期刊文献+
共找到618篇文章
< 1 2 31 >
每页显示 20 50 100
Effects of uniconazole with or without micronutrient on the lignin biosynthesis,lodging resistance,and winter wheat production in semiarid regions 被引量:11
1
作者 Irshad AHMAD MENG Xiang-ping +5 位作者 Muhammad KAMRAN Shahzad ALI Shakeel AHMAD LIU Tie-ning CAI Tie HAN Qing-fang 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2020年第1期62-77,共16页
Lodging stress results in grain yield and quality reduction in wheat. Uniconazole, a potential plant growth regulator significantly enhances lignin biosynthesis and thus provides mechanical strength to plants in order... Lodging stress results in grain yield and quality reduction in wheat. Uniconazole, a potential plant growth regulator significantly enhances lignin biosynthesis and thus provides mechanical strength to plants in order to cope with lodging stress. A field study was conducted during the 2015–2016 and 2016–2017 growing seasons, to investigate the effects of uniconazole sole application or with micronutrient on the lignin biosynthesis, lodging resistance, and production of winter wheat. In the first experiment, uniconazole at concentrations of 0(CK), 15(US1), 30(US2), and 45(US3) mg L^-1 was applied as sole seed soaking, while in the second experiment with manganese(Mn) at concentration of 0.06 g L^-1 Mn, 0.06 g L^-1 Mn+ 15 mg L^-1 uniconazole(UMS1), 0.06 g L^-1 Mn+30 mg L^-1 uniconazole(UMS2), and 0.06 g L^-1 Mn+45 mg L^-1 uniconazole(UMS3), respectively. Uniconazole sole application or with micronutrient significantly increased the lignin content by improving the lignin-related enzyme activities of phenylalanine ammonia-lyase, cinnamyl alcohol dehydrogenase, tyrosine ammonialyase, and peroxidase, ameliorating basal internode characteristics, and breaking strength. The spike length, spike diameter, spikes/plant, weight/spike, yield/spike, and grain yield increased and then decreased with uniconazole application at a higher concentration, where their maximum values were recorded with UMS2 and US2 treatments. The lignin accumulation was positively correlated with lignin-related enzyme activities and breaking strength while, negatively correlated with lodging rate. Uniconazole significantly improved the lignin biosynthesis, lodging resistance, and grain yield of winter wheat and the treatments which showed the greatest effects were uniconazole seed soaking with micronutrient at a concentration of 30 mg L^-1 and 0.06 g L^-1 , and uniconazole sole seed soaking at a concentration of 30 mg L^-1 . 展开更多
关键词 lignin biosynthesis lodging resistance semi-arid regions MANGANESE UNICONAZOLE WHEAT
下载PDF
Numerical Study of Impacts of Soil Moisture on the Diurnal and Seasonal Cycles of Sensible/Latent Heat Fluxes over Semi-arid Region 被引量:10
2
作者 宋耀明 郭维栋 张耀存 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2009年第2期319-326,共8页
The semi-arid regions, as climatic and ecosystem transitional zones, are the most vulnerable to global environmental change. Earlier researches indicate that the semi-arid regions are characterized by strong landatmos... The semi-arid regions, as climatic and ecosystem transitional zones, are the most vulnerable to global environmental change. Earlier researches indicate that the semi-arid regions are characterized by strong landatmosphere coupling in which soil moisture is the crucial variable in land surface processes. In this paper, we investigate the sensitivity of the sensible/latent heat fluxes to soil moisture during the growing season based on the enhanced observations at Tongyu in the Jilin province of China, a reference site of international Coordinated Energy and Water Cycle Observations Project (CEOP) in the semi-arid regions, by using a sophisticated land surface model (NCAR_CLM3.0). Comparisons between the observed and simulated sensible/latent heat fluxes indicate that the soil moisture has obvious effects on the sensible/latent heat fluxes in terms of diurnal cycle and seasonal evolution. Better representation of the soil moisture could improve the model performance to a large degree. Therefore, for the purpose of simulating the land-atmosphere interaction and predicting the climate and water resource changes in semi-arid regions, it is necessary to enhance the description of the soil moisture distribution both in the way of observation and its treatment in land surface models. 展开更多
关键词 semi-arid region soil moisture latent/sensible heat flux diurnal cycle seasonal evolution
下载PDF
Runoff of arid and semi-arid regions simulated and projected by CLM-DTVGM and its multi-scale fluctuations as revealed by EEMD analysis 被引量:4
