Located in Třeboň, South Bohemia
Head: doc. Mgr. Jiří Doležal, Ph.D.
People ׀ Projects ׀ Publications
- Plant life on altitudinal limits in the West Himalayas and the Andes
- Plant functional traits in species-rich meadows
- Dendrochronology and growth-climate responses
- Functional island biogeography
- Pollination systems
Selected recent results
1/ Microbial community from species-rich meadow supports plant specialists during meadow restoration
Soil properties and soil microbial communities can greatly affect plant communities, especially in disturbed ecosystems. We manipulated the soil microbial community in microcosms by inoculating sterilized soils originating from the preserved species-rich meadow and a restored meadow with a high and low diversity of microbial inoculum (manipulated by the dilution of microbial community extract) from those soils. In general, the biomass of plant meadow specialists was greater with the preserved meadow inoculum than with the restored meadow inoculum but tended to be greater in the restored meadow soil than in the preserved meadow soil. Meadow generalists were less sensitive to soil manipulations. Total above-ground biomass was not affected by the treatments, but total below-ground biomass was greater with microbial inoculum from the preserved meadow than from the restored meadow, and this increase was greater in the restored meadow soil than in the preserved meadow soil. Our results indicate strong responses of the preserved meadow specialists to the soil microbial community, which may explain why they are rare in the meadows that were restored following agricultural use.
- Ardestani M.M., Mudrák O., Vicena J., Sun D.Q., Veselá H. & Frouz J. 2022: Microbial community from species rich meadow supports plant specialists during meadow restoration. Functional Ecology 36, 1573 – 1584. doi:1111/1365-2435.14052
Grassland restored on the former arable land.
2/ Floral and reproductive traits are an independent dimension within the plant economic spectrum of temperate central Europe
While vegetative above and belowground traits have been increasingly covered and recognised as integral components of plant functional strategies, traits related to pollination and sexual reproduction have rarely attracted attention outside the more classical pollination biology related studies. Often, seed mass and flower phenology have been used as a sole representatives of “reproductive” traits. We demonstrated that flower characteristics such as shape and color and pollination type are indeed an important component of the general spectrum of plant form and function. Moreover, they seem to be little related to the leaf economic spectrum. Contrary, other characteristics of the sexual reproduction such as the degree of outcrossing are linked to leaf and size-related traits, therefore providing a potential link between floral and other vegetative traits. It follows that the suit of floral traits should be integrated in future lines of research that want to more completely address how plant species respond to environmental changes and how they affect ecosystem processes and services.
- E-Vojtkó A., Junker R. R., de Bello F. & Götzenberger L. 2022: Floral and reproductive traits are an independent dimension within the plant economic spectrum of temperate central Europe. New Phytologist 236, 1964 – 1975. doi:10.1111/nph.18386
Principal component analyses (A) and correlation network (B) of the studied traits. Note that the floral traits (pink color) are mostly independent from other studied traits, and that they contribute remarkably to the overall trait variation found among plant species.
3/ Tropical cyclones moving into boreal forests: Relationships between disturbance areas and environmental drivers
Tropical cyclones (TCs) are common disturbance agents in tropical and subtropical latitudes. With global warming, TCs began to move to northern latitudes, with devastating effects on boreal forests. However, it remains unclear where and when these extraordinary events occur and how they affect forest structure and ecosystem functioning. In October 2015, catastrophic TC Dujuan hit the island of Sakhalin in the Russian Far East. With a wind speed of 63 m·s−1, it became the strongest wind recorded in Sakhalin, damaging >42,000 ha of native forests with different levels of severity. We used high-resolution RGB satellite images, DEM-derived geomorphological patterns, and the U-Net-like convolutional neural network to quantify the damaged area in specific landform, forest type, and windthrow patch size categories. We found that large gaps (>1 ha) represent >40 % of the damaged area while small gaps (<0.1 ha) only 20 %. The recorded canopy gaps are very large for the southern boreal forest. We found that the aspect (slope exposure) is the most important in explaining the damaged area, followed by canopy closure and landform type. Closed-canopy coniferous forests on steep, west-facing slopes (typical of convex reliefs such as ridges, spurs, and peaks) are at a much higher risk of being disturbed by TCs than open-canopy mountain birch forests or coniferous forests and broadleaved riparian forests in concave reliefs such as valley bottoms. We suggest that the projected ongoing poleward migration of TCs will lead to an unprecedentedly large area of disturbed forest, which results in complex changes in forest dynamics and ecosystem functioning. Our findings are crucial for the development of mitigation and adaptation strategies under future changes in TC activity.
