Comparison of tree species and dependant insects

I saw this image posted on a Facebook group recently. There was no credit given but it seems to be a photograph of a book, pamphlet or maybe a slide from a presentation. I found it to be a very interesting reference and it's something I'll look back on when planting in the future.

I was particularly surprised to learn how supportive the birch and willows are. Both are fast-growing and often considered to be "weed trees" over here, taken out without much consideration. I have personally removed and cut back quite a few medium-sized willows on our land as they frequently fall over onto our fences and the hazel stools in our copse. They've always struck me as being a bit of a nuisance so it is nice to learn of their importance for insects.

We only have a small number of silver birch but, as a result of finding this image, I'll encourage a few more to grow and thicken up the boundaries of our woodland. They grow quickly, which will help thicken up the woodland around the barn that we will be building, shielding it from wind and view, and they look very pretty in the winter. If we have to remove any in the future, the wood burns very nicely too, as a bonus.

Great list! Leaves me wondering which willow variety they speak of and which oak particularly.
If you've got a lot growing of a species i doubt it's really helpful to be very careful not to lose one of those.
At least, that's what this group in southern France strategized. They got people to buy trees from their nursery, a choice of ninety tree species and varieties, they contacted farmers to plant them in their hedges for free and the farmer signed a contract never to cut down or sheer the tree. This way hedges would become refuges for insects and therefore insect biodiversity would increase over miles and miles. This diversity would keep plague insects much better in check in monocultures was their thinking. Because they'd be around somewhere in the hedges.
I proposed why not to make a forest, they claimed the hedge angle would be more effective, which ithought was an interesting one.

I always tend to focus on the the 'bad' bugs when it comes to specific trees.

In the case of the Birch tree, that is the Birch Leafminer and Bronze Birch Borer.

You get plenty of results when you look up birch specific insects, but not as many when it comes to the insects that don't hurt the tree but rely on it.

I wonder where some tree specific literature could be found...

Hugo Morvan wrote:Leaves me wondering which willow variety they speak of and which oak particularly.

I also wondered the same. My suspicion is that they lumped anything in the Salix genus together as "Willow" and both our native oaks (Quercus robur and Q. petraea) as "Oak". It would be helpful to know, though!

We have a mixture of willows (S. caprea, S. cinerea and hybrids, along with planted S. viminalis and S. fragilis) so I'm comfortable that they are supporting a good cross-section of those insects. Our oaks, to my knowledge, are all Sessile Oak (Q. petraea) and I have no idea how that compares to the English Oak.

The hedgerow scheme that you mentioned is interesting. There is a lot of conversation in the conservation community (hah!) about hedgerows acting like "wildlife corridors" and effectively connecting areas of smaller woodland into a larger, more resilient one. You may be aware that species require a minimum viable population size (= area of habitat) in order to cope with freak weather events, drought, disease, etc. The effect of connecting areas of woodland habitat using hedgerow corridors facilitates larger population sizes as well as maximising the amount of 'edge' that the woodland has.

Timothy Norton wrote:I always tend to focus on the the 'bad' bugs when it comes to specific trees.

That's an easy trap! I wonder if our language surrounding 'bugs' makes it easier to think of pests? 'Bugs' definitely brings to mind pests, parasites or 'creepy crawlies' - perhaps a word like 'invertebrates' is more neutral.

Another thought is that 'bad' bugs for one tree might be the food of 'good' bugs for another. My view is that more diversity is always better; sure there are more pest species but there tend to be more predators for them too. It's only in really unbalanced ecosystems, where a few species dominate, that issues seem to arise.

If you happen across any good literature, do post them for us to read!

In my ecosystem, willows provide pollen super early in the spring. Therefore, since few other things produce pollen during the willows flowering time, willows get mobbed by insects.

In the fall, asters fill that same niche.

Therefore, for maximum pollinator health, I'm increasing the population of willows and asters on my farm.