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SUMMARY: Understanding the genetic basis of population divergence and adaptation is an important goal in population genetics and evolutionary biology. However, the relative roles of demographic history, gene flow, and/or selective regime in driving genomic divergence, climatic adaptation, and speciation in non‐model tree species are not yet fully understood. To address this issue, we generated whole‐genome resequencing data of Liquidambar formosana and L. acalycina, which are broadly sympatric but altitudinally segregated in the Tertiary relict forests of subtropical China. We integrated genomic and environmental data to investigate the demographic history, genomic divergence, and climatic adaptation of these two sister species. We inferred a scenario of allopatric species divergence during the late Miocene, followed by secondary contact during the Holocene. We identified multiple genomic islands of elevated divergence that mainly evolved through divergence hitchhiking and recombination rate variation, likely fostered by long‐term refugial isolation and recent differential introgression in low‐recombination genomic regions. We also found some candidate genes with divergent selection signatures potentially involved in climatic adaptation and reproductive isolation. Our results contribute to a better understanding of how late Tertiary/Quaternary climatic change influenced speciation, genomic divergence, climatic adaptation, and introgressive hybridization in East Asia's Tertiary relict flora. In addition, they should facilitate future evolutionary, conservation genomics, and molecular breeding studies in Liquidambar, a genus of important medicinal and ornamental values. Significance Statement: We assembled a chromosome‐scale genome of Liquidambar formosana and resequenced 160 individuals of L. formosana and its high‐altitude sister species L. acalycina. Benefiting from advanced analytical methods and robust evidence, we found that multiple "genomic islands" mainly evolved as a result of divergence hitchhiking and recombination rate variation, as likely fostered by long‐term refugial isolation and recent differential introgression in low‐recombination genomic regions; and identified some candidate genes associated with climatic adaptation and reproductive isolation. [ABSTRACT FROM AUTHOR]

Reconstruction of the desert paleoclimate is important to understand the mechanisms that triggered and/or enhanced climate change. Through optically stimulated luminescence (OSL) dating, grain size, magnetic susceptibility, X-ray powder diffraction (XRD) and geochemical indicators, we provide a well-dated record of a sedimentary outcrop on the southeast margin of the Bardain Jaran Desert, Northwest China, during the last glacial period. Four Qz-OSL ages are obtained, 41.0±34 ka, 54.7±4.4 ka, 59.5±5.0 ka and 66.8±5.8 ka, corresponding to the depths of 35 cm, 70 cm, 150 cm and 200 cm respectively. Indicators like grain size, clay content, magnetic susceptibility, XRD and geochemical index (e.g. Sr, Ba, Sr/Ca) jointly indicate abrupt climate changes at the depth of 35 cm (age, ca. 41.0 ka) and 200 cm (age, ca. 67 ka). Namely, the 280 cm sedimentary outcrop perfectly records a warm wet climate stage, corresponding to the late Marine Isotope Stages (MIS) 4 to the early MIS 3. Besides, there is a trend of grain size increase after around 40 ka BP, which is most likely a signal of wind strength change. Our research supports that enhancing Siberian High pressure system during the late MIS 3 played a key role in NW East Asia climate evolution. [ABSTRACT FROM AUTHOR]

At a global scale, organisms are under threat due to various kinds of environmental changes, such as artificial light at night (ALAN), noise, climatic change and vegetation destruction. Usually, these changes co-vary in time and space and may take effect simultaneously. Although impacts of ALAN on biological processes have been well documented, our knowledge on the combined effects of ALAN and other environmental changes on animals remains limited. In this study, we conducted field experiments in semi-natural enclosures to explore the combined effects of ALAN and vegetation height on foraging behavior, vigilance, activity patterns and body weight in dwarf striped hamsters (Cricetulus barabensis), a nocturnal rodent widely distributed in East Asia. We find that ALAN and vegetation height affected different aspects of behavior. ALAN negatively affected search speed and positively affected handling speed, while vegetation height negatively affected giving-up density and positively affected body weight. ALAN and vegetation height also additively shaped total time spent in a food patch. No significant interactive effect of ALAN and vegetation height was detected. C. barabensis exposed to ALAN and short vegetation suffered a significant loss in body weight, and possessed a much narrower temporal niche (i.e. initiated activity later but became inactive earlier) than those under other combinations of treatments. The observed behavioral responses to ALAN and changes in vegetation height may bring fitness consequences, as well as further changes in structure and functioning of local ecosystems. [Display omitted] • We studied combined effects of ALAN and vegetation height on hamsters. • ALAN and vegetation height additively affected total time hamsters spent in a patch. • Hamsters exposed to ALAN and short vegetation suffered from loss of body mass. • Hamsters exposed to ALAN possessed lower search speed and higher handling speed. •Short vegetation prevented hamsters from foraging thoroughly in a patch. [ABSTRACT FROM AUTHOR]