3
作者 NING Like XIA Jun +1 位作者 ZHAN Chesheng ZHANG Yongyong 《Journal of Arid Land》 SCIE CSCD 2016年第4期506-520,共15页
Runoff is a major component of the water cycle, and its multi-scale fluctuations are important to water resources management across arid and semi-arid regions. This paper coupled the Distributed Time Variant Gain Mod... Runoff is a major component of the water cycle, and its multi-scale fluctuations are important to water resources management across arid and semi-arid regions. This paper coupled the Distributed Time Variant Gain Model (DTVGM) into the Community Land Model (CLM 3.5), replacing the TOPMODEL-based method to simulate runoff in the arid and semi-arid regions of China. The coupled model was calibrated at five gauging stations for the period 1980-2005 and validated for the period 2006-2010. Then, future runoff (2010-2100) was simulated for different Representative Concentration Pathways (RCP) emission scenarios. After that, the spatial distributions of the future runoff for these scenarios were discussed, and the multi-scale fluctuation characteristics of the future annual runoff for the RCP scenarios were explored using the Ensemble Empirical Mode Decomposition (EEMD) analysis method. Finally, the decadal variabilities of the future annual runoff for the entire study area and the five catchments in it were investigated. The results showed that the future annual runoff had slowly decreasing trends for scenarios RCP 2.6 and RCP 8.5 during the period 2010-2100, whereas it had a non-monotonic trend for the RCP 4.5 scenario, with a slow increase after the 2050s. Additionally, the future annual runoff clearly varied over a decadal time scale, indicating that it had clear divisions between dry and wet periods. The longest dry period was approximately 15 years (2040-2055) for the RCP 2.6 scenario and 25 years (2045-2070) for the RCP 4.5 scenario. However, the RCP 8.5 scenario was predicted to have a long dry period starting from 2045. Under these scenarios, the water resources situation of the study area will be extremely severe. Therefore, adaptive water management measures addressing climate change should be adopted to proactively confront the risks of water resources. 展开更多
关键词 Community Land Model (CLM) Distributed Time Variant Gain Model (DTVGM) Ensemble EmpiricalMode Decomposition (EEMD) decadal variability arid and semi-arid regions
下载PDF
Comparisons of plant calcium fraction between two different vegetation zones in semi-arid region 被引量:2
4
作者 MengQi Li XingDong He +2 位作者 XiangXiang Yang YueDan Zhao YuBao Gao 《Research in Cold and Arid Regions》 CSCD 2018年第4期340-346,共7页
To explore the characteristics of plant calcium(Ca) fraction, we analyzed 91 plant species in the Ningxia Habahu National Nature Reserve in Yanchi County of Ningxia and 84 plant species in Zhenglan Banner of Inner Mon... To explore the characteristics of plant calcium(Ca) fraction, we analyzed 91 plant species in the Ningxia Habahu National Nature Reserve in Yanchi County of Ningxia and 84 plant species in Zhenglan Banner of Inner Mongolia. Results show that, for the two regions, there is no significant difference between Ca fraction for the same growth type, and between water soluble Ca content or between hydrochloric acid soluble Ca content for plants of the same ecosystem and between hydrochloric acid soluble Ca content for plants of the same family. In similar vegetation zones, there is a significant difference among hydrochloric acid soluble Ca content for different growth types in Yanchi County and Zhenglan Banner,which was the highest for annual herbs and the lowest for perennial herbs. There is a significant difference between acetic acid soluble Ca content and between hydrochloric acid soluble Ca content for sandy land and grassland ecosystems in Yanchi County. There is a significant difference among the same Ca fraction of different families in the same region. Thus, the characteristics of plant Ca fraction are results of long-term adaptation to the environment. 展开更多
关键词 semi-arid region plant calcium FRACTION Ningxia Habahu National Nature RESERVE Zhenglan BANNER of Inner Mongolia
下载PDF
Evaluation of SEBS Algorithm for Estimation of Daily Evapotranspiration Using Landsat-8 Dataset in a Semi-Arid Region of Central Iran 被引量:3
5
作者 Mohsen Mohammadian Ramin Arfania Hossein Sahour 《Open Journal of Geology》 2017年第3期335-347,共13页
