Talk:Sequoiadendron

Sequoiadendron in Eastern Europa ?

Concerning source 4. "Shatilova, Eliso et al (2011)" about Sequoiadendron pollen in Georgia (Caucasus).

I want to place an objection against using this source.

Sequoiadendron pollen are mentioned 3 times, each time in a table only. There's not a single occurrence of the word in the whole text, where they would explain or discuss the probability of the assignment.

I've researched many of the more recent reports of genus fossils located anywhere else than in North America. They are few, anyway, and all had one thing in common: No reference as to who discovered and determined the records, and published their work where.

Shatilova 2011 is no different. I appreciate the serious and laborous work, but there is no way to trace back their Sequoiadendron account to the actual data source, and no way is offered to verify it.

According to personal email communication, the original description tells there is a only a 'morphologic similarity' and this description will also be used in a planned future pollen atlas project.

At the bottom of the problems around Sequoiadendron occurring in Europe lies the foundation work from Rudolf Florin 1963 (1), who, at that time, had en extremely limited knowledge base about Sequoiadendron (as he states himself on the single Sequoiadendron page), and was simply throwing into the map two related generi - just on suspect -, which got re-assigned to something else today: Sequoia reichenbachii and Sequoia couttsiae. In the last sentence of that very short text he even expresses his own doubt.

With that, Florin presented a map depicting an areal spread all over the Northern hemisphere. It's the only map in this work, where he explicitly expressed doubt. But later on, that map created a legend, leading to assumptions in nearly all of the secondary literature to date (like in all of the NPS publications).

Even when the Georgian paleobiotop of the Samartian was quite similar to the the Eocene / early Miocene of the North American Colorado plateau (volcan activity favoring pioneer species, sea ingressions and marine influenced clima, montane lauracea communities and probably cloud forests, and an amazing diversity of biotops and plant genera), it is questionable if there ever could have been such a long range migration or spreading of the Sequoiadendron gene pool, since the rather heavy seeds are definitely not pioneer-like long range flyers. Also, germination requires at least several weeks of continuous moisture, as do the emerging seedlings which are extremely sensitive to their environment (for example they can't tolerate even slight competition from other vegetation) - these are not traits of a long range wanderer.

The only option would be, IMHO, sea-travelling cones, where the probability of a successful initial settlement is extremely low (for a land based species).

My conclusion is that as long as no waterproof primary research of European Sequoiadendron records is published, we should consider that this genus was probably endemic to North America.

(1) Florin, Rudolf. The distribution of Conifer and Taxad genera in Time and Space. In: Acta Horti Bergiani 20 (4): 121–312 (1963).

