Jan Altman
A5006778503- Ecology and Vegetation Dynamics Studies
- Plant Water Relations and Carbon Dynamics
- Tree-ring climate responses
- Forest ecology and management
- Species Distribution and Climate Change
- Plant and animal studies
- Forest Ecology and Biodiversity Studies
- Botany and Plant Ecology Studies
- Plant Parasitism and Resistance
- Fire effects on ecosystems
- Tree Root and Stability Studies
- Geology and Paleoclimatology Research
- Tropical and Extratropical Cyclones Research
- Animal Ecology and Behavior Studies
- Remote Sensing and LiDAR Applications
- Landslides and related hazards
- Plant Taxonomy and Phylogenetics
- Forest Management and Policy
- Plant Ecology and Soil Science
- Remote Sensing in Agriculture
- Biocrusts and Microbial Ecology
- Wildlife Ecology and Conservation
- Lichen and fungal ecology
- Plant Diversity and Evolution
- Climate variability and models
Czech University of Life Sciences Prague
2021-2025
Czech Academy of Sciences, Institute of Botany
2016-2025
Czech Academy of Sciences
2015-2024
Staatliches Museum für Naturkunde Stuttgart
2023
Swiss Federal Institute for Forest, Snow and Landscape Research
2018-2021
University of South Bohemia in České Budějovice
2008-2016
Charles University
2015
Sewanee: The University of the South
2012
Vanderbilt University
1999
Research in global change ecology relies heavily on climatic grids derived from estimates of air temperature open areas at around 2 m above the ground. These do not reflect conditions below vegetation canopies and near ground surface, where critical ecosystem functions occur most terrestrial species reside. Here, we provide maps soil bioclimatic variables a 1-km2 resolution for 0-5 5-15 cm depth. were created by calculating difference (i.e. offset) between situ measurements, based time...
Understanding the variation in community composition and species abundances (i.e., β-diversity) is at heart of ecology. A common approach to examine β-diversity evaluate directional by measuring decay similarity among pairs communities along spatial or environmental distance. We provide first global synthesis taxonomic functional distance analysing 148 datasets comprising different types organisms environments.
A rapid warming in Himalayas is predicted to increase plant upper distributional limits, vegetation cover and abundance of species adapted warmer climate. We explored these predictions NW Himalayas, by revisiting uppermost populations after ten years (2003-2013), detailed monitoring changes permanent plots (2009-2012), age analysis plants growing from 5500 6150 m. Plant traits microclimate variables were recorded explain observed changes. The elevation limits several shifted up m, about 150...
Trees with hollows are key features sustaining biodiversity in wooded landscapes. They host rich assemblages of often highly specialised organisms. Hollow trees, however, have become rare and localised Europe. Many the associated biota is thus declining or endangered. The challenge its conservation, therefore, to safeguard presence hollow trees sufficient numbers. Populations numerous species tree dead wood found habitats that were formed by formerly common traditional silvicultural...
Significance Long-term variability in tropical cyclone (TC) activity is of high relevance for the development adaptation and mitigation strategies; however, our current knowledge based mostly on short-term records, with strong discrepancies among various datasets. We used tree-ring records past forest disturbances to show rapid increases destructive effects TCs during 20th century. changes TC imply that recent poleward migration not within range long-term natural may be associated climate...
Abstract Accurate remote detection of various forest disturbances is a challenge in global environmental monitoring. Addressing this issue crucial for health assessment, planning salvage logging operations, modeling stand dynamics, and estimating carbon stocks uptake. Substantial progress on problem has been achieved owing to the rapid development sensing devices that provide very high‐resolution images. Concurrently, image processing algorithms have witnessed extensive use artificial neural...
Forests are undergoing increasing risks of drought-induced tree mortality. Species replacement patterns following mortality may have a significant impact on the global carbon cycle. Among major hardwoods, deciduous oaks (Quercus spp.) increasingly reported as replacing dying conifers across Northern Hemisphere. Yet, our knowledge growth responses these to drought is incomplete, especially regarding post-drought legacy effects. The objectives this study were determine occurrence, duration,...
