are abundant on north and northwest facing slopes, while those on slopes less than 60 percent are common on west through south-southeast exposures."

"Tanoak (Lithocarpus densiflorus) is the most important tree species after redwood and is especially abundant in the understory. Although tanoak occupies a wide range of redwood types, it attains its highest cover in this relatively xeric habitat. Understory cover is sparse. Round-fruited carex (Carex globosa) and Douglas's iris (Iris douglasiana) characterize the herbaceous layer."

"Associations comparable to this type in the forest in the northern part of the species range are the Sequoia / Arbutus association in Humboldt County, California (Lenihan 1983). It occupies the depauperate upland Sequoia sempervirens forest in Curry County, Oregon (Dyrness and others 1972), and the Sequoia sempervirens-Pseudotsuga menziesii/Arbutus menziesii associations (Matthews 1986). All three types occur above the fog layer (1000 ft) on relatively dry sites and have significant southeast exposures."

Nun müsste man also dort mal die Baumhöhen messen.

Tuff:
http://www.scoop.co.nz/stories/WL0604/S01447.htm

Bakersfield:

--- Zitat von: Tuff am 29-Dezember-2013, 18:30 ---http://www.scoop.co.nz/stories/WL0604/S01447.htm

--- Ende Zitat ---

Tadschikistan also? Wusst' ich's doch!!!... :o ;D

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