Haloxylon Research Articles

古尔班通古特沙漠南缘梭梭(Haloxylon ammodendron)群落能量平衡及蒸散特征

梭梭是北方荒漠区重要的固沙植物，具有较强的荒漠环境适应能力。研究梭梭群落能量及蒸散变化对科学管理水资源、保护与建设生态植被等有重大意义。基于波文比自动观测系统在古尔班通古特沙漠南缘丘间地实时连续测定的2018年气象和能量数据，运用波文比-能量平衡法对梭梭群落能量平衡和蒸散特征进行了分析。结果表明：梭梭生长季（4-10月）太阳净辐射和土壤热通量的日变化呈单峰状分布，净辐射通量最高值出现在13：30左右，土壤热通量最大值出现时间比净辐射推迟2 h，波文比在梭梭生长旺盛期全天变化稳定，萌发期和枯落期白天变化较小，夜间波动较大，湍流通量以显热通量为主；在晴天和阴雨天条件下，梭梭生长旺盛期的日蒸散量均明显大于萌发期和枯落期，且日蒸散量在旺盛期呈双峰型，萌发期和枯落期呈单峰型；2018年梭梭生长季蒸散量为279.67 mm，日均蒸散强度1.31 mm/d，梭梭群落的蒸散受到气象、自身生长特性以及土壤水分的影响，4月蒸散强度开始逐渐增大，由于多阴雨天气导致6月的蒸散强度有所降低，7月达到最大，9-10月水分、温度等条件缺乏，梭梭生理活动微弱，蒸散强度急剧减小。

Seasonal variation of the stem sap flow of artificial Haloxylon ammodendron (C.A.Mey.) Bunge and its relationship with meteorological factors in Ulan Buh Desert

Seasonal variation of the stem sap flow of artificial Haloxylon ammodendron (C.A.Mey.) Bunge and its relationship with meteorological factors in Ulan Buh Desert

The establishment and development of Haloxylon ammodendron promotes salt accumulation in surface soil of arid sandy land

The establishment and development of Haloxylon ammodendron promotes salt accumulation in surface soil of arid sandy land

Cluster analysis of the Haloxylon ammodendron communities in Junnger Basin

Haloxylon ammodendron was the most important dominant plant in Junnger basin.On the basis of investigation results of typical Haloxylon ammodendron communities,the classification of these communities was carried on according to the similarity among communities by using numerical cluster.The results suggested that all 37 communities were included in 11 plant associations.According to the results of cluster analysis,11 plant associations were included in 5 formations.The results of classification analysis were basically consistent with the traditional classification of Haloxylon ammodendron communities.The researching results was meaning for protection and restoration of Haloxylon ammodendron community in the future.

Research on the Spectral Characteristic of Typical Vegetation in Desert-Oasis Crisscross Zone

Vegetations in desert play key a role in protecting eco-environment, especially in desert-oasis crisscross zone. Vegetations are of great significance in soil conservation and improving the shear resistance of land. Therefore, they can help to prevent soil from wind erosion and keep land from desertification. Analyzing the spectral data of typical vegetation in desert-oasis crisscross zone by using the hyper spectral technology can be a guidance for remote sensing vegetation classification and serve as the basis for remote vegetation monitoring. In our research, four kinds of typical vegetations have been selected: cotton, tamarix chinensis, Haloxylon ammodendron and Halostachys caspica. The researcher collected series of spectral data of different typical vegetations under different conditions with the help of Field Spec 4 high resolution spectrometer. The collected data was classified, flitted and synthesized with two kinds of transform methods: FDR (First Order Derivative Reflectance) and RLR (Reciprocal Logarithmic Reflectance) transformation. And then three kinds of data were used in further research to analyze the sensitive spectrum band and expression of different vegetation. The result shows that the spectral curve of different vegetations show the same changing trend; different vegetation show different expression in “red edge” with the near infrared band of 780~1 260 nm. The visible light absorption of vegetation is very strong, and the difference of absorption extent causes peaks and troughs. The “red edge” characteristic is unique, which will carry the proper information of certain vegetation, and the result of different kinds of transformation show that FDR can express the red edge characteristic much better than other ways. At last, three ways were used to calculate NDVI, using the original spectral data, transforming spectral data with FDR and transforming spectral data with RLR. Result shows that the NDVI , which calculated by RLR can help to distinguish the type of vegetation with higher accuracy is.

