In 2007, when the Association started, we did not expect the survey to last for so long but after ten years we have over 7000 records in our database.
The surveys of all accessible areas in six parishes have been completed, but records continue to be updated as trees are reported lost and new areas become open to survey. Two smaller parishes were completed in 2008 and we have still to verify the accuracy of their data. The survey is well underway in eight parishes and should be completed in the next year or two. In just one parish, Swallowfield, we believe the majority of the veterans remain unsurveyed.
We have become aware that we have under-recorded smaller species like hawthorn, hazel and orchard remnants, because we were initially focused on the large girth trees. Similarly we will have missed some large coppice stools hidden in dense undergrowth. As we cannot monitor all the recorded trees, we do not always know when trees have died or been felled, so our records may not have been updated.
Incompleteness and under-recording means we need to be cautious about drawing too many conclusions from the data, especially regarding smaller species; but we aim to correct these shortcomings and with time we should be able to extend the following analyses.
We knew we would find a lot of veteran oaks but we never expected English oaks to be the most common species in every parish, nor that they would account for over half the trees in the database. So far, 3900 (55%) recorded trees are English oaks, and we are still counting.
We are often asked about the ages of trees and in this Report we have given an estimated age for some of the large veterans. Dating is not a precise process and on our website there is an article on tree age based on species, growing conditions and girth. The graph below shows the number of recorded maiden English oaks with girths of 3m and over, together with their likely ages.
We can draw several conclusions from this graph. Even the youngest of these trees was growing before the end of the 19th century and the oldest ones, with girths around 7m, are probably 550 years old and germinated in the second half of the 15th century. The reduction in numbers as girth increases shows that we are losing about half the oaks of any given age every 40 years or so. This assumes that new oaks were germinating at a constant rate from the 15th to the 19th century but we do not know whether this was in fact the case. This is one area where our data might benefit from further analysis.
Apart from oak, we have recorded many other species, natives such as ash and hawthorn, naturalised trees such as sweet chestnut, and exotic species planted in parkland and gardens according to the fashions of the era, particularly the oriental plane and Wellingtonia. Many of these ‘exotics’, such as the Turner’s oak, were only planted in very small numbers, so 40 species have under 5 records and 19 species have just one tree recorded.
Eleven species have more than 100 trees recorded, and are shown in this table.
|Species with over 100 trees|
|Common name||% of Borough's trees|
English oaks grow everywhere, but the second and third most frequent species varies from parish to parish. Ash is the second or third most common tree in over half of the parishes, but in 5, including Wokingham Town, they are much less frequent at under 4%. Another tree that has a very uneven distribution is beech with no veterans recorded in 4 of the 17 parishes. Of Shinfield’s 1300 trees only two are beech and yet Arborfield, Finchampstead, Remenham, Sonning and Wokingham Without have all recorded significant numbers. Limes, too, are unevenly distributed.
Sweet chestnuts are the second most common tree in Wokingham Town and yet no veterans have been recorded in 5 parishes. As well as an uneven distribution, 46% of the recorded trees are coppice or multi-stem, probably a remnant of the managing and coppicing of sweet chestnuts for timber, widely used as a building material in earlier days.
Willows are the fifth most common species with 75% of the recorded trees being pollarded, coppiced or multi-stem. Pollarded willows have been recorded along the Blackwater and Loddon rivers as well as in areas close to the Thames and the Emm and Barkham brooks. The Ruscombe and Hurst parish reports link their willows to the osier industry and this historic tree management as a local industry was clearly widespread across the Borough in eight of the parishes, Swallowfield, Shinfield, Barkham, Woodley, Charvil, Hurst, Wargrave, Ruscombe and possibly also in Wokingham Town.
In parishes with significant parkland and large gardens, Victorian or earlier landowners planted ornamental species. These include horse chestnut, plane trees and avenues of limes and Wellingtonias. Not surprisingly, Finchampstead's second most common tree is the Wellingtonia, with 111 in the famous avenue. However, there are three other significant avenues of Wellingtonias - in Wargrave, Shinfield and Arborfield.
