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Abstract The need of more food production, an increase in acidic deposition and the large capacity of paddy to emit greenhouse gases all coincide in several areas of China. Studying the effects of acid rain on the emission of greenhouse gases and the productivity of rice paddies are thus important, because these effects are currently unknown. We conducted a field experiment for two rice croppings (early and late paddies independent experiment) to determine the effects of simulated acid rain (control, normal rain, and treatments with rain at pH of 4.5, 3.5 and 2.5) on the fluxes of CO 2 , CH 4 and N 2 O and on rice productivity in subtropical China. Total CO 2 fluxes at pHs of 4.5, 3.5 and 2.5 were 10.3, 9.7 and 3.2% lower in the early paddy and 28.3, 14.8 and 6.8% lower in the late paddy, respectively, than the control. These differences from the control were significant for pH 3.5 and 4.5. Total CH 4 fluxes at pHs of 4.5, 3.5 and 2.5 were 50.4, 32.9 and 25.2% lower in the early paddy, respectively, than the control. pH had no significant effect on CH 4 flux in the late paddy or for total (early + late) emissions. N 2 O flux was significantly higher at pH 2.5 than 3.5 and 4.5 but did not differ significantly from the flux in the control. Global-warming potentials (GWPs) were lower than the control at pH 3.5 and 4.5 but not 2.5, whereas rice yield was not appreciably affected by pH. Acid rain (between 3.5 and 4.5) may thus significantly affect greenhouse gases emissions by altering soil properties such as pH and nutrient pools, whereas highly acidic rain (pH 2.5) could increase GWPs (but not significantly), probably partially due to an increase in the production of plant litter. Graphical abstract Image 1 Highlights • We studied acid rain effects on the emission of greenhouse gases in rice croplands. • Global-warming potential (GWP) was lower with rain at pH 35–4.5 than in the control. • Acid rain at 3.5–4.5 may have affected GWP by altering soil pH and nutrient pools. • Rice yield was not appreciably affected by the pH of acid rain (at pH 3.5–4.5). • Low rain pH (2.5) could rise GWP partially due to higher plant litter production. [ABSTRACT FROM AUTHOR]

Abstract: Spatio-temporal dynamics of Spartina alterniflora marshes in the Shanyutan Wetland, Minjiang River estuary in 2006 and 2010 were studied by the aerial images and Google Earth stellite images and field investigations. The expansion of S. alterniflora was significant, the areas were 211.03 hm2 and 306.94 hm2, respectively in 2006 and 2010. They mainly distributed in the middle tidal flat and extended quickly from northwest to southeast. Number of Patches of S. alterniflora marsh decreased by 59.17%, Mean Patch Size increased by 266.67%, Patch Shape Index decreased from 23.28 to 19.50. 85.03 hm2 of mudflats changed to S. alterniflora marshes, accounting for 72.54% of the area of increased S. alterniflora marsh, and mainly occurred in low tidal flat and surrounding areas of tidal creeks in east and central zones. [Copyright &y& Elsevier]

Long-term, high-resolution proxy records containing temperature signals are relatively scarce over Central China, limiting our understanding of regional climate and the potential driving forces. In this study, a robust tree-ring width chronology is developed based on Pinus massoniana woods from two sites on the northeast Wuling Mountains, spanning from 1815 to 2014. The presented chronology is used to reconstruct regional long-term winter-spring (January-May) temperature changes over the past two centuries in Central China. The reconstruction reveals that cold epochs occurred in 1830 s–1840 s, 1850 s–1860 s, 1900 s–1910 s and 1960 s–1970 s. The correlation patterns between the reconstruction and global sea surface temperature (SST) are suggestive of the influence of SST of the western North Pacific Ocean (especially the Japan Current region) and the North Atlantic Ocean on regional temperature. In addition, persistent close matches are observed between the chronology and the Atlantic Multidecadal Oscillation (AMO) reconstructions over the past two centuries, suggesting the AMO may have been a key modulator of long-term temperature variations over Central China. [ABSTRACT FROM AUTHOR]