2 posts tagged with

grey alder (Alnus incana)

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Treeblog Video #1. Set A update: grey alders (October 2012 & June 2013)

I have been very lax for a while now in keeping Treeblog updated with the development of the Treeblog trees. I intend to make amends in the coming weeks by posting updates on all the grey alders, Scots pines, downy birches, rowans and beeches in the Treeblog stable – starting now with the Set A grey alders, which last appeared on these pages over fifteen months ago in this update from March 2012. But before I go into an standard update, please take a couple of moments to watch Treeblog’s first ever video which provides a brief overview of the life of my grey alders so far!


So I’d just like to say, if it wasn’t obvious enough already, that this was my first time doing anything like this on film (and I apologise for my weird Yorkshire accent)! It would be great to get some feedback on the video as I am genuinely interested in what you thought, and Dave Clancy and Steve Young, who did all the filming and editing, would also really appreciate hearing your views. You can leave a comment at the end of the post or you can send an email to the address top right. If you enjoyed our little film then I politely encourage you to spread the Treeblog word by tweeting a link or something!

Right then, on to the update proper!

This is grey alder No. 1 on the 9th of June 2013 (Set A Day 2265), the same day as we filmed the video. The tree is alive and well; the sheep haven’t been back to finish it off.

This is grey alder No. 1 a few months earlier on the 19th of October 2012 (Set A Day 2032), back when I made a pre-winter tour of the alders with my father.

This is No. 1 on the 9th of June again, taken from a similar angle.

When I visited in October I noticed that alder No. 1 had a cluster of maturing female catkins…

…as well as a couple of clusters of immature male catkins, ready to open up and release pollen in spring.

I also visited the alders on the 30th of December 2012, minus my camera. My notes from that day record No. 1 having some mature female catkins and a few male catkins, No. 3 having many male catkins but no female catkins, and No. 2 having no catkins at all.

On my June visit, No. 1 again had two or three clusters of immature female catkins. I didn’t see any sign of last year’s catkins.

This is grey alder No. 2 in October with yours truly for scale...

…and here’s No. 2 again on the 9th of June. It is still the best of the three grey alders in my opinion.

No. 2 had no catkins at all last year, but on my June visit I counted at least six clusters of immature female catkins (but no male catkins).

Here’s grey alder No. 3 in October…

…and here it is again in June.

In October, No. 3 had at least six clusters of male catkins but I didn’t notice any catkins at all on my June visit.

Now for some tree stats. I made measurements of height, stem circumference at base, and stem circumference at breast height (approx. 1.5 m) on my October and June visits, but made no measurements in December. Previously I estimated height by hanging a tape measure off a stick held up to the height of the trees, but (as seen in the video!) in June I took my bespoke measuring stick, fashioned by my father in 2008 and originally used during my dissertation fieldwork! Heights are approximate to the nearest 0.1 m and circumferences are approximate to the nearest centimetre.

Grey alder Height (m)
Oct 2012
Height (m)
Jun 2013
Increase (m)
No. 1 3.1 3.3 0.2
No. 2 3.5 3.6 0.1
No. 3 3.6 3.6 0
Grey alder Stem circ. at base (cm)
Oct 2012
Stem circ. at base (cm)
Jun 2013
Increase (cm)
No. 1 15 14 -1*
No. 2 18 18 0
No. 3 18 19 1
Grey alder Stem circ. at 1.5 m (cm)
Oct 2012
Stem circ. at 1.5 m (cm)
Jun 2013
Increase (cm)
No. 1 7 8 1
No. 2 9 10 1
No. 3 9 10 1

* This only goes to show the potential errors hidden in these measurements!

And here is the base of alder No. 1. It has a much more slender stem than Nos. 2 and 3 and still shows severe wounding caused by grazing sheep. The tree seems to be struggling to compartmentalise this damage by growing ‘wound’ wood.

In stark contrast, the base of alder No. 2 is in pristine condition!

The base of No. 3 still shows sign of sheep damage but the wounds are rapidly being covered over with new wood and should hopefully be undetectable in a few years.


* * * * *

Coming soon: behind the scenes on the Treeblog shoot!


Posted in The treeblog trees





More signs of spring: alder and hazel buds and catkins

Common alder (Alnus glutinosa) male catkins, perhaps slightly past their best which may be why they are more red than yellow.

Yesterday was a lovely warm day, perhaps even lovelier and warmer than the day before yesterday which, certain newspapers yesterday reported, was the warmest day of the year so far. To make the most of it, I went on an adventure down Ewden. As luck would have it, I was successful in my ongoing quest for photos of alder catkins. Hooray!

A closer look at a pair of alder catkins. Now hold that image, because I want you to compare them with the hazel catkins below…

Hazel (Corylus avellana) male catkins. Much prettier than the alder catkins, if you don’t mind my saying so.

More hazel catkins, but these ones aren’t fully ripe. The bottoms of the catkins haven’t opened up yet.

These unfurling hazel leaves were down in the valley bottom next to Broomhead Reservoir. It must be milder down there than higher up the hillside, where hazel leaf-unfurlage hasn’t yet begun.

Two kinds of alder, going head-to-head in a bud-off. On the left… the top of treeblog’s very own grey alder No. 4 from Set A; on the right… the end of a common alder (A. glutinosa) twig of Ewden provenance. Common alder, with its glamorous purple buds, is a British native. The grey alder (Alnus incana) is not.

Oh-ho! While the buds at the top of grey alder No. 4 aren’t showing any signs of bursting just yet, buds lower down are opening to reveal their infant leaves! (The twig below the bud may look sticky in this photo but it’s only water – I’d just given the trees a soaking with the watering can.)

And this is the post-Set A unknown seedling. It too is getting in on the spring action. See how it mobilizes that upper bud!

Other signs of spring sighted include hawthorns flushing, lambs, frogs, and bulbs sprouting up from the woodland floor.



Set C update – Day 5 (yesterday): No sign of germination yet.


Posted in Gone for a walk





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