When we survey an area we record stumps, fallen and dead trees as well as those that are living. When we become aware of trees being lost through felling, disease or old age, we update our records but as we often do not get to know about these changes our data on lost trees is definitely understated. 250 veteran trees were initially recorded as already dead and a further 108 have been updated as lost since they were surveyed, totalling 5% of all the records. There is no significant variation in the percentage of lost trees across the parishes and about half are English oaks, consistent with their proportion in the database. Of the trees lost since they were surveyed, we don't know the reason for just under half of the losses. Where we do know the reason, the numbers are approximately the same for trees that had fallen, ones that were diseased, ones that were causing health and safety issues and ones felled for development.
For the eight parishes which have finished their survey we can calculate the density of recorded trees. This graph shows this for all recorded trees and for recorded English oaks for these eight parishes.
The variation in oak density can also be clearly seen with the comparison between Charvil (53%), Ruscombe (91%) and Sonning (28%) where the total recorded tree densities are very similar. We may be able to understand the reasons for these variations once we have more complete data for the whole Borough. Using 2011 census data we have also looked at the population densities in these parishes, but there is no correlation at all between this and the tree densities.
Two of our veteran trees appear in the Champion Trees of Britain book ; the Ruscombe yew (MRN 2277) and the oriental plane in Wokingham Town (MRN 76).
There are a number of on-line sources of data for important trees within the UK, particularly the Tree Register of the British Isles (TROBI), the Ancient Tree Hunt and the Ancient Yew Register. Some of these use our survey data.
Our data is sent to the Ancient Tree Hunt and most of it has been added to their database, although we have made them aware of some significant omissions. As well as checking and sometimes correcting our species identification and tree form (maiden, multi-stem etc), they also classify the trees as notable, veteran or ancient. Four trees in the Borough have been given this 'ancient' classification, the pollarded oak (MRN 1134) and a sweet chestnut (MRN 1145) in Wokingham Without, the 'Henry VIII' oak (MRN 432) in Shinfield and the churchyard yew (MRN 2277) in Ruscombe. We hope to work with the Ancient Tree Hunt to rectify the missing data and to see if more trees qualify for this 'ancient' status, especially the sweet chestnut (MRN 5845) in Wargrave.
The Ancient Yew Register has recorded yews in six parishes: Arborfield, Finchampstead, Hurst, Remenham, Ruscombe and Swallowfield. These are in our database apart from those in Remenham which will soon be included.
TROBI uses classifications of County, Country or Great Britain & Ireland champions for height and girth, including historic champions, as well as 'remarkable' and 'heritage' categories. The May 2013 TROBI data lists 71 trees within the Borough. 34 of these are in our database while most of the others are too small to meet our criteria, often being champions for height rather than girth and three are trees that no longer exist. We are aware of five trees listed by TROBI that meet our database criteria but which we have not recorded. As TROBI records have no grid reference it is difficult to locate them. WDVTA contributed the survey data for 15 of the 71 TROBI records.
TROBI trees occur in 13 of the 17 parishes, the exceptions are Charvil, Shinfield, Twyford and Woodley. The University grounds have 28 in Earley and there are also a number in the Bearwood estate in Arborfield and Newland.
In our database, we have 3 'Britain & Ireland Champions for Girth', 28 'County Champions for Girth', as well as a 'Remarkable' and 'Heritage' Champion. The 3 national champions are in former estates where tree planting was fashionable. Two are on the University campus, a Cypress Oak in the Harris Gardens (MRN 3366) and a Lucombe Oak in the Wilderness (MRN 5714). The third is a True Service Tree in Park Place, Remenham (MRN 2138).
From the 7000 veteran trees we have surveyed, we can already conclude that:
This is very interesting information and as more parishes complete their surveys we will be able to draw even more conclusions. However, these conclusions only pose more questions, for example, 'is the proportion of English oaks typical for Berkshire?' and 'why are the parish veteran tree densities so different?'. With the publication of this Report and the open access to our data, we hope to stimulate interest in helping us answer these questions.
