Research projects

Quantifying the effects of phenology, growth rate, and growth occurrence for annual wood formation

The radial growth of woody plants has a crucial effect on the carbon sequestration capacity of forest ecosystems. Therefore, understanding its responses to climatic instability on various temporal scales ranging from diurnal to multi-decadal is essential for forecasting climate-biosphere interactions. However, there is a general lack of understanding about the importance of growing season duration, mean growth rate, and occurrence of growth events during the year as predictors of total annual growth. We aim to address this question by combining empirical observations of intra-annual growth dynamics using dendrometers with indirect process-based modeling of wood formation.

Principal investigator: Jan Tumajer

Grantor: Czech Science Foundation (GAČR)

Duration: 2024-2026

Grant number: GAČR 24-11757S

Natural and Anthropogenic Georisks

The main research objective of this project is to understand natural and man-made threats, hazards, and risks in the Earth’s upper spheres, to explore their causes and to quantify their potential impacts on human society and infrastructures. Both natural and anthropogenic geohazards are inherently very complex processes and require a high degree of interdisciplinarity within the natural sciences. Thus, the project should result not only in a fundamental understanding of the mechanisms of these processes, but also in a proposal of tools for their better monitoring, possible minimization of their effects and prediction, including mitigation of their negative effects on human society.

Principal investigator: Vojtěch Ettler (Jan Tumajer)

Grantor: Programme Johannes Amos Comenius

Duration: 2024-2028

Grant number: CZ.02.01.01/00/22_008/0004605

DivLand: Landscape and Biodiversity Research Center

The Landscape and Biodiversity Research Center aims to develop and monitor indicators of biodiversity and landscape changes. In particular, our goal is to analyze trends in stem biomass of the main forest tree species in the Czech Republic. The trends of stem biomass are calculated based on a network of tree-ring chronologies and allometric equations.

Principal investigator: Dušan Romportl (Václav Treml)

Grantor: Technology Agency of the Czech Republic (TAČR)

Duration: 2021-2026

Grant number: TAČR SS02030018

Using forward modelling to unravel the complex climatic control on intra-annual tree growth at cold distribution margins

There is growing evidence that temperature control on tree growth can vary across space and over time at treelines, and moisture availability can be a seasonally important limiting factor at otherwise cold-limited sites. Studies at the intra-annual (wood cell) level can help unravel these complex climate-growth responses, but long time series of wood formation data are rarely available. We will bridge this gap by combining 1) quantitative wood anatomy and 2) process-based models of wood formation to systematically assess the climate-driven intra-annual dynamics of tree growth at representative polar and alpine treeline sites in Eurasia and North America. Analyses will be based on a dataset of annually resolved tree-ring widths, intra-annually resolved xylem anatomical traits (e.g., cell number, lumen area), and (bi-) weekly xylogenesis observation data.

Principal investigator: Jelena Lange

Grantor: Czech Science Foundation (GAČR)

Duration: 2022-2024

Grant number: GAČR 22-26519S

TreeDataClim: Tree-ring database as a tool for evidence and prediction of response of main forest species to climate change

We are developing a tree-ring database called TreeDataClim. The database consists of hundreds of tree-ring site records with tree-ring series of more than 20 000 trees. The database is linked to a web GIS. Tree-ring records help determine the recent climatic limitation of tree growth with respect to regions, elevation, and site characteristics. Process-based climate-driven growth models are calibrated on tree-ring chronologies, and the derived parameters are then used to apply the model to climate scenario data. We produce maps of recent and future climatic constraints on tree growth that are published via a web GIS service.

Principal investigator: Václav Treml

Grantor: Technology Agency of the Czech Republic (TAČR)

Duration: 2021-2024

Grant number: TAČR SS0310134

See here for our completed projects.


Individual research fellowships

Using dendrometers and modeling to quantify effects of phenology, growth rate, and growth occurrence for wood formation

Radial growth of woody plants has a crucial effect on the carbon sequestration capacity of forest ecosystems. Since wood formation responds sensitively to climate change, a significant redistribution of the radial growth rate and growth phenology might be expected during the recent decades. We aim to address spatial and temporal gradients in this redistribution by combining empirical observations of intra-annual growth dynamics using dendrometers with indirect process-based modeling of wood formation. The results will contribute to our understanding of tradeoffs between the climatic system and forest ecosystems.

Fellowship holder: Jan Tumajer

Grantor: Charles University – PRIMUS

Duration: 2024-2027

Grant number: PRIMUS/24/SCI/004

Exploring the effect of seedling’s drought vulnerability on treeline dynamics under climatic change using quantitative wood anatomy

There is a lack of systematic observations to understand the causes of the differential response of treelines to global warming. The extent to which the treeline lags behind warming may be related to seedling survival. However, as temperature is considered the main limiting factor for the treeline, the role of seedling drought sensitivity as a driver of the differential response of the treeline to global warming is poorly understood. The project aims to investigate the effect of seedling drought susceptibility on treeline dynamics under climate change using quantitative wood anatomy.

Fellowship holder: Eunice Romero

Grantor: European Research Area (ERA), built on the MSCA Postdoctoral Fellowships action

Duration: 2023-2025

Impacts of a changing climate on past and future tree growth at the treeline

This research project focuses on the effects of climate change (temperature and water availability) on the growth of pines at different European treeline sites along a latitudinal gradient (polar and alpine treelines). Tree-ring width analysis and process-based modeling will be combined to better understand the climate-driven growth rate of pines in recent decades. Models will be refined using daily observations of stem growth from dendrometers and of microclimatic loggers. Analyses will be performed for different elevations, and a space-for-time approach will be used to estimate tree growth performance for the future.

Fellowship holder: Francesco Marotta

Grantor: Charles University Science Foundation (GAUK)

Duration: 2023-2025

Using forward modelling to unravel the complex climatic control on intra-annual tree growth at cold distribution margins

This project addresses the question of how temperature and moisture availability interact in limiting intra-annual wood formation at generally cold-limited sites. For representative cold-limited sites across North America and Eurasia, a dataset of annually resolved tree-ring width series, (bi-) weekly xylogenesis observation data, and decades-long time series of xylem anatomical traits (e.g., cell lumen area, cell number) is compiled. Both linear and non-linear, processed based models are used to systematically assess intra-annual growth dynamics across study sites over the past decades.

Fellowship holder: Jelena Lange

Grantor: Alexander von Humboldt Foundation / Feodor Lynen Research Fellowship

Duration: 2022-2023