Pavel Samonil

The Silva Tarouca Research Institute · Department of Forest Ecology

With ongoing global warming, increasing water deficits promote physiological stress on forest ecosystems with negative impacts on tree growth, vitality, and survival. How individual tree species will react to increased drought stress is therefore a key research question to address for carbon accounting and the development of climate change mitigati...

The fundamental trade‐off between current and future reproduction has long been considered to result in a tendency for species that can grow large to begin reproduction at a larger size. Due to the prolonged time required to reach maturity, estimates of tree maturation size remain very rare and we lack a global view on the generality and the shape...

The most species-rich grasslands worldwide are known from the Carpathian Mts and their periphery in East-Central Europe. They occur in forest-steppe regions, transitional between temperate forest and arid steppe biomes. Their climate, largely suitable for forests, raises questions about the origin of these grasslands. Have they been forested in the...

Based on international cooperation, we collect data on uprooted trees and prepare a global model. We currently have more than 2700 cases from various forest types in database. You can visit the Database, see its structure and site locations.

Herbivorous insects alter biogeochemical cycling within forests, but the magnitude of these impacts, their global variation, and drivers of this variation remain poorly understood. To address this knowledge gap and help improve biogeochemical models, we established a global network of 74 plots within 40 mature, undisturbed broadleaved forests. We a...

Research on biogeomorphic and soil evolutionary role of trees in temperate and tropical forests

Trees contribute to bedrock weathering in a variety of ways. However, evaluating their full impact is complicated by a lack of direct observation of unexposed root systems of individual trees, especially when the scale of the analysis goes down to the level of microbiomes. In the present study, we investigated the contribution of tree root systems...

Carbon accounting in the land sector requires a reference level from which to calculate past losses of carbon and potential for gains using a stock-based target. Carbon carrying capacity represented by the carbon stock in primary forests is an ecologically-based reference level that allows estimation of the mitigation potential derived from protect...

The future trajectory of global forests is closely intertwined with tree demography, and a major fundamental goal in ecology is to understand the key mechanisms governing spatio‐temporal patterns in tree population dynamics. While previous research has made substantial progress in identifying the mechanisms individually, their relative importance a...

15 The historical development of the vegetation of semi-dry grasslands in Central Europe is 16 not satisfactorily understood. Long-term continuity of open vegetation or, conversely, 17 deep-past forest phases are considered possible sources of current extreme species 18 diversity of these ecosystems. We aimed to reveal trajectory of paleovegetation...

The radial growth of trees significantly contributes to climate change mitigation by sequestering carbon into woody biomass. Radial growth trends observed in European temperate forests during the recent period of climate warming vary between growth acceleration due to longer growing seasons and growth declines due to amplified drought stress. Asses...

The most species-rich grasslands worldwide are known from the Carpathian Mts and their periphery in East-Central Europe. They occur in forest-steppe regions, transitional between temperate forest and arid steppe biomes. Their climate, largely suitable for forests, raises questions about the origin of these grasslands. Have they been forested in the...

Temperate forests are undergoing significant transformations due to the influence of climate change, including varying responses of different tree species to increasing temperature and drought severity. To comprehensively understand the full range of growth responses, representative datasets spanning extensive site and climatic gradients are essent...

One mechanism proposed to explain high species diversity in tropical systems is strong negative conspecific density dependence (CDD), which reduces recruitment of juveniles in proximity to conspecific adult plants. Although evidence shows that plant-specific soil pathogens can drive negative CDD, trees also form key mutualisms with mycorrhizal fung...

Rock weathering drives landform formation and soil evolution. The main focus of the present study is the biological component of weathering caused by tree root systems and soil properties under trees. Our goal was to assess the impact of tree roots and associated microbiota on the potential level of biological weathering. Soil samples were taken fr...

Tree regeneration is a key demographic process influencing long‐term forest dynamics. It is driven by climate, disturbances, biotic factors and their interactions. Thus, predictions of tree regeneration are challenging due to complex feedbacks along the wide climatic gradients covered by most tree species. The stress gradient hypothesis (SGH) provi...

In this paper, we examined the degree to which inherent spatial structure in soil properties influences the outcomes of machine learning (ML) approaches to predicting soil spatial variability. We compared the performances of four ML algorithms (support vector machine, artificial neural network, random forest, and random forest for spatial data) aga...

Rock weathering drives both landform formation and soil production/evolution. The less studied biological component of weathering and soil production caused by tree root systems is the main focus of the present study. Weathering by trees, which likely has been important in soil formation since the first trees emerged in the middle and late Devonian...

