This is a more complex subject than you might imagine, and before we get too involved with answering the question of what the list of native trees should be. I think it important to understand just what a "tree" is.
In botanical terminology, "tree" is simply a woody perennial plant just like say, a sprig of heather is. However, everyone imagines a "tree" to be taller than a man; to have a woody trunk and branches; and for it to live to a grand age. So a botanist might describe a woody perennial plant forming a tree. But then what is a bush? You might have read a dictionary definition of a tree having a "single" woody trunk taller than a man. Well many tall trees branch from ground-level and don’t have a single trunk. A bush is perceived to be nothing more than a small tree, with nothing to describe it other than it being "bushy".
Take birch trees Betula sp. for an example. Before some of you say there are more native birches than these! I’ll mention the recently described B. celtiberica from Wales, and the B. odorata forms from Scotland. But for this example I want to use the traditional view that we have 3 species of birch in Britain, namely, B. pendula, B. pubescens both of which are clearly trees with trunks taller than a man. But then we come to the third native birch B. nana which is a prostrate, ground-hugging shrub no more than 1 m tall. Yet we call the birch a tree. The list of native "trees" is therefore not clearly defined, as any woody perennial plant might make it onto one person’s list but not someone else's.
Great Britain and Ireland is a group of islands, which were all connected via a frozen land-bridge to the European continent over 8000 years ago. Soon after the sea-levels began to rise to create our islands. Therefore, we in the British Isles have a benchmark of about 8000 years ago where we can say that species that made their way to these lands by themselves before 8000 years ago are considered native to Britain. Continental Europe doesn’t use our benchmark, instead they regard species that have seemingly arrived in their countries unassisted more than 5000 years ago are considered native.
Botanists in Britain & Ireland have a term "Archaeophyte" for ancient introductions that arrived, either assisted or unassisted by humans, in the British Isles after we became cut-off 8000 years ago up to the 16th century when our ancestors first started recording and documenting our species. Since we started recording c.1570 we can know roughly when species arrived because we have a record of it. So these more recent arrivals we call "Neophytes". On continental Europe they describe many of what we describe archaeophytes as being natives, because for them, anything being there over 5000 years ago are native. We also use the term "Denizen", for an archaeophyte, which behaves like a native species but suspected to be a possible human introduction, albeit either intentionally or accidentally. And then we also use the term "Cultivated", for an archaeophyte, or neophyte, which was introduced by humans as crops, now persisting in the wild. Often these terms are interchangeable or used in conjunction.
So consider this – the Midland Hawthorn Crataegus laevigata probably arrived in northern Europe around 6000 years ago, and it arrived in eastern Britain soon after. Having probably been a weed seed species traded in a harvest of wheat seed brought over from the continent by early farmers. In France this is native, but in Britain this is an archaeophyte. On a similar pattern – the Sycamore maple Acer pseudoplatanus probably arrived in northern Europe about the same time, so for them it is native. However, Sycamore was first recorded as a new arrival in Britain in 1632. Probably, again, in a harvest of wheat traded from the continent. You may well have considered Sycamore native, but it is actually a neophyte invasive species. Furthermore, it is quite a problem species for Britain as it reproduces fast, and it’s leaves shade-out British natives, consequently Sycamore is taking-over our woodlands at the detriment of native species, which are struggling to compete. For this reason Trebrown Nurseries does not offer Sycamore.
The Romans are certainly responsible for introducing many species to Britain nearly 2000 years ago. Some we know, many we guess were Roman introductions. To name a few species – Box Buxus sempervirens, Barberry Berberis vulgaris, Pears Pyrus sp., and the English Elm Ulmus procera. So these are denizen archaeophytes in Britain.
At Trebrown Nurseries we specialise in both natives and archaeophytes of the South-west of Britain. Therefore, we list natives and archaeophytes separately. But consider them all important species in the wild. It is almost impossible to put a number on how many natives we have in Britain, as we’d first need to determine how many different species of birch, willow, sorbus, and elm we actually have. Expert opinions differ and it will probably require DNA fingerprinting to work-out individual species in many genera. However, the current list of natives & archaeophytes we’re growing at Trebrown Nurseries is well over 100 species, and the largest number being grown anywhere in Britain.
