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Britain’s widest conifer, a giant redwood, at Cluny House Gardens

Britain’s widest conifer.

After I’d been around the Birks o’ Aberfeldy, I drove to the nearby Cluny House Gardens because I’d recently heard that Britain’s biggest-girthed conifer grows there…

…and I wasn’t disappointed. What an impressive tree it is! Not only is the trunk massively massive, it also reaches some pretty lofty heights. This champion tree is, surprise surprise, a giant redwood (Sequoiadendron giganteum) a.k.a. a Sierra redwood or giant sequoia or Wellingtonia. An information board in front of the tree informs the eager tourist:

A Perthshire plant collector, John D Matthew, introduced Giant Sequoias into the country from California, in 1853. The two Cluny trees were planted around this time possibly from the original seed collection. This magnificent specimen stands at around 45 m (135 feet) in height, has a girth of 11 m (35 feet) and is the widest conifer in Britain.

Giant Sequoias are very fast growing averaging 0.75 m (2 feet) per year in height until they reach a height of about 60 m (200 feet). Vertical growth then slows down but growth of the trunk continues at a rate of 50-70 mm (2-3 inches) a year sometimes as much as 150 mm (6 inches) annually.

The woody cones are 50-100 mm (2-4 inches) long and roughly spherical reaching full-size in the first year but maturing in their second. They can remain on the tree for over 20 years. In their native woodlands in California, forest fires are necessary to open the cones while they remain on the tree. The heat releases the seed which falls and germinates in the ash. The trees themselves are protected from fire by a very thick fissured layer of soft bark up to 300 mm (12 inches) thick.

A bit of zoom to peer into the canopy.

This is the massive tree at ground level with a human scale. It’s much more impressive in real life. The Tree Register’s excellent handbook, Champion Trees of Britain & Ireland by Owen Johnson, lists the tree as having a diameter at breast height (1.4 m) (dbh) of 360 cm and a height of 41 m in 2009. By comparison, the largest tree in the world (by stem volume) is the giant redwood General Sherman in California – Wikipedia records it as being 83.8 m tall with a maximum basal diameter of 1,110 cm and a dbh of 770 cm – therefore it is more than twice as tall and twice as thick as the British girth champ. There are even taller sequoias - the tallest is 95 m! - and even wider sequoias - General Grant has a dbh of 880 cm! (Wikipedia’s Sequoiadendron page has all the stats.)

A visitor to Cluny House Gardens is bound to see red squirrels. There is a feeder beside the redwood, and while I was marvelling at the tree one of the little fellas was eating its fill. This was my first opportunity to observe red squirrels up close – although I couldn’t class them as ‘being in the wild’. The info board next to the tree says that they have been seen just 2 metres from the top!

The Gardens have a relaxed vibe to them. Mind you, I was the only visitor in there! You can borrow a walking stick as you enter (free entry when I visited, but there’s a donation box), and one of the first things you see is a sign asking you to PLEASE WALK ON THE LAWN - I knew straight away this was a cool place.

There is a second giant redwood, although it isn’t quite as big as its buddy. My Champion Trees of Britain & Ireland gives its height as 33 m and its dbh as 331 cm (although it seemed to me there wasn’t much between the two redwoods’ heights).

This is where the second giant meets the grounds. Incredible.

Looking up at the No. 2 redwood. What a fantastic tree!

Here’s one of the cones. I’d love to collect some seed one day and grow my own redwoods.

Under the second redwood, a delicate mushroom: could it be a pink waxcap (Hygrocybe calyptriformis)? But then wouldn’t it have a split cap, or is this just a young specimen?

Posted in Holidays and field trips + Notable trees

Photos from a walk down Ewden (21st February 2009): Part Two

Carrying on from where I left off... While Part One was all about the broadleaves (and there was holly and hawthorn and sycamore and ash), Part Two is all about the conifers (and there is pine and Sitka spruce and larch, plus cameos from holly and oak). Enjoy!

Right on the edge of Broomhead Reservoir, a couple of the wee nippers that are springing up from seed dropped by the big forestry trees overhead. On the left, a luscious young pine (Pinus); on the right, a Sitka spruce (Picea sitchensis) seedling.

One particular spot, again right at the edge of the reservoir, was rich in chewed up spruce cones. The one shown in this photo is wedged between the spikes of a holly leaf. I saw another also wedged on a holly leaf and one wedged upright into a crack in the stump of a felled tree (see photo below). This stump was the centre of the cone stripping activity - obviously a favoured eating spot for some creature. From my Animal Tracks and Signs book, by Preben Bang and Preben Dahlstrøm:

Cones are a very important food… and conifer seeds form the bulk of [a squirrel’s] diet for a large part of the year… Fallen cones… are generally gnawed on the ground. The squirrel will usually sit on a little hillock or tree stump, so it has a good view all around and can spot possible danger in plenty of time… Squirrels begin gnawing at the base of the cone, holding it tilted with their forepaws… When it cannot tear off any more scales… it holds the cone firmly against the ground or branch, with one forepaw on the tip and the other on the scale-bearing section… Squirrels do not normally gnaw off all of the scales, but leave the top ones like a little tuft at the top of the axis. Clearly it would be difficult for it to gnaw off these last few scales, as this is where it has hold of the cone with its paw… As a particular squirrel will always hold a cone the same way, squirrels can be divided into right- or left-handed…

The distinctive, redonculously long leader of a Sitka sapling in an area of natural regeneration following clearfelling.