- Korznikov, K., Kislov, D., Doležal, J., Petrenko, T. & Altman, J. 2022: Tropical cyclones moving into boreal forests: Relationships between disturbance areas and environmental drivers. Science of the Total Environment 844, 1 – 8. doi: 10.1016/j.scitotenv.2022.156931
Distribution of forests and windthrow patches among landform classes and the examples of windthrow patches segmentation by the U-Net-like CNN.
4/ Alpine plant growth and reproduction dynamics in a warmer world
Climate warming affects the growth and survival of mountain plants. In the Tatras, Rumex alpinus produces rhizomes three times longer and twice as many leaves as 40 years ago. High summer temperature, however, leads to a lack of water in dense vegetation and stronger competition. Our results from the Himalayas suggest that warming‐induced responses in alpine plants will be multidimensional and spatiotemporally variable and will hinge on the physiological tolerance of species to climate change.
Illustration of the monodominant sites of Rumex alpinus in the Low Tatras, Slovakia, Central Europe, the belowground rhizome system and measured growth parameters: annual segment length, leaf and inflorescence scars.
- Doležal J., Kurnotová M., Šťastná P. & Klimešová J. 2020. Alpine plant growth and reproduction dynamics in a warmer world. New Phytologist 228: 1295-1305. doi: 10.1111/nph.16790
- Liancourt P., Song X., Macek M., Šantrůček J. & Doležal J. 2020. Plant’s-eye view of temperature governs elevational distributions. Global Change Biology 26: 4094-4103. doi: 10.1111/gcb.15129
5/ Relationship between stability and diversity of plant communities
Understanding how diversity affects ecosystem stability is crucial for predicting the consequences of continued habitat and biodiversity loss on ecosystem functions and services. Long-term productivity stability in plant communities is often associated with greater species, phylogenetic or functional diversity, more complex size and age structures, or higher asynchrony in species fluctuations (compensatory dynamics), all potentially increasing community resistance to perturbations. However, the relative importance of these stabilizing pathways is still poorly understood. We collected long-term time series of vegetation data across the world, stemming from a variety of biomes and habitats. Results showed that stability, measured as temporal stability of total community abundance, was more strongly associated with the degree of synchrony than with species richness (Valencia et al., 2020a, Valencia et al. 2020b, Dolezal et al. 2020). These results highlight the prevalence of biotic drivers on ecosystem stability, with the potential for additional environmental drivers to alter the intricate relationships among richness, synchrony, and stability. To consider these different drivers of stability in concert is critical for defining the potential of communities to remain stable in a global change context.
Piecewise structural equation model showing the direct and indirect effects of multiple abiotic and biotic drivers on the stability across the 79 datasets (Valencia et al. 2020a).
Valencia E., de Bello F., Lepš J., Galland T., E-Vojtko A., Conti L., Danihelka J., Dengler J., Eldridge D. J., Estiarte M., García-González R., Garnier E., Gómez D., Harrison S., Herben T., Ibáñez R., Jentsch A., Juergens N., Kertész M., Klumpp K., Louault F., Marrs R. H., Ónodi G., Pakeman R. J., Pärtel M., Peco B., Peñuelas J., Rueda M., Schmidt W., Schmiedel U., Schuetz M., Skálová H., Šmilauer P., Šmilauerová M., Smit C., Song M.-H., Stock M., Val J., Vandvik V., Wesche K., Woodcock B. A., Young T. P., Yu F.-H., Zobel M. & Götzenberger L. 2020. Directional trends in species composition over time can lead to a widespread overemphasis of year-to-year asynchrony. Journal of Vegetation Science 31: 792-802. doi: 10.1111/jvs.12916
Valencia E., de Bello F., Galland T., Adler P., Lepš J., E-Vojtko A., van Klink R., Carmona C. P., Danihelka J., Dengler J., Eldridge D. J., Estiarte M., García-González R., Garnier E., Gómez-García D., Harrison S. P., Herben T., Ibáñez R., Jentsch A., Juergens N., Kertész M., Klumpp K., Louault F., Marrs R. H., Ogaya R., Ónodi G., Pakeman R. J., Pardo I., Pärtel M., Peco B., Peñuelas J., Pywell R. F., Rueda M., Schmidt W., Schmiedel U., Schuetz M., Skálová H., Šmilauer P., Šmilauerová M., Smit C., Song M.-H., Stock M., Val J., Vandvik V., Ward D., Wesche K., Wiser S. K., Woodcock B. A., Young T. P., Yu F.-H, Zobel M. & Götzenberger L. 2020. Synchrony matters more than species richness in plant community stability at a global scale. Proceedings of the National Academy of Sciences of The United States of America 117: 24345-24351. doi: 10.1073/pnas.1920405117
Doležal J., Fibich P., Altman J., Lepš J., Uemura S., Takahashi K. & Hara H. 2020. Determinants of ecosystem stability in a diverse temperate forest. Oikos 129: 1692-1703.
