Responses of soil moisture to vegetation restoration type and slope length on the loess hillslope

Soil moisture, a critical variable in the hydrologic cycle, is highly influenced by vegetation restoration type. However, the relationship between spatial variation of soil moisture, vegetation restoration type and slope length is controversial. Therefore, soil moisture across soil layers (0-400 cm depth) was measured before and after the rainy season in severe drought (2015) and normal hydrological year (2016) in three vegetation restoration areas (artificial forestland, natural forestland and grassland), on the hillslopes of the Caijiachuan Catchment in the Loess area, China. The results showed that artificial forestland had the lowest soil moisture and most severe water deficit in 100-200 cm soil layers. Water depletion was higher in artificial and natural forestlands than in natural grassland. Moreover, soil moisture in the shallow soil layers (0-100 cm) under the three vegetation restoration types did not significantly vary with slope length, but a significant increase with slope length was observed in deep soil layers (below 100 cm). In 2015, a severe drought hydrological year, higher water depletion was observed at lower slope positions under three vegetation restoration types due to higher transpiration and evapotranspiration and unlikely recharge from upslope runoff. However, in 2016, a normal hydrological year, there was lower water depletion, even infiltration recharge at lower slope positions, indicating receiving a large amount of water from upslope. Vegetation restoration type, precipitation, slope length and soil depth during a rainy season, in descending order of influence, had significant effects on soil moisture. Generally, natural grassland is more beneficial for vegetation restoration than natural and artificial forestlands, and the results can provide useful information for understanding hydrological processes and improving vegetation restoration practices on the Loess Plateau     

Optimum temperature for the growth performance of juvenile orange-spotted grouper （Epinephelus coioides H.）

Effects of water temperature （17, 21, 25, 30 and 35℃） and body size （14.75-281.41 g initial body weight） on food consumption, growth, feed conversion, and dry matter content in orange-spotted grouper fed to satiation were investigated. The combined effect of temperature （T, ℃） and body weight （W, g） on maximum food consumption （Cmax, g/day） was described as： InCmax=-7.411＋0.828 InW＋0.317T4）.004 7T2, and the optimum feeding temperature was 33.9℃. The combined effect of temperature and body weight on growth （G） was described as： lnG=-4.461-0.2081nW＋0.394T-0.006 3T^2. The optimum growth temperature was 31.4℃, whereas overall growth rates were high at 25, 30 and 35 ℃. Feed conversion efficiencies （FCE, %）, increasing first and then decreasing with increasing temperature, averaged from 1.8 to 2.1 in terms of dry weight of food fish. The optimum temperature for FCE tended to be lower than that for growth or feeding. Dry matter content increased with both increasing water temperature （17, 25, 30 and 35℃） and body weight, and the combined effect of temperature and body weight on dry matter content （DM, %） was described as： lnDM =3.232＋0.01 4 lnW-0.004 4T＋0.001 2TInW.     

Biodegradation of <Emphasis Type="Italic">Enteromorpha</Emphasis> polysaccharides by intestinal micro-community from <Emphasis Type="Italic">Siganus oramin</Emphasis>

Micro-communities are supposed to have more potential functions of biodegradation of polysaccharides than single strain; however, the intestinal micro-communities involved in the biodegradation of Enteromorpha polysaccharides (EP) were seldom reported. In order to obtain the EP-degrading micro-community, the intestines of Siganus oramin was obtained to isolate the micro-communities, which were enriched by 0.3% of EP as the sole carbon source. A stable micro-community with EP degradative capability was achieved after seven generations of subculture, named H1. Results showed that H1 was able to degrade 75% of EP within 24 hours, and the activity of EP lyases reached 500 U mL^?1 in 32 hours. With denaturing gradient gel electrophoresis (DGGE) and 16S rRNA gene clone library analysis, ten bacteria closely related to Marinomonas pontica, Microbacterium sp., Leucobacter chironomi, Cyclobacterium sp., Algoriphagus winogradskyi, Pseudoalteromonas sp. and Vibrio sp. were determined. Furthermore, compared with the DGGE bands sequence and the clone library analysis, the dominant bacteria of the EP-biodegrading micro- community were Pseudoalteromonas sp. and Vibrio sp., with the respective proportion of 38% and 46%, and they should play an important role in EP degradation together with other degrading bacteria in the micro-community H1.     