Evapotranspiration is one the most important parameters in the hydrological cycle and plays a significant role in energy balance of the earth’s surface. Traditional field-based measurements approaches for calculation... Evapotranspiration is one the most important parameters in the hydrological cycle and plays a significant role in energy balance of the earth’s surface. Traditional field-based measurements approaches for calculation of daily evapotranspiration are valid only for local scales. Using advanced remote sensing technology, the spatial distribution of evapotranspiration may now be quantified more accurately. At the present study, daily evapotranspiration is estimated using Landsat 8 datasets based on the Surface Energy Balance System (SEBS) algorithm over the Zayanderud Dam area in central Iran. For this purpose, three Landsat 8 datasets in the years 2013, 2014 and 2015 covering the study area were atmospherically corrected using the FLAASH approach. The biophysical parameters of the earth’s surface for SEBS algorithm, such as normalized difference vegetation index (NDVI), Leaf area index (LAI), fractional vegetation cover (FC) were extracted from the visible and near infrared bands and land surface temperature was computed from thermal bands the Landsat 8 datasets. The spatial distribution of daily ET was provided separately for each year. In addition to the SEBS algorithm, the Penman-Monteith method was applied to estimate the daily ET from meteorological datasets which was obtained from two synoptic stations within the study area. Finally, the simulated daily ET values from both SEBS and Penman-Monteith method were compared to observed values obtained from a lysimeter within the study area. Although the estimated results from both SEBS and Penman-Monteith show a strong correlation with the observed values, the derived ET maps and following analysis demonstrated SEBS has higher accuracy and strength in estimation of daily ET in Zayanderud Dam region. 展开更多
关键词 EVAPOTRANSPIRATION SEBS PENMAN-MONTEITH LANDSAT 8 arid and semi-arid regions
下载PDF
Emergy-based study on eco-economic system of arid and semi-arid region:a case of Gansu province,China 被引量:5
6
作者 Xue, Bing Chen, XingPeng +3 位作者 Geng, Yong Yang, Mian Yang, FuXia Hu, XiaoFen 《Journal of Arid Land》 SCIE 2010年第3期207-213,共7页
Taking Gansu province as a model case,this study provides an integrated analysis on the eco-economic system of arid and semi-arid region based on emergy synthesis theory. Through calculating the values of renewable em... Taking Gansu province as a model case,this study provides an integrated analysis on the eco-economic system of arid and semi-arid region based on emergy synthesis theory. Through calculating the values of renewable emergy flow,non-renewable resources,imported emergy,exported emergy,waste emergy,and total emergy during the period of 1978-2007,the performance of Gansu eco-economic system was analyzed. The results indicated that the renewable emergy flow within the province basically remained steady state which was estimated at 2.99×1022 solar emjoules (sej) from 1978 to 2007. The imported emergy and exported emergy were estimated at 3.75×1017 sej and 2.99×1020 sej in 1978 and increased to 1.07×1022 sej and 1.44×1022 sej respectively in 2007. The nonrenewable emergy flow was estimated at 1.62×1022 sej and increased to 1.85×1023 sej,with annual growth rate of 8.7%,while the estimated total emergy was 4.58×1022 sej in 1978 and increased to 2.11×1023 sej in 2007,with annual growth rate of 5.41%. Our results indicate a deteriorate situation between economic development and environmental protection in the region. The rapid economic growth in the past thirty years was based on a great consumption of nonrenewable resource and caused continuous decrease in the capacity of sustainable development. The environmental loading ratio was 0.53 in 1978,increased to 6.06 in 2007,indicating a rapid degradation of the regional environment quality. We calculated that the actual population was 1.53 times the renewable resource population in 1978,increased to 7.06 times in 2007. During the period of 1978-2007,the emergy rose from 2.45×1015 sej/(capita·a) to 8.07×1015 sej/(capita·a). Our analysis revealed that the emergy density presented a trend of gradual increase,and then the emergy currency ratio in Gansu decreased from 7.08×1013 sej/Chinese Yuan to 7.82×1012 sej/Chinese Yuan. 展开更多
关键词 emergy analysis economic geography regional sustainable development arid and semi-arid area Gansu province
下载PDF
The Analysis of Spring Precipitation in Semi-Arid Regions: Case Study in Iran
7