6/ Tree growth responses to global change and advancement of dendrochronological techniques
The determination of long-term spatiotemporal growth responses is essential for understanding forest dynamics and its shifts under global changes. However, the current understanding of the modulation of the impact of climatic change on forest ecosystems by elevational differences and by species interaction is still limited. We analyzed tree-ring-based growth-climate relationships of Quercus mongolica and Abies koreana along an 800-m elevational gradient on Jeju Island, South Korea (Altman et al. 2020). Recent warming has positively affected the growth of oak, while fir growth is reduced by high temperatures.
To standardize methodological approaches for tree-ring-based disturbance reconstruction and hence enable comparison between various studies and regions, Altman (2020) provides a comprehensive review of these techniques. Besides, a methodological guide for interdisciplinary studies is suggested as well as several future challenges.
Lastly, we focused on the precise demarcation between earlywood and latewood (Samusevich et al. 2020). A suggested methodology is universal and can help to calibrate criteria for earlywood-latewood demarcation under specific conditions.
Main research fields with high potential for utilization of growth release detection as a record of past disturbances.
- Altman J. (2020) Tree-ring-based disturbance reconstruction in interdisciplinary research: Current state and future directions. Dendrochronologia 63: 125733. doi: 10.1016/j.dendro.2020.125733
- Altman J., Treydte K., Pejcha V., Cerny T., Petrik P., Srutek M., Song J.S., Trouet V. & Dolezal J. (2020) Tree growth response to recent warming of two endemic species in Northeast Asia. Climatic Change 162: 1345-1364. doi: 10.1007/s10584-020-02718-1
- Samusevicha A., Lexa M., Vejpustková M., Altman J. & Zeidler A. (2020) Comparison of methods for the demarcation between earlywood and latewood in tree rings of Norway spruce. Dendrochronologia 60: 125686. doi: 10.1016/j.dendro.2020.125686
7/ Restoration ecology of disturbed sites
We tested the influence of landscape parameters, such as the landscape cover around the target area, and the abiotic environment (macroclimate, substrate) on the development of vegetation during succession. It turned out that although all these factors influence the development of vegetation, abiotic factors have a greater influence. The traditional division into primary and secondary succession had only a small effect on vegetation development (Vítovcová et al. in press). Research into purposefully forested and spontaneously overgrown sand pits has shown that although the course of succession has a similar course in both types of habitats, spontaneously overgrown sand pits are more naturally valuable habitats (Šebelíková et al. 2020). However, for the prevention of degradation of these valuable and species-rich sandy habitats, a regular disturbance is needed (Řehounková et al. in press). The importance of disturbed and spontaneously overgrown areas for biodiversity was also confirmed by the study Řehounková et al. (2020), which showed that 14% of endangered species of the Czech Republic occur in disturbed habitats.
Mining area around the city Sokolov, SW of the Czech Republic.
- Vítovcová K., Tichý L., Řehounková K. & Prach K. (2020) Which landscape and abiotic site factors influence vegetation succession across seres at a country scale? Journal of Vegetation Science, doi: 10.1111/jvs.12950
- Řehounková K., Jongepierová I., Šebelíková L., Vítovcová K. & Prach K. (in press) Topsoil removal in degraded open sandy grasslands: can we restore threatened vegetation fast? Restoration Ecology, doi: 10.1111/rec.13188
- Řehounková K., Vítovcová K. & Prach K. (2020) Threatened vascular plant species in spontaneously revegetated post-mining sites. Restoration Ecology, 28, 679–686. doi: 10.1111/rec.13027