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Arid and semiarid regions are environmentally vulnerable to global warming. Thus, studying their environmental history during warm periods (e.g., the Last Interglacial, LIG) is crucial for understanding their future changes too. The West Gobi Desert is a transitional zone influenced by the westerlies and the East Asian monsoon system. Therefore, the variation in atmospheric circulation profoundly affects its water vapor transport and landscape evolution. Due to the scarcity of continuous records, the moisture transport process remains ambiguous, which limits further research on paleolake evolution and aeolian activity. Here, we combine paleoclimate simulations from the Coupled Model Intercomparison Project 6 (CMIP6)-Paleoclimate Modeling Intercomparison Project 4 (PMIP4) and geological records to clarify the water vapor transport pathways and aeolian activity in the West Gobi Desert during the LIG, compared to the reference period (the piControl). Our results show that increased rainfall and meltwater were possible supplies for surface water during the LIG and were associated with enhanced East Asian summer monsoon and higher surface air temperatures. Concomitantly, weakening aeolian activity and dormant dune fields occurred in the West Gobi Desert, resulting from higher surface moisture content and weaker surface wind regimes associated with the weakening westerlies and East Asian winter monsoon. Notably, the limited weakening of aeolian activity that occurred in the LIG winter and spring was caused by weaker surface wind and deteriorating surface moisture conditions, while the significant dormancy of dune fields in the LIG summer and autumn was initiated by the combined effects of ameliorative surface moisture conditions and lower surface wind speed. • West Gobi Desert water supply rose due to stronger East Asian summer monsoon and warm climate during the Last Interglacial (LIG). • Weaker winds and higher moisture led to dormant aeolian activity in West Gobi Desert during the LIG. • LIG warm season saw more significant weakening of aeolian activity than the cold season in West Gobi Desert. [ABSTRACT FROM AUTHOR]

[Display omitted] • "Yardang-controlled dune" is systematically illustrated with morphology and dynamics. • In three patterns, dunes form before, beside and behind the yardangs. • CFD simulations reveal that the yardang-induced low-velocity winds shape the dunes. • Remote sensing measurements support the CFD, which agrees with three patterns. • The aspect ratios of the streamlined yardangs control the linear dune formation. The yardang-dune coexistence and the control of yardangs on dune formation reveal the joint action of wind erosion and deposition. Yardangs exhibit distinctive characteristics of streamlining and clustering, which apply unique and complicated impacts on the wind field and sand transport. However, previous studies lack systematic investigation on how yardangs exert control over dune morphology, and the intricate wind dynamics and mechanisms involved remain unclear. In this study, the "yardang-controlled dune" is systematically illustrated, supported by thorough studies of the yardang-controlled dune morphology and dynamics. Through the monitoring of the 6722 km2 dunes in the Qaidam Basin (QB), three typical yardang-dune coexistence patterns are identified and summarized: Pattern I-windward dune, crescentic dunes form on the upwind sides of the sparsely arranged yardangs; Pattern II-corridor dune, crescentic dunes form beside the narrowly arranged yardangs in the corridors and migrate; Pattern III-leeward dune, linear dune forms on the downwind side from isolated yardang tail. Computational fluid dynamics (CFD) modeling is used to analyze the dynamics and mechanisms of the three patterns and the corresponding real yardang topographies. CFD simulations show that with the control of yardangs, the winds in the locations corresponding to the dunes have significantly low velocities, leading to the wind entrainment decrease, sand accumulation and subsequent dune formation. CFD also reveals that the aspect ratios of yardangs control the formations of wind shadows and linear dunes on the yardang tails. The simulation results agree well with the actual landforms observed in the QB of the three patterns. Additionally, the dune leeward slope width and migration velocity statistics based on remote sensing provide further support for the observations and simulations. This study sheds light on the intricate influences of yardangs on wind deposition, underscoring their role in shaping the landform of dunes. [ABSTRACT FROM AUTHOR]

SUMMARY: Rosa roxburghii and Rosa sterilis, two species belonging to the Rosaceae family, are widespread in the southwest of China. These species have gained recognition for their remarkable abundance of ascorbate in their fresh fruits, making them an ideal vitamin C resource. In this study, we generated two high‐quality chromosome‐scale genome assemblies for R. roxburghii and R. sterilis, with genome sizes of 504 and 981.2 Mb, respectively. Notably, we present a haplotype‐resolved, chromosome‐scale assembly for diploid R. sterilis. Our results indicated that R. sterilis originated from the hybridization of R. roxburghii and R. longicuspis. Genome analysis revealed the absence of recent whole‐genome duplications in both species and identified a series of duplicated genes that possibly contributing to the accumulation of flavonoids. We identified two genes in the ascorbate synthesis pathway, GGP and GalLDH, that show signs of positive selection, along with high expression levels of GDP‐d‐mannose 3′, 5′‐epimerase (GME) and GDP‐l‐galactose phosphorylase (GGP) during fruit development. Furthermore, through co‐expression network analysis, we identified key hub genes (MYB5 and bZIP) that likely regulate genes in the ascorbate synthesis pathway, promoting ascorbate biosynthesis. Additionally, we observed the expansion of terpene synthase genes in these two species and tissue expression patterns, suggesting their involvement in terpenoid biosynthesis. Our research provides valuable insights into genome evolution and the molecular basis of the high concentration of ascorbate in these two Rosa species. [ABSTRACT FROM AUTHOR]