All posts from

March 2007

I love pine

In early February I stumbled upon Trees for Life's I love pine page. They had a competition running where they asked for a short answer to the question 'Why do you love pine?', with a winner and two runners-up selected each day from the 1st to the 14th of February. I won on the 6th of February with this tongue-in-cheek entry:

Because of the evocative aroma of its resin which conjures up memories of the Black Wood of Rannoch. Because of how sublime and majestic a mature pine appears when silhouetted against the setting sun. Because of the mesmerising nature of its wonderfully patterned bark. Because the incomparable experience of sauntering over the needle-carpeted floor of a pristine pine wood is undeniably divine. I love pine for all these reasons and more.

Here’s my prize:

This beautiful watercolour painting of a Scots pine tree in Glen Affric is by Joan Fairhurst, who has generously donated it to Trees for Life. This large, portrait-format print measures 40.5 x 51 cm. (picture area is 24 x 32.5 cm) and when framed will grace any wall with the beauty of the Caledonian Forest.

Thank-you, Trees for Life!

Posted in Miscellany

The Mother Beech

This fine figure of a beech is on the southern shore of Loch Tay in the central Highlands of Scotland. I spent the first week of September 2006 at the Firbush field centre there as part of my Ecological Science course with the University of Edinburgh. It was an awesome time, and we all had good fun. The titular beech was the focus of a project I worked on with three friends. Our field work was aimed at measuring and recording all offspring of the Mother Beech in the surrounding hectare. The diagram below shows the offspring around the parent, which is the centre point of the hectare. Solid dots represent offspring with a height below eye level; hollow dots represent offspring with a height above eye level (where eye level is defined as 160 cm). The upper bold dashed line represents the high-water level of Loch Tay, and the lower bold dashed line represents the northern boundary of a road and conifer plantation.

Posted in Holidays and field trips

The Capon Tree

The Capon Tree is situated on the bank of the River Jed about two miles south of the Scottish Border town Jedburgh. It is one of the last remnants of the ancient Jed Forest, most oaks of which were cut down during the Napoleonic Wars. Estimates of its age vary, although it must have reached a decent size by the mid-eighteenth century for in 1746 six of Bonnie Prince Charlie’s men were hung from its branches. Some time during the twentieth century its massive trunk split in two, and its branches are now supported by wooden struts. However, the Capon Tree is still alive and apparently doing well. I have visited it a few times, as it is on the way to Edinburgh from my home in Yorkshire.

In 2002, in celebration of the Golden Jubilee of Queen Elizabeth II, the Capon Tree was designated one of fifty Great British Trees by the Tree Council in ‘recognition of its place in the natural heritage’

The Capon Tree in December 2010.

Posted in Notable trees

The Mother Beech (September 2006)

the Mother Beech (7th September 2006)

I took this photograph from the cosy confines of a rowing boat on the still waters of Loch Tay (less than 2 hours after this one was taken). See the Mother Beech in the centre, her crown raised above the other trees crowding the shoreline. Ain't she a beauty? 35 metres tall with a girth of 3.8 metres at breast height were her measurements. For the record, the trees dwarfed by the big beech are mainly silver birch, alder and some immature oak and ash.

Posted in Holidays and field trips

A walk in the Hermitage of Braid (Part 1)

Yesterday I took a walk in the Hermitage of Braid, a small valley woodland area in Edinburgh. The trees are mainly broadleaved species, and there are quite a few big old specimens. Take the following, for example:

unidentified tree - maybe a Tilia?

Unfortunately, I didn't pay too much attention to what flavour tree it was. From the photograph the branches look beechey but judging by the bark I'd say this is probably some kind of lime (Tilia) or maybe an oak.

The next photograph shows another tree of the same species with an impressive wound. There was a fair bit of wind damage like this in the Hermitage.

wounded soldier

Even with all the deciduous trees still devoid of leaves, this little sycamore seedling growing on a burn-side rock appeared like a symbol of the impending spring.

sycamore seedling

The beech buds in the next picture might remain closed for another month or so yet. Bring on the summer!

beech buds

Posted in Gone for a walk

El Grande, Australia's largest tree, toppled

Poor old El Grande. Australia’s largest tree, killed through the folly of man, has been blown over in strong winds. The Herald Sun reports:

Standing at 79m [259 feet], the massive Eucalyptus regans - known as El Grande - stood unharmed by man for almost four centuries until the Forestry Tasmania burn-off went out of control.