作者 Hossein Ali HASANIHA Majid MEGHDADI 《Journal of Water Resource and Protection》 2010年第1期69-76,共8页
In this study, Zanjan from Iran has been chosen from among all the semi-arid regions of world, which has Synoptic station and statistical data since 1955. Spring and monthly precipitations are also provided in the per... In this study, Zanjan from Iran has been chosen from among all the semi-arid regions of world, which has Synoptic station and statistical data since 1955. Spring and monthly precipitations are also provided in the period of 1956-2005. First, all data has been controlled by double mass method with the help of adjacent stations, and then it was normalized by the box-cox transformations method. The global SPI index was calculated for all months and spring, also drought and wet periods were determined and finally compared. In the drought category view, spring months have represented the great similarities. The moving averages are represented all months and spring’s precipitations such as three years, five years, seven years and nine years are shown. Statistical period was observed and analyzed based on five periods of ten years, and results precipitation with more than 5mm and 10mm has gradually decreased on April. However the number of days with precipitation has increased. The calculated spring precipitations and all of the atmospheric factors represented the dependence of this model to maximum average of spring temperature and relative humidity of spring and winter by the use of multi variable regression method. The predicted precipitation of spring also showed the gradual decline of precipitation in the next 30 years by the arima model. 展开更多
关键词 Iran semi-arid regionS PRECIPITATION DROUGHT Box-Cox TRANSFORMATIONS Method ARIMA Model
下载PDF
Improvement of Supplementary Irrigation Water Quality for Rain-Fed Agriculture in the Semi-Arid Region Using Magnetization Techniques
8
作者 Deepak Bornare Ramakrishna Nagarajan Rajiv Barge 《Journal of Water Resource and Protection》 2018年第12期1198-1209,共12页
Rain-fed agriculture depends on the groundwater as a supplementary source of irrigation. The poor quality of water from the hard rock area is applied to the crops to save the crop. Continuous irrigation leads to degra... Rain-fed agriculture depends on the groundwater as a supplementary source of irrigation. The poor quality of water from the hard rock area is applied to the crops to save the crop. Continuous irrigation leads to degradation of soil, drip irrigation system as well plants. This study assessed the damages on the drip irrigation system and soil, inflicted by the use of low-quality irrigation water. The quality of water was improved with reference to raw water in terms of pH (1.57% - 5.88%), EC (3.08% - 10.08%), ions (0.96% - 46%) by using magnetization method, without disrupting the existing irrigation system in the basaltic aquifer in semi-arid to the arid condition. This was demonstrated before the farmers in central India. 展开更多
关键词 SUPPLEMENTARY IRRIGATION Low Water Quality Hard Rock AQUIFER Dissolved SALTS semi-arid region MAGNETIZATION Method
下载PDF
How to Build Artificial Grassland in the Cold and Semi-Arid Regions? ——A Case Study in Naqu
9
作者 Dor JHee Town DRop 《Asian Agricultural Research》 2016年第9期58-59,63,共3页
Construction of artificial grassland is a key factor to solve the shortage of grass and forage balance in cold and semi-arid areas of high plateau,and it is the key measure to ensure the sustainable development of gra... Construction of artificial grassland is a key factor to solve the shortage of grass and forage balance in cold and semi-arid areas of high plateau,and it is the key measure to ensure the sustainable development of grassland animal husbandry in this area. At present,the artificial grassland construction is neither reasonable nor scientific,which restricts the healthy and rapid development of artificial grassland in the cold and semi-arid areas of high plateau. In this research,with Naqu Area in Tibet as a case,problems and current status in construction process of artificial grassland are analyzed in cold and semi-arid areas of high plateau. Suitable artificial forage species in Nagqu are elaborated,and recommendations for the construction and development of artificial grassland are discussed. 展开更多
关键词 Cold and semi-arid regions Artificial grassland PROBLEMS RECOMMENDATIONS
下载PDF
Progress in Semi-arid Climate Change Studies in China 被引量:19
10
作者 Jianping HUANG Jieru MA +2 位作者 Xiaodan GUAN Yue LI Yongli HE 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2019年第9期922-937,共16页
