Biology subjects

Kadej, M.

Publications and source records attributed to Kadej, M..

3 recordsLinked to original sources

bioRxiv2026

Metric-dependent genomic diversity reveals phylogenetic and ecological structure in saproxylic beetles

Abstract 1. Comparative studies can reach different conclusions when genomic-diversity metrics use different denominators. 2. We analysed standardized ddRAD-seq data from 759 individuals, 149 species-by-site population records and 26 saproxylic beetle species across eight Polish forest complexes. 3. Species identity and sampling hierarchy explained most population-level variation. Deciduous-associated species had higher variant-site expected heterozygosity than conifer-associated species. 4. All-position nucleotide diversity showed stable phylogenetic signal, whereas occurrence tier and exploratory forest-management and protection contrasts showed no consistent associations. 5. Genomic-diversity metrics are not interchangeable; comparative assessments should report their denominator and test lineage sensitivity.

evolutionary biology↗

bioRxiv2026

Beyond deadwood volume: structural heterogeneity and species-specific dispersal shape saproxylic beetle genetics

Many rare saproxylic (deadwood-dwelling) beetles are among Europes most threatened insects, yet the relative importance of local microhabitat quality versus broad-scale landscape connectivity in shaping their genetic integrity remains poorly understood. We evaluated environmental drivers for 13 saproxylic beetle species--rare old-growth specialists, common taxa, and economically significant pests--across eight major forest complexes in Poland, using double digest restriction-site associated DNA sequencing (ddRAD-seq) paired with plot-level structural inventories and estimated effective migration surfaces (EEMS) modelling. A beta generalized linear mixed model identified deadwood diversity as the only significant within-species predictor of observed heterozygosity ({beta} = 0.041, 95% CI 0.0227-0.0586, p < 10-); total deadwood volume, forest age, time since logging, stump density, and veteran tree density were not significant. Management-category contrasts in observed heterozygosity (Ho) and the inbreeding coefficient (Fis) were non-significant after Tukey adjustment. Predictor x ecological-tier interactions did not differ detectably between rare and common species for five of six structural predictors; time since last logging was the exception ({chi}{superscript 2} = 4.56, p = 0.033). EEMS patterns differed among species and fell into three broad groups: regional lineage barriers, asymmetrical corridors, and surfaces close to isolation- by-distance expectations. These results associate plot-level heterozygosity with deadwood diversity and show that regional gene-flow patterns cannot be generalised across saproxylic beetles. Conservation planning should therefore combine local deadwood restoration with species-specific assessment of landscape connectivity.

evolutionary biology↗

bioRxiv2025

Geography and forest naturalness as drivers of genetic diversity in saproxylic beetles

Understanding how geography and forest management shape genetic diversity is pivotal for the conservation of saproxylic beetles, the key indicators of forest ecosystem integrity. Using a multi-species Double Digest Restriction-site Associated DNA sequencing approach, we analyzed genome-scale SNP variation in 12 saproxylic beetle species (rare and common, incl. pests) differing in abundance, ecology, and mobility across central European forests, with respect to both geographic location and forest status. Analyses of distance-based redundancy test, molecular variance, and population structure consistently revealed that geography is the main determinant of genetic differentiation, with clear east-west clustering in several species. Forest status represented in four levels (commercial not protected, nature reserve, primeval not protected, and primeval protected) exerted a secondary but detectable effect in a subset of taxa, especially among rare and habitat-specialized species. For these species, populations from primeval protected sites showed distinct genetic structure compared to those from commercial stands. Our results highlight that regional connectivity, maintaining gene flow across a large spatial scale, should be prioritized in conservation planning, complemented by the protection of primeval forest refugia and the maintenance of structural complexity in commercial forests. By integrating high-resolution genomic data with geographical and management context, this study provides actionable insights into the processes shaping genetic structure in forest-dependent insects and underscores the importance of incorporating genetic monitoring into sustainable forest biodiversity management.

genetics↗