Miroslav Dvorský

Nutrient contents in plant tissues reflect adaptations and environmental constraints, varying across and within species along ecological gradients. Interspecific differences reflect long‐term adaptations, while intraspecific variations may indicate acclimation to present conditions. Examining these responses across elevational ranges is therefore crucial for understanding how nutrients influence species performance. We investigated whether organ nutrients play a significant role at the upper limits of the world's highest occurring herbaceous angiosperms by analysing intraspecific and interspecific variations in leaf carbon (C), nitrogen (N), and phosphorus (P) contents in 22 species, and root N and P contents in 15 species along a gradient from 4560 to 6150 m a.s.l. in the Western Himalaya. Our findings reveal contrasting patterns in nutrient contents. Interspecifically, leaf N and P decreased and C:N increased with elevation, indicating selective pressure for adaptations to reduced nutrient availability. In contrast, intraspecific leaf N content generally increased with increasing elevation. Root N trend did not change interspecifically with elevation, while overall intraspecific trends increased. Surprisingly, subnival species at the highest localities around 6000 m had relatively high tissue N and P contents. This suggests that high‐elevation Himalayan herbs require high nutrient levels, likely for photosynthesis, to achieve a positive annual carbon gain during the short growing season and to accumulate sufficient root reserves. Elevated N and P content, especially at the highest localities, imply that the upper limits of the world's highest‐growing plants may not be limited by nutrient acquisition constraints.

Aim: Understanding temporal patterns of vegetation change is crucial for assessing the ecological integrity of forest understoreys under shifting management and climate regimes. This study investigates long‐term (60‐year) and short‐term (10‐year) changes in species composition, functional traits, and phylogenetic diversity (PD) of understorey communities in Central European floodplain forests. The goal is to determine how different temporal scales capture ecological dynamics and to identify trait‐based mechanisms underlying community shifts. Location: The research was conducted in floodplain forests across Central Europe, encompassing oak, ash, hornbeam, and willow‐dominated stands distributed along a gradient of soil moisture availability. Methods: We analyzed repeated vegetation plot records across two temporal scales. Changes in species richness, functional diversity (FD), and PD were quantified. Species‐level shifts were linked to plant traits such as height, seed mass, and leaf dry matter content (LDMC), with analyses stratified by forest type. Results: Over 60 years, species richness and PD declined, driven by the loss of phylogenetically distinct light‐demanding specialists and an increase in tall woody generalists with conservative strategies. FD remained stable but showed directional trait shifts. In contrast, the 10‐year data showed limited changes in diversity indices, despite continued increases in some woody species and temporary gains of specialists in drier hornbeam stands. Trait–abundance correlations indicated that taller species with high LDMC or heavier seeds were favored under conditions of canopy closure and drought. Invasive species also increased in abundance over the 60‐year period, whereas short‐term trends exhibited weaker signals. Conclusions: Long‐term data revealed compositional and trait‐based transformations missed in short‐term assessments, emphasizing the value of extended temporal monitoring. Trait–environment interactions varied among forest types, reflecting site‐specific drivers such as differences in moisture conditions. These findings highlight the need for temporally informed forest management strategies that promote resilience by addressing both species impoverishment in the forest understorey and trait‐based filters.

Plants store nonstructural carbohydrates (NSCs) like starch, fructans and soluble sugars to support metabolism, stress tolerance and defence during low photosynthesis, ultimately influencing their growth and longevity. However, the relationship between NSC composition and growth or persistence in wild plants remains unclear. This study explores trade‐offs between growth, longevity and NSCs in 201 plant species across diverse climates in the Western USA, spanning 500–4300 m in elevation and 80–1000 mm in precipitation. Annual growth rates and plant ages were derived from the ring widths of semidesert, steppe and alpine herbs and shrubs, along with NSC profiles in their roots and rhizomes. Results showed an inverse relationship between growth and age, with total NSC, starch and fructan levels negatively correlated with growth, supporting the growth‐longevity and growth‐storage trade‐off hypotheses. Conversely, higher growth rates were linked to soluble sugars, suggesting that climate‐driven growth limitations alone do not explain increased NSCs. Fructans were positively associated with longevity, especially in long‐lived desert shrubs and alpine herbs, underscoring NSCs' active role in survival strategies. These findings challenge the carbon surplus hypothesis, suggesting that plants actively use specific NSCs to balance growth and persistence, with energy‐rich sugars promoting growth and osmoprotective fructans enhancing longevity.

Background and Aims: Understanding biomass allocation among plant organs is crucial for comprehending plant growth optimization, survival and responses to the drivers of global change. Yet, the mechanisms governing mass allocation in vascular plants from extreme elevations exposed to cold and drought stresses remain poorly understood. Methodology: We analysed organ mass weights and fractions in 258 Himalayan herbaceous species across diverse habitats (wetland, steppe, alpine), growth forms (annual, perennial taprooted, rhizomatous and cushiony) and climatic gradients (3500–6150 m elevation) to explore whether biomass distribution adhered to fixed allometric or optimal partitioning rules, and how variations in size, phylogeny and ecological preferences influence their strategies for resource allocation. Key Findings: Following optimal partitioning theory, Himalayan plants distribute more biomass to key organs vital for acquiring and preserving limited resources necessary for their growth and survival. Allocation strategies are mainly influenced by plant growth forms and habitat conditions, notably temperature, water availability and evaporative demands. Alpine plants invest primarily in below-ground stem bases for storage and regeneration, reducing above-ground stems while increasing leaf mass fraction to maximize carbon assimilation in their short growing season. Conversely, arid steppe plants prioritize deep roots over leaves to secure water and minimize transpiration. Wetland plants allocate resources to above-ground stems and below-ground rhizomes, enabling them to resist competition and grazing in fertile environments. Conclusions: Himalayan plants from extreme elevations optimize their allocation strategies to acquire scarce resources under specific conditions, efficiently investing carbon from supportive to acquisitive and protective functions with increasing cold and drought. Intraspecific variation and shared ancestry have not significantly altered biomass allocation strategies of Himalayan plants. Despite diverse evolutionary histories, plants from similar habitats have developed comparable phenotypic structures to adapt to their specific environments. This study offers new insights into plant adaptations in diverse Himalayan environments and underscores the importance of efficient resource allocation for survival and growth in challenging conditions.