Over the ten years of our survey we have seen trees lost from both natural and man-made causes. Age, weather, pests, diseases and the impact of development are all real threats to Wokingham's trees.
Trees age and may suddenly die or decline over many years. Ageing oaks in particular will cease to put out spring growth on some high branches which then die leaving visible dead wood in the crown. This ‘stag headed’ stage is typical of veteran trees which may eventually shed the dead branches. By itself it is not a sign of a tree in decline and indeed many ‘stag headed’ trees will have decades of life remaining (1996, p 226) .
Trees that have been weakened in some way are more susceptible to storm damage. Most winter storms will see branches taken off trees and some will be completely uprooted. Residents recall the number of trees that were lost in the severe storms of 1987 and 1993, long before WDVTA was formed. In 2016 an oak in Wokingham (MRN 3562) was struck by lightning and lost branches which fell into Reading Road. Two black poplars in Shinfield were lost in 2016 due to storms and had to be completely felled (MRN 5365 and MRN 5366).
Housing developments in Wokingham bring serious direct and indirect threats to its trees. The direct threats are where the building and road plans propose felling. We review planning applications and using our survey map and data we assess the impact of the development on the affected trees. Unfortunately we do not have enough resource to do this over the whole Borough.
The indirect threats arise where houses, roads or pathways are situated too close to trees. Many of the oaks alongside the routes into Wokingham are affected by ground compaction and lack of open ground for their root systems to flourish. This causes the crowns to develop dead branches which then have to be pruned for safety reasons. These effects are stressing the trees, limiting their lives and in some cases has led to felling.
Poor maintenance standards are an occasional issue. Some tree surgeons have been over zealous and excessive reduction work can result in stressed trees which do not always survive. In some parkland areas, the grass is cut too close to the trees damaging the bark and allowing fungal and bacterial infections to take hold.
There are many significant threats to trees in the UK from a variety of pests and diseases. The increase in these threats over the last ten to twenty years is thought to arise from international travel and increased importation of plants from across the globe bringing in new diseases. Trees have mechanisms to defend themselves against infection but these take time to evolve and the UK’s tree stock has not yet had time to adapt to these new threats.
The best known example is Dutch elm disease which devastated most of the mature elms in England in the 1960s and 1970s. There would have been many veteran elms in Wokingham, but of course we have none recorded in our survey.
The Forestry Commission website  gives information on the main pests and diseases, how to identify and report them  as well as giving updates on where outbreaks have occurred. The DEFRA website  has a risk register.
There are currently seven significant pest and disease threats to Wokingham’s trees. Up to January 2017 just three of these have been recorded but all seven could have an impact in the next few years.
All images in this section, apart from that of the oak processionary moth nest, are Crown Copyright and have been supplied courtesy of the Forestry Commission.
The larva stage of this insect pest eats the leaves by mining inside them and turning them brown long before autumn. Most of the horse chestnuts in the Borough are infected and are probably being gradually weakened.
This bacterial disease causes dark oozing stains down the branches or trunk. Trees severely affected by the leaf miner seem less able to withstand an attack from the bleeding canker which is now found throughout Wokingham.
This is a fungal infection which causes the leaves to turn brown and fall, the crown to die back and lesions to form on the bark. There have been confirmed cases of this disease in the Borough. The current view is that this infection will have a major impact on mature trees but some root stock will remain uninfected. It is also hoped that some native trees will tolerate or fight the infection and be a source of resistant trees for the future.
This insect arrived in England in 2005 and is spreading but has not yet (as of January 2017) reached the Borough. The caterpillars have tiny hairs which can cause skin and eye irritation as well as sore throats and breathing difficulties to people and animals. All sightings of infestation should be reported to Tree Alert.
This is believed to be a bacterial infection. The main visible symptom is oozing of dark fluid from cracks in the bark and a rapid decline in the health of the tree which will die, typically within five years of the first symptoms. Cases have been reported across most of eastern and central England, but none in the Borough (as of January 2017).