rosetta (talk) updated 04. April 2019

collapse conversation not-relevant article improvement

Addition rosetta (talk) 22:24, 3 January 2021 (UTC) : Let me add the reason (except pure scientific discipline) why i am so concerned. If the genus Sequoiadendron was able to long-range migrate even between continents, it must have crossed and thrived in a lot of different environments; then people will easily think their ecological niche must be quite broad. Consequently, they will think replanting them all around the world already made their gene pool safe. Because of that, they will miss to see how that genus is exactly the opposite: Extremely sensitive and only capable of regenerating in environments that possibly do not even exist anywhere else than in the Sierra Nevada of California today. Meaning, naturally regenerating (without human support) groves are highly endangered. I've been looking for Giant Sequoia seedlings in Europe for 2 decades now and although there are a few legends, none of them are applicable: In two verified cases of Germany and Switzerland, lawn sprinklers and gardeners removing of weeds were involved, and a third in South Tirol was an error about an originally planted seedling. Not any single occurrence more could i find. And i searched under hundreds of mature trees, under groups and in forest stands, for seedlings myself. And i am able to safely indentify them and how and when they germinate and what these seedlings need, not only from literature, but also from 20 years of growing them myself, experimentally, in very different environments. I even burned small forest areas where i sew thousands of seeds. Sometimes a few seedlings occured but not single one survived. Why ? The seeds need several weeks to soak water (best in melting spring snow); then next some 2 weeks of warmth when the same time, they cannot be directly exposed to sun and/or dry out even for a short time; then next a week for germination and another 3+ weeks to grow the initial tap root deep enough to connect to water, before summer drought cuts in. Provided the soil is penetrabel and has some moisture in depth. It boils down to 6-8 weeks of continuous moisture, when sun cannot dry out seeds or seedlings for more than maybe 2 days; yet warmth; and then, when the seedlings tap root is deep enough, enough radiation (or alternatively topographic elevation) to prevent mold fungi diseases. In California, deep ashes of forest burns, on wet meltwater soils provide for all this. Also, these are conditions which you will not find anywhere on earth without a vigorously growing vegetation of ground plants, bushes, and trees. It's ideal for about everyone. The fire regime of the mountaineous zones of the Sierra Nevada provides for all that - and yet only in some places, where the groves are today. (It's possible that the highly volcanic rim of Tertiary Northamerica provided for suitable soils even without forest fires.) Thus, regeneration of Sequoiadendron is fully adapted, and fully dependent, on ground-clearing catastrophes like - ideally - fire. The combination of all these factors are hard to find anywhere else, no matter in recent times or in the Tertiary, of Europe. It is certainly not possible for this species to do any kind of long range migration! The fact that, according to the fossil evidence, their North American Tertiary areal was also clearly limited to the (then emerging) mountain ranges close to the paleo coast around the Colorado plateau, and stretching into Nevada and exceptionally up to Idaho, supports my case. In any case, the ancient groves should have mostly been in a cloud forest plateau situation. If there was an ancestor still of the same genus in Europe, which by migration would be directly related to the Northamerican genetic pool, then that ancestors ecological range must have been totally different from recent Sequoiadendron. It is hard to imagine and i strongly doubt it. (End of addition ) rosetta (talk) 22:24, 3 January 2021 (UTC)

---

@Rosetta: Thanks for contributing to the article! The problem with the wording is that Shatilova did not say "very similar to Sequoiadendron", but said that it was Sequoiadendron itself (both pollen and macrofossils). We have to accurately represent what our reliable sources say, otherwise the encyclopedia is not verifiable.

If you think that Shatilova is not a reliable source (according to our criteria), then we can discuss it here on Talk. But that's a discussion about the reliability of the publisher and author, as opposed to the content of the material.

If you think that the research into worldwide sequoiadendron is incorrect, what you need to do is come up with other reliable sources that support your position. Wikipedia's neutral point of view policy would then have us describe the controversy. Of course, we have to make sure that we don't put undue weight on a minority viewpoint --- if the large majority of botanists believe that Sequoiadendron had a worldwide distribution in the Pilocene, then we have to put more weight on that opinion.

Notice that your own personal research or email communication don't count as reliable sources. That would be original research, which would not be allowed to support material in an article.

Looking forward to your further research on this topic! —hike395 (talk) 13:58, 5 April 2019 (UTC)

@Hike395: I do not want to discredit Shatilova or her work. I just think there is an error in the data description, and more generally, in believing that the genus Sequoiadendron is not endemic in North America. Errors are human. I got personal communications which support my case, from different authors, including one of the authors of the work in question. However, they all refuse to be quoted personally, because (and may i dare to quote this, in translation) "(...) i want to rule out that my answer could question the research of a whole generation of collegues, which is something i don't want to do and don't want to intend in any case."

I understand your point about original research and the fact ist, there simply is none dealing with the question i put up. And to support my position i had to proofread and check a lot of fossil record descriptions. I've done that for a couple already (in private), and could come up with written analysis, but there's still much more to do.

Well, actually many are already corrected. Many errorneous Sequoiadendron assignments were already changed to Sequoia affinis, reichenbachii, couttsiae or to Metasequoia (the latter especially in older publications, because some assignments were made before Metasequoia was well known), some even to Athrotaxis. But apparently many scientists refer to (old) sources which never get updated. I sometimes wonder how slow new knowledge disseminates.

Unless they've since been moved back, also some to Taxodium - and there are also some that have been moved to Austrosequoia. Lavateraguy (talk) 10:54, 6 April 2019 (UTC)

The problem is that to my knowledge, there is no systematic review of exactly this topic yet. And if i tried, then there would be many sources where i had to investigate the actual record itself, and by scanning electron microscope (light microsopes are NOT sufficient) and that's impossible for me. (I also doubt the publishing sources would like that.) Also, some 'original' sources don't even tell their records, they just state the fact.