This article reviews recent progress in semi-arid climate change research in China.Results indicate that the areas of semiarid regions have increased rapidly during recent years in China,with an increase of 33%during ... This article reviews recent progress in semi-arid climate change research in China.Results indicate that the areas of semiarid regions have increased rapidly during recent years in China,with an increase of 33%during 1994-2008 compared to 1948-62.Studies have found that the expansion rate of semi-arid areas over China is nearly 10 times higher than that of arid and sub-humid areas,and is mainly transformed from sub-humid/humid regions.Meanwhile,the greatest warming during the past 100 years has been observed over semi-arid regions in China,and mainly induced by radiatively forced processes.The intensity of the regional temperature response over semi-arid regions has been amplified by land-atmosphere interactions and human activities.The decadal climate variation in semi-arid regions is modulated by oceanic oscillations,which induce land-sea and north-south thermal contrasts and affect the intensities of westerlies,planetary waves and blocking frequencies.In addition,the drier climates in semi-arid regions across China are also associated with the weakened East Asian summer monsoon in recent years.Moreover,dust aerosols in semi-arid regions may have altered precipitation by affecting the local energy and hydrological cycles.Finally,semi-arid regions in China are projected to continuously expand in the 21st century,which will increase the risk of desertification in the near future. 展开更多
关键词 semi-arid regionS DRYING EXPANSION WARMING dynamics
下载PDF
Soil respiration response to precipitation reduction in a grassland and a Mongolian pine plantation in semi-arid northeast China 被引量:3
11
作者 Yalin Hu Jintao Li +1 位作者 Shanyu Zhao Dehui Zeng 《Journal of Forestry Research》 SCIE CAS CSCD 2019年第5期1925-1934,共10页
Climate change is predicted to alter global precipitation regimes.However,the response of soil carbon and nitrogen cycles and soil microorganisms to precipitation reduction is poorly understood but is dependent on eco... Climate change is predicted to alter global precipitation regimes.However,the response of soil carbon and nitrogen cycles and soil microorganisms to precipitation reduction is poorly understood but is dependent on ecosystem type.To evaluate the impacts of reduced precipitation on soil respiration,soil inorganic nitrogen(i.e.,NH4^+–N and NO3^-–N),nitrogen mineralization,and soil microbial community composition,a precipitation manipulation experiment was initiated in a Mongolian pine plantation and a naturally restored grassland in semi-arid northeast China.Precipitation reduction led to decreases of soil respiration rates by 14 and 8%in 2014 and 2015 in the Mongolian pine plantation but no changes in the grassland.Soil inorganic nitrogen,ammonification and nitrification rate,and soil phospholipids fatty acids were not significantly changed by reduced precipitation but significantly differed between the two ecosystems and among growing seasons.Our results suggest that the impacts of precipitation reduction on soil respiration were different between the Mongolian pine plantation and the grassland,and that ecosystem type and growing season had more pronounced impacts on soil carbon and nitrogen cycles. 展开更多
关键词 PRECIPITATION REDUCTION Soil RESPIRATION rate N mineralization PHOSPHOLIPIDS fatty acids semi-arid region
下载PDF
Interaction between climate and management on beta diversity components of vegetation in relation to soil properties in arid and semi-arid oak forests, Iran 被引量:3
12
作者 Heydari MEHDI Aazami FATEMEH +4 位作者 Faramarzi MARZBAN Omidipour REZA Bazgir MASOUD Pothier DAVID Prévosto BERNARD 《Journal of Arid Land》 SCIE CSCD 2019年第1期43-57,共15页
This study aimed to investigate the interaction between regions with different climatic conditions(arid vs. semi-arid) and management(protected vs. unprotected) on the turnover and nestedness of vegetation in relation... This study aimed to investigate the interaction between regions with different climatic conditions(arid vs. semi-arid) and management(protected vs. unprotected) on the turnover and nestedness of vegetation in relation to physical, chemical and biological properties of soils in the Ilam Province of Iran. In each of the two regions, we sampled 8 sites(4 managed and 4 unmanaged sites) within each of which we established 4 circular plots(1000 m^2) that were used to investigate