Biology subjects

Konrai, K.

Publications and source records attributed to Konrai, K..

3 recordsLinked to original sources

bioRxiv2026

Molecular evolutionary evidence for coexistence within oak hybrid zones.

Resource allocation trade-offs in seedlings have been widely proposed to facilitate the coexistence of tree species; however, whether selection can maintain the underlying genetic variation under gene flow remains insufficiently investigated. Using a natural hybrid zone between two East Asian oaks, we evaluated whether loci associated with allocation trade-offs showed signatures of selection despite hybridisation. Acorns collected across the zone were cultivated in a common garden, where we quantified 25 seedling growth and functional traits, and analysed whole-genome variation. We identified trade-offs between leaf function and plant architecture. Trait-associated genomic regions demonstrated strong inter-chromosomal linkage disequilibrium in the hybrids, consistent with genetic coupling, and exhibited elevated interspecific differentiation and more pronounced genetic clines. These results indicate that multilocus selection counteracts gene flow through the development of genetic coupling, thereby maintaining resource allocation trade-offs that may contribute to tree coexistence.

evolutionary biology↗

bioRxiv2026

Thermophilization, climatic debt, and consequent declines in primary productivity

Species have optimal environmental conditions, and ongoing climate warming is reshaping community composition. In particular, many ecosystems exhibit thermophilization, a shift toward species adapted to warmer conditions. However, this process is often slower in forests, leading to a mismatch between community composition and ambient temperature, referred to as climatic debt. Despite increasing attention, its effects on forest productivity remain unclear. Quantifying tree community responses to warming is therefore essential for predicting future forest dynamics and informing biodiversity conservation. In this study, we analyzed natural forests across Japan using data from the 3rd and 4th National Forest Inventory periods (2009-2018). We first assessed compositional consistency between survey periods using the Bray-Curtis index and excluded plots with high dissimilarity ([≥] 0.8). Species-specific thermal optima were estimated using species distribution models and used to calculate the Community Temperature Index (CTI). Thermophilization was quantified as the temporal change in CTI, while climatic debt was defined as the difference between CTI and mean annual temperature. We then examined the relationship between climatic debt and changes in aboveground biomass, used as a proxy for productivity, using linear mixed-effects models. We found a mean thermophilization rate of 0.005 {degrees}C yr-{superscript 1}. Despite this shift, climatic debt increased at an average rate of -0.022 {degrees}C yr-{superscript 1}, indicating a growing mismatch between climate warming and community thermal composition. Although thermophilization showed no statistically significant association with stand structure, it tended to vary with the proportion of small-diameter trees, suggesting the influence of multiple interacting drivers. Importantly, increasing climatic debt was significantly associated with declines in forest primary productivity, even after accounting for stand structure and regional variation. These results demonstrate that delayed thermal adjustment of tree communities can constrain forest productivity under ongoing climate warming, highlighting the importance of evaluating community-level thermal responses for sustaining forest ecosystem functioning.

ecology↗

bioRxiv2026

LeafContourEFD: a reproducible workflow for elliptic Fourier analysis with orientation normalization and lateral asymmetry

PremiseElliptic Fourier analysis is widely used to quantify leaf shape variation, but inconsistent normalization and orientation alignment can introduce biologically irrelevant variation. In addition, a reproducible workflow from raw images to normalized elliptic Fourier descriptors (EFDs) is still lacking. Methods and ResultsWe developed LeafContourEFD, a GUI application for reproducible leaf morphometrics. It integrates image segmentation, contour extraction, EFD calculation, and an extended normalization framework, termed oriented true EFD normalization, based on a user-defined biological reference axis. Analyses of Quercus serrata, Q. crispula, and Triadica sebifera showed that existing normalization methods can introduce orientation-related variance when the first-harmonic major axis does not match the leaf base-to-tip axis. In contrast, oriented true normalization removed these artifacts, yielding clearer shape transitions along principal components allowing shape variation among leaves to be captured while preserving biologically meaningful lateral asymmetry. ConclusionsLeafContourEFD improves interpretability and reproducibility in outline-based morphometrics and provides transparent outputs and metadata for data sharing and cross-study comparisons.

plant biology↗