..."This is the last chapter of a very sad story of mismanagement of our forests by Forestry Tasmania," Wilderness Society Tasmania campaign coordinator Geoff Law said. "Forestry Tasmania admitted killing the tree with a forestry burn in 2003. They would have cut it down in 2002 except the Wilderness Society blew the whistle on them.

…"It could have been an icon to the planet, but instead it has disappeared through incompetence."

Following the fatal burning, an inspection of El Grande was undertaken in April 2003 by the Wilderness Society. Some of the observations are quite amazing:

- The lower butt of the tree had been exposed for approximately ½ - 1 metre by a bulldozer or a similar machine. Some roots had been exposed and damaged.
- The fire had burnt to the tree and then had been drawing into the ground-level openings.
- The dry rot and wood inside the trunk had ignited and the configuration of draught holes at the base with outlet holes further up had acted like a furnace and chimney.
- The temperatures generated within the tree core mush [sic] have been extremely high, virtually "cooking" the tree from the inside-out!
- The external furnacing had extended to 60-65 metres where the flames appear to have exited from some hollow branches of this level. N.B. The charring is visible!

El Grande, although not the tallest tree in Australia, was the largest in terms of volume. According to (managed by the Giant Trees Consultative Committee), El Grande had volume of 439 cubic metres and a diameter of 595 cm (234 inches). Alas, this champion Eucalyptus regnans, estimated to be 350 years old, is sadly no more.

Posted in Notable trees

Anne Frank’s chestnut tree to be felled

Hot on the heels of the fall of El Grande, more bad news from the tree world:

The famous chestnut tree mentioned in Anne Frank’s diary is to be cut down. Amsterdam council said on Thursday it has no option but to agree to the felling of the 27 tonne tree which is diseased and could be dangerous if it falls. The tree, which is officially listed, is situated in the enclosed courtyard between Prinsengracht and Keizersgracht.

The horse chestnut (Aesculus hippocastanum), popularly known as the ‘Anne Frank Tree’, featured in the famous diary. The tree was visible from the attic where she and her family hid from the Nazis during the Second World War. It is estimated to be between 150 and 170 years old, making it one of the oldest chestnuts in Amsterdam. For several years the tree has been attacked by the Artist’s Conk fungus (Ganoderma applanatum). Horse chestnut leaf miner moths (Cameraria ohridella) have also been a significant problem. A study in 2006 concluded that 42% of the tree was rotten. Many botanists believe that the tree is close to collapsing, and the owners applied for a permit to carry out a preemptive felling which has now been granted. After the felling, grafts will be planted on the same spot where the chestnut tree is standing and a new tree will grow. A few quotes from Anne Frank’s diary:

February 23, 1944
The two of us looked out at the blue sky, the bare chestnut tree glistening with dew, the seagulls and other birds glinting with silver as they swooped through the air, and we were so moved and entranced that we couldn’t speak.

Nearly every morning I go to the attic to blow the stuffy air out of my lungs, from my favorite spot on the floor I look up at the blue sky and the bare chestnut tree, on whose branches little raindrops shine, appearing like silver, and at the seagulls and other birds as they glide on the wind. As long as this exists, I thought, and I may live to see it, this sunshine, the cloudless skies, while this lasts I cannot be unhappy.

April 18, 1944
April is glorious, not too hot and not too cold, with occasional light showers. Our chestnut tree is in leaf, and here and there you can already see a few small blossoms.

May 13, 1944
Our chestnut tree is in full blossom. It is covered with leaves and is even more beautiful than last year.

Posted in Notable trees

A walk in the Hermitage of Braid (Part 2)

More photos from my Wednesday wander in the Hermitage of Braid. Monochrome!

