Department of Vegetation Ecology

Located in Brno, South Moravia

Head: Mgr. Radim Hédl, PhD.

People ׀ Projects ׀ Publications

 

Research topics

  • Spatiotemporal patterns in plant communities
  • Human influence on ecosystems in the past millennium
  • Long-term dynamics of forest, wetland and grassland vegetation
  • History of Eurasian vegetation types
  • Conservation and restoration of temperate ecosystems

 

Selected recent results

1/ Historical management is a significant factor in explaining patterns in current forest ecosystems

In regions where humans have been continuously present for millennia, the past management of forests is a significant factor in explaining the current state of these ecosystems. It is usually the abandonment of traditional forest management that brings about the loss of biodiversity. For example, in the Slovak Karst, the end of coppicing caused the increase of beech, mesophication, local extinction of light-demanding species taxonomic homogenisation. The reintroduction of such management, however, has the potential to revert negative changes, as observed for ground-dwelling spiders in southern Moravia. At the same time, anthropogenic effects can be hard to set apart from natural patterns, as our research testing the assumed dominance of oak standards in coppice forests demonstrated. In special conditions, such as low pH and stable light in the Peak District National Park (UK), lack of management (grazing) can result in changes that are less pronounced than previously predicted. Overall, our results (some of which were published as part of a special issue in the Journal of Vegetation Science on “Historical Vegetation Ecology” that we co-edited) suggest that greater diversity of nature conservation techniques (including, but not limited to, traditional management) leads to the best results in halting biodiversity loss.

  • Hédl R., Cousins S. A. O., Decocq G., Szabó P. & Wulf M. 2021: The importance of history for understanding contemporary ecosystems: insights from vegetation science. Journal of Vegetation Science 32, e13048. doi:10.1111/jvs.13048
  • Máliš F., Bobek P., Hédl R., Chudomelová M., Petřík, P., Ujházy K., Ujházyová M. & Kopecký M. 2021: Historical charcoal burning and coppicing suppressed beech and increased forest vegetation heterogeneity. Journal of Vegetation Science 32, 1 – 14. doi:10.1111/jvs.12923
  • Szabó P., Hédl R. & Šipoš J. 2021: Standard trees versus underwood: historical patterns of tree taxon occurrence in coppice forests. Journal of Vegetation Science 32, 1 – 11. doi:10.1111/jvs.12963
  • Vild O. & Rotherham I. D. 2021: Long-term exclosure of sheep-grazing from an ancient wood: Vegetation change after a sixty-year experiment. Applied Vegetation Science 24, 1 – 10. doi: 10.1111/avsc.12543
  • Vymazalová P., Košulič O., Hamřík T., Šipoš J. & Hédl R. 2021: Positive impact of traditional coppicing restoration on biodiversity of ground-dwelling spiders in a protected lowland forest. Forest Ecology and Management 490, 1 – 10. doi:10.1016/j.foreco.2021.119084

Tento dub poukazuje svou rozložitou korunou na původně otevřenější vegetaci (Národní park Podyjí, duben 2021).

Trees are important witnesses of past landscape management. The large crown of the oak in this picture points out at once relatively open vegetation (Podyjí National Park, April 2021).

 

2/ Biodiversity in temperate forests reacts to climatic change

Forest ecosystems host a major part of biodiversity in the temperate climatic zone. This biodiversity is rapidly changing under the influence of climatic change. To understand the driving mechanisms of biodiversity change, we studied the structural characteristics of forest stands and the subsequent reaction of herb species to light availability across European broadleaved forests. However, easily measurable structural variables proved to be inadequate – it is necessary to take further environmental factors into account. Individual forest species significantly differ in their niches, which is partly reflected in their geographical distribution. It is then possible to infer temperature optima, which we did for 968 plant species of European forests. The resulting ClimPlant database is freely available for all researchers. We also compared macroclimatic conditions with the microclimate inside forest stands. In our analysis of long-term changes (through 37 years) in more than 2000 plots, we focused on the differences between adult trees and seedlings. For 25 common tree species, adults and seedlings showed increasing differences in their climatic niches. This can have a significant effect on the future composition of forests. Climatic niches should therefore be considered not only for adult trees but also for their seedlings.

