Sep 272016
 

Evidence from Egyptian pharaonic pharmacology papyri, shows that medicines made from white willow and other salicylate-rich plants, were used as early as the second millennium BC. Aspirin use is now an everyday worldwide occurrence. Some 50,000 plant species are used medicinally and global trade exceeds £45bn/year. Trees play a major role in this industry, with medicines extracted from the wood, bark, roots, leaves, flowers, fruits and seeds. More information on the healing (and deadly!) properties of plants can be found in the recent RBGE publication “Plants: healers and killers” (available to buy from http://rbge-publications.myshopify.com/collections/all/plants )

Sustainable extraction of medicine from wild trees can help to conserve forests, but we need to be careful not to over-exploit these valuable resources. Medicinal demand and excessive harvesting threatens the survival of some species. The Cebu cinnamon (used in the Phillipines to ease stomach ache) is now critically endangered. International trade of the Red Stinkwood tree (used to treat malaria, fever and prostate cancer) and harmful extraction methods are causing species decline across Central/Southern Africa and Madagascar. Yew trees are used to produce Taxol for use in cancer treatment. Over-use of the Himalayan yew for medicine and fuel in Afghanistan, India and Nepal, threatens this tree’s future survival.

Recent tests on chemicals found in the needles of eastern red cedar (ERC) showed they are effective in treating several strains of MRSA, and in treating skin cancer cells in mice. In 2005, in the US alone, some 94,000 people developed life-threatening MRSA and nearly 19,000 died in hospital stays related to these infections. Many lives could be saved in the future if medicines derived from ERC are developed and made commercially available.

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Ash deaths in USA linked to increased human mortality rates

Tree and forest environments also have a very positive impact on health. A study in the US, indicates that an additional 15,080 deaths from cardiovascular disease and 6,113 from lower respiratory disease occurred in counties where many ash trees were lost following emerald ash borer infestation (after accounting for other influencing factors). A 2009 study in Tokyo, showed that ‘Forest Bathing Trips’ (3 days/2 nights in forests) significantly increased natural killer cells (white blood cells used to fight off cancer and virus-infected cells) and that the levels stayed elevated for up to a month after the trips. Other Japanese studies found forest visitors have decreased cortisol (stress hormone) levels, lower blood pressure and heart rate, resulting in more ‘relaxed’ biological systems.

Jun 172016
 
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Ancient Ash in Clackmannanshire, with Judy Dowling (Regional Verifier for the Ancient Tree Inventory)

It is estimated that about 70% of Europe’s oldest trees are to be found in the UK. The Woodland Trust and Tree Register of the British Isles, have been compiling a database of ancient, veteran and notable trees within the British Isles and over 150,000 records have now been made, and most have been verified as accurate. Recorded to date are 12452 ‘ancient’ trees (very old/large for the species and/or possessing many ancient features, such as hollow stems or branches) 93437 ‘veteran’ trees (not yet ancient, but possessing some of the features associated with ancient trees) and 40896 ‘notable’ trees (can sometimes be veteran, and may be significant in a local/historical context). So far, 1133 ancient ash, 6480 veteran ash and 2372 notable ash have been recorded, of which 65 ancient ash, 282 veteran ash and 176 notable ash are in Scotland.

Ancient and veteran trees provide invaluable habitats for invertebrates, birds and mammals. 1700 species (6% of UK total) of invertebrates depend on decaying wood for completing their life cycles. 400 0f the 447 macrofungi on the British Red Data List, derive from ancient woodland and lowland pasture woods. Many birds and bats nest in cavities in ancient and veteran trees, and rely on them for food sources too.

The main threats to ancient and veteran trees are from felling, changes in land use and competition from surrounding trees. Increasingly, new pests and diseases (such as ash dieback) and problems related to climate change, pose a real threat to our oldest trees. There have been some recent developments in increasing protection for this valuable resource, which is encouraging.

This ancient ash provided an invaluable habitat for the author to take lunch in

This ancient ash provided an invaluable habitat for the author to take lunch in

“10,000 oaks of 100 years are not a substitute for one 500 year old oak” – Oliver Rackham (conservation author and historian)

“Ancient trees are precious. There is little else on Earth that plays host to such a rich community of life within a single living organism” –  Sir David Attenborough

 

 

 

 

Mar 162016
 
Photo: Ancient Pollarded Ash near Killin (and the Author)

Photo: Ancient Pollarded Ash near Killin (and the Author)

Archaeological studies have shown that, ‘Biochar’, or at least a similar product, was used by ancient Amazonians to add to the soil to help with their food growing. Today, an advanced form of Biochar is made from the slow charring of waste woody biomass, using a restricted oxygen supply (a process known as pyrolysis). A stable form of carbon is produced and one tonne of carbon locked into biochar, is equivalent to removing three tonnes of atmospheric carbon. Adding it to the soil around trees and food crops, enhances soil nutrition and improves soil structure and drainage – and hence plant growth rates, without the need for further artificial fertilisers.

Biochar has a honeycomb-like microscopic structure, which makes it an ideal habitat for beneficial soil microrganisms, like mycorrhizal fungi. It also aids with the retention of water in soil, reducing irrigation requirements.

Biochar was applied to the soil around ash trees, to assess effects on growth. During the trial many of the trees on the experimental site became infected with Hymenoscyphus fraxineus, leading to Ash Dieback. Surprisingly enough, not a single ash tree treated with the Biochar, showed any signs of the disease, whilst many adjacent trees were badly affected. A PhD study into the potential for use of Biochar to prevent Ash Dieback, has now been commissioned – another potential sprig of hope for the UK’s 126 million ash trees! The link given below takes the reader to a video about the original findings.

Video Outlining Potential for Biochar to Reduce Ash Dieback Infection Rates