Over the years, i've got a huge collection of data, books and articles and would be prepared to start a discussion like 'Controversy over endemic status' like with other controversical topics. I don't know if that's appropriate when i'm the only one challenging the status quo. And i'm not in a research institute and timewise not in the position to publish myself (i'm working in te field of recent ecology, not paleobotany).

But i think this discussion should be launched sooner or later.

rosetta (talk) 15:08, 5 April 2019 (UTC)

@Rosetta: OK, that sounds like your own research, so we cannot include it into the article. (see also WP:SOAPBOX). —hike395 (talk) 02:18, 6 April 2019 (UTC)

There's a (paywalled) paper describing a Sequoiadendron species from Cretaceous North East Asia. There is a report of Sequoiadendron breviauriculatum from the Miocene of Bulgaria, and Sequoia aff. giganteum from the Upper Miocene of Bulgaria. IFPNI gives some more fossil species. So regardless of the status of the report of pollen from Georgia, a conclusion that the genus is endemic to North America is questionable.

@Lavateraguy: Thanks for these refs ! I will reply to them further down. rosetta (talk) 23:10, 10 April 2020 (UTC)

Citing the putative Georgian record, and not the more extensive North American fossil record, raises WP:UNDUE issues.

A review paper would be helpful - fossil plants have often been misidentified, so has to take papers, and especially abstracts, with a pinch of salt. Lavateraguy (talk) 15:16, 5 April 2019 (UTC)

Will attempt to add more references. —hike395 (talk) 02:18, 6 April 2019 (UTC)

Chaney's 1950 review sinks Sequoiadendron in Sequoia, but he describes several extra-American taxa as closer to gigantea than to sempervirens. I skimmed its citations to see if there was anything more recent that could be treated as WP:RS, but nothing jumped out. The material at Sequoioideae about a reticulate origin for S. sempervirens gives me concerns about the placement of fossil taxa. Lavateraguy (talk) 10:52, 6 April 2019 (UTC)

@Lavateraguy: I added Chaney's monograph as a reference (citing to page 188). Would you recommend any other edits or references? —hike395 (talk) 15:05, 6 April 2019 (UTC)

This paper at BioRXiv seems to put the kibosh on the idea that S. sempervirens is an allopolyploid - it uses a lot more data than the earlier paper. It perhaps should be cited at Sequoioideae. Lavateraguy (talk) 20:27, 6 April 2019 (UTC)

The S. tchucoticum paper is available at ResearchGate. We could ask @Rosetta: for his opinion - he seems to have considerable knowledge of the group, while all I have is the ability to use Google. I would have hoped that such a recent paper would give a clear answer, but while the foliage is described as similar to Sequoiadendron giganteum (macroscopically it is dominated by scale-leaves) the paper doesn't directly compare the foliage with Sequoia. As Sequoia has both scale and needle leaves convergence of foliage morphology by emphasis on one or the other form is possible, so there are two possibilities that have to borne in mind - that Sequoiadendron-like foliage in the fossil record might be convergent, and that the leaf morphology of the extant taxon might be derived within Sequoiadendron. But all this is WP:OR from an underinformed amateur. Unless we can find a recent review using total evidence there may not be a WikiPedia acceptable answer to the question. Lavateraguy (talk) 20:56, 6 April 2019 (UTC)

One identifiable clade within Sequoia sensu lato might be a "hexaploid clade", based on stomatal guard cell sizes, which apparently has been traced back to the Eocene. That would allow a total evidence approach to be avoided for the species of that clade.

The general problem is that plant fossils tend to be disarticulated parts which tend to be difficult to assign reliably to taxa, especially if poorly preserved or not studied with modern techniques, as I found out when I did a review of fossil Malvaceae. In the particular case of Sequoioideae, particular problems include shoehorning specimens into Sequoia or Sequoiadendron before people were aware of Metasequoia, disagreements about whether to recognise Sequoiadendron as generically distinct from Sequoia, confusion with Taxodium and other related genera, and the general problem of assigning species to genera and specimens to species. We could change the article to say that because of these issues the former range of Sequoiadendron is unclear, but that might be WP:OR as well.

