Are the seasons changing? Phenology provides results
Growing up in the West Country in the late 1960s and through
the 1970s, I distinctly recall tramping over ground still hard with frost
at mid-day in late December. These days, Christmas seems to herald the
approach of winter rather than being in the midst of the coldest period.
So, is it just my memory failing, or are the seasons changing, even over
such a short time?
The answer is to study the changes in timing of events i.e. phenology, across a wide range of species groups. If you find the natural world interesting, perhaps you'd like to participate in recording changes in the environment around you, which can assist in understanding global warming and potentially even lead to better prediction of pollen timing. Dr Tim Sparks has very kindly provided information to me on phenology following an open day visit to the Centre for Ecology and Hydrology (previously the Institute of Terrestrial Ecology), at Monks Wood, Abbots Ripton.
We Brits are famed for talking, or is that moaning, about the seasons, second only to our predilection for discussing the weather. However, it seems that for at least 270 years there have been some people keen enough to physically record the arrival of spring and autumn thus allowing researchers to compile data to ascertain if changes are really taking place. Today, such studies continue and now there is sufficient evidence to show that commencement of Spring has advanced, the start of Autumn is delayed, and thus Winter is shortening by some eight days per decade.
The observations made by individuals include flowering of plants, leafing of trees, appearance of insects, return of migrant birds, breeding of birds and amphibians etc. From these historical records it is now possible to draw comparisons between changes in temperature and the time of occurrence, for example, for flowering. Whilst there are issues associated with species such as snowdrops which have different varieties , the evidence indicates that for every 1°C rise in temperature, crocus, daffodil and snowdrop will flower respectively 7, 6 and 6 days earlier. Further, tree leafing (bud burst) studies in Surrey (Jean Combes, in Ashtead) from 1947 to the present, show significant changes in the post-war period, with oak particularly, leafing earlier by 10 days over the past two decades.
Participation by a large number of individuals across the country will allow more substantial data to be collated and thus provide the basis for improved understanding of the changes occurring around us. There has recently been renewed interest worldwide and the UK Phenological Network commenced in 1998 for spring observations with the addition of autumn observations from 1999. The network aims to record simple events of easily recognised species that are generally widespread across the UK, and seeks to encourage participation by a wide range of people, from children to the elderly, including those who may be housebound.
Tim is keen to obtain data from people of all ages, on observations made in their own garden and surroundings about easily recognised species. Recording sheets can be found at www.phenology.org.uk, run in association with the Woodland Trust, or from the Centre. Thus through a network of observations over the country it should be possible to correlate changes with global warming and similar studies elsewhere, and also assist in better prediction of pollen timing which will be beneficial to those with allergies.
The typical observations requested in spring include leafing of elder, hawthorn, horse chestnut; flowering of wild snowdrops, hazel, primrose, ox-eye daisy; arrival of migrant birds such as wheatear, swallow, house martin; nest building of rooks, blackbird and appearance of insects and amphibians etc.
These can all be observed from within your garden and the local footpaths, perhaps when taking a regular stroll.
Historically, Robert Marsham FRS, is considered the father of British phenology. Born in 1708, this Norfolk resident began recording "Indications of Spring" in 1736, which he continued until his death in 1798. His family descendants continued down the generations until 1958 and more recently, further observations have been made by family members as part of the Phenological Network. The interest grew across the country in the early years, to the extent that in the late Eighteenth Century it was possible to purchase printed diaries to specifically record meteorological and phenological data. From 1875 until 1947 the Royal Meteorological Society organised a network of recorders seeking to relate vegetable and animal life to meteorology. Similar schemes existed elsewhere, but those which have survived to date are often in Eastern Europe.
Could Godmanchester, with the local flora and fauna so close to hand, become a location with a number of people participating in these studies? Personally I would like to think we can all contribute to knowledge generation and this is an excellent way of not just enjoying our wonderful location, but learning more of the continual ebb and flow of changes as the seasons progress. Now is the time to contact the Phenological Network so that they can provide you with information on making observations in the coming autumn and next spring.
For recording sheets, visit www.phenology.org.uk
or contact Dr Tim Sparks at the
Also, keep an eye out for their open days each year, it makes for a very interesting visit to learn about the activities of woodland and hedgerow conservation right on our doorstep.
My sincere thanks to Tim for provision of the material for this article.
© 2001 Godmanchester Community Association
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