Woodland strawberry monitoring: an example of international collaboration despite covid-19.

Summer and autumn have passed and now the strawberry plants rest under a mantle of snow. From June to October, at the Research, Monitoring and Evaluation Centre, we have continued with flowering and fructification measurements as well as herbivore damage quantification.

As introduced in the latest blog posted on the 29th April 2020:  ‘Sierra de Guadarrama’ National Park Research, Monitoring and Evaluation Centre took the baton from the international researchers leading the study who were facing the impossibility of travelling abroad to conduct the monitoring measurements due to the COVID-19 pandemic restrictions.

Based on the initial project, a larger EU BiodivERsA project will start in March, named – PlantCline: “Adapting Plant Genetic Diversity to climate change along a continental latitudinal gradient”- carried out in collaboration with Ghent University, Swedish University of Agricultural Sciences, University of Turku, University of Malaga and University of Helsinki. This project will investigate how natural enemy communities and drought affect defense and performance of woodland strawberry along a European latitudinal gradient, whether such changes in plant traits are mostly determined by their genotype or by the environment, and what the underlying physiological and genetic mechanisms are. This gradient consists of 5 common gardens, of which the southernmost is located at the Research Center.

In nature, this species can be found in the north of Spain at sea level, occupying shadowy areas along wooded slopes. However, in the centre and southern areas, summer drought makes them scarce and confined to the mountains. In fact, woodland strawberries are unusual in these latter areas and do not do not occur at elevations lower than 1,700 m, hiding in Pyrenean oak forests as part of the understory vegetation as well as in mesophilic pine woodlands and willow groves by mountain streams. It is more abundant in Gredos and Ayllón mountain ranges than in Guadarrama range which has a drier climate. Hence, it was to be expected that summer drought would be a limiting factor for our plants’ growth at the Research Centre, which is one of the pressures on plant performance this project aims to study.

With all last season’s data already collected, we know that 68.75% of the plants have flowered and 63.44% have produced ripe fruits with well-developed seeds. It has also been observed that summer drought has altered the end of the fructification process and prevented the ripening of the late fruits.

Ripe fruit. Author: Jose Luis Izquierdo.

This long drought period has also affected the plants’ survival. By the end of the field study period, almost half the plants (47.50%) had been gravely affected by drought and most of them were located under the rainout shelters, which intercept 50% of the incoming precipitation.

Drought effect on plants. AUtor: Jose Luis Izquierdo

In contrast, plants have been barely attacked by herbivores; only 3.00% of the ones that had survived presented some mild damage.

Once the field work season was finished and thanks to the frequent blizzards we are currently having this winter, the plots are buried under a thick layer of snow, although there are short periods in between when some melting takes place. It is at those moments when the effect of the shelters can be widely observed –- whose protection enhances the melting process- and thus, some of the pots located under them timidly peek out whilst the rest remain covered in snow.

Common garden in January. Autor: Jose Luis Izquierdo.

It has yet to be determined what effect the shelters’ conditions have imposed on the different genotypes, as well as how genotype interacts with shelter effects on both growth and plant phenology, in order to achieve some of the scientific objectives of the project:

• Generating fundamental new insights into the mechanisms of climate adaptation in plants.
• Creating guidelines for the conservation of plant functional diversity in natural systems under climate change

Over the next few months, new plants of the same 16 genotypes from all across Europe will be established in the common garden at the Research Center and in the four other locations along the latitudinal gradient, to repeat the experiment. This year, we will use somewhat bigger pots capable of retaining moisture for a longer time to reduce drought-induced mortality. Potted plants rather than runner material will be used this year, to give the plants a better start, as well. Currently all the plants have been grown in the greenhouse in Finland, and their transport to each of the five sites is being prepared. We hope that the international team can gather at the National Park again this spring, not only to establish the next phase of the experiment, but also to catch up and exchange ideas.