A list of taxa can't be taken directly from IFPNI - that's an index of names, not an index of taxa. Lavateraguy (talk) 00:25, 7 April 2019 (UTC)

__

(i'm not really familiar with wikipedia so please excuse my style)

Thank you for your answers and suggestions!

I won't dive into the family phylogeny discussion since this is an extensive field and was not my topic in the first place. But i accept it is related. And it always must be made clear if we are talking about the genus - which opens up for lots of phenologic differences - or the exact species Sequoiadendron giganteum, which Axelrod placed to be less than 20 mio years old (e.g. in Axelrod, D. I. Late tertiary evolution of the Sierran big-tree forest. Evolution 13:9-23; 1959. and in: Axelrod, D. I. The Miocene Trapper Creek flora of southern Idaho: Univ. Calif. Publ. Geol. Sci. 51:1-148; 1964.)

In the same line, we should always be aware that any common ancestor of Sequoia and Sequoiadendron would be not Sequoiadendron.

--rosetta (talk) 23:39, 8 November 2019 (UTC)

I second anything that Lavateraguy said about the methodical difficulties, so far.

This is a publication about Sequoia, and a well done work with thorough analysis of primary records:

* Cristina Alcalde Olivares, Mercedes Garcia Anton, Fernando Gomez Manzaneque, Carlos Morla Juaristi (2004): Palaeoenvironmental interpretation of the Neogene locality Caranceja (Reocin, Cantabria, N Spain) from comparative studies of wood, charcoal, and pollen. Review of Palaeobotany and Palynology 132 (2004).

If i read that correctly, they think that there are no (reliable) European Sequoiadendron records in the geolocical Tertiary (85 - 3 mya) which by the records is the very main period of genus Sequoiadendron: : "All authors relate this species to present-day Sequoia sempervirens and the descriptions of the fossil are completely applicable to samples from Caranceja. Considering that Sequoia and Sequoiadendron are two taxonomically close genera, our samples share features of both taxa, and in European Tertiary only Sequoia or Sequoioxylon is described (Fernandez Marron and Alvarez Ramis, 1967) we have identified them as Sequoia sp."

My point here alas is a different one. I read many publications stating a paleo-Sequoiadendron in Europe, like Bulgaria, Turkey, Russia, British Islands. Most of these are far from the quality of the above publication, they don't present primary records nor analysis of those and often not even references to their statements. I've sometimes difficulties to count them as scientific.

For example the Turkey Black sea publication (UCAR G.; STACCIOLI C. G.; STOLL M. (1996): Chemical composition and ultrastructure of a fossil wood from the genus of ancestral sequoia. In: Holz als Roh- und Werkstoff vol. 54, no6, pp. 411-421 (28 ref.). ISSN 0018-3768 CODEN HOZWAS. Springer, Berlin, ALLEMAGNE (1937)) just start with a fact of fossil Giant Sequoia wood which then is chemically analzyzed and comparedto the recent species - there is no explanation who exactly where found the wood, who determined it, no reference, nothing.

As for the source i initially targetet, did i make it clear that the respective email answer was from the author herself and that she admitted there is only 'morphologic similarity' and not definite identity and that they would probably change the wording in their next publications.

In mail communications, i pointed several paleo Cupressacea authorities to the general issue but not one was ready to take it on, either for lack of time or lack of interestm, but sometimes even explicitly because they did not want to stir things up and confront the mainstream.

I understand that without primary sources supporting my case, i will not be able to defend my point, even if i would debunk and take down every misleading source one after the other. I am unsure how to preceed. There are several good arguments (geolocial and biological) why any migration of Sequoiadendron between Europe and North America is highly unlikely. But i guess i'd still need at least one publication raising the topic in the first place.

--rosetta (talk) 23:39, 8 November 2019 (UTC)

Section break

OK, here is my reply to the above mentioned new sources.

The Palmarev (2005) source is just a catalog. It lists Sequoiadendron sp. affinis (?) and Sequoiadendron breviculatum.

