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The shrub patch pattern has important influence on the ecosystems in the arid water-wind erosion crisscross regions. The objective of this study was to examine the effects of vegetation pattern of shrub spot patch on species diversity and soil water content at the sand in slopes in water-wind erosion crisscross region on the Loess Plateau. In this study, the shrub patch size was classified to four size classes, contrasting with bare land patch, and herbaceous plants, and soil water content of the shrub patch were measured in each patch. The Shannon–Wiener indices were 0.364 and 1.074 respectively in small and large patches, which were higher than 0.231 in the bare land patch. The Richness index was 1.41 in bare land patch, which was lower than 1.704 in small shrub patch and 4.370 in large shrub patch. The above- and below-ground biomass and surface soil water content were also significantly ( p < 0.05) higher in the shrub patch than that in the bare land patch. These results suggest that the shrub patch could significantly increased species diversity, the above- and below-ground biomass, and surface soil water content. Based on these results, the soil was aggregated in shrub patch and the vegetation pattern was successive and each cycle of vegetation pattern was benefited by its previous stage in the water-wind erosion crisscross region on the Loess Plateau. [ABSTRACT FROM AUTHOR]

Understanding how grazing exclusion affects carbon exchange by the plant and soil features is essential for clarifying the contribution of grassland management to the carbon budget. This paper studied effects of grazing exclusion on soil respiration, ecosystem respiration, net ecosystem carbon exchange, plant and soil characterizes for two growing-seasons (2012 and 2013) in a steppe grassland on the Loess Plateau, China. Grazing exclusion markedly increased soil respiration, ecosystem respiration and net ecosystem exchange about 0.36, 0.65 and −0.10 g C m −2 d −1 , respectively. Grazing exclusion enhanced aboveground biomass, belowground biomass and cover, and which were positive correlated with CO 2 flux. Soil water content, rather than soil temperature, was the major environmental factor controlling soil respiration and ecosystem respiration by partial least-squares regression. The ratios of soil respiration, ecosystem respiration and net ecosystem exchange to atmospheric CO 2 assimilated by photosynthesis at fenced grassland were similarly with them at grazed grassland. Results suggested that grazing exclusion was a positive management practice to help maintain or increase carbon stocks in a steppe grassland on the Loess Plateau. [ABSTRACT FROM AUTHOR]