This is a fungal disease which is usually fatal. It is spreading in Europe and there have been cases in the UK but none yet (as of January 2017) in Wokingham. The infection attacks the bark and forms a girdle around the branch or trunk. Leaves above the girdle turn brown but frequently remain on the tree.
This insect is a recent arrival and has been found in Surrey, but none in Wokingham (as of January 2017). The larvae of the wasp cause galls to grow on the buds, leaves and stems of affected trees. Initially green, the galls turn red in late spring, become brown and woody over the summer and can cause early leaf drop. The galls do not have a significant impact on infected trees, but in large numbers they weaken the tree and make it more susceptible to other adverse environmental factors.
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As described above, Wokingham's trees are facing many threats from several sources but there are opportunities for reducing and minimising their impact.
We use our newsletter ‘Tree Watch’ and our website to keep our members aware of pest and disease symptoms and advise them how to report trees that they are concerned about. Prompt reporting and identification of infected trees will mean faster treatment.
We are aware of many local hedges where young elms continue to grow from residual root stock. We are pressing for the retention of these hedges and hope that when Dutch elm disease can be treated or eradicated, these saplings can help to return mature elms to our landscape. Some disease resistant elms are being propagated in specialist nurseries and four planted in the Borough are being monitored by our Tree Wardens.
Ash can also regrow from existing root stock and should ash die-back arrive in Wokingham, this may help regeneration. Identification of ash trees that appear resistant to the disease will enable the planting of replacements.
There are many opportunities to reduce the impact of the man-made threats to trees. Local planning controls exist and should be used to minimise tree loss. Once planning applications have been granted, the detailed plans and designs can be examined to ensure they are sensitive to the most important trees. New roads should avoid existing trees wherever possible and new buildings should be positioned far enough from retained trees to avoid damage to either. Development plans should define adequate root protection areas.
Over the last ten years the standards used for tree protection during development have improved. Erecting robust barriers around the trees and their root protection area before ground work starts is critical. This should prevent compaction of the ground, disturbance and breakage of roots as well as vehicle damage to the trees. Ensuring that these barriers are not moved or removed until the development is completed is needed on all sites.
Local people have a very important role to play in keeping an eye on developments during construction and should report any concerns to WBC Trees & Landscape.
Under TPO legislation trees with protection orders that have been felled MUST be replaced and we try to ensure that this happens. Whilst it will take decades for the new tree to reach the size and maturity of the one it is replacing, it is still very important that the historic, environmental and aesthetic reasons for the original tree order are recognised with the planting of a successor.
The photograph shows the ‘Storytelling Chair’ (MRN 151) created in 2012 at the Hawthorns School from a diseased English oak. Steve Radford carved the stump into a seat with animal designs as an alternative to removing the tree after felling.
In Earley, The Duck & the World carving in Maiden Erlegh Lake has made a feature of a storm damaged tree.
In Shinfield, an open area bordering Pearmains Copse was used to site a number of tall tree trunks that were felled when the roundabout was constructed in 2005. The area has been nicknamed 'Woodhenge', featured in the Shinfield Parish Walk leaflet, where the trunks provide a habitat for bats, woodpeckers, insects and fungi.
Finding innovative, aesthetic and environmentally attractive uses like these for the remains of felled trees is to be encouraged and applauded.
With all new developments, whether road upgrades, bypasses, housing or new public open spaces, there come many opportunities for tree planting. Planning ‘the right tree in the right place’ is an evolving skill. Trees too close to roads where the root growth will be restricted and the ground compacted, or trees that will look good for a few years but then grow too large for the space available are not good choices. But schemes where a new hedge is planted interspersed with saplings designated as hedge trees or a specimen tree is planted in a new public area are measures that we are beginning to see more widely adopted in Wokingham and are very much to be welcomed.
For too many years, we have been losing trees faster than we have been planting them. With all the developments in the Borough all residents should be encouraging the Council and developers to be innovative and inspired in tree planting schemes to redress this historic imbalance.
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