Cylch Blodeuwedd

OAK BEFORE ASH: PHENOLOGY

by Grove Member, Holger Burkhart

“Oak before ash … in for a splash – ash before oak, in for a soak!” Who has not heard this old proverb? But, in our everyday lives, how many of us do really take notice of, let alone record the times of the appearance of flowers, leaves, insects, migratory birds etc.? I can not help thinking that this sort of thing should come almost naturally to us as Druids.

Reading in a recent issue of Greenway (the journal of the Hedge Druid Network) about a man who recorded the appearance of the dog rose over many years brought back memories of ‘my other life’ back in East Germany where I worked for the Meteorological Service as a weather observer and later as forecaster. We did not just deal with purely meteorological data but also recorded the occurrence of the first snowdrops, first leaves, flowers and fruits on certain trees and bushes, the first grass cutting, the beginning of the grain and potato harvest, in autumn things like the beginning of leave colouring and their falling off, the last grass being cut and so on. All this was (and still is) used for monitoring and researching changes in the natural cycles of the seasons and has also got a name. Phenology is, broadly speaking, the study of times of recurring natural phenomena, especially in relation to climate. By recording the times of arrival and departure of the various species we are getting an insight into the changes that are taking place in our environment and allows us to monitor the effects that climate change has on our wildlife. The wealth of historical phenological data allows us to examine trends from the past and make cautious predictions as to what happens to species in the future

This year happens to be the tricentenary of the birth of Robert Marsham, the founding father of phenology in Britain. He started recording his ‘Indications of Spring’ as far back as 1736 on his family estate at Stratton Strawless in Norfolk. Until his death in 1798 he recorded 27 natural events for more than 20 plants and animals, such as tree leafing times and the arrival of migrant birds. What by then had become a family tradition was continued by his descendants and only stopped in 1958 with the death of Mary Marsham, at a time when the impact of burning fossil fuels and large scale deforestation began to have an accelerating effect on the world’s climate and with it on the natural world. Phenology took a major step forward in 1875 when the Royal Meteorological Society established a national recorder network. By 1899 there were 155 observers contributing records of the flowering of 13 plants and the appearance of birds and insects. Between 1891 and 1948 the RMS run a nation-wide programme to which up to 600 observers contributed. Their findings were summarized the RMS’s annual reports. When these Phenological Reports suddenly ended Britain was left without a national recording network for almost 50 years, unfortunately a period during which climate change was becoming widely evident. However, a number of individual dedicated observers such as the naturalist and author Robert Fitter still contributed valuable records.

In 1998 the Cambridge based Centre for Ecology and Hydrology started a pilot scheme to revive phenology in Britain and in 2000 joined forces with The Woodland Trust to form the UK Phenology Network. Today over 24000 volunteers, amongst them thousands of young Nature Detectives, submit records once again on a national scale. And yet, more helpers are needed! The UKPN aims to have one observer in each 10km square grid of the country. Volunteers are welcomed from anywhere, but are most needed in the west and north of mainland Britain and in northern Ireland. In co-operation with the BBC, the UKPN launched a spring watch and a autumn watch survey in 2005 to which over 100000 people contributed over 200000 records. The results of this ongoing project can be seen on their fascinating website www.naturescalendar.org.uk where one can also register in order to submit observations on-line. I personally have done so straight away and recorded the first flowers on the elder tree in my back garden on the 19th May. This website allows you to watch animated maps showing the appearance of phenomena amongst trees, shrubs, grasses, flowers, birds, amphibians, insects and even fungi!

Getting involved with phenology appears such a wonderful opportunity to reaffirm our connection to the natural world around us and and take our place in it literally with wide open eyes. That’s why I would like to encourage everybody to become part of it, whether on a grand scale as part of the UKPN or a more personal level, whether you record dozens of sightings or just a few. Admittedly, it may take many years of recording to obtain reliable trends in the changing nature of the seasons but not as long as one might think. Apparently, spring these days comes 2 weeks earlier and autumn one week later than 30 to 50 years ago which, in historical terms, is a frighteningly short time and clearly illustrates the growing speed of these changes. That’s one more reason for us to keep the finger on the pulse of the Earth!
Oh yes, as for the ‘Oak before Ash…’, both historical and more recent data show that there is no evidence of the leafing times of oak and ash being linked with subsequent rainfall. But there seems to be a strong influence of the temperature with oak being more responsive and gaining advantage over ash in warmer springs. By the way, there are sayings about oak and ash in German and Norwegian too, but these suggest the opposite relation to the English rhyme! Confused? Well, best thing is do start your own observations and, over time, find out for yourself.

Happy recording!

22/05/2008