Andrew Ormerod’s personal view of the subject as little ‘snap shot’s’ exploring the importance of trees.
Part 2/3 Some uses of trees
Farming in three dimensions with trees
As a complete package agroforestry if run with the right consideration makes perfect sense – in terms of diversification of farmers income, supporting biodiversity and supporting ecosystem services. Inclusion of trees can make the land more efficient at harvesting sunlight – once the annual crops below have ripened and been harvested.
Apple trees and organic wheat land, helping to increase harvest of sunshine. The bush apple trees are planted at 32 metre centres in rows in East Anglia so they don’t interfere with wheat cultivation and harvest. They are harvested after the wheat in the autumn and help to break up the Fenland blow on Stephen Briggs farm near Peterborough.
In addition the tree roots adapt and grow below the shallow cultivated layer of the annual crops so they don’t compete. The trees can contribute as a carbon sink and with mineral mobilization. Roger Leakey, former head of The World Agroforestry Centre (ICRAF), wrote a compelling book based on a lifetimes experience – ‘Living with the trees of life’. This outlined the benefits of production systems including a diversity of species of trees. These trees may have local economic significance in the tropics – but are less well known globally. ICRAF developed ways of working with local communities; to listen to local farmers; to identify the best forms of productive trees; to develop propagation protocols that could be applied locally and to develop village trials. Perhaps the best examples of engaging with local communities to select, propagate and trial fruit trees can be found in the Cameroon.
Representation of the participatory selection of fruit trees in Cameroon in the West Africa exhibit in the Eden Projects tropical biome.
Agroforestry can have a roll to play in temperate production systems too. For example Mark Shepherd in Wisconsin in the USA has developed an agroforestry system that has improved soil fertility and increased crop and income diversity – compared to his neighbouring farmers whose land may be depleted and are relying on a limited range of crops for their income.
Trees as browse
Trees can provide food – in silvopasture this may be as browse. Use of certain tree species for browse has a long tradition in various parts of the world – but perhaps has been overlooked in recent times as a feed source for livestock. It is remarkable to see how quickly young cattle who haven’t encountered leafy cut branches munch the leaves and twiglets when fed dried browse over winter. Is it the aroma of the dried foliage or do they sense that the browse contains valuable nutrients I wonder? It’s not just silk worms that like White mulberry – I failed to photograph livestock eating it in the tropics – because they were just to hungry for it!
Trees for nuts
In addition trees can be a source of carbohydrate and protein and vitamins and from their nuts and fruits. In Sicily the Sweet chestnut is known as the ‘bread tree’ – it can have an equivalent yield to cereals under organic conditions. In the USA Kevin Waltz at the University of Illinois has recently planted an agroforestry system with sweet chestnut and hazel nuts that may go someway to replicate organic field crop systems based on maize and soya. There are many examples of caloric staples from trees that could be more widely adopted – ranging from breadfruit to peach palm and sago from the sago palm.
Just think when you next bite and crunch a piece of a Brazil nut from the packet of assorted nuts – that its history of production was very different from the other nuts in the mix! Brazil nut Bertholletia excels trees can reach 150’ in height and around 1,100 years in age – but they are wild harvested from the. Brazil Amazon, Eastern Peru and Northern Bolivia as attempts to grow them in plantations have failed. A small rodent with strong jaws the Agouti is the main creature naturally able to open the Brazil nut pods (more correctly called pyxidium) and one of the principle means of seed dispersal. There is also a squirrel capable of opening pyxidium. Harvesting Brazil nuts employs around 400,000 Amazonians supporting families and the rainforest habit. The Castañales Project in Peru is gauging the income levels from Brazil nut harvest from rainforests with all its ecological advantages, as an alternative to cattle farming. It is attempting to uncover ways to make the harvests more efficient, improve the workers´ livelihoods and ensure a healthier forest. The Castañales Project and other environmental groups have convinced the government to lengthen the concession periods from two years to five. Longer time frames give collectors a stable basis for their enterprise and incentive to manage their area with an eye for its long-term healthfor example, protecting seedlings to help natural regeneration.
Trees for fruit
As far as fruit crops although there are a range of herbaceous and shrub forms – where would we be without apples, pears, cherries and plums in our UK climate? With climate change there are some growers in particularly in the south of England are trying more tender and exotic species with varying degrees of success. Some city planners are considering productive as well as ornamental trees planted in green corridors to provide modern day foraging opportunities for inhabitants.
Cider apple – Devon orchard; fruit is from a dessert apple Devonshire Crimson Queen or ‘Queenie’.
