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[Objective] The effects of different long-term vegetation restoration types on differences of soil surface infiltration and water storage in the loess gully region of Western Shanxi Province were studied in order to screen and enhance the ecological benefits of natural vegetation restoration as well as artificial vegetation restoration in Loess Plateau in the future, thereby providing a scientific reference for an in-depth understanding of the ecological benefits of vegetation restoration. [Methods] We measured infiltration in the top 30 cm of soil under four types of restored vegetation (Pinus tabulaeformis pure forest, Robinia pseudoacacia pure forest, Platycladus orientalis pure forest, natural forest). We also measured soil physical and chemical properties such as soil bulk density and mechanical composition, and monitored soil moisture dynamics in the four types of restored vegetation in the loess hilly-gully region. We calculated soil water storage and analyzed differences due to vegetation type, and conducted correlation analysis and principal component analysis. Three soil infiltration models were then fitted to the measured processes in order to compare their suitability for use in vegetation restoration areas of the loess hilly-gully region. Differences in soil infiltration and water storage between different vegetation restoration types were also determined. We also evaluated the ability of the models to supplement and improve the surface soil water infiltration pattern under different vegetation restoration types in the Loess Plateau region. [Results] ① Natural forest was more effective in improving the physical properties of the 0—30 cm surface soil compared with pure planted forests. Natural forest had greater water content and better water retention, and planted forests were more effective in improving the infiltration capacity of the soil in the study area compared with natural forest. ② The stable infiltration rate of soil under different vegetation types from largest to smallest followed the order of natural forest > Robinia pseudoacacia pure forest > Pinus tabulaeformis pure forest > Platycladus orientalis pure forest (for the 0—10 cm layer); Pinus tabulaeformis pure forest > Robinia pseudoacacia pure forest > Platycladus orientalis pure forest > natural forest (for the 10—20 cm layer); Pinus tabulaeformis pure forest > Robinia pseudoacacia pure forest > Platycladus orientalis pure forest > natural forest (for the 20—30 cm layer); ③ The Horton model performed better than the Kostiakov and Philip models in fitting soil infiltration in the study area (R2=0.94), and will be helpful in better understanding the soil infiltration pattern in the study area. ④ The main physical characteristics affecting soil infiltration rate were soil bulk density, soil organic carbon, soil water storage capacity and soil clay particle content. [Conclusion] There were significant differences in soil infiltration properties due to different long-term vegetation restoration types. Compared with long-term replanted forests, the long-term natural forest had greater vegetation restoration benefits, and could effectively improve soil quality and enhance soil water retention capacity for the Loess Plateau.

Large-scale vegetation restoration has been performed to improve the fragile ecological environment of the Loess Plateau in the last decades. At present, the effects and mechanism of long-term vegetation restoration on soil properties in ecosystems require further exploration to provide a reference for rational ecological construction. Hence, we investigated the differences in vegetation attributes and soil properties between three typical vegetation types (Pinus tabulaeformis plantation forest, PTPF; Robinia pseudoacacia plantation forest, RPPF; natural secondary forest, NSF) after long-term (30–40 years) vegetation restoration in the western Loess Region, China. Our results showed that (1) the arborous synusia biomass of the plantation forests was twice that of NSF, whereas NSF had almost 50% higher near-surface synusia biomass than the plantation forests; (2) the soil nutrient contents of the plantation forests were lower (30%) than those of NSF; (3) the soil bulk density, organic matter, total nitrogen, and phosphorus were positively related to arborous and shrub synusia biomass; (4) the coupling effects of four biological synusiae (with the contribution of 47.67%) were the dominant factors affecting soil physicochemical properties. Natural forests have the better vegetation attributes and soil properties than plantation forests, indicating that the close-to-nature restoration should be considered in ecological restoration. These findings can provide scientific support and theoretical basis for reforestation and ecological restoration in the Loess Plateau region and similar areas in the future.

Aquatic vegetation of different heights is widely scattered in natural rivers and is conducive to their environmental function while affecting the flow hydrodynamic conditions. A semi-analytical velocity model is constructed and used to study the longitudinal velocity profile in open channel flow through double-layered rigid vegetation. The double-layered vegetation flow is separated into three zones according to the velocity profile: 1) nearly uniform distributed velocity zone 1A in the lower region of the short vegetation layer, 2) a mixing layer zone B, 3) uniform distributed velocity zone 2A in the upper region of the tall vegetation layer. Two force equilibrium equations about the gravity-driving and vegetation drag are solved to obtain the uniform velocity distribution equations in zone 1A and 2A. The velocity of zone 1A and B is further modeled as a linear superposition of two concepts: the uniform velocity distribution term of zone 1A and a hyperbolic tangent profile. Meanwhile, longitudinal velocity and the lateral vorticity profiles of open channel flow through double-layered rigid vegetation are studied by laboratory flume tests of different vegetation arrangements exposed to two water depths and three slopes. The experimental results show that the longitudinal velocity increases with the slope increase. The verification of the velocity model is based on the instantaneous velocity measured by Acoustic Doppler Velocimetry (ADV), which shows acceptable agreement, indicating that the model can give a reference to the longitudinal velocity of multi-layered vegetation flow in some cases. The effects of wake vortices and boundary friction on the model are further explored in the discussions. The results presented in this study could contribute to the management of aquatic vegetation configurations and the restoration of freshwater ecology.

