Biology subjects

Csillery, K.

Publications and source records attributed to Csillery, K..

8 recordsLinked to original sources

bioRxiv2026

Gene-environment interactions govern early regeneration in fir and beech: evidence from participatory provenance trials across Europe

O_LIForest regeneration is shaped by strong demographic filters during germination and early establishment, yet the relative contributions of provenance and environment remain poorly resolved under natural conditions. C_LIO_LIWe combined climate-chamber trials with a continental-scale, field-based citizen science seed-sowing experiment to quantify germination, early phenological development, and three-year post-germination survival fir (Abies spp.) and beech (Fagus spp.) provenances across Europe. Using mixed-effects models and a state-based Markov framework to reconstruct phenological trajectories, we quantified successive demographic filters from seed to established seedling. C_LIO_LIGermination was structured by genotype-by-environment interactions (G x E) in both genera, but with contrasting expression: fir showed broadly parallel environmental responses among provenances and partial concordance between climate-chamber and field, whereas beech showed strong provenance-by-environment responses and weak predictability from controlled conditions. Seed weight was a key axis in beech (lighter seeds germinated more and developed faster), but confounded with geographic differentiation in fir. C_LIO_LIIn contrast to germination, post-establishment survival was dominated by site-level environmental filtering with limited consistent provenance effects, revealing a life-stage shift from fine-scale G x E during germination and early development to broader environmental control of survival--an important consideration for regeneration--based management and assisted migration. C_LI

evolutionary biology↗

bioRxiv2025

Harnessing foresters' engagement for climate change adaptation: the emerging tool of next-generation citizen science

Citizen science is an increasingly common approach for collecting large amounts of data across extensive spatial and temporal scales in ecology and environmental sciences. To facilitate participation, the majority of citizen science projects are based on opportunistic smartphone-based tasks that can be completed in just a few minutes. We reviewed 639 citizen science projects and coordinated distributed experiments, assessing the level of engagement expected from participants, and found that citizens can also perform highly engaging tasks, including conducting experiments, similar to those expected from collaborating scientists. We coined the term "next-generation citizen science" for experiments conducted by citizens with specialized knowledge and addressed the benefits and risks of such projects using the example of MyGardenOfTrees. This unprecedented continent-wide transplant experiment involves over 300 forester-citizens who dedicate their time and expertise to testing different seed origins in their forests over a five-year period, and co-develop a prediction tool with researchers for selecting suitable species and provenances for assisted migration. We used marketing analysis of recruitment data to identify strategies for participant recruitment and retention across the multi-cultural landscape of Europe, thereby expanding the boundaries of citizen science beyond its traditional use. Furthermore, we present the development of the experimental design and protocols aimed at optimizing logistical feasibility, scientific rigor, and social acceptance. Our findings highlight the untapped potential of such experimental citizen science approaches to increase the scale of ecological experiments and ultimately obtain generalizable findings, thereby overcoming context dependence.

evolutionary biology↗

bioRxiv2024

Leveraging remote sensing to distinguish closely related beech species in assisted gene flow scenarios

European beech (Fagus sylvatica L.) forests are suffering under increasingly severe and frequent drought. Three closely related, hybridizing beech species, ranging from Bulgaria through Asia Minor and the Caucasus to Iran, offer potential resources for assisted gene flow (AGF) with the aim of increasing the adaptive capacity of European beech forests. However, due to similar morphology and leaf color, as well as hybridization, it is challenging to track the fate of introduced beech genotypes from these related species. Traditional identification methods relying on detailed morphological characterization and genetic testing are labor-intensive and costly, making them impractical for large-scale applications. Using multispectral data from PlanetScope SuperDove, we developed a classification approach that captures phenological differences between the European beech F. sylvatica and co-planted Caucasian beech (Fagus hohenackeriana Palibin). The approach focuses on key temporal windows and spectral features to optimize classification performance. We evaluated various machine learning algorithms with stratified spatial and temporal cross-validation on data from more than 200 genetically classified individuals in two well-studied sites in France and Switzerland, where Caucasian beech was introduced over a century ago. Our approach was then tested on three different study areas in Germany, where Caucasian beech was also planted, but without specific tree coordinates. Our results reveal consistent temporal and spectral differences during spring and autumn, aligning with budbreak and senescence periods. Most algorithms achieved classification accuracies of 90% and above. The algorithms effectively identified candidate zones for Caucasian beech within or near areas indicated by local foresters. This study demonstrates the potential of high-resolution multispectral satellite imagery and machine learning for scalable classification of closely related and hybridizing species, thereby facilitating forest management in the face of global change. HighlightsO_LIRemote sensing of unique phenological differences between closely related beech species C_LIO_LIModels with optimized classification parameters differentiated highly similar, introduced trees C_LIO_LIReal-world application to assisted gene flow sites yielded high performance and testable predictions C_LI

