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Despite decades of research, fundamental questions remain about how China's deserts and desert margins function, how they interact with regional and global scale environmental systems, and how they have responded to recent natural and anthropogenic forced climate change. The predominant focus of desert research in China, and globally, has been site specific case studies within sub-disciplines. This highly focused view makes development of a comprehensive interdisciplinary understanding of these deserts difficult. The fields of database creation, data mining and modern statistics have advanced the analysis of complex real-world data, however these methods enjoy only a relatively modest penetration into the geosciences. We report herein on the application of these new technologies to desert environmental systems in China, and illustrate the potential value of well-constructed databases and tool-rich analysis environments at regional, local and site specific scales. Regional analysis suggests significant warm season decrease and cold season increase in cloudiness in China's deserts suggesting that contrasts between cold and warm season cloudiness may be increasing. At a local and site specific scale at central China's Tengger Desert/Helan Mountains climate transition we find a significant climate forced greening of the desert margin over the past decade which may be reversing desertification trends aiding China's remediation efforts. We note that this new approach provides a “living” archive that allows capture of changes currently occurring in China's deserts as well as allowing assessments of human efforts to modify desert and desert margin environments. [ABSTRACT FROM AUTHOR]

Abstract: Large areas in western China were wetlands or less arid between 40 and 30 ka, corresponding to the “Greatest Lake Period” on the adjacent Tibetan Plateau. During the last glacial maximum, some of these western Chinese deserts again experienced wetter conditions; however, at the same time the sandy lands in the eastern Chinese desert belt experienced an activation of aeolian dunes. While interpretations of the mid-Holocene environment in the deserts of China are controversial, it is quite likely that it was more humid not only in the eastern areas influenced by monsoon climate systems but also in the western deserts where moisture is currently associated with westerlies. Evaluation of lacustrine records in the lakes recharged by dryland rivers and the complex interactions of these systems, as well as other paleoenvironmental proxies such as the Artemisia/Chenopodiaceae ratio, should be interpreted with greater caution. Facing the highlighted uncertainties in our understanding of climate changes in Chinese deserts, it is hoped that this special issue will improve our knowledge considerably. [Copyright &y& Elsevier]

Abstract: The formation of cracks is a fundamental first step in the physical weathering of rocks in desert environments. In this study we combine new field data from the Mojave (U.S.), Gobi (Mongolia) and Strzelecki (Australia) deserts that collectively support the hypothesis that meridional cracks (cracks with orientations not readily attributable to rock anisotropies or shape) in boulders or cobbles form due to tensile stresses caused by directional heating and cooling during the sun''s daily transit. The new studies indicate that rock size, surface age, and latitude play important roles with respect to their influence on rock fracture. Rock size and pavement surface age exert an influence on the development of rock cracks as the average clast size of mature desert pavements may be at or below the threshold-clast size for thermal cracking of rocks. Latitude-controlled seasonal temperature variations play a key role, as demonstrated by: 1) tightly clustered mean resultant orientations that differ by latitude, as predicted in McFadden et al. (2005), and 2) very cold wintertime temperatures and strong diurnal gradients that may favor crack development in wintertime, given the likelihood for strong clast heating during early morning hours. The consistent evidence for meridional cracks in surfaces of diverse age and desert environments, climate, vegetation, and distance of clast transport indicate that directional insolation may play the key role in initially generating and propagating rock fractures, rather than a secondary role as implied in recent field and modeling studies of physical weathering in deserts. [Copyright &y& Elsevier]