  • Carón M. M., Zellweger F., Verheyen K., Baeten L., Hédl R., Bernhardt-Römermann M., Berki I., Brunet J., Decocq G., Díaz S., Dirnböck T., Durak T., Heinken T., Jaroszewicz B., Kopecký M., Lenoir J., Macek M., Malicki M., Máliš F., Nagel T. A., Perring M. P., Petřík P., Reczyńska K., Pielech R., Schmidt W., Świerkosz K., Teleki B., Wulf M., De Frenne P. (2021): Thermal differences between juveniles and adults increased over time in European forest trees. Journal of Ecology 109, 3944–3957. doi:10.1111/1365-2745.13773
  • Depauw L., Perring M. P., Landuyt D., Maes S. L., Blondeel H., De Lombaerde E., Brūmelis G., Brunet J., Closset‐Kopp D., Decocq G., Den Ouden J., Härdtle W., Hédl R., Heinken T., Heinrichs S., Jaroszewicz B., Kopecký M., Liepiņa I., Macek M., Máliš F., Schmidt W., Smart S. M., Ujházy K., Wulf M. & Verheyen K. (2021): Evaluating structural and compositional canopy characteristics to predict the light-demand signature of the forest understorey in mixed, semi-natural temperate forests. Applied Vegetation Science 24, 1 – 13. doi:10.1111/avsc.12532
  • Vangansbeke P., Máliš F., Hédl R., Chudomelová M., Vild O., Wulf M., Jahn U., Welk E., Rodríguez-Sánchez F. & De Frenne P. 2021: ClimPlant: Realized climatic niches of vascular plants in European forest understoreys. Global Ecology and Biogeography 30, 1183 – 1190. doi:10.1111/geb.13303

Centroidy evropských areálů rozšíření 968 druhů temperátních lesů, zahrnutých do databáze ClimPlant

Centroids of the distribution range in Europe of the 968 temperate forest species contained in the ClimPlant database, with the 1970–2000 mean annual temperature (MAT; in degrees Celsius) as background raster.

 

3/ Treetops protect forest biodiversity from global warming

The cooling leaf canopy protects forest organisms from extreme temperatures and has a significant influence on their adaptation to global warming. In an international research team, we studied the effect of climate warming under the forest canopy, thus also showing how warming in the forest differs from warming in open spaces. We measured the temperature in the forest interior at 100 sites and combined these measurements in a computer model with up to 80 years of data on the density of the forest canopy. This latter series comprised data taken from almost 3,000 repeated vegetation plots in European forests. If the tree canopy is denser, it buffers climate warming for the organisms living beneath it. If it becomes sparser, the plants living beneath it experience additional warming. Their previously cool, shady and generally more humid habitat is suddenly exposed to warmer and also drier conditions. Many species cannot adapt quickly enough, are displaced by warm-affinity species and may die out locally. Forest managers should therefore take account of the effects of forestry work on the climatic conditions in the forest interior and its potential impact on biodiversity.

  • Zellweger F., De Frenne P., Lenoir J., Vangansbeke P., Verheyen K., Bernhardt-Römermann M., Baeten L., Hédl R., Berki I., Brunet J., Van Calster H., Chudomelová M., Decocq G., Dirnböck T., Durak T., Heinken T., Jaroszewicz B., Kopecký M., Máliš F., Macek M., Malicki M., Naaf T., Nagel T. A., Ortmann-Ajkai A., Petřík P., Pielech R., Reczyńska K., Schmidt W., Standovár T., Świerkosz K., Teleki B., Vild O., Wulf M. & Coomes D. (2020): Forest microclimate dynamics drive plant responses to warming. Science 369(6492): 772­–775. doi: 10.1126/science.aba6880

Rich biodiversity of plants grows under the tree canopy in European forests
Plant diversity in European forests can be protected from climate warming by tree canopy.

 

4/ Rare plant species are increasingly missing in forests. It is due to nitrogen increase

In Europe’s deciduous forests, rare plant species are being displaced by more abundant ones. This development may be due to increased nitrogen deposition and, rather surprisingly, to the species occurrence range. In our international study based on an analysis of large database of repeated records in permanent plots in 68 sites with deciduous forests across Europe, we examined how the occurrences of a total of 1,162 plant species in European forests have changed in the past decades. Species with a small range, or area where they occur naturally, tend to decrease in time. These species are often adapted to relatively small amounts of nutrients in the soil. Our analysis pointed to a link between nitrogen emissions, produced mainly by the combustion of fossil fuels, and an increased risk of extinction of these species. On the contrary, plant species, which prefer nutrient-rich soils and occupy large range at the same time, have increased on a long term. Thus, while competitively weak and rare species are disappearing from forests, common species are increasingly frequent throughout Europe. Even more disturbing is the fact that many of the study sites are in protected areas, which tends to improve the general picture. The observed trend may be even more pronounced in commercially managed forests.

