Quercus - Science topic

You can use the tools available on the internet such as Molar Mass, Molecular Weight and Elemental Composition Calculator

For the additional information please kindly consult:

Zarroug Y et al. (2020), Extraction and Characterization of Tunisian Quercus ilex Starch and Its Effect on Fermented Dairy Product Quality. Int J Anal Chem. 2020 Aug 4;2020, doi: 10.1155/2020/8868673. PMID: 32831842; PMCID: PMC7424496.

Hi Fabrizio,

We have to start with a boundary condition. The boundary condition is that all the carbon in the Quercus wood is converted in CO2 (like burning wood in a stove till only inorganic ash remains.

If this boundary condition is met, then the problem is reduced to a good estimate of the carbon content of (Quercus) wood.

Let's assume that we take 1 m³ as a standard volume to convert. The carbon content of trees is usually calculated from wood volume equations (in m³) which include basic wood density (Mega-gram of dry biomass per m³) and a conversion factor for the %C in dry biomass (Houghton et al. 1990).

Basic wood density is defined as the oven dry weight of wood divided by the volume of wood. It is commonly considered as an indicator of wood quality and varies widely among species. On the other hand, a concentration ratio of 50% is used to convert tree biomass to carbon stock for operational level purposes. This simplification has been proposed as a default value by the IPCC (Houghton et al. 1990), even though carbon content varies between tree species. See also:

Variation in carbon concentration and basic density along stems of sessile oak (Quercus petraea (Matt.) Liebl.) and Pyrenean oak (Quercus pyrenaica Willd.) in the Cantabrian Range (NW Spain).

Available from the URL:

Example:

For Quercus petrea the %C varies between 46 and 50 or in MgC/ha between 184 and 216.

For Quercus pyrenaica the %C varies between 45.6 and 50 or in MgC/ha between 94 and 121.

To go from C to CO2 (equivalent), apply the rule of three, based on the molecular weights of C and C02.

Hope this helps,

CHeerz

Frank

Thank you sir

This is outside of my area but I do know that acorns were one of the major food sources for hogs fattening in the Fall. Today people just think of acorns as a possible twisted ankle. This had led to a tragic decline in young oaks in US cities. Most complaints are that they are messy. Gettting back to medieval trees, I would look for areas of pasture for pigs. Unlike chestnuts and wallnuts, people can't live on acorns fof long, only as a famine food. Acorns are just too hard to turn into meal on a regular basis and we certainly can't chew them. The Early Medieval Irish Chronicles record mast falls in the second half of the seventh century and no one has ever figured out why.

Dear Derradj,

Thank you very much for your collaboration offer.

Since the last records of C paludivagus that I know date from several decades ago, I had even thought that this species was extinct.

From your address I suposse that the material will be from the mountains near Constantine.

Best

Luismi

Interested

Thank you Allen James Coombes for your insight into the botanical Code.

Please also go through the following RG links.

Please take a look at this useful PDF attachment.

Hope this demonstration will help.

https://www.wikihow.com/Determine-the-Age-of-a-Tree

Thank you

Hi Simon,

To my knowledge Jan Cermak from the University of Brno (Czech Republic) is one of the best scientists internationally concerning the measurement of sap flow in trees. Jan has performed these measurements on a lot of species. You should contact him to know whether he and/or a Spanish colleague have measured sap flow in Quercus suber. Jan is a forester working on whole tree water relations and macro structure.

See:

Cheers,

Frank

Generally speaking, almost all the native species are suitable.

However, from the practical point of view, it is necessary to take into account also the previous use by human population and if the distribution of a species is effectively correspondent to its potential distribution.

As an example, we studied the elevation shift of Picea abies and Larix Decidua in the Italian Alps.

In our case it is fundamental to know where the upper potential limit is reached thus we can say that the plants that will grow at higher elevation are exploring unprecedented height. On the contrary, if the potential limit was influenced by cuttings or pasture or any other reason this means that at present times the treeline is much lower than it should be and part of the occurring regrowth is due to the reconquering of an already suitable space.

This situation is quite frequent in the European Alps.

I hope it help you to clarify some issues,

all the best,

Marco

Freshly seeds can germinate easily. After a long time storage > 2 months, embryonic dormancy will settle and the seeds will be difficult to germinate.

You can find info here:

It seems naturalised in the Baleares and Canary islands

I didn't know this article, thank you it is very interesting and helpful !

Thank you very much for your reply. The current forest comes from some plantations about 200 years ago, but it is quite dense, and as you can see in the image the importance of root sprouts is very large. I imagine that the structure of the vegetation that we find in the Canary Islands is more similar to the dense forest than to the open formations. Thanks again for your comment.

Yes they extensively do as an integral part of symbiosis ....

Hallo Anastasia,

ich antworte mal in Deutsch, da Du ja auch in Deutschland auf der Suche nach Samen bist. Der wahrscheinlich einfachste Weg, an gutes Samenmaterial für heimische Bäume zu kommen, ist irgendeinen staatlichen Revierförster zu fragen, also den zuständigen Förster für eine bestimmte Region. Wer das in welcher Region ist, erfährst Du beim zuständigen Amt für Ernährung, Landwirtschaft und Forsten (Name des Amtes kann von Bundesland zu Bundesland ein bißchen variieren.

Gruß

Martin

Thank you for sharing your photos!! It is very nice color. I hope you will be able to propagate this plant in one way or another. I am convinced it would be a success for home gardens and municipal green areas.

Hello check those 2

Dear, Nathan J. Wright

please go through this link

With photos is difficult to ID at species and genus level, however  try to see if your specimen follow this characteristics of Gelis.

