iCONic tree trail – Part 2

This is the second in a six-part series about how Perthshire Big Tree Country is helping to save internationally threatened species of conifers. Felicity Martin visits Scone Palace and Blair Castle to see mature specimens of the trees that the early plant hunters found, and learns about a modern plant collecting expedition.

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30 April 2014

Plant hunting past and present

Shaped by history

Three factors have combined to turn Perthshire into ‘Big Tree Country’: a long tradition of innovative tree planting, ready access to newly introduced species and an ideal climate and soils for growing a wide range of trees.

Scotland’s first experiments in plantation forestry took place at Drummond Hill, near Aberfeldy in the 17th century, but it was the landowners of the 18th and 19th centuries who truly transformed the landscape with tree planting on a large scale. The Dukes of Atholl are famous for planting millions of European larch around Dunkeld and Blair Atholl, whilst many estate owners created policy woodlands that featured exotic specimen trees.

In order to supply the demand for novel species, plant hunters accompanied expeditions exploring and mapping recently discovered parts of the world. Many of those plant hunters were born and bred in Perthshire, the best known being Archibald Menzies (1754–1842) and David Douglas (1799–1834).

Archibald Menzies was born at Weem and his father worked in the gardens of Castle Menzies. He sailed the world as a naval surgeon, visiting many lands – including North and South America, Hawaii, China, Australia and New Zealand – and collecting botanical specimens along the way.

He discovered a number of important forestry trees, including Sitka spruce, coast redwood and western red cedar, and brought several new species back to Britain, including perhaps his most famous introduction, the monkey puzzle. While in Chile, so the story goes, he was served its seeds as dessert. Rather than eat them, he sowed them in a frame onboard ship and returned to England with five healthy plants.

Although widespread around the Andes in Menzies’ time, the monkey puzzle is now threatened. As a useful timber tree, it has suffered from historic logging and, despite now being protected, it is at continued risk from fire, grazing and the encroachment of commercial plantations.

A living legacy

Many gardens around Perthshire have mature monkey puzzles growing as individual trees, but at Scone Palace they can be seen en masse. Scone pinetum is home to a great variety of spectacular conifers, grown in single species rows. Many were planted over 150 years ago and today they form cathedral-like avenues of towering trees.

North American species are particularly well represented and include soaring giant redwoods, noble firs and western hemlocks. Nearby a new pinetum is home to the next generation of conifers, among them several iCONic species.

David Douglas was born at Scone in 1799 and worked as a gardener at Scone Palace for seven years before becoming an explorer and a plant hunter. It was a precarious occupation and he faced many dangers and hardships before being killed at the age of 35 in Hawaii.

While in America in 1827, he sent back seeds of a tree that now bears his name – the Douglas fir. A magnificent specimen raised from his original seed now grows in the palace grounds. Its scientific name, Pseudotsuga menziesii, acknowledges the fact that it was Menzies who first described the species, although his attempted introduction was unsuccessful because the specimens he collected were destroyed on board ship in a storm.

Preserving landscapes as well as species

A very different but equally impressive collection of trees is to be found in Diana’s Grove at Blair Castle, the ancestral home of the Dukes of Atholl. Between 1872 and 1880 many conifers brought back from the North America were planted there and they have since attained enormous proportions, with several setting UK species records for height or girth.

The trees in Diana’s Grove are now ageing and they are suffering increasingly from wind damage. The estate management team have taken the decision to let the arboretum grow old gracefully, while creating a new collection of trees that will be as majestic in the future. With the aid of the iCONic project, they are planting a variety of trees, such as Nordman fir, Cicilian fir and Oriental spruce, in the Hercules Wilderness at the far end of the Hercules Garden.

A new generation of plant hunters

When Menzies and Douglas were travelling the world, the new species of conifers they discovered were often growing in vast, old growth forests. Since then most of those ancient giants have been felled and the survival of many of the species they introduced is threatened.

Through the iCONic project, a new generation of plant hunters is now collecting seeds and cuttings from conifers in the wild and preserving that valuable genetic material by giving threatened species a safe haven in Perthshire.

The iCONic project officer, Tom Christian, grew up near Aberfeldy like Menzies. One of his first expeditions was to Lebanon, where he collected seed from the Cedar of Lebanon, including from the very tree that appears on the nation’s flag. Mature trees like the one depicted on the flag have large, spreading canopies. Unfortunately, human pressures mean that such specimens are now a rare sight. The seedlings Tom has nurtured from his seed collection will soon be ready to plant out in sites around Perthshire.

Although modern conveniences have increased safety and comfort, plant hunting can occasionally lead to alarming experiences, as Tom recounts.

“When we visited Bosnia three of us travelled from the UK, and we worked with Bosnian guides and foresters visiting populations of the Serbian spruce, which is endemic to a very small area.  One of the populations we wanted to visit could only be accessed by walking through an area known to contain landmines.  Fortunately we had an excellent guide who knew the safe route, but we had to follow him precisely.  It was scary stuff”.

Serbian spruce have a spire-like shape and can tolerate extreme cold and heavy snow. They are highly threatened, with probably less than 8,000 trees surviving in the wild. The species is a glacial relic, wiped out from most of its original range by ice ages, but it is also being out competed by beech, which is becoming much more successful due to climate change.

In 2013, the iCONic project undertook a major expedition to Chile to collect a range of threatened species and to see how the monkey puzzle is now being conserved in its native habitat. Working with local experts, they faced various challenges, such as scaling rock faces and fording rivers, as well as wild camping and horse riding to access more remote areas.

“In some areas, we would have been stuck for a considerable time waiting for help if anything had gone wrong,” Tom remembers. “I found it unnerving horse riding down a deep, steep-sided canyon, where if the horse slips you’ve had it. There was absolutely nothing to do except sit there, trust the horse and not look down.

“Fortunately, it all went well on the Chile expedition and we had one particular bonus. We hadn’t expected to collect Prince Albert yew but we stumbled across a fallen, decaying trunk that was covered with hundreds of seedlings, and were able to collect a good selection very easily.”

In next month’s article we will look at how many iCONic species, including Serbian spruce, Cedar of Lebanon and coast redwood, are contributing to the designed landscape around Dunkeld.