Trebrown Nurseries is a botanist-led nursery. Therefore, we’re science-led and of-course we’re always correct! Or at least aim to be, and correct ourselves as and when the science changes.
We can grow whatever trees we like, and we can sell our trees to whoever wishes to buy them. However, when it comes to selling trees for forestry use they come under the regulations imposed by the Forestry Commission (now known as Forestry England). They produce a list of regulated forestry species known as Forest Reproductive Material (FRM), and you should go and read our document about FRM and what it means, before continuing reading here.
The Forestry Commission are not going to like what I have to say about their FRM list of natives. But what I say is correct, as of their native list accessed on this date 08/09/2024. Remember, it is not defamatory language if the facts expressed are true. I have discussed these issues with the Forestry Commission at length; I have explained the reasons why they’re wrong; I’ve even advised them on ways to try and correct some of their errors to make it easier for them. I’ll provide their response in a moment. First let me talk you through the Forestry Commission list of native FRM species:
The Forestry Commission produced their list of 116 woody plant species. Much of that list is non-native commercial timber producing trees, as you’d expect, and there’s nothing wrong with that. However, of that list they include 64 species as their list of British natives. Of those 15 are controlled species. Meaning they cannot be sold for forestry purposes without certification. The remaining 49 on their native list are certified under the voluntary scheme. Meaning they can be sold without FRM certification, but of-course foresters prefer their trees to be certified, so we aim to certify them where we can.
I refer to their list of natives as "The Scottish List" because it lists only the natives that happen to occur or regularly planted in Scotland, and was evidently drawn-up by a nurseryman in Scotland. For example: it lists Daphne laureola, but neglects Daphne mezereum from England; they include rare species like Juniper communis subspecies nana, as that occurs in Scotland, but they neglect Juniperus communis subsp. hemisphaerica from Cornwall. And you can also notice that they even spell the scientific name wrong with that! They also list Ulmus glabra, as that is the Scottish elm, but neglect the 70 or so elm species from England and Wales.
When I told them this is the Scottish list, they replied with, "The list was complied by the leading experts". No! They never asked me! And as a botanist I know all the leading experts in Britain, and they didn’t ask them either!
When I explained to them that they forgot to list Sea buckthorn Hippophae rhamnoides and that it’s odd because that one also grows in Scotland, they had no reply.
The main issues I have with their list is that it omits all the elms of which we really need to be certified for forestry use. Also, the list of Sorbus sp. is lacking. They’ve obviously tried to be accommodating for they include Sorbus aria sensu lato, the Latin of-which means "S. aria in the broad sense". So under this title we can list the complex Subgenus Aria group S. aria sensu stricto and the Sorbus eminens group of S. eminens, S. eminentiformis and S. eminentoides; and of the Sorbus porrigentiformis group S. cheddarensis, S. leighensis, S. porrigentiformis, S. whiteana and S. wilmottiana; finally, of the Sorbus rupicola group we can list S. margaretae, S. rupicola, S. vexans and S. rupicoloides. However, under this heading we can’t list the 4 species from the Subgenus Tormaria group or the 2 species from the Subgenus Soraria group, because they’re simply not Sorbus aria sensu lato. Neither can we certify Sorbus domestica because that is in a completely different Subgenus Cormus group.
The Forestry Commission’s response to all this is: "We’ve only just published these new documents, we have no plans to update them in the coming years."
But that leaves us in a situation where only some of our species can be certified for forestry use, and we have to issue statements of "Not for forestry use" to stay within the regulations. Or, as we do with our elms, we simply don’t allow you to purchase more than 1000 elms in any one order for forestry use, so that we can sell for forestry use but abide by the 1000 plant FRM exemption regulations’ workaround.