Abstract Temperature is a fundamental driver of species distribution and ecosystem functioning. Yet, our knowledge the microclimatic conditions experienced by organisms inside tropical forests remains limited. This because ecological studies often rely on coarse-gridded temperature estimates representing at 2 m height in an open-air environment (i.e., macroclimate). In this study, we present high-resolution pantropical estimate near-ground (15 cm above surface) temperatures forests. We...
Temperate forests are undergoing significant transformations due to the influence of climate change, including varying responses different tree species increasing temperature and drought severity. To comprehensively understand full range growth responses, representative datasets spanning extensive site climatic gradients essential. This study utilizes tree-ring data from 550 sites temperate Czechia assess trends six dominant Central European (European beech, Norway spruce, Scots pine, silver...
Abstract Background and Aims Understanding interspecific differences in plant growth rates their internal external drivers is key to predicting species responses ongoing environmental changes. Annual vary among plants based on ecological preferences, forms, ecophysiological adaptations, evolutionary history. However, the relative importance of these factors remains unclear, particularly high-mountain ecosystems experiencing rapid Methods We examined how habitat associations, elevational...
Background Coppicing was one of the most important forest management systems in Europe documented prehistory as well Middle Ages. However, coppicing gradually abandoned by mid-20th century, which has altered ecosystem structure, diversity and function coppice woods. Methodology/Principal Findings Our aim to disentangle factors shaping historical growth dynamics oak standards (i.e. mature trees growing through several cycles) a former coppice-with-standards Central Europe. Specifically, we...
Abstract Aim Temporal dynamics of biodiversity along tropical elevational gradients are unknown. We studied seasonal changes Lepidoptera the only complete forest gradient in Afrotropics. focused on shifts species richness patterns, turnover communities and species’ ranges, latter often serving as an indicator global change effects mountain ecosystems. Location Mount Cameroon, Cameroon. Taxon Butterflies moths (Lepidoptera). Methods quantitatively sampled nine groups by bait‐trapping (16,800...
Very high resolution satellite imageries provide an excellent foundation for precise mapping of plant communities and even single plants. We aim to perform individual tree recognition on the basis very RGB (red, green, blue) images using deep learning approaches northern temperate mixed forests in Primorsky Region Russian Far East. used a pansharpened image by GeoEye-1 with spatial 0.46 m/pixel, obtained late April 2019. parametrized standard U-Net convolutional neural network (CNN) trained...
Abstract Understanding how climate influences plant reproduction and growth at contrasting range limits is crucial for predicting species' ranges may shift in response to ongoing change. Trees shrubs have shown warming‐induced increases performance upper elevation but reduced lower distributional due warming‐driven drought limitation. Whether these differential responses are also valid alpine forbs exposed accelerated warming remains largely unknown. We examined signal recorded annual...
Abstract Aim Theoretical, experimental and observational studies have shown that biodiversity–ecosystem functioning (BEF) relationships are influenced by functional community structure through two mutually non‐exclusive mechanisms: (1) the dominance effect (which relates to traits of dominant species); (2) niche partitioning [which diversity (FD)]. Although both mechanisms been studied in plant communities experiments at small spatial extents, it remains unclear whether evidence from...
Understanding biomass allocation among plant organs is crucial for comprehending growth optimization, survival and responses to the drivers of global change. Yet, mechanisms governing mass in vascular plants from extreme elevations exposed cold drought stresses remain poorly understood.
Many cushion plants ameliorate the harsh environment they inhabit in alpine ecosystems and act as nurse plants, with significantly more species growing within their canopy than outside. These facilitative interactions seem to increase abiotic stress, thus supporting stress-gradient hypothesis. We tested this prediction by exploring association pattern of vascular dominant plant Thylacospermum caespitosum (Caryophyllaceae) arid Trans-Himalaya, where occur at one highest worldwide elevational...