广州城市居民地方依恋测度与机理

“地方依恋”问题涉及地理学、心理学、社会学、城市学等多个学科,已经成为中国快速城市化时期亟待解决的重要问题。伴随大城市内部空间的剧烈重构,城市居民对其居住空间的地方依恋也在不断变化,需要进行深入研究。本文选取广州23个典型社区,通过量表测度居民的地方依恋,并采用结构方程模型等计量方法,探索社区信任、社区满意度等要素对居民地方依恋的作用机理。同时,系统对比了居民对于不同空间尺度的地方依恋,如社区尺度和城市尺度,并对本地居民和外来移民两组人群的地方依恋及其差异进行了系统研究。研究发现：① 城市居民的社区依恋程度高于城市依恋程度;② 本地居民的社区依恋和城市依恋程度均明显高于外来移民;③ 城市居民的社区依恋同时受到社区信任和社区满意度的直接影响,但两者需通过社区依恋的中介效应间接影响居民的城市依恋;④ 社区信任与社区满意度对外来移民的社区依恋和城市依恋均具有显著作用,但对本地居民的城市依恋作用较弱。基于实证结果,本文认为,相同因素对于不同尺度的地方依恋作用机理存在差异,不同人群的地方依恋机理亦有不同,地方依恋同时具有尺度差异性和群体差异性。     

新疆和田河流域柽柳沙堆的生物地貌发育过程

Tamarix nabkha is one of the most widespread nabkhas,distributing in the arid region of China.Based on the observations outdoors and the simulation experiments in laboratories,analysis in this paper refers to the biological geomorphologic features and growth process of Tamarix nabkhas in the middle and lower reaches of the Hotan River,Xin- jiang.And the results indicate that the ecological type of Tamarix in the study area is a kind of Tugaic soil habitat based on the deep soil of the Populus Diversifolia f...     

Aluminum Consumption and Economic Growth: Evidence from Rich Countries

The article attempts to test the aluminum consumption–economic growth nexus for 20 rich economies for the period 1970–2009. Various panel data unit root and cointegration tests are applied. The series are found to be integrated of order one and cointegrated, especially after controlling for cross-sectional dependence. Moreover, the Blundell–Bond system generalized methods-of-moments is employed to conduct a panel causality test in a vector error-correction mechanism setting. Unidirectional causality running from aluminum consumption to real GDP is uncovered in the short-run, while real GDP is found to Granger-cause aluminum consumption in the long-run. Moreover, a 1% increase in real GDP generates an increase of 0.44% in aluminum consumption in the long-run for the whole panel.     

Automatic mapping of lunar landforms using DEM-derived geomorphometric parameters

Developing approaches to automate the analysis of the massive amounts of data sent back from the Moon will generate significant benefits for the field of lunar geomorphology. In this paper, we outline an automated method for mapping lunar landforms that is based on digital terrain analysis. An iterative self-organizing (ISO) cluster unsupervised classification enables the automatic mapping of landforms via a series of input raster bands that utilize six geomorphometric parameters. These parameters divide landforms into a number of spatially extended, topographically homogeneous segments that exhibit similar terrain attributes and neighborhood properties. To illustrate the applicability of our approach, we apply it to three representative test sites on the Moon, automatically presenting our results as a thematic landform map. We also quantitatively evaluated this approach using a series of confusion matrices, achieving overall accuracies as high as 83.34% and Kappa coefficients (K) as high as 0.77. An immediate version of our algorithm can also be applied for automatically mapping large-scale lunar landforms and for the quantitative comparison of lunar surface morphologies.     

树轮稳定同位素记录:进展、问题及展望

树轮稳定同位素比率(δ13 C、δ18O 和δD)变化与树木生长季的气候和环境条件密切相关。控制实验表明, 树轮稳定同位素比率变化可较好地记录树木叶片气孔活动、水分来源、水分利用效率等相关信息, 已成为古气候和全球变化生态学研究的重要代用指标和手段之一。树轮稳定同位素记录能够较好地保留低频气候环境变化信息, 与年轮宽度相结合, 可有效地进行区域古气候重建和全球变化生态学方面的研究。文章综述了树轮稳定同位素的分馏机理及其发展, 系统阐述和评价了利用树轮稳定同位素指标进行古气候和古环境的相关研究成果, 并指出树轮稳定同位素研究在中国未来亟须着重发展的方向。     

Automated mapping of rock slope geometry,kinematics and stability with RSS-GIS

A GIS-implemented, deterministic approach for the automated spatial evaluation of geometrical and kinematical properties of rock slope terrains is presented. Based on spatially distributed directional information on planar geological fabrics and DEM-derived topographic attribute data, the internal geometry of rock slopes can be characterized on a grid cell basis. For such computations, different approaches for the analysis and regionalization of available structural directional information applicable in specific tectonic settings are demonstrated and implemented in a GIS environment. Simple kinematical testing procedures based on feasibility criteria can be conducted on a pixel basis to determine which failure mechanisms are likely to occur at particular terrain locations. In combination with hydraulic and strength data on geological discontinuities, scenario-based rock slope stability evaluations can be performed. For conceptual investigations on rock slope failure processes, a GIS-based specification tool for a 2-D distinct element code (UDEC) was designed to operate with the GIS-encoded spatially distributed rock slope data. The concepts of the proposed methodology for rock slope hazard assessments are demonstrated at three different test sites in Germany.     

基于J2EE的分布式WebGIS研究

在对比分析传统的WebGIS各种实现模式优缺点的基础上，探讨了利用企业级J2EE技术实现分布式WebGIS的解决方案，使WebGIS更好地满足企业级应用的需要。