The man who sampled a grassland for 25 years – and his data got eventually published
The post provided by Kryštof Chytrý, Milan Chytrý, Felícia M. Fischer and Jakub Těšitel
This post refers to the article Weather fluctuations drive short-term dynamics and long-term stability in plant communities: a 25-year study in a Central European dry grassland by Fischer et al. published in the Journal of Vegetation Science (https://doi.org/10.1111/jvs.12895).
In 1992, Jiří Danihelka, a fresh graduate from the Faculty of Forestry with a deep interest in plants, was appointed as a botanist at the administration of the Protected Landscape Area (PLA) Pálava, a famous site with steppe grasslands in the south-eastern Czech Republic including the Pavlov Hills. It was soon after the political changes of 1989, which profoundly transformed the whole society, including nature conservation, which was trying to develop new approaches to nature management and monitoring. However, such approaches were often applied hastily with only a blurred idea about their purpose, poor planning, weak coordination and nearly no funding that would secure their sustainability. Jiří was aware of that, and when he was commanded, in 1993, to establish some permanent vegetation plots somewhere in Pálava, he was not happy at all. Still, he followed this vague instruction of his bosses. Trendy waves go up and down, and Jiří believed that the monitoring programme established in that way would fade away soon. He was right: most of the permanent plots established during this campaign in different protected areas across the country were abandoned soon, the data have never been analysed, and in most cases, the documentation was lost. But there was a notable exception: Jiří’s permanent plots established in a limestone steppe grassland on the summit of Děvín, the highest hill in the Pavlov Hills. Even after he changed the job, becoming the curator of the Herbarium of Masaryk University in Brno, he kept sampling his permanent plots every May or June. He usually went by train from Brno, often alone, but sometimes accompanied by students or international visitors, sometimes with field courses of plant ecological methods led in the early 2000s by Milan Chytrý. It is hard to say what kept him sampling the permanent plots for such a long time. Perhaps it was the nostalgia for the landscape where he spent his early career as a field botanist, perhaps it was his thoroughness and belief that once started, the work should continue, and probably both. While other ecologists who established their permanent plots for research purposes published several papers about vegetation changes soon after the plot establishment, Jiří published nothing for 25 years, being busy with work in the herbarium, plant taxonomy and cataloguing and mapping Czech flora.
In spring 2015, Jiří sampled his permanent plots together with Helena Prokešová, who was just about to start her job as a botanist at the PLA Pálava administration. It was the year of a severe spring drought, which the participants of the 58th IAVS Symposium in Brno may remember from excursions (by the way, some guided by Jiří). Helena participated in sampling again in 2016, this time also with Kryštof Chytrý, then a student of the last year of secondary school, and she noticed a striking change in the dry grassland plant community. She was shocked because she remembered the fescue-dominated steppe grassland from 2015 and now the grassland looked like an abandoned parking lot. The interannual turnover was striking, but Jiří, being calm about that, argued that the species are still there, just their cover values are dynamic between years. Hence, Helena asked Jiří for the full dataset (Danihelka 2019), and together with Kryštof, they made the first attempts to analyse it, focusing on the effect of weather fluctuations on vegetation change. However, their statistical skills at that time were not sufficient to properly analyse the data from vegetation and climatic time series.
The situation changed when Felícia M. Fischer started as a post-doc at the Department of Botany and Zoology of Masaryk University, and Jakub Těšitel, a plant ecologist with solid statistical background, was appointed as an Associate Professor there. Both of them were interested in the dynamics of grassland vegetation and also had their research interests in dry grasslands on Děvín Hill. Thus, after 25 years of sampling, the data were analysed for the first time by Jakub and Kryštof, and Felícia linked the results to the ecological theory. As she is from Brazil, she had the advantage of having no preconceptions about the particular species in the dataset, which gave her a more independent view of the general trends than had the Czech botanists. The results were interesting, and for someone perhaps surprising: the grassland was very stable over several decades, which was also confirmed by the analysis of historical vegetation plots that existed from this area from different periods since 1930. The permanent plots showed that this stability was maintained by inter-annual weather fluctuations, which were reflected in considerable short-term vegetation dynamics. However, a series of dry years occurring since 2015 seems to have a stronger impact on this dry grassland than any climatic extremes recorded so far. Still, some more years of sampling will be needed to understand what is happening right now.
When the manuscript was ready for submission, Jiří and Kryštof went together to sample Děvín permanent plots again. They were both glad that the first results of a 25-year study will be published soon, but at the same time, they felt it did not change anything in the life of permanent plots. They are not sampled primarily for the production of scientific papers. There is something more behind.
References:
Danihelka, J. (2019) Permanent plots in dry grasslands on Děvín Hill, southern Moravia, Czech Republic. https://doi.org/10.6084/m9.figshare.9971039.v1
Brief personal summary: The authors of the JVS article are botanists and plant ecologists at the Department of Botany and Zoology, Masaryk University, Czech Republic. Felícia M. Fischer is a postdoc who previously studied and worked at the Universidade Federal do Rio Grande do Sul, Porto Alegre, Brasil. Kryštof Chytrý is a Master student working on the ecology of steppe and forest-steppe vegetation. Jakub Těšitel is an Associate Professor of Botany interested in hemiparasitic plants, vegetation ecology and restoration ecology. Milan Chytrý is a Professor of Botany with a broad interest in different topics in vegetation science, macroecology, invasion ecology and palaeoecology. And finally, Jiří Danihelka, the main character of this blog story, is an Assistant Professor and Curator of the Herbarium of Masaryk University (BRNU) interested in plant taxonomy, floristics and phytogeography.