The apple is particularly interesting – as it comes in many forms – most now of local interest only – with a few national and international varieties predominating. Apples Malus domestica have come along way from their centre of origin in the mixed fruit and nut species forests on the Tien Shan Mountains on the Kazakhstan and Chinese boarder. Spread originally by bears and later by humans along what became the Silk Route. They are a key cultural species in the USA – thanks to the efforts of John Chapman (also known as Johnny Apple Seed) who established seedling nurseries ahead of pioneer settlements established by communities spreading out West in North America. New communities required orchards as part of their establishment. John Chapman supplied the seedling trees. These were mainly fit for ‘hard cider’ (called cider in the UK) however a few seedlings have endured as dessert apples – notably Golden Delicious and Red Delicious (not related!).
The domesticated apple is very plastic you can graft a variety to produce a range of tree sizes and accelerate fruit production on easier to harvest small trees. If your fruit varieties falls out of fashion – you can top work them with new shoots to change verities. Apple trees go through their life cycle fairly rapidly (a standard sized tree is about the same as a human life span) so in traditional orchards support a wide diversity of organisms after a relative short period of time. If standard trees fall over – particularly in the wetter west of the UK they can go on living and fruiting. Often here they produce roots from the trunks and the branches and side branches facing upwards can become new trees. By contrast they say Pears you plant for your heirs as they can live for 300 years!
I pick two interesting fruit crops better known locally than around the globe to illustrate global diversity. Firstly Acai Euterpe oleracea a multi stemmed palm that grows in wetland around the Amazon. Little known globally until the surfing community near Rio and then in California cottoned on to its potential. Thanks to frozen transport the purple fruit pulp somewhere between a drink and a nutritious meal and ideal for smoothies, desserts and drinks has spread out of its epicentre of traditional use in and around Belem. Here local people bring boatloads of the purple fruit from natural stands of palm along the riverside. The valuable local fruit probably helps to conserve their local habitats. There is an active market where the fruit is purchased and it is processed and on sale in local bars there. The fruit are available in lean times when other plant foods may be in short supply. Acai is so significant locally that songs are written about it, by contrast its significance is little known to the rest of the world.
Left. The multi stemmed Acai in the palm exhibit in the tropical biome at the Eden Project. Right. Date palms displayed in the Mediterranean biome at the Eden Project. They are highly valued in the Middle East and there are many different varieties producing fruit with different qualities. Traditionally they were propagated vegetatively from side shoots – but difficulty of propagation of desirable clones could push prices up. Micropropagation now can help to produce young healthy date palms in reasonable quantities.
Baobab is a symbolic tree in the subtropical areas of Africa – the symbolic image is of these bottle shaped giants at the centre of communities a central point for meeting and discussion, though in reality they are wider spread. Baobab’s interest as a food – are the natural white dusted cubes surrounding the seeds – a little bit like hand crafted sherbet dusted sweets which taste a little like dried pineapple chunks! In reality nature rather than human hands created these. The woody swede covered rugby ball shaped fruit capsules have to be opened to reveal the sweet treasures within. Phytotrade Africa – patiently went through the process of red tape that allowed Baobab to be sold in Europe under the European Novel Food Regulations. Originally designed with a view to prevent the introduction of genetically modified crops – this legislation also prevented the marketing within the EU of crops that can be traditionally consumed by communities around the world but have no track record in commerce in the EU prior to May 1997. Perhaps the legislation could be deemed unfortunate in restricting the development of economic export of traditional crops that would help those communities move out of poverty – I believe that new updates are being implemented.
Multipurpose food trees
If I had to choose one tree for development work connected to an interesting story – I would choose Moringa oleifera (horse-radish tree) widely cultivated in tropical and subtropical areas. Virtually every part of the tree is useable – it is cultivated for its leaves, pods, and/or its kernels for oil extraction and water purification. The leaves are the most nutritious part of the plant being a significant source of vitamins including Vitamin C, manganese, protein and other essential nutrients. The oil can be used as a food supplement, as a base for cosmetics, and for hair and the skin. The moringa tree is not affected by any serious diseases in its native or introduced ranges, though there are a few pests. I am grateful for Francis Hansen for introducing me to this tree – he grows it in his small kitchen in Falmouth, Cornwall using it in his cooking. He has been involved in development projects in Indonesia and Haiti encouraging the use of this tree.