ecology↗

bioRxiv2022

Tracing the origin of Oriental beech stands across Western Europe and reporting hybridization with European beech - implications for assisted gene flow

Human-aided translocation of individuals within the species range, assisted gene flow (AGF), has been suggested as a climate change mitigation strategy, especially for foundational species, such as forest trees. The benefits and risks of AGF largely depend on the genetic divergence between host and donor populations, their rate and direction of hybridization, and the climate distance that the transfer involves. In this study, we explored the use of Oriental beech (Fagus sylvatica subsp. orientalis), growing from Iran to the Balkans, for AGF in populations of European beech (F. sylvatica subsp. sylvatica), which grow throughout Europe and are increasingly affected by climate warming. Using 16 microsatellite loci and samples from 13 and 6 natural populations of Oriental and European beech, respectively, we identified 5 distinct genetic clusters in Oriental beech with a divergence (FST) of 0.15 to 0.25 from European beech. Using this knowledge, we tracked the origin of 11 Oriental beech stands in Western Europe, some established in the early 1900s. In two stands of Greater Caucasus origin, we additionally genotyped offspring and found evidence for extensive hybridization, with 41.3% and 17.8% of the offspring having a hybrid status. Further, climate data revealed a higher degree of seasonality across the Oriental beech growing sites than across the planting sites in Western Europe, with some sites additionally having a warmer and drier climate. Accordingly, in one of these stands, we found evidence that bud burst of Oriental beech occurs four days earlier than in European beech. These results suggest that AGF of Oriental beech could increase the genetic diversity of European beech stands and may even help the introgression of variants that are more adapted to future climatic conditions. Our study showcases an evaluation of the benefits and risks of AGF and calls for similar studies on other native tree species.

evolutionary biology↗

bioRxiv2021

Fine-scale spatial genetic structure across the species range reflects recent colonization of high elevation habitats in silver fir (Abies alba Mill.)

Variation in genetic diversity across species ranges has long been recognized as highly informative for assessing populations resilience and adaptive potential. The spatial distribution of genetic diversity, referred to as fine-scale spatial genetic structure (FSGS), also carries information about recent demographic changes, yet it has rarely been connected to range scale processes. We studied eight silver fir (Abies alba Mill.) population pairs (sites), growing at high and low elevations, representative of the main genetic lineages of the species. A total of 1368 adult trees and 540 seedlings were genotyped using 137 and 116 single nucleotide polymorphisms (SNPs), respectively. Sites revealed a clear east-west isolation-by-distance pattern consistent with the post-glacial colonization history of the species. Genetic differentiation among sites (FCT=0.148) was an order of magnitude greater than between elevations within sites (FSC=0.031), nevertheless high elevation populations consistently exhibited a stronger FSGS. Structural equation modeling revealed that elevation and, to a lesser extent, post-glacial colonization history, but not climatic and habitat variables, were the best predictors of FGSG across populations. These results may suggest that high elevation habitats have been colonized more recently across the species range. Additionally, paternity analysis revealed a high reproductive skew among adults and a stronger FSGS in seedlings than in adults, suggesting that FSGS may conserve the signature of demographic changes for several generations. Our results emphasize that spatial patterns of genetic diversity within populations provide complementary information about demographic history and could be used for defining conservation priorities.

evolutionary biology↗

bioRxiv2021

Recovery of silver fir (Abies alba Mill.) seedlings from ungulate browsing mirrors soil nitrogen availability

