In the last article of her column, Patricia, our Trustee, wrote about climate change and how it may affect ancient trees in the Forest. In this issue, she explained how warmer weather can have a knock-on eect on nature’s seasonal events. This article was first published in Epping Forest Heritage Trust’s Spring 2024 issue of ‘Trust in the Forest’ magazine.
Living organisms respond in various ways to the ambient temperature of their surroundings, most being more active during the warmer months. All have evolved strategies to overcome such problems as freezing conditions, too much heat or lack of water. Deciduous trees shed their leaves in autumn, reducing the need for water uptake when soils may be frozen. Hedgehogs, bats, reptiles and amphibians hibernate as their food supplies are less available during the colder winter months.
Since the 1960’s the average minimum winter temperatures have been increasing and frosty days are less frequent. You may have noticed that Primroses and other flowers are opening earlier, in fact researchers recorded that the first flowering of some 406 plant species has advanced by about 30 days since 1986!
This has a knock-on eect for the time of emergence of pollinating insects such as bees and hoverflies. Trees are leafing earlier, providing food for so many hungry caterpillars, ideal food for nestlings, if their parents have managed to breed earlier too! Frog and toad spawn has appeared about two weeks earlier this year, but the developing tadpoles are vulnerable if ponds then freeze over.
The seeds of many trees will not germinate unless they have been chilled and thawed several times, a process known as stratification. This softens the seed coat enabling germination to take place. Thus, after a warmer winter there may be a reduction in natural regeneration, essential for woodland continuity. Frosty nights also seem to be required for the successful production of flowers in bulbs such as Bluebells.
This year the Field Studies Council, which operates the Epping Forest Field Centre, is working in partnership with the Royal Society of Biology and asks you to take part in their Signs of Spring survey to record when you first see 10 indicator species or events. These include flowering Bluebells, or emerging ladybirds, butterflies, bees, dragonflies or damsel flies, all of which are present in Epping Forest! So, when out and about if you spot any of these please send in your records as it will help monitor how such organisms are adapting to warmer springs across the UK as well as here in Epping Forest.
To find out more about Signs of Spring survey, please visit: https://www.field-studies-council.org/signs-of-spring/
Notes:
About the author: Patricia Moxey B.Sc. Hons. FBNA: With a professional background in environmental education, Tricia’s work has been to encourage others to understand and engage with the natural world. She has been associated with Epping Forest for over 50 years, initially helping to establish the Field Centre at High Beach, where she became enthralled with the complexity of the Forest’s history and ecology. In 1992, she joined the City of London staff at the Warren as Information Officer for Epping Forest.