Ginkgo changing sex (from male to female) after many years

[ShimpakuBonsai]

Yesterday I was watching a TV show about houses (in the Netherlands) and their owners.
When the owner of the house showed his garden he told that the old Ginkgo tree changed sex (from male to female) a couple of years ago.
He said the tree has done this because the tree "knows" that there are no female trees in the neighbourhood and it needs to produce seeds because of that.

I had never heard anything about this and I have searched Google a little bit about this subject.
I read something about examples of individual branches on Ginkgo trees changing sex from male to female but the phenomenon is rare making it difficult to study.

Before I saw it on TV I have never heard anything about this and I would like to know if this is something specific for Ginkgo trees or that you can also see it with other tree species.

 

[Bonsai Nut]

I have heard about this in the animal kingdom... but never with plants.

I have a few sexually dioecious plants (American hollies, winterberries, princess persimmon, American persimmon) and have never heard about them "changing" sexes. Interestingly, there are two native occurring varieties of American persimmon in the US. The variety that is native in the northern part of the east coast has 90 chromosomes and can set fruit parthenocarpically (without pollination). The variety in the south has 60 chromosomes and requires pollination.

 

[Nybonsai12]

 

[Lutonian]

Ginkgo: The Tree That Time Forgot by peter crane is about the best deep dive on ginkgos there is, he covers this topic and many others worth a read

 

[Wires_Guy_wires]

Cannabis can do that too. It seems to be mostly wind pollinators that are able to do this, because they're usually the only ones that need to.
It can be a result of stress (drought, heat) or chemical treatment (silver thiosulphate).

The mechanism isn't well understood. I myself hypothesized that sex genes in plants aren't as straight forward as XX and XY, but more likely to be a multitude of those (like XXYY) with one sex supressed "unless".
It's very rare to see a full gender switch in which the previous one isn't presented anymore.

 

[Wires_Guy_wires]

He said the tree has done this because the tree "knows" that there are no female trees in the neighbourhood and it needs to produce seeds because of that.

Peoples love for trees sometimes makes them do weird things. Male plants are never on the receiving end, so they have no way of knowing whether or not they succesfully pollinated another plant.
Female plants do not reduce pollen presence in the air either.

So it either has a biochemical sensor that scans nearby soil, and a feedback system to tell the tree any results.. Or it's just a made up story. A romantic one! But probably made up.

 

[Cajunrider]

Peoples love for trees sometimes makes them do weird things. Male plants are never on the receiving end, so they have no way of knowing whether or not they succesfully pollinated another plant.
Female plants do not reduce pollen presence in the air either.

So it either has a biochemical sensor that scans nearby soil, and a feedback system to tell the tree any results.. Or it's just a made up story. A romantic one! But probably made up.

I don't know about ginkgo but a male papaya can be stressed by injuries such as severe chops and start to produce female flowers and bear fruits. I have done this a few times in my years. However, it will still have a heavier slant toward being a male tree ( fewer fruits, fruit more elongated, still produce lots of male flowers, etc..)

I submit that the male trees know nothing about the success of their pollens. They are just genetically coded to maximize possible offspring in time of stress to improve the chance of survival.

 

[ShimpakuBonsai]

Thanks for the replies so far. It's a very interesting subject.
Because it was only mentioned casually in the TV show and the Ginkgo was only shown partly I'm not sure if the owner meant that the tree completly changed sex or only partly (some branches).

It was a very old tree in the middle of the back yard of a very old house (build in 1613).
On the picture below you can see the trunk of the tree partly on the right side of the picture behind the glassdoor.