I completely agree that not all nigra seedlings will suffer from the same problem and maybe the odd seedling will be a fast grower… My seedlings all produce a tremendous amount of roots which I estimate to be about 3/4 of the total biomass of the plant but still they grow slowly. It is indeed a fact that they consume less water than other mulberry species and will more likely suffer from root rot than dehydration.
As for the “invasiveness”…I think that the person who wrote this paragraph doesn’t really know what Morus nigra is and is actually referring to black fruited Morus alba as is so often the case. Morus nigra is only borderline hardy in Denmark and Austria and it certainly can’t “escape from cultivation” that is actually a quite ludicrous statement…
Another hoax is the oldest nigra tree in the UK… this tree was supposed to be growing during the time of Shakespeare. It has long since been proven that this particular tree is not at all the same tree that was referred to during Shakespearian times. Nigras do indeed grow very old but not that old. I think that 200 years will be more than enough! The thing with M.nigra is that their typical habitus always makes them look much older than they actually really are and that is just the beauty of this species. After +/- 50 years they will already be windswept, gnarled and twisted if left alone and exposed to the elements and they will look like they are over 100 or 150 years old…
Well that would be scientists world wide. The info is from the Invasive Species Compendium. The Invasive Species Compendium (ISC) is an encyclopedic resource that brings together a wide range of different types of science-based information to support decision-making in invasive species management worldwide.
The US Department of Agriculture is a lead partner with CABI in the development of this Compendium which has been resourced by a diverse international Consortium of government departments, non-governmental organizations and private companies (further information is provided on this page).
The ISC could not have been produced without the collaboration of experts from around the world. See Contributors for the list of the authors, reviewers and consultants who have helped develop the Compendium.
I would describe that as a short to normal life span for a tree. Figs in the same family have numerous examples of 500 year old trees. In China they have peach trees over 500 years old.
Trees know their clonal age, so the fig tree called Violeta was brought to Portugal 600 years ago. We still grow clones of it, and the clones because of natural mutation have a clonal age. Eventually you will not be able to clone it. Too many damaged genes.
More info on clonal age.
In my country old Morus nigra trees are protected by law because they are so rare…far from being invasive! It is commonly agreed that Morus nigra is a species that barely reproduces by seed and furthermore growing conditions in Denmark and Austria are far from ideal for Morus nigra…for both reasons I would think it very unlikely that Mn could be an invasive species, especially in countries with unfavourable growing conditions. Scientists sometimes force research into a certain direction or copy papers from unreliable sources just for the sake or obligation to publish sth. Much “scientific” literature on Mn is especially prone to this type of abuse. The false info on Mn which is distributed over the internet, scientific or not, is just staggering.
About the age of Mn trees: I fully agree that the ability to sexually reproduce will finally be lost if a tree is continually asexually reproduced. Maybe that is the reason why they are generally hard to reproduce by seed…genetical damage… When referring to the age of individual trees, not clonal reproduction of the same tree, I really think that Mn doesn’t grow that old. The wood of Mn is not very durable and will soon start to decay when exposed or damaged. The natural ability of Mn to take root when branches touch the soil can rejuvenate the tree and create new clones while the original tree succombes but that too is clonal reproduction and the original tree finally disappears. In the case of the Shakespeare mulberry in the UK…the tree was removed in 1756… there are a few really old mulberry trees in Stratford-upon-Avon and these may have originated from the same tree but in any case the original tree is no more…
In China they can grow native peach trees to 500 years but here they live 25 at best. Plants react differently in different environments. The article is foot noted to death with references to countries that consider it invasive. The website is very impressive. They still conclude that the invasiveness needs further study. I’m very impressed with this project. Heck they even go over other uses of the plant.
Wood Products
Boats
Charcoal
Containers
- Boxes
- Cases
- Cooperage
- Crates
Furniture
Sawn or hewn building timbers
- For light construction
Woodware
- Industrial and domestic woodware
- Tool handles
Gaps in Knowledge/Research Needs
Further research is needed to assess the invasiveness of this species. While it is currently reported to be a cultivation escape in Austria and Denmark (Randall, 2012), and invasive in Parana, Brazil (Biondi and Muller, 2013), the combination of invasive traits and its continued cultivation in temperate regions around the world warrant a review of invasive status. Other areas of recommended areas for research include prevention and control methods of the species, important particularly for areas surrounding plantations and land where the species is cultivated
https://www.cabi.org/isc/datasheet/34830#tosummaryOfInvasiveness
It is definitely worthy of consideration…There is no telling how long Morus nigra has been clonal propagated; could have been several thousand years.
When @jujubemulberry postulated this in reference to jujubes in his book, I was quite suspicious, but happened upon that article you referenced here, and realized once more that I am still not omniscient.
LOL! Funny, yes agree 
Me too, once I thought I was wrong
A great story about Bamboo and clonal age. Bamboo flower once every 120 years. Well in the 1800’s clumping bamboo became popular for ornamental reasons. I agree, they are lovely! I have a very nice clumping cultivar myself. Anyway they cloned and sold a lot of them. One hundred and twenty years later they all flowered and died! All across the USA. If the clone was not old enough to flower, when it was, it did and died. They knew their age! Clone or not! About 5% will survive, but not without specific care.
