Nature 2003 March

A Climate of Change

By the time you read this January will be a distant memory. Meteorologically speaking temperatures were above average although, I suspect the highlight was the snow which came at the end of the month. For once though, we escaped the blizzards which chose to fall on Amersham instead and hence the excessive coverage in the Bucks Advertiser about the chaos a bit of snow causes! We think we get our fair share of rain up here but actually we fare much better than most and during January notching up a mere 3 inches or 85mm (3.75 inches in Jan 2001). It has more to do about how it falls rather than how much, I guess. All but a drop or two falling on 4 particular days including New Year when the Vale once again reverted to type for a few hours after lunch. The warmest day was 25th (12.5°C). Whilst the coldest was at 5am on 12th (-8°C) to which should be added a wind chill of -9°C! So far, February can be described as ‘damp but uneventful’. As Michael Fish would say hurricanes are not expected! But more on this next month.

Global warming (GW) no longer makes the headlines. Notwithstanding more immediate world crises this is perhaps also because we are now conditioned into hearing about its impact on the climate and hence the distribution and behaviour of our native flora and fauna as well as the growing season of crops. In reality single events or one-off sightings of unusual wildlife cannot be attributed to the GW phenomena. However, it has sparked a renewed interest in the science of phenology, which is the recording of events connected to the climate. Records have been collected for over 300 years (e.g. Gilbert White). In the last 100 years there has been a 0.6°C increase in world temperatures. This is sufficient to encourage some plants and animals to extend their ranges northwards and will be more significant 600ft up in the Chilterns than in the Aylesbury Vale for instance.

Species eventHilltop villages
2002
UK Averages
200019211895
Wood anemone flowers12 Mar25 Mar 14 Mar 28 Mar
Hawthorn first leaves20 Mar20 Mar 7 May
Blackthorn flowers26 Mar15 Mar 12 Apr
Bumble bee first seen15 Mar 7 Mar 31 Mar

In 2000 the UK Government started using such observations to track climate change. I thought you might be interested in a few records from March 2002 for particular species for the ‘Hilltop Villages’ and UK average dates for some previous years. Whilst it does not provide a basis for predicting when the sea will engulf most of East Anglia it might encourage you to look out for when these events occur near you this year. Make a note of when you first cut your lawn this year. The UK average last year was 15th March!

For more information about these records and how you can contribute visit www.woodland-trust.org.uk/phenology.