Despite the similarities, sp. affinis was usually placed into Sequoia, not Sequoiadendron, as Sequoia affinis. As i already warned - a truly ancestral genus of the two extant ones should be neither of them - at least if crossing two different geni was not happening. (The relations between the different geni is an awfully huge and controversical discussion and i won't dive into it here. It's just my opinion that a 2n Seqoiadendron should not be a crossbreed result of 6n Sequoia, and the sharply opposite ecotypes of extant Sequoia vs. Sequoiandron support this too.)

Anyway, the affinis assignment should be a stopgap solution - it can not prove anything; beause there are very clear similarities between the extant Sequoia and Seqoiadendendron species too. For example the 'scaled' (cupressoid) terminal / top crown shoots of Sequoia, the bark, and the microscopic wood strcuture which is as good as identical. The seeds are also very similar except their size, but you can find small Seqoiadendron seeds in the cone top (where the scales get very small), and there are just small cones with generally small seeds too, even within a single tree. Cone size also varies with cone age. Thus, it is no exception that it is quite impossible to differ the genus by too few fossil fragments. It probably needs a different approach then, probably considereing the ecotype and biotope. (I like the idea to scan for hexaploidy!)

The entry for Sequoiadendron breviculatum refers to

Palamarev, E. 1994b. Neogene carpoflora from the Rhodopes Mountains and its palaeoecologic and biostratigraphic significance. Paleontol. Stratigr. Litol., 30: 22-36.

and there, on page 23, we find this:

Family TAXODIACEAE

Sequoiadendron breviculatum sp. n. Pl. I, figs . 1, 2

Materials: 10 seeds.

(...)

Remarks. The species described differs considerably from the already known fossiI forms of genus Sequoiadendron Buchholz, reported from Eurasia. It also differs considerably from the only recent representative of the genus S. giganteum (Lind.) Buchh. Their similarity is only in the presence of auricles and of a narrow massive germ, placed throughout the whole length of the seed.

You may try this link (pls just edit it here, in place, if you find a better one): https://yadi.sk/i/Om90i1sXsFcjE

Well, it is true the description of the seeds is very similar to (small) S. giganteum, but it can be just as similar to (big) Sequoia seeds. I have to lookup Sequoia seeds again (they are much more rare to find than S. gig.) but AFAIR most of the close relatives' seeds can be auricles -- especially when you take into account that inmature seeds do warp when dessicating. And there possibly are quite a few more miocene conifers which we would need to consider.

And remember, Palmarevs judgement is based on just 10 seeds. I don't want to doubt her sincerity but given the importance of the problem i am trying to rise (which she most probably was not aware of) it is at least justified to clarify there is some space to doubt.

I need to review S. tchucoticum another day. rosetta (talk) 23:10, 10 April 2020 (UTC)

@Rosetta and Lavateraguy: My apologies: I didn't notice the update of this Talk page until today. I added a sentence describing the dispute, with a reference to (Alcalde Olivares, 2004). I'm not sure that I portrayed the controversy correctly, so please take a look. Thanks! — hike395 (talk) 08:37, 3 January 2021 (UTC)

@Hike395 and Lavateraguy: Fair play. Seems ok to me. Thanks ! rosetta (talk) 19:17, 3 January 2021 (UTC)

@Rosetta: Unless you can supply a reliable peer-reviewed or secondary source that has moved Sequoiadendron brevIAURiculatum to a different genus, you suppositions are not actually usable to change the prose of the article. Currently its still placed in Sequoiadendron from what I find. That it had a wider pre-glacial range is VERY common among plants and animals.--Kevmin § 23:49, 3 January 2021 (UTC)

@Hike395: I just had a chance to read over the Alcalde Olivaresa et al paper. The sentence that seems to be used in our article currently is this one correct? "Considering that Sequoia and Sequoiadendron are two taxonomically close genera, our samples share features of both taxa, and in European Tertiary only Sequoia or Sequoioxylon is described we have identified them as Sequoia sp." If so, this sentence is making a statement that covers the wood fossils from Europe, and that they have placed the Caranceja location fossils into Sequoia rather then into the morphogenus Sequoioxylon. The paper does not cover compression fossils from foliage or ovulate cones, such as the ones used to describe Sequoiadendron breviauriculatum, so I have tagged out the added sentence for now. I dont feel there is a strong argument presented here for adding undo questioning weight to European Sequoiadendron fossils.--Kevmin § 19:42, 4 January 2021 (UTC)

@Kevmin: Yes, that was the sentence I was basing the material on. My interpretation of the sentence was "other researchers only use Sequoia and Sequoioxylon in the European Tertiary, so we will assign our ambiguous samples to Sequoia." I thought the statement went beyond wood samples.