The benefits of masting (volatile, quasi-synchronous seed production at lagged intervals) include satiation of seed predators, but these benefits come with a cost to mutualist pollen and seed dispersers. If the evolution of masting represents a balance between these benefits and costs, we expect mast avoidance in species that are heavily reliant on...

Aim Our understanding of the mechanisms that maintain forest diversity under changing climate can benefit from knowledge about traits that are closely linked to fitness. We tested whether the link between traits and seed number and seed size is consistent with two hypotheses, termed the leaf economics spectrum and the plant size syndrome, or whethe...

Aim: Global forests and their structural and functional features are shaped by many mechanisms that impact tree vital rates. Although many studies have tried to quantify how specific mechanisms influence vital rates, their relative importance among forests remains unclear. We aimed to assess the patterns of variation in vital rates among species an...

Tree regeneration is a key demographic process influencing long-term forest dynamics. It is driven by many biotic and abiotic factors. Thus, predictions of tree regeneration are challenging because of complex feedbacks along climatic gradients. The stress gradient hypothesis (SGH) and life-history strategies (LHS) provide a framework for assessing...

Despite a long-term human impact, Central and Eastern Europe exhibit patches of steppe ecosystems having the highest plant species diversity worldwide. These unique ecosystems have persisted over millennia even though the local climatic conditions would support the formation of a closed forest. Several sources of disturbances have contributed to th...

The formation of spatial pedocomplexity in forested landscapes is an issue that has not yet been comprehensively resolved. This study analysed the effects of tree disturbances on the spatial variability of soil chemical properties in order to explain the spatial pedocomplexity in one of the oldest forest reserves in Europe. A total of 1545 sites ov...

Tree mortality can fundamentally affect soils, which in turn shape forest regeneration and dynamics. Here, we quantify the dynamics of soil volumes associated with tree mortality, parsing effects by mode of tree death (broken vs uprooted) and species. The concept of ecosystem biogeomorphic succession was also tested. We used repeated tree censuses...

Natural regeneration of European beech (Fagus sylvatica) and Norway spruce (Picea abies) plays a crucial role in the future of many European mountain forests. It is affected by various soil and stand-related factors whose relative importance, especially in mixed stands, is still not known. In this study, we assessed the importance of stand composit...

The height growth of the trees depends on sufficient mechanical support given by the stem and an effective hydraulic system. On unstable slopes, tree growth is affected by soil pressure from above and potential soil erosion from below the position of tree. The necessary stabilization is then provided by the production of mechanically stronger wood...

The driving forces of tree mortality following wind disturbances of mountain mixed European temperate forests belongs among issues not comprehensively resolved. Hence, we aimed to elucidate the key factors of tree resistance to historical severe disturbance events in the Boubínský Primeval Forest, one of the oldest forest reserves in the Czech Repu...

Deadwood is a resource of water, nutrients, and carbon, as well as an important driving factor of spatial pedocomplexity and hillslope processes in forested landscapes. The applicability of existing relevant studies in mountain forests in Central Europe is limited by the low number of data, absence of precise dating, and short time periods studied....

Tree rings provide an invaluable long‐term record for understanding how climate and other drivers shape tree growth and forest productivity. However, conventional tree‐ring analysis methods were not designed to simultaneously test effects of climate, tree size, and other drivers on individual growth. This has limited the potential to test ecologica...

Arbuscular mycorrhizal (AM) and ectomycorrhizal (EcM) associations are critical for host-tree performance. However, how mycorrhizal associations correlate with the latitudinal tree beta-diversity remains untested. Using a global dataset of 45 forest plots representing 2,804,270 trees across 3840 species, we test how AM and EcM trees contribute to t...

Stand-replacing disturbances are a key element of the Norway spruce (Picea abies) forest life cycle. While the effect of a natural disturbance regime on forest physiognomy, spatial structure and pedocomplexity was well described in the literature, its impact on the microbiome, a crucial soil component that mediates nutrient cycling and stand produc...

Increasing growing season temperatures and the seasonal redistribution of precipitation due to climate change have recently been recorded across the globe. Simultaneously, increases of severe droughts and windstorm frequency have also been documented. However, the impacts of climate change on tree growth performance and fitness might largely differ...