woody species, while two micro-plots(1 m×1 m) were established in each 1000-m^2 plot to analyze herbaceous species. In each sample unit, we also extracted three soil samples(0–20 cm depth) for measuring soil properties. The results indicated that the interaction between region and conservational management significantly affected the percent of canopy cover of Persian oak(Quercus brantii Linddl), soil respiration, substrate-induced respiration, as well as beta and gamma diversities and turnover of plant species. The percent of oak canopy cover was positively correlated with soil silt, electrical conductivity, available potassium, and alpha diversity, whereas it was negatively correlated with plant turnover. In addition, plant turnover was positively related to available phosphorus, while nestedness of species was positively related to organic carbon and total nitrogen. According to these results, we concluded that physical, chemical, and biological characteristics of limited ecological niche generally influenced plant diversity. Also, this study demonstrated the major contribution of the beta diversity on gamma diversity, especially in semi-arid region, because of the higher heterogeneity of vegetation in this area. 展开更多
关键词 CLIMATIC conditions conservation MANAGEMENT beta diversity OAK FORESTS physical-chemical property semi-arid region
下载PDF
Aboveground nutrient components of Eucalyptus camaldulensis and E. grandis in semiarid Brazil under the nature and the mycorrhizal inoculation conditions 被引量:2
13
作者 Marcela C. Pagano Antonio F. Bellote Maria R. Scotti 《Journal of Forestry Research》 SCIE EI CAS CSCD 2009年第1期15-22,共8页
A study was conducted to evaluate the aboveground biomass, nutrient content and the percentages of mycorrhizal colonization in Eucalyptus camaldulensis and Eucalyptus grand& plantations in the semiarid region ( 15&#... A study was conducted to evaluate the aboveground biomass, nutrient content and the percentages of mycorrhizal colonization in Eucalyptus camaldulensis and Eucalyptus grand& plantations in the semiarid region ( 15° 09′ S 43° 49′ W) in the north of the State of Minas Gerais in Brazil. Results show that the total above-ground biomass (dry matter) was 33.6 Mg.ha^-1 for E. camaldulensis and 53.1 Mg·ha^-1 for E. grandis. The biomass of the stem wood, leaves, branches, and stein bark for E. camaldulens accounted for 64.4%, 19.6%, 15.4%, and 0.6% of the total biomass, respectively (Table 2); meanwhile a similar partition of the total above-ground biomass was also found for E. grand&. The dry matter of leaves and branches of E. camaldulensis accounted for 35% of total biomass, and the contents of N, P, K, Ca, Mg, and S in leaves and branches accounted for 15.5%, 0.7%, 12.3%, 22.6%, 1.9%, and 1.4% of those in total above-ground biomass, respectively. In the trunk (bark and wood), nutrient accumulation in general was lower. Nutrient content of E. grand& presented little variation compared with that orE. camaJd^llensis. Wood localized in superior parts of trunk presented a higher concentration of P and bark contained significant amounts of nutrients, especially in E. grand&. This indicated that leaving vegetal waste is of importance on the site in reducing the loss of tree productivity in this semi-arid region. The two species showed mycotrophy. 展开更多
关键词 Eucalyptus biomass nutrient components semi-arid region mycorrhizal symbioses Brazil
下载PDF
Effect of Plant Fiber-Polyacrylamide Blend on Retention and Evaporation Water at Arid and Semi-Arid Soils of Algeria 被引量:2
14
作者 Maghchiche Abdelhak Haouam Abdelkarim Immirzi Barbara 《Journal of Chemistry and Chemical Engineering》 2012年第1期7-17,共11页
Soil and water conservation is essential for sustaining food production and for preserving the environment in arid and semi arid lands (ASALs) where conditions for agriculture and other land use systems are often ha... Soil and water conservation is essential for sustaining food production and for preserving the environment in arid and semi arid lands (ASALs) where conditions for agriculture and other land use systems are often harsh and unpredictable. The ASALs of Algeria are an important source of a variety of non wood forest products like Stipa tenacissima L. plant (esparto grass). This research was conducted to determine the effects of different low concentration (〈 I%) polyacrylaJnide, Stipa tenacissima L. fiber (esparto grass fibers) and its mixtures with the polymer at water retention in arid and semi arid soil. All samples are characterized by infrared spectroscopy, X-ray Diffractometry, thermal analysis TG DSC and scanning electron micrographs (SEM). The results showed that polymer blend in soil could improve better soil physical proprieties decreased evaporation and increase water retention in arid soils compared with application of any other blend at the same concentration. The use of Polyacrylamide-Cellulose blend appears to promise for reducing the labor cost of irrigation at arid and semi-arid soils, and offers safe and environmentally friendly inexpensive materials. The importance of Polyacrylamide-Cellulose blends to alleviate poor physical properties and retain water in these arid regions to sustain plant growth. 展开更多