Tree ingredients associated with our everyday food shop
I think a trip down to the corner shop is called for to get some snacks in is called for a children’s party. Among the list I have a few items – what do they have to do with trees? On my list I have cola drink – although now synthesized the original would have contained extract of Kola nuts Cola nitida (held in high esteem in parts of Nigeria) and we have got some chewing gum on our list – well although the latex is now synthetic the original is from Manicara zapota – whose fruit you can still buy from specialist markets in the UK. We have some nice red sweets, which contain Carnauba wax from a palm tree Copernicia prunifera. In my list of food items I have down fish fingers and red cheese – both of which contain annatto the natural red colorant around the seeds of the South American tree Bixa orellana
the ‘achiote’ tree. Many of us have consumed this in the UK without realizing the depth of traditionally knowledge developed about its uses by Indian tribes in Latin America as a food colourant, spice, body paint, sunscreen, hair dye, insect repellent and for medical and aphrodisiac properties probably. It has now become one of the world’s most important natural food colourant. Finally we mustn’t forget to pick up some chocolate dark in nature (even when milk chocolate!) dark in life – traditionally preferring the shade of other trees.
Growing trees for timber
So what about materials from trees? Well the first that comes to mind is timber. Forestry Certification Certificates FSC have been used to indicate sustainable methods have been used for production of the timber. Length of time it takes to grow hardwood trees and impact on secondary forestry and wildlife are all factors that can affect sustainability. In Sabah, Malaysia – harvesting of hardwood Diptocarp species has over the years been an important industry. The Eden Project has been in touch with the Danum Valley Conservation Area where the research station has been experimenting with different methods to understand the best ecological measures that allows harvest while conserving biodiversity and encouraging the regrowth of Dipterocarp species. Many of the Dipterocarp hard wood timber trees do not have seeds that remain viable if dried out. The Danum Valley Conservation Trust collaborated with the Eden Project to enable Eden to grow these timber trees in the tropical biome and represent a tropical timber tree nursery.
The Mediterranean Landscape, as we know it today has been re-shaped by the unsustainable demand on timber by ancient empires leading to deforestation and erosion of soils. Past demand for timber lead to rather indiscriminate harvesting of trees for timber in the UK. This has lead to ‘The Future Trees’ initiative to be established in the UK to select, trial and breed elite forms of timber, such as oak, cherry and ash.
Agroforestry experiment with different clones of cherry grown for timber and willow for coppice AFBI Loghgall Norther Ireland.
Historic use of timber for paper
Trees have been used widely for paper – in historic terms some unusual species have been used such as Broussonetia papyrifera (paper mulberry) a small tree or shrub. Paper mulberry played a significant role in the development of papermaking in China 100 AD, and reached Japan by about 600 AD and was used for textiles in the Pacific. Now fast growing species such as pines and eucalyptus are important tree crops for paper.
Fibres and latex
Kapok and Balsa feature as some of the tallest trees at the Eden Project – these are pioneer species.
It is interesting to think of the myriad of products made from rubber globally from tyres; mats to boots and gloves. The Eden Project has an exhibit linked to rubber trees and the myriad of products made out of rubber. When the young rubber trees arrived for the rubber exhibit from France they had to be warmed up as they arrived in a chilli delivery van! In a similar way for better or worse rubber seeds took some effort to establish outside their home country of Brazil – but once moved on to South East Asia they formed the basis of the centre of the worlds rubber production in Malaysia, Indonesia, India and also in Guinea, West Africa. Lesser known is Gutta-percha trees of the genus Palaquium from the Malay Peninsula used to seal under sea joints in cables and traditionally used in cricket balls. Unlike rubber it doesn’t need vulcanization it becomes more pliable with heating – it could be extruded for wire coating until supplanted by polythene in the 20th century. .
Trees for medicine
As far as medicine trees that come immediately to mind include Cinchona officinalis from South America as a source of Quinine an anti fever agent used for the prevention and treatment of Malaria. Prunus africana from West Africa used for male prostate problems. The European Yew Taxus baccata leaves from hedge clipping can be used to make Taxol an anti cancer drug. From a historic perspective willow bark extract became recognized for its specific effects on fever, pain and inflammation in the mid-eighteenth century salicylic acid, was the active component of willow extract.
Healing or ‘cloutie’ trees often associated with sources of sacred water are found in West Cornwall a modern relict of pagan traditions. A hazel tree comes to my mind as an example I have seen growing next to a Cornish hedge over a spring. The tree is decorated with a bright array of strips of cloth and rags or ‘cloutie’ and mementos – the traditional belief is that as these fade away so does the ailment.
Trees for musical Instruments
Though not a tree I like the idea of hollowed out elderflower stems being used for whistles. At Eden two ‘musical trees on display are the African Black Wood Dalbergia melanoxylon used for making oboes and clarinets and Rose Wood Dalbergia nigra used for – among other things – guitar making. Initiatives such as SoundWood highlighted improvements in the management and availability of certified wood used to manufacture musical instruments and other wood products.