Abies alba has a high potential for mitigating climate change in European mountain forests, yet, its natural regeneration is severely limited by ungulate browsing. Here, we simulated browsing in a common garden experiment to study growth and physiological traits, measured from bulk needles, using a randomized block design with two levels of browsing severity and seedlings originating from 19 populations across Switzerland. Genetic factors explained most variation in growth (on average, 51.5%) and physiological traits (10.2%) under control conditions, while heavy browsing considerably reduced the genetic effects on growth (to 30%), but doubled those on physiological traits related to C storage. While browsing reduced seedling height, it also lowered seedlings water use efficiency (decreased{delta} 13C) and N supply by mycorrhizal fungi as indicated by an increase in{delta} 15N. Different populations reacted differently to browsing stress, and for Height, Starch and{delta} 15N, population differences appeared to be the result of natural selection. We found that the fastest growing populations, originating from the warmest regions, decreased their needle starch level the most as a reaction to heavy browsing, suggesting a potential genetic underpinning for a growth-storage trade-off. Further, we found that seedlings originating from mountain populations growing on steep slopes had a significantly lower N discrimination in the common garden than those originating from flat areas, indicating that they have been selected to grow on N poor, potentially drained, soils. This finding was corroborated by the fact that N concentration in adult needles was lower on steep slopes than on flat ground, strongly indicating that steep slopes are the most N poor environments. Seedlings from these poor environments generally had a low growth rate and high storage, thus might be slower to recover from browsing stress than fast growing provenances from the warm environments with developed soils, such as the Swiss plateau.

evolutionary biology↗

bioRxiv2019

Adaptation to drought is coupled with slow growth in marginal silver fir (Abies alba Mill.) populations

Drought is increasingly considered as the most important selection pressure for forest trees in the context of climate change. We studied adaptation to drought in marginal populations of silver fir (Abies alba Mill.) from the French Mediterranean Alps. Drought tolerance was assessed using proxies both from seedlings and adult trees. We measured water stress response, growth and bud break of seedlings originating from 16 populations in a greenhouse common garden experiment (N=8199) and water use efficiency via{delta} 13C of adult trees of the source populations in-situ (N=315). Further, 357 single nucleotide polymorphisms (SNPs) were used to uncover the demographic history of the populations. Demographic distances between populations were used to generate a null expectation for trait divergence, thereby detect the signature of natural selection. We found evidence for adaptive population divergence in drought tolerance across life stages. Seedlings originating from source populations with low soil water capacity resisted better to water stress in the greenhouse, and additionally, adult trees from these populations had a higher water use efficiency. Seedling growth showed an evolutionary trade-off with drought tolerance: seedlings with fast growth and high stature came from populations that had lower drought tolerance. In contrast, population divergence in bud break showed only a weak signal of adaptation, which was independent of that in drought tolerance. Variation in phenology between populations was associated with variance in temperature and drought frequency and severity at the source populations. Our results highlight the adaptive value of marginal populations, advance our understanding of the different processes that have allowed silver fir to cope with drought stress under a warming climate, and contribute to our knowledge to advise assisted migration programs.

evolutionary biology↗

bioRxiv2018

Adaptation to local climate in size, growth and phenology across 19 silver fir (Abies alba Mill.) populations from Switzerland

Attempts to identify and understand selection pressures responsible for local adaptation are central to evolutionary research. We tested whether populations of silver fir (Abies alba Mill.), sampled across a heterogeneous environment, have more strongly diverged at quantitative traits than expected from genetic drift. We genotyped 387 trees from 19 Swiss populations at 374 single-nucleotide polymorphisms (SNPs) to estimate their demographic distances, and used these to generate a null expectation for divergence in a multi-trait space including morphology and life-history traits obtained from a published common garden trial. Local soil and historical climate data were used to identify the selective environment of the source populations. Our results revealed a strong selection on height driven by temperature: trees from warm sites evolved to become taller than those from cooler sites. The evolution of growth rate, growth duration and bud break were correlated, and populations evolved towards two extreme strategies, \"start early and grow slow\" or \"start late and grow fast\", driven by precipitation seasonality. We conclude that local climate has shaped the morphology and life-history of silver fir populations since they recolonized the Alps. Our methodology provides a show-case for empirical evaluation of adaptive evolutionary strategies combining genetic data and common gardens.

evolutionary biology↗