Worcestershire Record No. 16 April 2004 p. 35

ACER v PYRUS? WORCESTER HIGH STREET TREES

Joy Ricketts

In late Autumn 2003 a seemingly innocuous article appeared in our local newspaper. It appeared to bear glad tidings telling how Worcester City’s High street is to be updated and, naturally, this will bring much needed increased revenues to the commercial world. Superficially this sounds fine, but no one seems to have seriously thought out the non-commercial implications and the effects these plans will have on wildlife. This raises the question just how committed are councils to bringing wildlife into city centres?  In the early 1980s Worcester’s High street became pedestrianised to make the High Street more commercially appealing through improved access and attractiveness to the city visitor. The work entailed replacing the macadamised road with paving blocks set on sand raised to pavement level. The entire length of the street was planted linearly with Norway Maple Acer platanoides saplings, with a stand of five birch Betula pendula towards the northern end. The planting programme has since continued, replacing damaged Acers when necessary and by adding four young Liriodendron tulipfolia trees at the end known as The Cross. Bench type seating has been interspersed under the tree shade canopies for visitor comfort and needless to say opportunistic pigeons regularly patrol this seating area.  Within 20 years the trees have grown well, despite the determined attempts by a minority of visitors to fertilise them with discarded cigarette stubs and decorate the bark fissures with chewing gum. The older trees now have useful shade canopies and girth measurements ranging between 65 to 134 cm. However, it is their role as hosts in providing much needed habitats for a number of creatures that has brought significant changes. Without a doubt these trees have eliminated a previously alien and sterile environment, replacing it by a living world right in the heart of Worcester City. 

The proposed alterations prompted an immediate and detailed lichen survey of the High Street’s thirty-two trees; this was carried out during late December 2003 and completed in early January 2004. Additional observations were noted and these include ants and resting winged insects on Acer bark, and at eye level 12 empty mollusc egg cases (identified by John Micklejohn) were discovered in a bark fissure surrounded by Phaeophyscia orbicularis - a small leafy lichen. More obvious however, is the role the Acers play in providing a winter roost for Pied Wagtails. (Confirmed by Harry Green.)  Although taken for granted, and much over-looked, lichens are important not only for their visual appeal, but also as primary producers (e.g. food for molluscs) and as environmental indicators. In early 2000 the first, early indications of lichen colonisation were seen, but formal identification was not possible. During the past four years the trees have become a suitable, stable lichen substrate, with a few trees now having good cover. The December 2003 survey found six species, albeit pollution tolerant, on all but three trunks, of which, Phaeophyscia orbicularis is the most common. 

The city’s commercial centre has continued to mature into a very pleasant and attractive area. Sadly, the re-vamp is purely for commercial and cosmetic purposes, and the plans include the removal of possibly up to half of the present trees replacing a proportion with the pear, Pyrus chanticlere. From my point of view it is indeed most regrettable that the only stable corticolous lichen substrate will be lost. It appears that I am not the only person unhappy with this proposal for there have been many letters of protest printed in the local press. The “improvement” plan is due to be implemented in early February 2004. Sadly, despite councils professing to be all things to all issues, it seems that High Street commerce remains king and wildlife will continue to be expendable, the needs and requirements of the natural living world do not warrant even the briefest of considerations.