Soil water is the limiting factor that determines ecosystem development in arid and semi-arid regions. Thus, determining the relationships between soil water and vegetation can inform the restoration of vegetation and water resource management. However, these relationships have not been fully investigated at the regional scale. In this study, field observations were conducted in two typical vegetation zones of the Loess Plateau of China: forest-steppe and semi-arid steppe zones. Variation in soil water content (SWC) and vegetation characteristics (plant density and species richness) in addition to their correlations were analyzed in grasslands and forestlands (occupied by black locust) in each zone. SWC, plant density, and species richness in the forest-steppe zone were significantly higher than those in the semi-arid steppe zone (p < 0.01). Plant density and species richness were positively correlated with SWC in both zones (all the correlation coefficients were higher than 0.7). Thus, higher soil water resources could support more plants of varied vegetation types. Moreover, plant density and richness could be important indices that reflect soil water vegetation carrying capacity at the regional scale. SWC, plant density, and species richness of the forestlands all significantly decreased in the two zones, indicating that continuous loss of soil water may lead to the degradation of afforestation. Notably, these trends all exhibited increasing trends in grasslands as restoration length increased in the forest-steppe zone, but exhibited decreasing trends in grasslands of the semi-arid steppe zone. Consequently, grasslands may be a more sustainable ecosystem type in this region. Taken together, these results indicate that both vegetation types and plant density should be taken into consideration when planning vegetation restoration in arid and semi-arid regions in order to promote long-term soil water conservation.

土壤水分是黄土高原植被恢复的主要限制因子,退耕还林工程在恢复生态环境的同时也造成了区域土壤含水量下降和土壤干燥程度的加剧,土壤干燥化正日益威胁到土壤水资源的持续利用和人工植被建设的成效。选取黄土高原退耕还林试点县吴起境内刺槐、杏树、柠条和沙棘4种分布广泛的退耕植被类型,对照撂荒草地,分析了不同林龄和不同植被类型样地0—500cm的土壤水分特征和土壤干燥化效应,并根据作物耗水量估算土壤干层水分的恢复时间。结果表明:不同退耕还林植被类型样地土壤含水量由表层向深层呈降低趋势,随林龄增加,各植被类型样地土壤含水量、有效储水量逐渐减少。刺槐林土壤含水量较同龄沙棘和柠条林低,而杏树林则较同龄柠条林高。各植被类型样地土壤剖面均不含渗透重力水与极易效水层,随林龄增加,土壤相对湿度及易效水土层厚度占比逐渐减少,中效水、难效—无效水土层厚度逐渐增加。随林龄和土层深度的增加,各植被类型样地土壤干燥化强度、土壤干层厚度逐渐增加,土壤湿度恢复到土壤稳定湿度所需要的时间及难度呈上升趋势。

在黄土高原大规模退耕还林(草)背景下,土地利用变化对土壤水分及其时空结构会产生极大影响.以坡面为研究对象,根据两种植被恢复类型(撂荒草地和人工刺槐林地)土壤水分坡面变化趋势的差异,探究不同植被恢复方式对土壤水分坡面空间结构影响.结果表明:所调查的两个区域(延安羊圈沟和长武烧盅湾)皆表现为人工刺槐林地坡平均土壤含水量显著低于撂荒草地坡;且人工刺槐林地坡的土壤水分的坡面差异性皆比撂荒草地坡低.虽然两种恢复类型的土壤水分沿坡底到坡顶皆呈现降低的趋势,但是该降低趋势在两种恢复类型间存在一定差异:撂荒草地坡土壤水分沿坡面的变化趋势随深度增加有加强的趋势,且总体上,长武烧盅湾撂荒草地坡土壤水分沿坡面变化趋势比延安羊圈沟更明显;相比之下,人工刺槐林地坡土壤水分沿坡面的变化趋势随深度增加有变弱的趋势,且该趋势明显比撂荒草地坡弱;两个地区刺槐林地坡土壤水分沿坡面变化趋势不存在明显差异.综上所述,虽然不同降雨背景下土壤水分会表现出一定差异,但土壤水分的坡面变化趋势及不同恢复方式对其影响是相似的,即人工刺槐林地坡对土壤水分的过度消耗不仅会导致土壤水分亏缺,而且削弱了土壤水分的坡面变化趋势;而撂荒草地对土壤水分及其空间结构的维持有相对积极的意义.通过分析不同植被恢复方式对土壤水分坡面变化趋势的影响,能够更深入的了解不同植被恢复方式的土壤水文效应,同时可为以坡面为单元的退耕还林中植被科学配置提供一定的参考.