In the dryland and degraded regions, soil moisture is the primary factor determining ecological restoration. Proper land preparations and vegetation restoration can improve soil moisture and benefit land restoration. Identifying their effects on soil moisture is thus essential for developing suitable management strategies. In this study, four typical land preparation techniques (level ditches, fish-scale pits, zig terraces, and level benches) and non-native vegetation types (Prunus armeniaca, Platycladus orientalis, Pinus tabulaeformis, and Caragana microphylla) were planted on a semiarid loess hilly catchment, China. Soil moisture was monitored by a time-domain reflectometer, and its spatial-temporal variations were analyzed during the 2014-2015 growing seasons. The following results were captured. (a) Soil moisture was highest for the combination of P. orientalis and fish-scale pits (P. orientalis/fish-scale pits, 10.37%), followed by P. armeniaca/level ditches (10.23%), P. orientalis/zig terraces (9.67%), C. microphylla/level benches (8.62%), P. tabulaeformis/fish-scale pits (8.05%), and P. tabulaeformis/zig terraces (7.72%). (b) Fish-scale pits offered a better rainwater-harvesting capacity during the rainy months, whereas zig terraces had a higher water retention capacity under extremely dry conditions (as indicated by the temporal soil moisture variation and soil water retention curves). (c) P. tabulaeformis consumed more water than other vegetation types (26.7% lower than that of P. orientalis). (d) Soil moisture in shallower layers (0-80 cm) was more affected by land preparations and was more effected by vegetation types in deeper soil layers (80-180 cm). We thus suggest that fish-scale pits may be a better choice in wetter regions whereas zig terraces and P. orientalis are more suitable in the driest parts of the Loess Plateau to restore the fragile ecosystems. [ABSTRACT FROM AUTHOR]

Farmland shelterbelt system (FSS) in oasis desert ecotones can effectively improve ecosystem services, especially in fragile agricultural areas. However, the spatial-temporal heterogeneity of its ecological effects still needs further clarity, because the interactions are complex and multiple. Understanding this allows us to know the key practical significance of ecological construction and agricultural management. In this study, four typical patterns of FSS (i.e. two lines pattern, TWLP; four lines pattern, FOLP; five lines pattern, FILP; eight lines pattern, EILP) were selected in a desert oasis ecotone in northern China to assess the distributions at vertical (0–100 cm), horizontal (0–3 H) and temporal (May- October) scales of soil properties, vegetation attributes, microclimates and variations of soil moisture storage (SMS) and soil salt contents (C) during the three growing seasons. The results showed that the major difference in soil properties and vegetation attributes of FSSs are the soil particle composition and canopy size, respectively. In FOLP and EILP, the silt contents were 51.6% and 41.5% respectively. The canopy size ranked from the highest to lowest values as follows: FOLP (8.70 m2) > EILP (6.91 m2) > TWLP (4.64 m2) > FILP (4.47 m2). Compared to the control, all patterns of FSSs registered significant effects on microclimate improvement. The FOLP and FILP achieved the same effects as well as EILP, with less spatial costs. Moreover, the variations of SMS and C were mainly different at the vertical scale. As indicated by the Redundancy (RDA) and variation partitioning (VP) analyses, soil properties played a more important role in reserving soil water and controlling soil salinity than vegetation attributes and microclimates, which the independent influence can explain 48.5% of total influence among all factors. Our results provide an efficient theoretical basis for FSS construction and agricultural water management practices. • Farmland shelterbelt system (FSS) can improve ecosystem services. • A spatio-temporal heterogeneity of ecosystem functions in FSSs is observed. • Soil properties play a more important role in controlling soil water content and salinity. • Results provide an efficient theoretical basis for agricultural water management in deserts. [ABSTRACT FROM AUTHOR]

A new method is proposed to establish the statistical fractal model for liver diseases classification. Firstly, the fractal theory is used to construct the high-order tensor, and then Generalized N-dimensional Principal Component Analysis (GND-PCA) is used to establish the statistical fractal model and select the feature from the region of liver; at the same time different features have different weights, and finally, Support Vector Machine Optimized Ant Colony (ACO-SVM) algorithm is used to establish the classifier for the recognition of liver disease. In order to verify the effectiveness of the proposed method, PCA eigenface method and normal SVM method are chosen as the contrast methods. The experimental results show that the proposed method can reconstruct liver volume better and improve the classification accuracy of liver diseases. [ABSTRACT FROM AUTHOR]