Characteristics of Gelis include: 1. Body size (mm) (excluding antennae and ovipositor):<10mm; 2. Position of spiracle on Tergite 1 (T1 of metasoma):clearly behind the centre; 3. Shape of aerolet in forewing:other; 4. Colour of face:only black; 5. Metasoma compressed:dorsal-ventrally; 6. Size of Ocelli:small; 7. Length of antennae:shorter than body; 8. Length of ovipositor:not longer than body; 9. Wings:present; 10. Colour of wings:mostly clear but with dark patches/spots; 11. Sternaulus (on mesopleuron):short; less than 0.5x length mesopleuron; 11. Sternaulus (on mesopleuron):long; more than 0.5x length mesopleuron; 12. Shape of face in lateral view:flat or only weakly bulging; 13. Sternite on T1(viewed laterally):sternite not extending past spiracle; 14. Shape of T1(viewed laterally):evenly curved; 15. Number of teeth in mandibles:1 or 2; 16. Patterns on metasoma:same colour throughout; 17. Length of T1 vs T2:subequal in length; 18. Sculpture on mesoscutum:finely pitted, many hairs; 19. Width of T1 (viewed dorsally):gradually widening from anterior to posterior; 20. Glymma on T1:absent; 21. Sculpture on metasoma:smooth with a semi-glossy or satin appearance at least on T2; 22. Propodeum length:Propodeum very short (not reaching beyond coxal insertion).

Thank you very much for your help Aseesh. We will keep in contact

Here it the large file document

Oil quality not affected if you used low temperature. You can try de-moisturized by drying seeds in an oven under vacuum at 40-50 Celsius degree  for 24-36 h according to moisture content of seeds before extraction of oil.

Hi, sorry for cross posting. I would be grateful if we work on the origin and dispersal of Quercus species. If anyone would have interest and as our peers already have mentioned here.

Thanks a lot Dear Rudolf! Any idea what species it could be?

Gy

Nathan,

I am not too familiar with coppicing and pollarding. What I see is farming, where fast growth species such as popular (Populus sp.) or maple (Acer sp.) are grown to ~25 cm and then harvested for firewood. With staggered planting, the supply is constant. I suppose with coppicing and pollarding you would not necessarily have to worry about distinguishing between young growth trees and limbs, since young trees would be uncommon?

Hello Xiong,

There are two broad options for testing species identification using barcoding: 1) Percent Identity (PI) and 2) Genetic Distance (GD).

For PI most researchers use BLAST, however this method has been shown to either have similar or worst ability at correct identification and typically has far worst incorrect identification rate. Thus, using this method typically leads to a much higher probability of false identification then the GD methods. See Parmentier et al. (2011) for an example in rain forest trees (attached below). This method is also not robust to changes in the length of the sequences and is especially error prone with closely related species.

Thus, I would suggest using a GD method. These methods typically require building a global alignment and then gather distance data using a model of evolution. Then using these distances you can either build a phylogeny and look at what nodes sample fall in or just simply examining the matrix of distances and see what the closest match is. The Parmentier et al. paper has a good explanation of these methods and I also attached two other papers that are highly cited in the barcoding world that are great reads and may be helpful.

Best Regards.

 I have not come across such metric, although I did study oaks. From first principle I would assume such metric is not a species but rather but a site characteristic. Particularly, site management history will impact on both LAI and WAI, but with a time different time lag 

Symptoms on oak infected by Pezicula cinnamomea.

Try contact Dr. Spungis in Riga or Dr. Mamaev in Moscow - these are leading taxonomists for gall midges and may suggest something useful 

Hi, dear Omid Fathizadeh.

What about the leaf xylem water potential?

Dear Jean,

You can find most of the publications related to Q.ithaburensis in the reference list at the end of my paper mentioned above by Wendy.

If you need a PDF let me know.

The distribution of Qii and the characteristics of its populations in Lebanon are undocumented so your work can fill the gap and bring valuable information about this special oak.

Good luck

Hi,

Which Quercus? Different Oak ecosystems exist in the Mediterranean (Ilex/Coccifera/Suber for instance), with very specific ecological profiles, different fire regimes and therefore different response type to fire. So before telling you any preferred method, if one exists, what kind of Oak ecosystem do you want to study ?

Hello -Regarding oak provenences surry but I am not a genetist I am a selviculturalist for some information on oak provenence you can ask to Fulvio Ducci a collegue of mine.  happy new year

Oak and hornbeam trees also grow in the forests of northern Iran.Hornbeam leaves decomposed faster than oak and help to regeneration them.Pure oak forests with poor soils can be seen.

Hornbeam trees cause less light reaches the trunk of the oak trees.Oak trees will result in better quality.

Hi!

PCR conditions vary in minute details between labs, so annealing tempartures from the literature will always be guesses (or points to start optimizing from) to any user elsewhere, at best. Also, try to get high quality primers synthesized & purified.

The spacer you are using is useful for more detailed studies within genera and species, especially if you plan to sequence. Simply because it is a spacer and not a slowly evolving gene!

But then again, chloroplasts are tricky. In every "new" organism, there may be new mutations that make primer sites useless, or often there are repeats that mess up things. There should be Fagaceae complete chloroplast genomes available in GenBank, you could try and look at the exact region you want to amply in those sequences, for any repeats or unusual stuff.

Finally, the hint for my database on the web which lists hundreds of chloroplast primers:

(go to database - table - and filter for genes of interest). You may be able to find alternative primer sequence suggestions close to the region you are interested in.

Hope this helps somehow!