Watching the seasons

As I sit down to write this, the COP26 climate summit is underway in Glasgow. Hundreds of diplomats from around the world have assembled - face to face - to try and curb the impacts of climate change.

What is phenology?

But how do we know what impact climate change is having? Phenology is the study of the timing of biological events. When you look out your window and observe the changing seasons, a snow drop appearing in spring, strawberries ripening in summer or a migratory bird arriving in autumn, you are observing phenology. How does this tell us about climate change, you might ask? Well, plants and animals are sensitive to their environment and the timing of these events can shift with changes in temperature, for example. If we record exact dates each year that a certain event takes place, we can compare these dates across many years and see if there is any change. This is what has been done for not just decades but many hundreds of years in some cases and it tells an interesting story about climate change. Phenology is also one of the important factors that convinced governments around the world of the impact of climate change on our environment.

Why is it important?

Accurate records of the timing of phenological events have a broad and expanding range of uses. These include medical, agricultural, cultural and climate change monitoring and forecasting. Exceptionally early springs can have severe impacts for hay fever sufferers, increasing hospitalisations. Alerting farmers when certain pest species will emerge allows for improved pest control strategies. Predicting when daffodils, snowdrops and blossoms appear can help organisers plan cultural and tourist events. Probably the most important use of phenology though, is in monitoring the impact of climate change on our living environment and making predictions about future change to inform the public and government.

Phenology monitoring on the Iveragh Peninsula

Phenology observations have been made at the Valentia Meteorological Observatory for over 50 years as part of a Europe-wide network called the International Phenological Gardens (IPG) network (Figure 1). So, we now have a long record of observations such as those shown in

(Figure 2) for our small native willow species (eared willow, Salix aurita). These long-term observations indicate a general trend across many species towards an earlier spring each year.

Figure 1. The phenological gardens at Valentia Observatory.

Figure 2. Summary of spring phenology for Salix aurita (eared willow) as recorded at Valentia Meteorological Observatory on the Iveragh Peninsula, Kerry. While the timing of leaf unfolding appears to be staying relatively constant across time, the timing of flowering for this small native tree looks to be advancing quite rapidly at this location. This is just one example of trends we are seeing.

What is the Iveragh phenology project?

We would like to monitor spring phenology across the whole Iveragh Peninsula and see if the plants grown at the Valentia Meteorological Observatory are representative of the wild plants. Information gathered will also provide insight into the timing of spring in different townlands on the Iveragh Peninsula.

How can you get involved?

If you have some native trees on your land or near your house that you would like to monitor, we would be very excited to include you in our study. We are currently only looking at downy birch, hazel, and eared willow. Please contact us with a photo of the plant if you are unsure of the species. We are very grateful to have already had three sites join the study (one such site pictured in figure 3).

We held our first in-person workshop on 27th November 2021, where we shared more information on phenology and give guidance on how to collect records in your local area.

January 2021

Our next workshop takes place online, on Wednesday 12th January 2022, from 1pm - 2pm. You can register here.

Please contact if you have any questions.

Figure 3. Adding trees to the study in November 2021, ready for spring phenology monitoring!

Calum Sweeney is very interested in the seasonal changes that plants go through every year. The timing of when these changes occur - such as leaf fall and bud burst - is known as phenology and is used as an indicator of climate change. He is collaborating with Valentia Meteorological observatory on an important phenological project looking at the timing of spring on the Iveragh Peninsula.