Trees for Aroma – flowers, leaves, fruit, bark, resin and wood
A couple of examples with fragrant flowers come to mind include members of the citrus family – whose leaves, flowers and fruit are sources of perfume ingredients as are Magnolia grandiflora another tree with highly perfumed flowers. The fruit of the fruit of the quince tree Cydonia oblonga that has stopped me in my tracks in the autumn and the wonderful burnt sugar or toffee smell of the Katsura tree Cercidophyllum japonicum.
Bark and wood of trees can be aromatic too such as Cinnamon made from the inner bark strips dried and rolled as ‘Quills” varying in quality used as a culinary spice and flavouring from the extracted oil from Cinnanomun spp. Sandalwood is the second most expensive wood in the world after African Blackwood – due to its high desirability and impacts its unsustainable wild harvest. It maintains the aroma from its wood for decades.
Frankincense means ‘high-quality incense’ its aromatic resin used as incense or for other religious ceremonies (Jewish, Christian and Islamic), traditional medicines perfume, cosmetic and pharmaceutical Industries. It is the world’s longest continually traded luxury crop. The resin has been tapped from the branches of Boswellia species since ancient times growing in tropical dry forests. 25 different species are found in the Horn of Africa and Arabian Peninsula of which four species predominate in trade. Quality depends on species, soil and other environmental conditions. Over exploitation affects seedling viability together with clearing woodlands for agriculture, burning, grazing, and attacks by the longhorn beetle have reduced some tree populations. Part of the solution is habitat management. Replanting appears not to be working. Better options include careful in situ management and most particularly retention of traditional tenure patterns where families own particular trees.
Humanities desire for spices
Wars have been fought to secure trade access to spices, in the 17th century the English India Company fought with their Dutch counterparts for control of the tiny island of Run where nutmeg trees Myristica fragrans flourished. When nutmeg fruit are harvested you get ‘two spices for the price of one’ as the outer reddish coating (the aril) produces mace while the seed produces nutmeg. Both feature in cuisine around the world essential oils from ground nutmeg are used by perfumery and pharmaceutical industries. One consequence of the Dutch taking back Run – was English taking the Dutch colony of Manhattan in revenge – hence when peace settlements were signed New York (named after the Duke of York – later King James II) is now New York and not New Amsterdam. Partly at its base a trade dispute over some trees on a spice island!
The dried aromatic flower buds of cloves Syzygium aromaticum are used as a spice us in cuisine and beverages in many parts of the world. They are used in Indian, Chinese and Western traditional medicine and dentistry. You might have some clove oil in your bathroom cupboard to treat toothache!
Importance of flowering time …..
Almond blossom coincides with the religious festival Tu BiShvat ‘The New Year of the Tree’ celebrations in Israel associated of renewal, rejuvenation and new planting of trees. Similarly Cherries or ‘Sakura’ blossom time in Japan creates an opportunity ‘Hanami’ “flower viewing” for families to picnic and enjoy their transient beauty. Traditionally this is when the coming years farming plan were finalised.
Cherry blossom such a transient pleasure to see – thankfully extending from winter into spring by planting different species and varieties of trees. In this case an old Burcombe cherry in the Tamar Valley in Cornwall. Trees go through there life cycle at very different rates – in the case of this cherry tree 80 years – is old age!
…..and time into leaf.
One reason why Paulownia tomentosum in China and walnut in temperate countries have been used in agroforestry systems is that they come into leaf late – preventing shading out of earlier developing annual crops such as cereals.
…Providing shade and shelter.
By contrast trees provide shade for humans and animals alike in hotter climates and for shade loving crops, they can protect grazing from the heat of the day. In the winter and spring they create shelter for livestock, orchards providing shelter at lambing and carving. Presence of trees on grassland have been shown to allow livestock back on to the grass earlier in the spring due to improved drainage.
Sheep sheltering in an ash and grassland agroforestry trial at AFBI Loughgall, Northern Ireland. There are economic benefits from combining the trees and grassland.
I have a few favourite highly ornamental temperate trees. Sorbus cashmiriana takes some beating in a small garden – a mountain ash of modest proportions with pink flowers in spring and beautiful white marble like fruit that birds don’t eat in the winter. For winter colour some birch trees with pure white or pink bark provide interest, as does Acer griseum with its pealing chestnut brown bark translucent in low winter sunshine. It is commonly planted as a garden ornamental but now rare in the wild in China.
Sorbus cashmiriana sympathetically displayed with herbaceous plants in harmonious colours at Sissinghurst Castle.
Thanks to Dr. Mike Maunder and Professor Iain Prance for some suggested corrections to the article.
Andrew Ormerod copyright @ 2017