First up: a stand of trees on a small mound. Some beech and a huge sycamore in there, so I remember. A lot of storm damage though, with plenty of deadwood on the ground and a couple of dead trunks.

trees on a mound

This next photo is a closeup of a nicely decomposing dead standing trunk. Check out the little holes made by woodworm or perhaps some kind of bark beetles.

deadwood close-up

This tall and skinny tree looked like a sycamore. I'm not totally certain it was though - I can't ever remember seeing one so gaunt. But with this being in the bottom of a narrow valley, it would have had to grow tall out of necessity.

tall and skinny sycamore?

Finally, I have a photograph of a fallen branch in the Braid Burn (a burn is the Scots word for a stream or small river).

fallen branch in the burn

Posted in Gone for a walk

Mycorrhiza - a brief introduction

If you don’t have a clue what a mycorrhiza is, or if you have a vague idea but nothing substantial, then read on: I will do my best to edify you.

Simply put, mycorrhizas are intimate mutualisms between fungi and plant root tissue. Almost all higher plants are mycorrhizal, and those that are will be either obligative (the mutualistic species cannot survive if separated) or facultative (the mutualistic species can survive if separated, but mutualism is preferable). Trees are generally mycorrhizally facultative, whereas orchids are generally mycorrhizally obligative. ‘Mutualism’ is ecology jargon, but its meaning is fairly obvious – two organisms live in intimate association with mutual benefit.

With mycorrhizas, the host plant benefits by receiving nutrients from the fungal network that it is not capable of extracting from the soil itself. The mycorrhizal fungi benefits by receiving carbon from the plant in the form of photosynthate sugars. This mutualism is millions of years old, with the fossil record suggesting that the earliest land plants were heavily infected by mycorrhizal fungi.

There are a number of different types of mycorrhiza. When it comes to trees, two kinds are really important: arbuscular mycorrhizas and ectomycorrhizas. Arbuscular mycorrhizas are found in about two thirds of all plant species, particularly tropical trees and non-woody species. The fungi involved are not host specific, and there are only a few hundred known species. Ectomycorrhizal fungi generally are host specific, and there are about 6000 known species world-wide. They dominate in boreal and temperate forests.

What I find most interesting is that large (typically arbuscular) mycorrhizal fungal networks in forests often simultaneously colonise hosts of differing age and species. Even more interesting is the fact that nutrients can be exchanged between different tree individuals via the mycorrhizal fungi! A study* reported that "91% of paper birch and 56% of Douglas fir intermingled mycorrhizal roots examined were colonized by the same mycorrhizal fungi. In these tree species, a 4–7% net transfer of isotopically labelled carbon from birch to Douglas fir has been demonstrated". Amazing! Recently an ericoid mycorrhizal fungus (mutualistic with ericaceous plants such as heather) was shown to associate with Quercus (oak) roots. This suggests the possibility of some trees sharing nutrients with ericaceous plants!

* Durrell, D. M., Jones, M. D., Molina, R., Myrold, D. D., Perry, D. A. and Simard, S. W. (1997). Net transfer of carbon between ectomycorrhizal tree species in the field. Nature, 388, 579-582.

Posted in Miscellany

Habitat fragmentation

Habitat fragmentation is a significant obstacle to the long-term conservation of biodiversity. Research and monitoring have revealed a continual decline in biodiversity, caused in part by decreasing habitat quality and increasing fragmentation. Models have predicted that fragmentation can increase the extinction threshold (the minimum population level needed to ensure survival) by up to 60–80%. As a result, greater amounts of habitat are required for population persistence in fragmented landscapes. Isolated woods often have a simplified structure with levels of biodiversity lower than would be expected if they formed part of a large, continuous forest.

The species most at threat have high area, specialist habitat requirements and low dispersal potential; for example, certain birds, wintergreens, orchids and detritivore invertebrates. Many species have already been lost from the British Isles, including the lynx, wild horse, moose, brown bear, beaver, boar, and wolf.