POWDERY MILDEW CAUSED BY LEVEILLULA SAXAOULI ON ILJINIA REGELII IN THE GURBANTUNGGUT DESERT OF XINJIANG

Iljinia regelii (Bunge) Korov., family Chenopodiaceae, one of the most important stabilizers of sand dunes for the control of desertification only occurs in the desert area of Central Asia (Zhu et al., 2003). In summer 2014, severe outbreaks of a previously unknown powdery mildew were observed in the Gurbantunggut desert in Xinjiang (China). The upper surface of leaves and stems was covered with a white mycelium. In severe infections, distortion of the leaves was observed. Conidia were single, dumbbell-like, cylindrical with cingulum-like rings near the apex and base, 41-63×16-25 μm in size. Chasmothecia 158-239 μm in diameter were scattered or gregarious, often immersed in mycelium patches, had appendages mostly poorly developed, mycelioid, simple or irregularly branched, 40-148 μm long. Asci were numerous (10 to 32), ellipsoid-obovoid, saccate-clavate, 80-112×30-49 μm in size, stalked and contained two ellipsoid-ovoid, colourless ascospores measuring 23-41×14-27 μm. These morphological characters were consistent with those of Leivellula saxaouli (Braun and Cook, 2012). To confirm the identification, the internal transcribed spacer (ITS) rDNA was amplified and sequenced, and deposited in GenBank (accession No. KP345898). Comparison with sequences available in database revealed that the ITS sequence shares 99% similarity with that of L. saxaouli recorded in Haloxylon sp. from Iran (accession No. AB044382.1) (Khodaparast et al., 2001). Based on the host, morphology, and ITS sequence analysis, the fungus was identified as L. saxaouli. To our knowledge, this is the first report of L. saxaouli causing powdery mildew on Iljinia regelii. The presence of L. saxaouli on I. regelii could pose a potential threat to the fragile ecological systems of desert areas of Xinjiang, China.

Galling insects associated with Haloxylon spp. (Bunge) in Abu Dhabi, United Arab Emirates

This article introduces the arthropods that induce galls or are associated with galls in two plant species (Haloxylon persicum and Haloxylon salicornicum) in the Emirate of Abu Dhabi, United Arab Emirates. In connection with a baseline survey conducted to establish species knowledge to assess the habitat and diversity of the flora and fauna in proposed Houbara bustard (Chlamydotis (undulata) macqueeni) release sites of the Western Region of Abu Dhabi, Emirate. The galls were collected and studied to understand the gall-associated arthropods. In the current observation, four different types of galls were observed from stem and leaf portion of the two plant species: Swollen galls and flower-like galls from H. persicum; flower-like galls and spike-like galls from leaves and stem of H. salicornicum. In the present study, we have additionally observed arthropods associated with plant galls from both species ofHaloxylon (gall-associated species). No attempts were made to classify them into further categories like gall inducers or parasitoids of gall-inhabiting insects. The taxon observed in the current study belong to different arthropod groups: 1) Arachnids: Acari and Araneae; 2) insect orders like Hymenoptera: Pteromalidae, Thysanoptera: Thripidae, Hemiptera: Psyllidae, Pseudococcidae, Diptera and Lepidoptera: Pyralidae. Key words: Biodiversity, Haloxylon persicum, Haloxylon salicornicum, gall inducers, inquilines, gall associates, Western Region.

Phytochemical screening and insecticidal activity of three plants from Chenopodiaceae family

Natural insecticides have been used for pest control, offering an effective alternative to synthetic pesticides. The insecticidal activity of three species belonging to family Chenopodiaceae (Atriplex farinosa Forssk, A. nummularia Lindl. and Haloxylon salicornicum (Moq.) Bunge ex Boiss.) were investigated. Plant material from each species was ground and each extract was subjected to fractionation. Insecticidal activity of total extracts and fractions were tested in feeding, contact, and egg hatchability tests usingHelicoverpa zea (Boddie), a major agricultural pest that feeds on numerous crops, including cotton (cotton bollworm), corn (corn earworm) and tomato (tomato fruit worm). A. farinosashowed the highest mortality of the larvae in contact test. A. nummularia and H. salicornicum also exhibited lower activity. Similar results were obtained on the hatchability of eggs test, but no significant effects were detected in feeding tests. Key words: Atriplex farinosa, Atriplex nummularia, Haloxylon salicornicum, insecticidal activity, Helicoverpa zea.

Inhibition of beta-lactamase enzyme of Pseudomonas aeruginosa by clavulanic acid of Rumex vesicarius L.

