Phenology is the study of recurring seasonal events, such as flowering and leaf fall in plants and hibernation and migration in animals. Parameters such as the date and duration of flowering can be compared with climatic parameters such as temperature, rainfall and humidity to see if there is any correlation.
Phenological research at RBGE dates back to the 1850s, when the Curator, James McNab first recorded the flowering dates of more than 60 species - see J. McNab (1857) Transactions of the Botanical Society of Edinburgh 5: 173, 184.
The current phenology programme at RBGE has been running since 2002 and involves recording the frequency and duration of flowering and stages with each flowering season and changes in foliage for over a hundred species. These data will increase the understanding of the mechanism in plants which responds to climate changes and will enable scientists to predict how plants will respond to climate change. This has important consequences for conservation, agriculture, horticulture and forestry; what gardeners are able to grow in the future will, without doubt, be influenced by climate change.
Over some of the past 10 years early spring has been getting warmer and some spring-flowering plants flowered more than two weeks earlier. However, there have also been later than average years, and the current trend (2014) has a slight positive value (i.e. spring happening later). The "Edinburgh Spring Index" is a measure gained from the average of first flowering dates of all the taxa flowering before the Spring Equinox, relative to the (arbitrary) standard of 2002. This is a unique experimental opportunity comprising plants from regions across the world, growing at a single site, and subject to the same approximate climatic variation.
The phenology programme based at RBGE is in collaboration between staff and research associates in the Science and Horticulture Divisions and volunteers. The programme includes a daily monitoring project, a weekly monitoring project and the special examination of Rhododendron species. These studies include the development of semi-quantitative rapid-survey methods for monitoring phenological characters.
The International Phenology Gardens Project (IPG) is coordinated by Humboldt University (Berlin), with sites throughout Europe. The project monitors up to eight aspects of the phenology of cloned material for a range of tree species. RBGE is currently establishing sites at its gardens at Dawyck, Logan and Inverleith. Dawyck has, for Scotland, an unusual crisp continental climate and will provide important new observations for the project; Logan, by contrast is known for its mild winters and clement summers. A comparison of the data will be very interesting...
updated 10 April 2014