Land-use/vegetation is an essential variable on controlling the heterogeneities and distribution pattern of soil water content (SWC). Along with large-scale re-vegetation in arid and semi-arid areas, the variations of SWC ascribed to the land-use conversion have been considered as an important factor to assess the re-vegetation efforts. In this study, soil water data at the depth of 0-300 cm were obtained by field observation in two eco-hydrologic zones in Loess Plateau of China. The mean annual precipitation was 350-400 mm (zone-A) and 500-550 mm (zone-B), respectively. The differences in SWC were analyzed among different land-use types; and the SWC in different restoration years was also discussed using the method of space replacing time. Results indicated that (1) the differences in SWC between the two zones were lower in re-vegetated lands (2.76%, forestland and 4.22%, for shrub land) than in abandoned farmland (5.85%). The differences in re-vegetated lands diminished gradually as the soil depth (0-300cm) increased, whereas the abandoned farmland represented an opposite trend. (2) Although the variation trends of SWC in abandoned farmland of the two zones were different as the restoration years increased, the differences in SWC between abandoned farmland and native grassland both diminished gradually. This meant the soil water deficit relative to native grassland would be alleviated as the progress of abandoned farmland. (3) As the restoration years increased, the differences in SWC between re-vegetated lands and native grassland increased gradually because of the continuous decrease of SWC in re-vegetated lands. The consequence will be that the soil water deficit in the re-vegetation lands is aggravated continually. From the perspective of soil water restoration and conservation in semi-arid areas, the abandoned farmland should be a more reasonable method than re-vegetated lands covered with introduced plants. (C) 2017 Elsevier B.V. All rights reserved.

This study was conducted in the semi-arid the Loess Plateau of China.On the basis of the differences in soil water content due to different slope aspects,the dynamic characteristic of soil water content in an abandoned farmland and artificial forestland with an increase in restoration years was analyzed,and on the basis of the amount of soil water in a native grassland,the soil water deficit in the artificial forestland on different slope aspects was also analyzed.Overall,thesoil water content in the shady slope was significantly higher than that in the sunny slope;the difference in soil water content between the two slope aspects was 3.1％ for the abandoned farmland;2.6％,native grassland;and 1.5％,artificial forestland.Therefore,the excessive consumption of the artificial forestland with respect to soil water diminished the difference in soil water due to the different slope aspects.The soil water content of the abandoned farmland presented a significantly increasing trend with an increase in restoration years,and the degree of increase would also increase with the increase in restoration years.However,in the artificial forestland,a decreasing trend was observed;for the sunny slope,the degree of decrease in soil water content would decrease with an increase in restoration years at the layers of 0-1 n and 1-2 m;however,the degree of decrease in soil water content at the layers of 2-3 m and 3-4 m would increase with an increase in restoration years,and that was contrary at the shady slope.The soil water deficit in the artificial forestland presented an enhanced trend with the progress of ecological restoration and increase in soil depth.Overall,excepting the layers of 0-1 m,the soil water deficit in the artificial forestland on the sunny slope was lower than that on the shady slope.

为筛选乌鲁木齐松树头煤田火区植被恢复时的适宜植物种类,采用样方法调查了煤田火区废弃地及周边环境的植物种类、数量、盖度以及频度等指标,分析其在矿区及东、南、西、北4个相邻区域内的分布,计算多样性、优势度.结果表明,研究区共有16科38属43种植物;南区的Margalef指数和Shannon指数最大,Pielou指数最小,均匀性差;西区的Margalef指数和Shannon指数最小,均匀度也比较小;南区与东区之间的β多样性最低,南区与西区之间的β多样性最高,而与矿区相关的β多样性中,西区与矿区之间最小,南区与矿区之间最大.针茅(Stipa capillata)在整个调查范围内分布最广,在南区、东区、矿区,针茅为第一优势种.草原苔草(Carex liparocarpos)在南区、东区、北区、西区都是优势种.黄芪(Astragalus penduliflorus)在南区、东区、西区、矿区均有分布,且优势度较高.通过上述分析,筛选出针茅、黄芪、草原苔草作为煤火废弃地生态恢复的优先植物种,以南区与西区植物群落作为参照标准进行植被恢复.