This is fascinating because how can they tell? It would be cool to figure out how the plant does it. It’s not a mutation thing, like with the Aspens. Genes get hit by random radiation and mutate from the damage. That is fairly straight forward.
In humans this happens too. Do you look the same as when you were 20 years old? No, age is a symptom of genetic damage to our cells from radiation and other factors. Mitosis is like a photo copy of a photo copy of a photo copy. They fade with time, like the color of my hair. Damage to our genes results in color loss, wrinkles, and a host of other things. Loss of hormones etc. All caused by radiation that changes our DNA by striking it. Nothing can stop it. Just as true for trees or any other living thing.
Funny as I hear people say cancer rates are high, and to me I think it is amazing we all don’t die of cancer right away! We are up against the universe. We are not going to win, yet we maintain for almost 100 years. Keep eating those berries! Get some alba while waiting for the nigra seedlings!!!
Yesterday I ate raspberries, tayberries, marion, black currant, honeyberry, blueberries, New Berry, mulberry, and White Gold Cherries. Just a few of each as I was harvesting them, and working on the garden. I like to snack while working!
Yesterday’s White Gold cherry harvest. A little over 7 pounds.
Amazing what is stored in genetic code. “Cracking” genetic code will most likely be not only the biggest challenge that genetics research will ever face but perhaps the ultimate challenge of any scientific endeavor. They can already assemble genetic code, so once it is possible to read it (know precisely every command in the code), the next step would be to create whatever life-form desired. But…it ain’t a happening anytime soon. It will be most likely something akin to solving the ultimate question in “The Hitchhiker’s Guide to the Galaxy”.
https://www.youtube.com/watch?v=aboZctrHfK8
I have recently invested into companies using the brand new CRSPER gene splicing technique. I invested in stock. Four companies. CRSPER is so easy and so cheap you can gene splice at home. And people are doing it too. One guy who breeds dogs wants to make a glow in the dark dog. Has been home splicing his dog’s sperm with the jellyfish gene for glowing. . Another guy is injecting himself to correct a genetic flaw. It’s kinda crazy out there right now.
I checked the whole article and after reading it carefully one would actually believe the content to be correct because of it being so complete and professional. But checking the references I did not find any real description of what the authors consider to be “Morus nigra”. Morus is a plant family that is so complicated because of the large amount of species within it and subspecies within the species. Furthermore all these species (except Morus nigra) will hybridize freely and make things even more complicated. I fully understand that many scientists get things confused and would actually consider black fruited Morus ssp to be Morus nigra. The first picture in the article on Morus nigra from Invasive Species Compendium which you are referring to, showing branches with leaves and fruit in various stages of ripeness, is actually 100% Morus alba and not Morus nigra…this proves my point exactly…
I agree…It is a rather blatant oversight on their part.
After successfully hybridizing Morus nigra, do you still feel that it is a rare occurrence?
That is troubling… In the hands of the general public, I feel that the first widespread use of the technology will be to enhance a certain body part.
As a scientist I do not! It is 100% unacceptable no exceptions.Since alba is considered invasive too. If they can’t tell the difference they should be replaced with somebody who can. it’s not that hard after all.
But to say because one of hundreds of scientists (maybe thousands, did you see that list?)got a photo wrong, It would be stupid to disregard the whole project. It actually matters very little. It’s a simple error.which I myself would not use to reflect on the project in any way.
i like the word ‘postulated’ , Mark, and not ‘concluded’ 
radiation, cancer, and lifespan are three paradoxical things:
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radiation can cause cancer, but many times-- to cure cancer, the afflicted must undergo radiation therapy
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cancer cells are practically immortal(think HeLa cancer cells which are still cloning indefinitely in laboratories all over the world since 1951). Who would have thought that dangerous radiation can result in immortality?!?
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cancer cells maybe immortal, but it is its own enemy, since cancer will first kill the host which would, in turn, cut their supposedly immortal lives short…
lastly, i have whimsically digressed far and wide from two species of M nigra… am forever banned say the mods… again…
I did indeed hybridize Morus laevigata x Morus nigra but that certainly took some effort and the seedlings took a lot of nursing (and many years) to finally grow them out as fruiting trees. I don’t really believe they actually would have survived in the wild… but you never know…
About Morus nigra being an invasive species… The distribution map https://www.cabi.org/isc/datasheet/34830#tosummaryOfInvasiveness shows presence in many tropical countries. I was wondering about the possibility of growing this species in a tropical climate… unlike many tropical Morus species, Morus nigra is a deciduous temperate-subtropical species that needs chilling during a dormant period in order to thrive. These conditions are not present in tropical regions. It is impossible to grow apples, pears or even persimmons (temperate-subtropical) in tropical regions because of the chilling requirement. How then does Morus nigra grow and even thrive in tropical regions?
Elevation will allow for chilling.
A couple of years ago I attempted to chase down surviving Morus nigra’s in hot, humid regions of the world, but every possibility proved false. I was hoping to find genetics that would allow Morus nigras to thrive in the southeast US.
I suppose it might be possible for Morus nigra to survive in a tropical location that is dry (without consideration for the chill factor), but having been to St. Lucia, I don’t believe it is plausible…St. Lucia is about as tropical you can get.
Chilling during a dormant period means a significant seasonal variation in temperature. This is not the same as a daily drop in temperature or a momentary temperature drop because of weather conditions at high elevation in tropical regions.