This study plays an important role in solution of beta-lactam resistance problem. This aim has been achieved by clavulanic acid production as beta-lactamase inhibitor. Beta-lactam-resistant Pseudomonas aeruginosa possesses beta-lactams resistance machinery by secretion of extracellular beta-lactamase enzyme. The present study was begun with collection of eighty nosocomial bacterial isolates from Riyadh hospitals through one year. Nosocomial bacterial isolates were treated by amoxicillin (250 µg ml -1 ) to determine resistant isolates. Among them fifty amoxicillin-resistant isolates could be found with different minimum inhibitory concentrations (MICs). However, one isolate considers the most potent which has MIC over than 1000 µg ml -1 and also was identified by using polymerase chain reaction (PCR) technique as P. aeruginosa . Isolated gene of P. aeruginosa has 870 bp. The second phase of this study was begun with collection of six plants which are growing in Saudi Arabia, then were identified by professionals of Science College herbarium, King Saud University. These plants were extracted by methanol and then dried. These plants are Rhazya stricta , Calotropois procera , Maerua crassifolia , Haloxylon salicornicum , Rumex vesicarius L. and Lycium shawii . The plant extracts were tested to detect and determine their antagonistic effect for amoxicillin-resistant P. aeruginosa and of course for its beta-lactamase enzyme. Only one extract of R. vesicarius L. has antagonistic effect for beta-lactamase enzyme. Beta-lactamase inhibitor was purified and characterized as clavulanic acid by using nuclear magnetic resonance (NMR) spectroscopy analysis, infra-red (IR) spectroscopy analysis and elemental analysis. Eventually, amoxicillin-resistant P. aeruginosa was inhibited by amoxicillin-clavulanic acid combination at 125 µg ml -1 and 128 mg ml -1 , respectively.

Estimating the production in two shrub species of Atriplex canescens and Haloxylon ammodendron using some morphological parameters

In this study, the relationship between production as an independent variable and small diameter, large diameter, height, canopy cover, volume, average diameter height as dependent variables in Atriplex canescens and Haloxylon ammodendron were evaluated to select the best variables for estimating production in these species. The study site was located in Yousef Abad Neyshabur Rangelands, North East of Iran, Khorasan Razavi Province. Samplings were done random-systematic along Transects with 300 m length and 100 m distance from each other (samplings were done at the first, middle and end of each Transect and in the plots with dimensions of 2 × 4 m2 in H. ammodendron and 4 ×4 m2 in A. canescens). Production was measured by clipping and weighting method. Parameters like small and large diameter, height and canopy cover were also measured. To evaluate the relationship between dependent variables and production as independent variable, the multiple variables regression analysis and stepwise regression were performed. The results showed that volume in At. canescens and height in Ha. ammodendron was the most effective factors for estimating production. Key words: Shrub production, cover, stepwise regression, Atriplex canescens, Haloxylon ammodendron, Yousef Abad Neyshabur, Arid rangelands.

Spatial heterogeneity of soil chemical properties between Haloxylon persicum and Haloxylon ammodendron populations

Spatial heterogeneity is a ubiquitous feature in natural ecosystems, especially in arid regions. Different species and their discontinuous distribution, accompanied by varied topographic characteristics, result in soil resources distributed differently in different locations, and present significant spatial heterogeneity in desert ecosystems. In this study, conventional and geostatistical methods were used to identify the heterogeneity of soil chemical properties in two desert populations, Haloxylon persicum Bunge ex Boss., which dominates on the slopes and tops of sand dunes and Haloxylon ammodendron (C. A. Mey.) Bunge, which inhabits interdunes in the Gurbantunggut Desert of Xinjiang, China. The results showed that soil pH, electrical conductivity (EC), soil organic carbon (SOC), available nitrogen (AN) and available phosphorus (AP) were significantly higher in H. ammodendron populations than that in H. persicum. The coefficient of variation (CV) indicated that (1) most parameters presented a moderate degree of variability (10% < CV < 100%) except pH in both plots, (2) the variability of soil pH, EC and AP in H. ammodendron populations was higher than that in H. persicum populations, and (3) SOC and AN in H. ammodendron populations were lower than that in H. persicum populations. Geostatistical analysis revealed a strong spatial dependence (C0/(C0+C) < 25%) within the distance of ranges for all tested parameters in both plots. The Kriging-interpolated figures showed that the soil spatial distribution was correlated with the vegetation distribution, individual size of plants, and the topographic features, especially with the plants nearest to sampling points and the topographic features. In each plot, soil EC, SOC, AN and AP presented similar distributions, and fertile islands and salt islands occurred in both plots but did not affect every individual plant, since the sampling distance was larger than the size of such fertile islands. The results of topographic effects on soil heterogeneity suggested s

Discussion on the Method of High-resolution Remote Sensor Data Interpretation of Haloxylon Ammodendron in Ulan Buh Desert

According to ALOS,SPOT5 high-resolution remote sensing image analysis and field investigation,we have completed the remote sensing information visual extraction and vegetation mapping in Ulan Buh Desert,while combined with GPS field records,we have finished accuracy evaluation,the result was satisfactory.The accuracy of visual interpretation was about 93.3%,the area Haloxylon Ammodendron was 165 410.62 hm2,accounting for Ulan Buh Desert 17.27% of total land area.Meanwhile,methods of remote sensing image interpretation,which were suitable for Haloxylon forest in the Ulan Buh Desert,were also discussed.