Plant lifespan has important evolutionary, physiological, and ecological implications related to population persistence, community stability, and resilience to ongoing environmental change impacts. Although biologists have long been puzzled over the extraordinary variation in plant lifespan and its causes, our understanding of interspecific variability in plant lifespan and the key internal and external factors influencing longevity remains limited. Here, we demonstrate the concurrent impacts of environmental, morphological, physiological, and anatomical constraints on interspecific variation in longevity among > 300 vascular dicot plant species naturally occurring at an elevation gradient (2800–6150 m) in the western Himalayas. First, we show that plant longevity (ranging from 1 to 100 years) is largely related to species' habitat preferences. Ecologically stressful habitats such as alpine and subnival host long‐lived species, while productive ruderal and wetland habitats contain a higher proportion of shorter‐lived species. Second, longevity is influenced by growth form with monocarpic forbs having the shortest lifespan and woody shrubs having the highest. Small‐statured cushion plants with compact canopies and deep roots, most found on cold and infertile alpine and subnival soils, had a higher chance of achieving longevity. Third, plant traits reflecting plant adaptations to stress and disturbance affect interspecific differences in plant longevity. We show that longevity and growth are negatively correlated. Slow‐growing species are those that have a higher chance of reaching a high age. Finally, higher longevity was associated with high leaf carbon and phosphorus, low root phosphorus and nitrogen, and with large bark‐xylem ratio. Our findings suggest that plant longevity in high elevation is intricately determined by a combination of habitat preferences and growth form, as well as the plant growth rate and physiological processes.

Question: Which vegetation and soil parameters limit species establishment in restored grasslands? Do these parameters operate predominantly on a fine or a community scale?Location: White Carpathian Mountains, SE Czech Republic.Methods: We compared 16 grasslands restored on former arable land with 9 well‐preserved reference grasslands. We sampled cover of plant species in plots of 2 m × 2 m (community scale) in which four 20 cm × 20 cm subplots (fine scale) were nested. We quantified fine‐scale heterogeneity as the mean Sørensen dissimilarity index among the species composition of the subplots. To characterize site conditions, we analyzed soil properties, above‐ground plant biomass and its nutrient content.Results: Restored grasslands had a lower number of plant species at both the community and fine scales. Species number at the community scale was positively associated with the species number at the fine scale (irrespective of grassland type), but was not associated with fine‐scale heterogeneity. This indicates the importance of fine‐scale biotic interactions for overall species diversity. In support of this, in both grassland types, the species number was negatively associated with the cover of grasses, but only at the fine scale. Total cover (but not the biomass) was lower in restored grasslands, and was positively related with species number, particularly in restored grasslands. This indicates that the lower species number in the restored grasslands mainly resulted from deteriorated abiotic conditions. Such deterioration of the plant environment can be attributed particularly to the soil of the restored, formerly plowed grasslands. They had a lower soil organic matter content and a higher proportion of fine soil particles (silt and clay), indicating reduced soil water availability. The lower soil N content of restored grasslands was also reflected in the nutrient content of plant biomass, where lower N:P and N:K ratios indicated a limitation of plant growth by N‐supply.Conclusion: The species number was generally driven by fine‐scale biotic interactions, which operated similarly in both grassland types. The reduced number of plant species in restored grasslands is the result of several factors among which altered soil conditions in the former arable land appears to be highly important.

European forests are facing a rapid decline in light‐demanding biota. This has prompted active interventions to re‐establish and maintain partial habitat openness in protected areas. Managers of protected areas, however, need substantially more scientific evidence to support their decisions on where, when and how to intervene. We investigated the importance of spatial continuity of open forest habitats in different years of succession, using six pairs of experimental clearings established in the formerly open, oak‐dominated forests of the Podyji National Park (Czech Republic). In each pair, one clearing was connected to the forest edge, while the other was isolated in closed forest. We sampled butterflies (74 spp.), moths (435 spp.), saproxylic beetles (465 spp.) and vascular plants (567 spp.) on the 12 clearings during the first 5 years of succession. We then compared species richness, abundance and composition of the four taxa between the two clearing types and along the succession. All studied insect groups were substantially more species rich and more abundant in connected than in isolated clearings. Species composition of plants, moths and butterflies differed between the clearing types. The number of species of all studied taxa generally increased from the first to the second or third year after cutting; species composition of all taxa differed among years. This suggests rapid changes in habitat quality and thus limited time for colonisation by light‐demanding organisms. Synthesis and applications. Our results offer an evidence that spatial connectivity and rapid temporal dynamics are important habitat features for light‐demanding insects. Attempts to create or restore habitats for light‐demanding forest biota should take into account that: (a) Insects benefit from direct connection of new open patches to open habitats or flight corridors such as forest edges. (b) Considering plants, the optimal solution is to connect newly created open forest habitats to existing habitats with established biota of high conservation value. (c) Interventions should be carried out within short time intervals, that is within years rather than decades. (d) A fine mosaic of interconnected, open woodland patches in various successional stages is more beneficial than a single large patch with a single successional stage.