Effects of Tamarisk shrub on physicochemical properties of soil in coastal wetland of the Bohai Sea

There are many different and even controversial results concerning the effects of Tamarisk on the physicochemical properties of soil. A year-round monitoring of soil salinity, p H and moisture is conducted beneath the Tamarisk shrub in a coastal wetland in the Bohai Sea in China, to ascertain the effects of Tamarisk on the physicochemical properties of soil in coastal wetland. Compared with the control area, the soil moisture content is lower around the area of the taproot when there is less precipitation in the growing season because of water consumption by Tamarisk shrub. However, the soil moisture content is higher around the taproot when there is more precipitation in the growing season or in the non-growing period because of water conservation by the rhizosphere. The absorption of salt by the Tamarisk shrub reduces the soil salinity temporarily, but eventually salt returns to the soil by the leaching of salt on leaves by rainfall or by fallen leaves. The annual average soil moisture content beneath the Tamarisk shrub is lower than the control area by only 6.4%, indicating that the Tamarisk shrub has little effect on drought or water conservation in soils in the temperate coastal wetland with moderate annual precipitation. The annual average salinity beneath the Tamarisk shrub is 18% greater than that of the control area, indicating that Tamarisk does have an effect of rising soil salinity around Tamarisk shrubs. The soil p H value is as low as 7.3 in summer and as high as 10.2 in winter. The p H of soil near the taproot of the Tamarisk shrubs is one p H unit lower than that in the control area during the growing season. The difference in p H is less different from the control area in the non-growing season, indicating that the Tamarisk shrub does have the effect of reducing the alkalinity of soil in coastal wetland.

宁东鸳鸯湖矿区矿井废水处理工艺设计与利用

红柳矿井下水处理站工艺分预处理与深度处理两大部分,预处理部分包括混凝、沉淀、除油及过滤,深度处理部分包括机械过滤、活性炭过滤、精密过滤、反渗透及消毒。预处理部分处理对象为红柳矿井井下排水,深度处理部分处理对象为经过预处理的红柳矿井、麦垛山矿井井下排水,其中麦垛山矿井井下排水经过麦垛山矿井井下水处理站预处理,水质达到深度处理进水要求(pH:6～9、色度:≤30度、浊度:≤3NTU、悬浮物粒径:<0.3mm、CODcr:≤30mg/L、氨氮:≤10mg/L、石油类:≤1mg/L)后,加压供至本处理站进行深度处理。

Physiological Responses of <i>Tamarix ramosissima</i>to Extreme NaCl Concentrations

Hydrologic alterations of river systems in western North America over the past century have increased soil salinity, contributing to the establishment and spread of an introduced halophytic species, Tamarix ramosissima (Ledeb.). The physiological responses of Tamarix ramosissima to salinity stress are incompletely known. To assess the salinity tolerance of this species, we measured several whole plant and leaf-level physiological responses of Tamarix ramosissima cuttings grown in a controlled environment over three NaCl concentrations (0, 15 and 40 g l-1). Tamarix ramosissima photosynthesis (A2000), stomatal conductance to water (gs), water potential (Ψw), and the maximum quantum yield of photosystem II (Fv/Fm) decreased at 15 and 40 g l-1 NaCl compared to control treatments. However, after approximately 35 days, Tamarix ramosissima had increased photosynthetic rates, maximum quantum yield of photosystem II, and stomatal conductance to water. These data suggests that physiological functioning of Tamarix ramosissima acclimated to extremely high NaCl concentrations over a relatively short period of time. Additionally, we present preliminary evidence that suggests proline synthesis may be the mechanism by which this species adjusts osmotically to increasing salinity.

Erosion-Resistant Surfaces Inspired by Tamarisk

Tamarisk, a plant that thrives in arid and semi-arid regions, has adapted to blustery conditions by evolving extremely ef- fective and robust anti-erosion surface patterns. However, the details of these unique properties and their structural basis are still unexplored. In this paper, we demonstrate that the tamarisk surface only suffers minor scratches under wind-sand mixture erosion. The results show that the anti-erosion property of bionic sample, inspired by tamarisk surface with different surface morphologies, can be attributed to the flow rotating in the grooves that reduces the particle impact speed. Furthermore, the simulation and experiment on the erosion wear behavior of the bionic samples and bionic centrifugal fan blades show that the bionic surface with V-type groove exhibits the best erosion resistance. The bionic surface on centrifugal fan blades with opti- mum parameters can effectively improve anti-erosion property by 28.97%. This paper show more opportunities for bionic application in improving the anti-erosion performance of moving parts that work under dirt and sand particle environment, such as helicopter rotor blades, airplane propellers, rocket motor nozzles, and pipes that regularly wear out from erosion.

Using SPOT 5 fusion-ready imagery to detect Chinese tamarisk(saltcedar)with mathematical morphological method

Chinese tamarisk(saltcedar)is a deciduous shrub that occurs widely across the Yellow River Delta in China.The spatial structure of Chinese tamarisk is believed to have an influence on the landscape and habitats of rare birds.In this study,first,Chinese tamarisk is detected using Canny edge detector and mathematical morphological operators based on SPOT 5 fusion-ready imagery.Then the numbers,areas,locations,and patch spacing of Chinese tamarisk patches are calculated.The experiments show that the detection accuracy of Chinese tamarisk patches is about 93.4%after the disconnection of connected patches.The distribution orientation of about 70%of the patches is approximately south-north.About 91%of the minimum distances among the patches are between 12.5 and 57.5 m.The rose graph indicates that the main azimuth between patches is north--northwest,and the second is northeast and southeast.The present study indicates that the integrating Canny edge detector with the algorithms for extracting circular and elliptical objects based on mathematical morphology is simple and effective for detecting Chinese tamarisk patches and is easy to identify the spatial structure of Chinese tamarisk patches,which reduces the time and labor for the visual interpretation of Chinese tamarisk patches.

Lake Level Changes Recorded by Tree Rings of Lakeshore Shrubs： A Case Study at the Lake West-Juyan, Inner Mongolia, China

Variation in water resources is a main factor influencing ecohydrological processes and sustainable development in arid regions. Lake level changes are a useful indicator of the variability in water resources. However, observational records of changes in lake levels are usually too short to give an understanding of the long-term variability. In the present study, we investigated the tree rings of shrubs growing on the lakeshore of Lake West-Juyan, the terminus of the Heihe River in western China, and found that Lake West-Juyan had undergone degradation three times over the past 200 years. The lake level decreased from 904.3 to 896.8 m above sea level （a.s.1.） during the period 1800-1900, to 892.0 m a.s.1, from around 1900 to the late 1950s, and the lake dried out in 1963. The trend for changes in lake levels, which was represented by the composite chronology of three beach bars, showed that the phases of increasing lake levels over the past 150 years were during the periods 1852-1871, 1932-1952, 1973-1982, and 1995-1999. Comparison with the history of regional economic development showed that human activity has played an important role in regulating the water resources of the lower reaches of the Heihe watershed over the past 200 years.