To reduce the fragmented nature of our woodlands without establishing continuous woodland cover across the UK (which is obviously unfeasible), habitat networks are being developed. Habitat networks are intended to reverse the decline in biodiversity by linking and expanding habitats to sustain a greater biodiversity. The Forestry Commission has worked on the recognition and development of forest and woodland habitat networks. Existing native woods (in particular ancient woods) are the main pool of native woodland biodiversity, and must therefore play a key role in the network system. The development of ecologically sustainable landscapes requires that patterns of future landscapes sustain the necessary ecological processes in the landscape. Habitat networking can help achieve this requirement. There is potential for the creation of networks for most habitats and species.

It must be borne in mind, however, that by creating woodland corridors and new areas of woodland, other habitats are becoming more fragmented. Take the figure below, for an oversimplified example. In panel A, the woodland is fragmented. In panel B, a woodland corridor has been established to form a habitat network. However, the moorland habitat has now become fragmented.

habitat network example

Connectivity can be defined as physical or functional. Physically isolated woodland fragments may be functionally connected. The permeability of the surrounding ‘matrix’ has a significant impact of functional connectivity for many species; semi-natural habitats are considered to be more permeable than land used intensively. It is possible to have high functional connectivity in a fragmented area of low physical connectedness. Matrix use is considered to be a predictor of species sensitivity to fragmentation. This assumes that ‘functionally connective zones’ of varying quality exist around woodland fragments. An example of two matrix types of different permeability are ‘willow thicket’ and ‘coniferous forest’ to certain taxa of butterfly; a study* has shown that conifer was 3-12 times more resistant than willow.

*Ricketts, T. H. (2001). The matrix matters: effective isolation in fragmented landscapes. The American Naturalist, 158, 87-99.

Posted in Miscellany

treeblog seeds planted soon!

As the semester draws to a close, it is time to look to the very near future... to next week! To the planting of the first treeblog seeds. Scots pine and cider gum seeds, tiny seeds, planted, germinating, growing... It's getting down to the wire now. Expect good news early next week!

Posted in The treeblog trees

In the beech wood (5th April 2006)

beech trees (5th April 2006)

tiny stream in beech wood (5th April 2006)

Posted in Gone for a walk

treeblog's inaugural plantage! (Set A) Day 0

The long awaited day has finally arrived. treeblog has its first seeds in the soil! This initial set is comprised of 3 lots of seeds: a packet of Scots pine seeds, a packet of cider gum seeds, and a group of mystery seeds. Each species was planted in a special tree soil in individual trays. I tried to keep the pattern of seeds in each tray as uniform as possible, but only time will tell how that works out. The cider gum seeds were laid on top of the soil, as per the instructions on the packet. After plantage, I watered the trays and placed them in the garden. The cider gums get a clear plastic lid in a feeble attempt to bump up their humidity.

the Scots pine seeds

The Scots pine seeds prior to plantage.

the cider gum seeds

The cider gum seeds.

the seed trays. left to right: cider gum; Scots pine; mystery seeds

treeblog Set A. From left to right: cider gum; Scots pine; mystery seeds.

The first person out there who correctly identifies the species to which the mystery seeds belong will get something special. Oh yes! [Update (August 2008): The 'mystery trees' or 'treeblog surprises' are actually grey alders (Alnus incana).]

...treeblog Day 0... How long until the first seedlings rear their tiny heads? Will all three species have successful germinations? Will the seedlings get devoured by slugs? Check back soon!

Posted in The treeblog trees

Photos from a walk

last year's leaves (oak)

These oak leaves have doggedly remained on the tree all winter, but for how much longer can they hang on? It seems that oak and beech are always the last to lose their leaves.

lonesome hilltop tree

This tree is alone amongst the heather and bilberry (Vaccinium myrtillus) on the hilltop, and thus is especially exposed to the elements. Hence its diminutive stature. Species? Probably a silver or downy birch. [Update (August 2007): This is actually an oak.]

semi-fallen beech in wood

This poor beech tree was saved from a certain flooring by its unfortunate neighbour. It looks like the ground become too waterlogged and unstable to support the weight of a full tree (happens a lot in this wood). However, I bet that the tree is still alive and well.

Posted in Gone for a walk

treeblog's items Go to treeblog's photostream