关键词 Natural fiber plant fiber arid and semi arid regions polymer Stipa tenacissima.
下载PDF
Features on N/P ratio of plants with different functional groups between two types of steppe in semi-arid area
15
作者 YueDan Zhao XingDong He +4 位作者 Lei Chen XinFeng Ding MengQi Li PingYi Xu YuBao Gao 《Research in Cold and Arid Regions》 CSCD 2019年第5期371-381,共11页
The differences in nitrogen/phosphorus(N/P)ratios of different functional groups in ecology are more helpful in explaining species competition and community dynamics.Based on the functional groups of plant growth type... The differences in nitrogen/phosphorus(N/P)ratios of different functional groups in ecology are more helpful in explaining species competition and community dynamics.Based on the functional groups of plant growth type,carbon metabolism pathway,root type and phylogenetic type,we analyzed characteristics of leaf N/P ratios of 77 species in Sanggendalai(typical grassland zone)of Zhenglan Banner,Inner Mongolia,China and 91 species in the Habahu National Nature Reserve(desertified grassland zone)in Yanchi County of Ningxia,China.The results show that the N/P ratio(16.91)of C3 plants in the desertified steppe was significantly larger than that(12.72)in the typical steppe,but there was no significant difference between the N/P ratios of C4 plants in the two zones.There was no significant difference in N/P ratios between C3 plants and C4 plants in the same zone.Similarly,the N/P ratio(16.60)of dicotyledons in desertified steppe were significantly higher than that(12.98)in typical steppe,while differences in N/P ratios between monocotyledonous plants of the two zones was not significant,and there existed no significant difference in N/P ratios between dicotyledonous and monocotyledonous plants in the same zone.The N/P ratio had significant difference between gramineous and non-gramineous plants in the typical steppe but not in the desertified steppe,but there existed no significant difference in N/P ratios among different root types of perennial herbaceous plants in the same type of steppe or between two types of steppe.Thus,different features on the N/P ratios of C3 plants and dicotyledonous plants between typical steppe and desertified steppe may lead to different growth status of plants,and the N/P ratio stoichiometric of the same plant functional group may be a foundation of the changes of a plant community. 展开更多
关键词 semi-arid region PLANT N/P ratio PLANT functional GROUPS desertified STEPPE TYPICAL STEPPE
下载PDF
Application of spatially varying storage capacity model for runoff parameterization in semi-arid catchment
16
作者 Li-liang REN Gui-zuo WANG +1 位作者 Fang LU Tian-fang FANG 《Water Science and Engineering》 EI CAS 2009年第2期1-10,共10页
This paper introduces the method of designation of water storage capacity for each grid cell within a catchment, which considers topography, vegetation and soil synthetically. For the purpose of hydrological process s... This paper introduces the method of designation of water storage capacity for each grid cell within a catchment, which considers topography, vegetation and soil synthetically. For the purpose of hydrological process simulation in semi-arid regions, a spatially varying storage capacity (VSC) model was developed based on the spatial distribution of water storage capacity and the vertical hybrid runoff mechanism. To verify the applicability of the VSC model, both the VSC model and a hybrid runoff model were used to simulate daily runoff processes in the catchment upstream of the Dianzi hydrological station from 1973 to 1979. The results showed that the annual average Nash-Sutcliffe coefficient was 0.80 for the VSC model, and only 0.67 for the hybrid runoff model. The higher annual average Nash-Sutcliffe coefficient of the VSC model means that this hydrological model can better simulate daily runoff processes in semi-arid regions. Furthermore, as a distributed hydrological model, the VSC model can be applied in regional water resource management. 展开更多
