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Abstract: Arid and semiarid China have experienced multiple arid phases throughout the Quaternary, and over the past five decades, there have been several periods with relatively high or low rates of desertification and rehabilitation. The causes of these changes and their historical trends have been debated by scientists because of their potentially huge significance for China, as well as for the global ecology and food supply. This paper reviews recent studies of desertification in different regions of arid and semiarid China. In general, the results of systematic monitoring, and analyses of the causes of desertification and the contemporaneous human impacts, suggest that desertification in China has been primarily caused by climate change, and particularly by strong wind regimes (with high sand transport potential) accompanied by decreased spring precipitation. Unfortunately, although numerous scientists have claimed that desertification in China is primarily due to human impacts; there is surprisingly little unassailable evidence to support this claim. The review presented in this paper show that desertification in China is likely to be controlled by climate change and geomorphological processes, even though human impacts have undeniably exacerbated their effects. Our arguments for both climate change and human activity as factors responsible for the observed changes in desertification rely primarily on inferences based on correlations between trends, thus future research must seek stronger and more direct evidence for the causal relationships that we have proposed as possibilities. This improved information is essential to provide a firm basis for future policy decisions on how best to combat desertification. [Copyright &y& Elsevier]

China is the country with the most population in the world, and its climate is extremely diverse due to tremendous differences in latitude, longitude, and altitude, ranging from tropical in the far south to subarctic in the far north and alpine in the higher elevations of the Qinghai-Tibetan Plateau. Accurate assessment of its modern climate change is conductive to addressing global warming threat. Along with the development of Past Global Changes (PAGES) research, the focus has changed from paleo-climate reconstructions to using paleo-data for assessing the present and predicting the future. Previous studies have been devoted to climate change assessment using modern climate observations and simulations. This paper presents a new assessment approach based on the mid-Holocene, which provides a naturally oriented warming that can be compared to modern human-made global warming. A variety of climatic data, including modern observations, paleo-climate records, CMIP5 (Coupled Model Intercomparison Project Phase 5) and PMIP3 (Paleoclimate Modelling Intercomparison Project 3) simulations, as well as lake level models, were applied in this synthesis. Numerical climate classification was introduced to evaluate climate change impacts to Chinese climate zones on various time scales. The results show that winter and summer seasons have different response to the naturally oriented mid-Holocene warming but human-made global warming makes the warming trend appear in all seasons. Temperate and continental dry winter climates expand dramatically during the mid-Holocene warm period; however, the future global warming could have few impacts to Chinese climate zones. Furthermore, the East Asian summer monsoon was strengthened obviously by the mid-Holocene warm climate and strong low-latitude insolation. There is no consistent trend both for the winter and summer monsoon on the background of human-made global warming. In this study, a new benchmark was established based on paleo-climate to evaluate the impacts of human-made global warming. [ABSTRACT FROM AUTHOR]

• This study reviews and lists all Chinese papers on Devonian miospores. • The Late Devonian miospore diversity was greatly overestimated. • The rise of land plants and the oxygenation event are discussed. • The spore diversity is affected by both climate and sea-level changes. The microfossil-based pattern of the Devonian land plants of China is revised and discussed based on a new, comprehensive dataset. This dataset compiles the chronostratigraphical distribution of 1677 species belonging to 190 genera of spores and pollen from the primary literature, which covers the history of fossil Chinese terrestrial palynofloras. From this, we describe the patterns and biodiversity dynamics using both range-based and sample-based data to illustrate the main fluctuations of Devonian taxonomic richness, including rarefaction by filtering out uneven sampling. Results show that the apparent terrestrial palynofloral diversity of China increases progressively from the Early to Middle Devonian, with a genuine Givetian peak followed by a plateau persisting during the Late Devonian. Results further suggest that sampling effects may strongly influence the perception of biodiversity trends in China, as well as that the observed Late Devonian taxonomic diversification may have been greatly overestimated. Compiled evidence is discussed in the light of the global evolution of marine-terrestrial ecosystems. We hypothesize that the rise of Devonian floras may have played a remarkable role in an oceanic oxygenation event during this Period. [ABSTRACT FROM AUTHOR]