Biogeomorphological and ecological succession following a disturbance or the exposure of new ground often proceeds in stages, from domination by abiotic, geophysical factors through stages characterized by increasing effects of biota, biotic-abiotic feedbacks, and eventual domination by ecological processes. However, some studies in forest settings...

https://authors.elsevier.com/a/1blC23HcE1cwu3 Outbreaks of bark beetles, for example Ips typographus L. in Eurasia or Dendroctonus ponderosae Hopkins in North America, have serious impacts on forest resources, biodiversity, and ecological dynamics, with economical and social ramifications. Moreover, many models predict increasing frequency and seve...

We studied the effects of preferential flow on weathering of primary minerals in well-drained, sandy Spodosols (Podzols) in northern Michigan, USA. Preferential flow in these soils is manifested as deep eluvial/illuvial tongues. We hypothesized that sands in the best developed (strong) tongues would be more weathered than in tongues that are short...

Evolution of weathering profiles (WP) is critical for landscape evolution, soil formation, biogeochemical cycles, and critical zone hydrology and ecology. Weathering profiles often include soil or solum (O, A, E, and B horizons), non-soil regolith (including soil C horizons, saprolite), and weathered rock. Development of these is a function of weat...

Tree radial growth is influenced by individual tree abilities, climate, competition, disturbance regimes, as well as by biogeomorphic processes including biomechanical interactions between trees and soil. Trees are actively involved in hillslope dynamics, both responding to and affecting many (bio)geomorphic processes. Using dendrochronology we stu...

Evolution of terrestrial plants, the first vascular plants, the first trees, and then whole forest ecosystems had far reaching consequences for Earth system dynamics. These innovations are considered important moments in the evolution of the atmosphere, biosphere, and oceans, even if the effects might have lagged by hundreds of thousands or million...

The disturbance regime of mountain spruce–beech temperate forests has not yet been sufficiently elucidated. We hypothesized that spruce and beech express completely different disturbance histories and behavioural strategies, potentially causing exceptionally complex disturbance regimes. We further hypothesized that the spontaneous development of mo...

Research has shown that the performance of soil–landform models would improve if the effects of spatial autocorrelation were properly accounted for; however, it remains elusive whether the level of improvement would be predictable, based on the degree of spatial autocorrelation in the model variables. We evaluated this problem using 11 soil variabl...

Fire occurrence is driven by a complex interplay between vegetation, climatic, landform and human factors making it challenging to separate the individual effect of each variable. Here we present a reconstruction of the Holocene biomass burning history of two regions located in the Central European temperate zone that differ in the timing of the Mi...

Tree uprooting may distinctly affect landscape dynamics and slope denudation. Little is known, however, about the corresponding soil redistribution rates (erosion, accumulation), on either a long‐term (millennia; 10Be) or a short‐term (decades; 239+240Pu) scale. We determined these rates in a well‐investigated forest reserve (Zofinsky primeval fore...

A distinct boundary between unweathered and weathered rock that moves downward as weathering proceeds—the weathering front—is explicitly or implicitly part of landscape evolution concepts of etchplanation, triple planation, dynamic denudation, and weathering- and supply-limited landscapes. Weathering fronts also figure prominently in many models of...

Despite improvements of dendrochronological techniques in many forest ecosystems, studies describing the growth responses of trees following disturbance events including comprehensive data on factors and processes behind tree-growth release are rare, especially for European temperate forests, limiting the interpretation and generalization of dendro...

Aims The dynamics of forests dominated by European beech (Fagus sylvatica) and Norway spruce (Picea abies) have been studied intensively. However, mainly due to a lack of long-term data, little is known about how these dynamics interact with soil conditions. In an old-growth spruce-beech forest with high soil diversity we studied how the developmen...

In the present paper we report on the only known example of a hummocky meadow in Poland. The area of the Hala Długa in the Gorce Mountains is a hotspot of complex geomorphic edge effects that have been widely studied in relation to human impacts and forest disturbances. Applying an interdisciplinary approach, we aimed to study the geomorphic activi...

Mountain spruce–beech–fir mixed forests are an important type of vegetation at higher elevations in temperate Europe. We aimed to determine how fire disturbances have affected long‐term vegetation dynamics and to assess their contribution to soil formation. We detected fire episodes using a soil charcoal record extensively dated based on 14C and co...

A unique remnant of forest dating back to the period 9733–7897 yr BC and consisting of hundreds of tree bases was discovered in the Czech Republic. We aimed to reveal the complex disturbance history of this (sub)fossil forest using dendrochronology, and to describe its detailed plant species composition changes using palaeobotanical techniques. Ana...