  • Staude I. R., Waller D. M., Bernhardt-Römermann M., Bjorkman A. D., Brunet J., De Frenne P., Hédl R., Jandt U., Lenoir J., Máliš F., Verheyen K., Wulf M., Pereira H. M., Vangansbeke P., Ortmann-Ajkai A., Pielech R., Berki I., Chudomelová M., Decocq G., Dirnböck T., Durak T., Schmidt W., Heinken T., Schei F. H., Jaroszewicz B., Kopecký M., Macek M., Malicki M., Naaf T., Nagel T. A., Petřík P., Reczyńska K., Standovár T., Świerkosz K., Teleki B., Van Calster H., Vild O., Baeten L. (2020): Replacements of small- by large-ranged species scale up to diversity loss in Europe’s temperate forest biome. Nature Ecology and Evolution 4: 802–808. doi: 10.1038/s41559-020-1176-8

Isopyrum thalictroides, a rare species of deciduous forests

Isopyrum thalictroides, a rare species of deciduous forests.

 

5/ Tropical forests can handle the heat, up to a point

 Tropical forests can resist increasing temperatures without significantly losing their capacity to absorb excess carbon dioxide from the atmosphere. Forests release carbon dioxide into the atmosphere when the amount of carbon gained by tree growth is less than that lost through tree mortality and decay. Yet this positive finding is only possible if forests have time to adapt, they remain intact, and if global heating is strictly limited to avoid pushing global temperatures into conditions beyond the critical threshold. If we limit global average temperatures to a 2°C increase above pre-industrial levels this pushes nearly three-quarters of tropical forests above the heat threshold we identified. The study is the first to analyse long-term climate sensitivity based on direct observation of whole forests across the topics. The research suggests that over the long-term temperature has the greatest effect on forest carbon stocks by reducing growth, with drought killing trees the second key factor. To calculate changes in carbon storage required repeated measurements of tree stem diameter and height. This was connected with identifying nearly 10,000 tree species and over two million measurements of tree diameter, in 813 forests across 24 tropical countries.

  • Sullivan M. J. P., Lewis S. L. et al. (Incl. Hédl R.) (2020): Long-term thermal sensitivity of Earth’s tropical forests. Science 368 (6493): 869–874. doi: 10.1126/science.aaw7578

Tropical forests not only harbour high biodiversity, but also play key role in mitigating the climatic crisis
Tropical forests not only harbour high biodiversity, but also play key role in mitigating the climatic crisis.

 

6/ Interactive effect of environmental factors on tree growth in European forests

Our findings highlight how tree growth can be interactively determined by global-change drivers, and how these growth responses might be modulated by past forest management. By showing future growth changes for scenarios of environmental change, we stress the importance of considering multiple drivers, including past management, and their interactions, when predicting tree growth.           

Maes S. L., Perring M. P., Vanhellemont M., Depauw L., van den Bulcke J., Brūmelis G., Brunet J., Decocq G., den Ouden J., Härdtle W., Hédl R., Heinken T., Heinrichs S., Jaroszewicz B., Kopecký M., Máliš F., Wulf M. & Verheyen K. (2019): Environmental drivers interactively affect individual tree growth across temperate European forests. Global Change Biology 25: 201–217. doi: 10.1111/gcb.14493

 

7/ Qualitative and quantitative methods in historical ecology

We analyzed methods employed to date in historical ecology when working with qualitative and graphic materials. In addition, we explored the links between these methods and those used in general in qualitative research. Historical ecology requires source criticism methods and time line–based methods for landscape change. Some of the techniques used in historical ecology, but not originate from it, are presented.

  • Santana-Cordero, A. M., & Szabó, P. (2019). Exploring qualitative methods of historical ecology and their links with qualitative research. International Journal of Qualitative Methods Volume 18: 1–11. doi: 10.1177/1609406919872112

 

8/ Ecology and threats to Carex buekii in Central Europe

We found out that the ecological demands of Carex buekii are rather uniform across Central Europe. C. buekii exhibits fairly broad ecological range, it grows on open sunny places as well as in open alluvial forests. Within its broad optimum it forms dense, species-poor stands or monocoenoses. This sedge is due to its high competitive ability tolerable only for a limited number of accessoric species. Major threats of C. buekii are in habitat destruction, the quality of its stands is further affected by ruderalisation.

  • Więcław, H., Šumberová, K., Bosiacka, B., Hrivnák, R., Dajdok, Z., Mesterházy, A., Minuzzo C., Martinetto E. & Koopman, J. (2019). Ecology, threats and conservation status of Carex buekii (Cyperaceae) in Central Europe. Scientific Reports 9: 1-12. doi: 10.1038/s41598-019-47563-0