The way that is matrix materials mixing seed to improve seed growth environment is becoming a method of ecological restoration with convenient construction and high efficiency.Matrix components and combinations are the key in the research.Bonding agent,aquasorb,sheep manure,compound fertilizer,straw and paved thickness were chosen as impact factors,orthogonal experiment was done to design the test scheme,through extreme difference analysis and variance analysis of vegetation index,the schemes of optimization and influence of matrix on index were studied,for the purpose to provide a new way for ecological restoration of Urumqi coal field fire-fighting area.Results indicated that concerning vegetation cover,height and density after 1month,E(straw)is the main influencing factor of the vegetation cover with very significance.B(absorbent agent) is the main influencing factors of height and density with very significance.Concerning biomass,vegetation cover,height and density after 4month,D(compound fertilizer) is the main factors of three biomass indexes and density.E(straw)is the main influence factor of vegetation cover and the height,and B(absorbent agent),D(compound fertilizer),E(straw)and F(paved thickness)have notable effect on vegetation cover and height.According to the majority,economy and the importance of factors on index,the optimal scheme of A 3 B 2 C 5 D 4 E 4 F 3 is chosen on integral balance method.

【Objective】Mountain forest landscape of arid areas has significant heterogeneity of the spatial distribution,and different gradient distribution of landscape features restrict varieties of ecological processes of the landscape.The landscape ecology method was introduced to the quantitative analysis and scientific evaluation of the forest resources,which could provide a new tool of analysis and evaluation for the survey of forest resources.【Method】Based on the classification of forest resource plan design and land inventory,with the landscape ecological theory,by the method of landscape index,the paper analyzed 7 kinds of landscape patterns in Shawan Forest Station using the ArcGIS and Fragstats software.The indicators used to evaluate landscape patterns adopted included mean patch area,mean patch perimeter,patch density,landscape shape index,aggregation index,elevation,slope,aspect and so on.【Result】The results showed that: landscape patterns in Shawan Forest Station were not rich,and the distribution of number of patch in each pattern was uneven.From the area of the patch,forest station was dominated by unused landscape.The coniferous forest landscape(13.95%) and the shrubbery landscape(8.71%) were the main forest landscape type and the main components of forest resources in Shawan forest.And various types of landscape distribution are very uneven because of the impact of terrain.【Conclusion】Based on the classification of forest resource plan design and land inventory,landscape ecology offered actual method to analyze and appraise forest reservation and operation control that is based on type,number,quality and distribution of forest resources.

【Objective】 The purpose of this program is make a contrastive analysis of the transpiration water consumption between Haloxylon persicum and Tamarix elongate in Arid Regions.【Method】Flow4 was used to measure the sap-flow dynamics in outer margin of Karamay Cabe forest during 10-30 of July,2010.The correlation and regression between sap flow velocity and diameter of branch were analyzed.【Result】We found that there was a significant correlation between sap flow velocity and diameter of the branch.The relation can expressed as power function and logarithmic function.The sap flow velocity of Tamarix elongate was greater than Haloxylon persicum's and the sap flow velocity and difference between them bacame smaller with the increase of branch's diameter.【Conclusion】Haloxylon persicum's drought resistance was stronger than Tamarix elongate when diameter of branch ranging from 1.0 to 3.0 cm.The drought resistance became stronger with the development of the plant and reducing the differences between Haloxylon persicum and Tamarix elongate.

The current situation of industrial solid waste and its utilization in Urumqi were introduced.Then the generation and utilization quantity of industrial solid waste during the twelfth Five-Year period was predicted.Concerned with the problems in industrial solid waste utilization,some suggestions were put forward: reduce the industrial solid waste discharge;expand resource-oriented utilization approach;promote industrialization of recycling and comprehensive utilization;strengthen the supervision and management of industrial solid waste,etc.

[Objective and Method]This study adopted Xiegaodi eosystem services value system to assess ecosystem service values from 1986 to 2005 in Qitai oasis and desert criss-cross zone to analyse the change of space time of the landscape pattern in this area.[Result]The results showed that.The functional value of ecosystem service in oasis and desert criss-cross zone in Qitai region were significantly decreased year by year.The trend line slanting rate of service value system in Xiegaodi was-0.100 8.[Conclusion]The probabality transfer matrix was used to analyse the change of ecosystem service values,and the ecological service value came down because of reduce of forest and grassland area.Moreover the area of farm and city was increased,man-made activity interfered landscape pattern of this study which were the main factors causing the devolntion of ecological environment.