Background and aims The changing soils is a never-ending process moderated by numerous biotic and abiotic factors. Among these factors, trees may play a critical role in forested landscapes by having a large imprint on soil texture and chemical properties. During their evolution, soils can follow convergent or divergent development pathways, leadin...

Although many published studies have evaluated soil organic carbon (SOC) stocks in forest soils, none have yet focused on primary (i.e., unlogged) spruce (Picea spp.) forests on volcanic rocks. Previous research in the Călimani volcanic mountain range, Romania, revealed a close relationship between soil morphology and the canopy disturbance history...

Soil and regolith creep have been analyzed for at least the last 140 years, using many methodological configurations and temporal and spatial scales. The general concept of creeping soil and its mechanism, first proposed by W.M. Davis and G.K. Gilbert at the end of the 19th century, evolved since the 1940s towards theoretical models and precise sho...

The role of biomechanical effects of trees (BETs) in ecosystem and landscape dynamics is poorly understood. In this study, we aim to (i) describe a widely applicable methodology for quantifying the main BET in soil, and (ii) analyze the actual frequencies, areas and soil volumes associated with these effects in a mountain temperate old-growth fores...

Soils and forest ecosystems vary predictably along a 145-km transect in northern Lower Michigan. In the east, Entisols support open jack pine stands. In the central transect, weak Spodosols have formed under oak–pine–aspen forests. In the Lake Michigan snowbelt on the west, strongly developed Spodosols occur beneath mesic northern hardwoods. We hyp...

Tree breakage and uprooting are two possible scenarios of tree death that have differing effects on hillslope processes. In this study we aimed to (i) reveal the long-term structure of the biomechanical effects of trees (BETs) in relation to their radial growth and tree death types in four old-growth temperate forests in four different elevation se...

Post-disturbance pedogenetic pathways were characterized in three landscapes representing different degrees of weathering and leaching. Tree uprooting has been the main form of disturbance in all three landscapes. We hypothesized that the pedogenetic effect of trees due to uprooting is mainly governed by the regional degree of pedogenesis, which in...

Wyniki laboratoryjnych analiz chemicznych i fizycznych próbek gleb pobranych z poligonów badawczych w Gorcach, rezerwacie Zofin (Czechy) i stanie Michigan (USA) zostały poddane analizie i wizualizacji w pakiecie statystycznym R. W tym celu wykorzystano następujące pakiety: stats, aqp, corrplot, FSA, ggplot2, vegan, psych.

Spełzywanie gleby i regolitu analizowane było przez ostatnie 140 lat w wielu konfiguracjach metodycznych oraz zakresie przestrzennym i czasowym. Historia badań nad tym zagadnieniem i próba zrozumienia mechanizmów jego działania sięga pionierskich prac Gilberta (1877) i Davisa (1892). Jest to jeden z najwolniejszych procesów powierzchniowych analizo...

Deadwood represents a source of nutrients, carbon and water for metabolism within forest ecosystem. Nutrients are mobilized due to the decomposition of wood, which is a long-term process that can be best studied by analysing environmental data on a temporary scale. Our study provides physico-temporal data on the downed logs of three major tree spec...

Tree vs soil interactions

The role of biomechanical effects of trees (BET) in ecosystem and landscape dynamics is poorly understood. In this study, we aim to (i) describe a widely applicable methodology for quantifying the main BET in soil, and (ii) analyze the actual frequencies, areas and soil volumes associated with these effects in a mountain forest. The research took p...

Biomechanical effects of trees in forest soils represent a potentially significant factor in hillslope processes, pedocomplexity and forest dynamics. However, these processes have been only rarely studied so far. Within this study we aim (i) to elaborate a detailed and widely applicable methodology of quantification of the main biomechanical effect...

Razula forest preserve in the Carpathian Mountains of the Czech Republic is an unmanaged forest that has not been logged or otherwise anthropically disturbed for at least 83 years, preceded by only infrequent selective logging. We examined this 25 ha area to determine the dominant geomorphological processes on the hillslope. Tree uprooting displace...

In order to gauge ongoing and future changes to disturbance regimes, it is necessary to establish a solid baseline of historic disturbance patterns against which to evaluate these changes. Further, understanding how forest structure and composition respond to variation in past disturbances may provide insight into future resilience to climate-drive...

Fagus sylvatica (European beech) populations in Central Europe are currently expanding their dominance in many forest types. In this study we focused on the spatio-temporal dynamics of beech recruitment as a mechanism for successful expansion. Specifically we investigated: (1) the developmental trend of the tree community composition and spatial pa...