This oak has apparently been removed from the list of >9.00 m girth oaks on the www.monumentaltrees.com
website, although it still shows up on the map as tree No. 1681 in that size class (red symbol). This is presumably because it is considered multi-stemmed i.e. more than one tree. I have not visited this oak but doubt the validity of this judgement. In England several large oaks have this appearance, it resulted from splitting and subsequent reparation growth (as seen on the left). Is the stem on the right an integer stem grown without former connection to the rest or does it show evidence of connection similar as the stem on the left? What about the section facing the viewer?
This oak needs careful investigation before it is dismissed. I wonder if this has been done and if someone could inform me about it. If it is a single oak tree it is the only one in NL >9.00 m but if more than one tree, it has to come off my list of such oaks in Europe.
Royal Botanic Gardens, Kew
@ Aljos: multi-stemmed does not mean the same as "more than one tree" - it just means that one or more low branches have developed upright, trunk-like characteristics, making the girth measurement much larger than a single unbranched trunk for the same size of tree.
My own guess is that this could be derived from an old coppice stool.
Nice you came aboard at this website, I hope you will take part of the forum from time to time.
I agree with the opinion of Conifers.
The oak of Ruurlo has not been removed from the list, but just is not in the single trunk lists, only in the multitrunk lists wich you can click to from under all single trunk lists.
When you take the list of biggest oaks:http://www.monumentaltrees.com/en/world-quercusrobur/ you can see under the list: show also multistemmed trees; after clicking this link you get a list including the multitrunk trees. At the third page then you will find the oak from Ruurlo.
(or you can take the list trees of the Netherlands: see ttp://www.monumentaltrees.com/nl/nld/ and show or hide the multitrunk trees).
We don't consider this oak as more than one tree in the sense of several different trees planted or growing together from one point. No, we consider it indeed like Çonifers guesses as a coppice stool: it has a common base of only one or two decimeter height from wich originally around eight stems arose. Some of those have died, four large are alive and a small dead one can be seen.
From old photos can be seen that the oak in the early twentieth century was multi trunked. The stems did not result from splitting and subsequent reparation growth. I have seen several of those oaks in England. The photo here above is not very clear, but even the stem at left is not of the type you describe. I have placed some more photos of this oak at MT (as we call Monumental Trees), including some old ones from the beginning of the twentieth century (two of wich also can be seen at my old website:http://www.bomeninfo.nl/berkelland1.htm ).
So the oak is not dismissed as one tree but yes, dismissed as a tree wich has reached its great girth from one stem with one pith of growth. There has always been a lot of air between the trunks wich now together at the smallest point have a circumference of 10,25 metre, but the biggest of the single trunks at 1.3 m height only has a circumference of 4.6 metre.
About big oaks in Europe: you perhaps already have seen that there have been placed many photos / measurements of big oaks of Latvia. Only few have a girth of above 9 m, many are between 6 and 9 m. As can be seen they are mostly maiden trees, rarely they are pollarded oaks like many of the biggest in the UK. This is the same for Poland and Germany. The extreme high number of 9 m + oaks in the UK in part has something to do with the great number of pollarded oaks in the UK.
It should be interesting to count the numbers of maiden as well as pollarded oaks with a girth of over 9 m in the UK as well as all European countries. Better even of all oaks over 6 m in girth.
The maiden oaks wich have lost their haid from storm damage are of course a separate type, but sometimes it will be difficult to see if the tree has been a pollard for most of its life or it was a maiden tree wich lost its crown from relatively recent damage.
Nice pictures you added. Is to find out from which year the old foto's are?
The old photos are from around 1920 - 1930, I will look for it.