I went to my nearby meadow at the beginning of the week, and where a couple of weeks ago there were 4 butterfly orchids in bud out of a total of around 25 plants, the dry weather has had a significant impact, shrivelling up the buds and the leaves. There won't be any flowers this year, and given the state of the leaves they are unlikely to produce sizeable enough tubers for next year's plants to thrive. I fear that this relatively short spell of continuous dry weather might well have seriously impaired this little population of orchids for two to three years.
On Skye I looked at correlations between orchid populations and climate parameters. Now, in a more comprehensive study that is now in its fourth year, the landowner and I are undertaking a study of the population dynamics of butterfly orchids in a farm in the Chilterns. I have carried out some climate comparisons, taking monthly data, but in the analysis I might in the past have missed the importance of some short term extremes such as the current drought. Were it to rain heavily for a couple of days later this month the dry conditions day after day will be masked in the monthly total figure, so in future analyses I am going to incorporate the number of days when no appreciable rain fell. Heavy rain on a few days, with the ground drying out between bursts, is much less helpful than regular rainfall.
Meanwhile our study greater butterfly orchids in the Chilterns are just beginning to flower and I shall undertake a comprehensive count early next week, now that travel is less restricted.
I have been regularly moth trapping, and after a very slow start at the beginning of May, 2 nights ago I had 42 species (59 species year to date) several of which I had not seen before.
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| Miller |