A recently cut spruce stump. We planted you; we let you grow big and strong; and then we cut you down, because all we ever wanted was your body.

Don’t forget to look up! The green trees are Sitka spruce and the bare trees are larch (Larix), one of the few deciduous conifers.

Much of the land just north of Broomhead Reservoir is forestry plantations of pine, Sitka spruce and larch. It might be owned by the Forestry Commission, but I’m not sure. A few years ago they clearfelled a patch, and more recently some thinning has being going on. Some of the trees that consequently became more exposed have since blown over. The cone in the photo is right at the top of a windthrown Sitka spruce, somewhere I wouldn’t normally get to see. The cones of the other spruce commonly found in Britain, the Norway spruce (Picea abies), have pointy tips.

This is the very topmost tip of the same fallen tree. The distinctive twin blue-white bands on the underside of the needles are waxy strips where the stomata (‘breathing holes’ for photosynthesis) are located. Notice how the needles are pressed upwards close to the shoot at the top of the tree; lower down, the needles are held perpendicular to the tree (like those of the seedling in the first photo).

Posted in Gone for a walk

National Red Squirrel Week

red squirrel

Image © James Laing. See it on Flickr.

This week is National Red Squirrel Week (4th – 12th October).
Check out the Wildlife Trusts page here, which contains a list of events running during the Week. The Wildlife Trusts are using National Red Squirrel Week to get the public to record their sightings of red and grey squirrels to identify where the reds are thriving and where the raging hordes of greys are invading previously grey-free areas. Wildlife Extra’s National Red Squirrel Week page provides contact details to report your squirrel sightings to the relevant organisations around the UK. Get involved!

squirrel supporting itself between two tree trunks. “Awesome Ninja Skillz… I has dem”

Image from I Can Has Cheezburger.

Posted in Miscellany

Squirrels in Britain: the red v. the grey

Grey squirrel in the Royal Botanic Garden Edinburgh (25th of June 2008).

As you most likely already know, the red squirrel (Sciurus vulgaris) is Britain's native squirrel. But over the last century or so it has been largely superceded by the grey squirrel (Sciurus carolinensis), a native of North America. The greys outcompete the reds, which are then displaced from their territories. According to the Forestry Commission:

Greys can feed more efficiently [than reds] in broadleaved woodlands and can survive at densities of up to 8 per hectare. The density of reds is up to 1 per hectare in broadleaved woodland but can be as low as 0.1 per hectare in coniferous woodland.

The grey squirrel also hosts the ‘squirrel pox’ virus, by which it is rarely affected. But the disease can be passed on to reds to whom it is fatal. The range of red squirrels in Britain is therefore much smaller today than in the good old days before the greys were introduced.

From the point of view of British ecologists and conservationists the reds are the goodies and the greys are the baddies. Of course, individual grey squirrels don't know that they are invasive aliens causing the extinction of a fellow species. They are just doing what comes naturally. But the undesirability of the grey squirrel isn’t limited to its interactions with the reds; greys are predators of bird nests and strip the bark from trees, leading to poorer trees and poorer woodland owners.

Red squirrel at Cluny House Gardens, Aberfeldy (18th of November 2011).

So what is to be done? Land managers with a vested interest in reducing grey squirrel numbers (whether for the benefit of red squirrels, trees, or other wildlife) have a few options. Greys can be trapped, poisoned or shot. The Forestry Commission uses poisoned bait, but doesn’t advocate large-scale culls:

Eradication is not a feasible or desirable option given current methods. Worldwide, the record on eradicating small successful introduced mammals is very poor with research showing that low-level widespread culling has no impact on either grey squirrel numbers or upon damage to trees and priority species. As such it is ineffective and a waste of resources.

Even with new methods and unlimited resources, a successful eradication policy would require the total support of the public. Evidence suggests that a substantial proportion of the public would not support a grey squirrel eradication policy. This policy aims to create a balanced approach to wildlife conservation: controlling grey squirrel populations at a level which does not threaten our native woodlands and priority species.

So, member of the public… would you support a grey squirrel eradication policy? I would. The benefits are greater than one might first suspect: see these stories from the Guardian (quoted) and the BBC!

At Ridley's Fish and Game shop in Corbridge, Northumberland, the owner David Ridley says he has sold 1,000 [grey squirrels] - at £3.50 a squirrel - since he tested the market at the beginning of the year.


Simpson likens the taste to wild boar. Ridley thinks it is more a cross between duck and lamb. 'It's moist and sweet because, basically, its diet has been berries and nuts,' he said.

Both believe its new-found popularity is partly due to its green credentials. 'People like the fact it is wild meat, low in fat and local - so no food miles,' says Simpson. Ridley reckons that patriotism also plays a part: 'Eat a grey and save a red. That's the message.'


'A large squirrel would be enough for one-and-a-half people. The public really are being drawn to it. I think that it's because it is being perceived as a healthy meat. Southern fried squirrel is good. And tandoori style works. It is especially tasty fricasséed with Cornish cream and walnuts. But the one everyone seems to like is the Cornish squirrel pasty.'

Grey squirrel in the Royal Botanic Garden Edinburgh (25th of June 2008).

Posted in Invasive species + Pests and diseases

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