However, I know little about paleobotany. I'm not sure whether and how to report any controversy. It seems (to me) that the evolution of Sequoioideae is really messy (being possibly reticulate with polyploidy) and not well-understood. Maybe we should highlight some of this uncertainty in some way? I just don't know. Due to my lack of expertise, I'm content to leave the sentence commented out in the article. — hike395 (talk) 21:22, 4 January 2021 (UTC)

@Hike395: Both reticulate evolution and polyploidy are common themes in most plant orders, its not something restricted to this this subfamily, so its not actually something that, in paleobotany, is considered controversial. the section that is being talked about in Alcalde Olivaresa et al is a section specifically of wood fossils, which is why only Sequoia and the wood morphogenus Sequoioxylon are talked about, those are the two genera that wood fossils in Europe have been assigned to. I think there is a heightened level of weight being placed in this topic by @Rosetta:, based on the collapsed comment that they posted yesterday. I do not find any reliable sources that are supporting the level of stress being placed into the article currently.--Kevmin § 21:57, 4 January 2021 (UTC)

@Kevmin: First of all, thank you for the 'collapse' insertion. I was already hesitating how to put my explanation, and this is just fine now. Also thanks for correcting my misspelling of breviauriculatum. I've no idea why i abbreviated it like that!

Kevmin, i agree that i put a heightened level of weight on this topic. This was my declared purpose. Please teach me if my approach was wrong. Please note that i also declared from the start that i also did not find any reliable sources that are supporting my case. I could and can debunk some (maybe older) publications but that does not proove anything. That's why i was a little suprised that a controversy insertion was added to the text. But i would not object it - i am the one challenging the status quo. However, i understand now wiki rules can not accept a personal opinion even if there was some credibility behind it.

I also understood Alcalde Olivaresa to cover all kind of fossils. But it can be read like you suggest, and probably it was meant that way. I remember to have read another publication which expressed explicitly doubt like i do, maybe i can find it again. Please do not expect expeditious updates, i was a focused on these subjects only more than 15 years ago and it never was my field of research to begin with. I will need some time to reorganize.

@Hike395: pls allow me to resort your question below since it's the next thing which should be answered.

rosetta (talk) 23:24, 4 January 2021 (UTC)

Rosetta The structuring of Alcalde Olivaresa et al is typical of paleobotany papers, with discussion if specific fossil/fossil types limited to just those types unless they specifically narrow or broaden the topic. So in this instance, the authors only intend to discuss the Spanish wood fossils in reference to other wood fossils, rather then discussing the whole of the Sequoioidea fossil record in Europe. They are noting in the specific sentence that the wood fossil record is limited, and prior authors have binned the fossils into two of the four possible genera (Metasequoia, Sequoia, Sequoiadendron, and Sequoioxylon). All three genera are known to have pre-iceage fossil records in Europe. The thing to keep in mind is that this talk page is specifically for the improvement of the article Sequoiadendron, and isnt really meant for the type of disccusion that is currently happening. You really would be better off taking the concerns to a botany forum or to a group of paleobotanists.--Kevmin § 17:26, 5 January 2021 (UTC)

@Kevmin: to clarify --- are you content with the current state of the article? Or were there further edits you think are required? — hike395 (talk) 22:34, 4 January 2021 (UTC)

hike395 I am relatively content with the status as it is, and hope to get it fleshed out with more information at some point to match other genus level articles,--Kevmin § 17:26, 5 January 2021 (UTC)

Seriously defficient stub for a magnificent tree!

Compare it to Sequoia sempervirensh

2603:8001:3846:2D00:5CD3:AB16:BAEB:60CE (talk) 07:02, 19 January 2021 (UTC)

This is the article for the genus Sequoiadendron. See Sequoiadendron giganteum for the specific tree you're thinking of. — hike395 (talk) 15:11, 19 January 2021 (UTC)