关键词 VSC model hybrid runoff model water storage capacity semi-arid region
下载PDF
Study of Changing Features of Precipitation from 1900-2010 Years in Africa-Asia Arid and Semi-Arid Area
17
作者 Xiangkun Cheng Hang Cheng +1 位作者 Guowu Sun Xiaomeng Shi 《Journal of Geoscience and Environment Protection》 2017年第1期62-72,共11页
The relationship between time-space variation characteristics and the variation of the general atmospheric circulation of rainfall occurred in Asia, Africa through North Africa-Middle East-Western Middle Asia-Eastern ... The relationship between time-space variation characteristics and the variation of the general atmospheric circulation of rainfall occurred in Asia, Africa through North Africa-Middle East-Western Middle Asia-Eastern Middle Asia, Northwest China-Eastern Northwest China-North China and Northeast China is studied based on the analysis of GPCC rainfall data from 1901 to 2010 and annual precipitation in relevant cities of China from 1901 to 2010, and the data of NCEP of surface pressure as well as 500 Hpa potential high from 1950 to 2010. The result shows that the total precipitation presents a decreasing trend in north Africa to the northeast of China in recent 100 years. It has a mutation in 1950s. The precipitation presented a decreasing trend in North Africa and Middle East, in recent 100 years;it presented a further decreasing trend after 1950s. It presented a decreasing trend before 1950s and an increasing trend after 1950s in Middle Asia and Northwest china. It also presented a decreasing trend before 1950s and an increasing trend between 1950s to 1990s, and decreased later in Eastern Northwest China, North China and Northeast China which also presented in a more or less period in different areas from North Africa to Northeast China. The beginning of less precipitation years and less period occurred after it presented less period in north Africa in time and space. After it moved to the east areas as the year past, at last, the SLPA fields which presented more or less precipitations of years from North Africa to Northeast China were analyzed. It also shows that the SLPA fields which presented more were beneficial to the precipitations and presented negative effects of precipitations in the polar, high and mid- and lower latitudes. 展开更多
关键词 Asia-Africa arid and semi-arid region RAINFALL above or below the Normal PRECIPITATION Sea Lever Pressure ANOMALIES
下载PDF
旱区陆面非降水性水分研究进展和展望 被引量:1
18
作者 王胜 张强 +4 位作者 张良 王兴 杜昊霖 曾剑 问晓梅 《干旱气象》 2024年第1期1-10,共10页
随着全球气候变暖,自然生态系统和水资源压力不断增加,加剧了全球水资源的短缺。旱区非降水性水分(Non-precipitation Water,NPW),作为一种重要的水源,对旱区生态系统和陆面水分平衡具有显著影响。本文基于国内外非降水性水分研究现状,... 随着全球气候变暖,自然生态系统和水资源压力不断增加,加剧了全球水资源的短缺。旱区非降水性水分(Non-precipitation Water,NPW),作为一种重要的水源,对旱区生态系统和陆面水分平衡具有显著影响。本文基于国内外非降水性水分研究现状,总结其在西北旱区的观测方法、变化特征、形成机制及对陆面水分平衡和作物的影响。在结合非降水性水分研究国际趋势的基础上,指出当前研究的不足和问题,以及未来研究的重点方向:揭示陆面非降水性水分的复杂形成机制,加强对不同气候区和下垫面非降水性水分的认知,建立专门的陆面非降水性水分观测系统,发展其在数值模式中的参数化,以及制定陆面非降水性水分开发利用的技术标准。 展开更多
关键词 旱区(干旱半干旱区) 非降水性水分 露水 土壤吸附水 陆面水分平衡
下载PDF
干旱半干旱区果园生草条件下土壤微生物(细菌)的多样性
19
作者 李晓龙 马军 +3 位作者 褚燕南 岳海英 贾永华 田建文 《北方园艺》 CAS 北大核心 2024年第14期77-85,共9页
采选4种具备潜在“绿肥”功能的草种(黑麦草、苜蓿、高羊茅、长柔毛野豌豆)以及自然生草和清耕模式进行果园行间长期生草处理,应用高通量测序技术分析不同生草模式下果园土壤细菌群落结构、数量和功能的变化,以期为干旱半干旱区果园的... 采选4种具备潜在“绿肥”功能的草种(黑麦草、苜蓿、高羊茅、长柔毛野豌豆)以及自然生草和清耕模式进行果园行间长期生草处理,应用高通量测序技术分析不同生草模式下果园土壤细菌群落结构、数量和功能的变化,以期为干旱半干旱区果园的合理生草和苹果生产可持续发展提供参考依据。结果表明:生草处理下细菌OTUs被划分为39个已知细菌门、94纲、266目、541科、127属。其中苜蓿(458个OTUs)及自然生草(531个OTUs)处理具有更多的群体特异性OTUs,其次为黑麦草与长柔毛野豌豆处理,并且相较于清耕,生草处理的土壤显著富集了拟杆菌纲、梭状芽孢杆菌纲、放线菌纲、变形菌纲、拟杆菌门、草酸杆菌科、假单胞菌科、芽孢杆菌科等有益微生物。PCoA主成分、Adonis组间差异分析和α多样性(ACE指数)进一步表明,土壤细菌群落的组成主要受生草处理影响,其中自然生草、苜蓿及长柔毛野豌豆处理区域土壤样品中的细菌群落差异以及细菌多样性更显著。同时自然生草、苜蓿及长柔毛野豌豆生草处理下差异代谢通路主要聚焦于碳水化合物代谢,氨基酸代谢,能量代谢,跨膜转运及核苷酸代谢,其平均丰度分别为13.6%、9.5%、4.2%、3.4%、3.2%。综上所述,生草处理可影响细菌群落结构,其中自然生草、苜蓿及长柔毛野豌豆生草进一步显著促进了细菌群落的功能。 展开更多
关键词 干旱半干旱区 果园生草 细菌群落
下载PDF
半干旱地区秸秆还田对土壤有机碳组分及产量的影响
20
作者 高盼 王宇先 +3 位作者 徐莹莹 杨慧莹 王晨 张巩亮 《安徽农业科学》 CAS 2024年第8期149-151,共3页
为了探索半干旱区玉米秸秆还田对土壤有机碳组分和产量的影响,以黑龙江省农业科学院齐齐哈尔分院秸秆长期定位试验田为研究对象,对CK(常规种植)、FM(秸秆翻埋还田)和FG(秸秆覆盖还田)3种处理下土壤颗粒有机碳、水溶性有机碳含量及玉米... 为了探索半干旱区玉米秸秆还田对土壤有机碳组分和产量的影响,以黑龙江省农业科学院齐齐哈尔分院秸秆长期定位试验田为研究对象,对CK(常规种植)、FM(秸秆翻埋还田)和FG(秸秆覆盖还田)3种处理下土壤颗粒有机碳、水溶性有机碳含量及玉米产量进行分析。结果表明:不同处理各土层均是黏粒(<0.053μm)有机碳含量最高。FM处理4个土层砂粒(>0.250μm)和黏粒(<0.053μm)有机碳含量平均值分别提高了21.78%和20.51%,FG处理分别提高了25.87%和13.52%。FM处理在各土层水溶性有机碳含量最高,在0~10和>10~20 cm土层中顺序为FM>FG>CK,其中FM处理分别较CK增加22.73%和38.25%,FG处理分别较CK提高2.48%和26.32%。在>20~30和>30~40 cm土层中,土壤水溶性有机碳含量依次为FM>CK>FG,其中FG降低幅度分别为14.55%和9.41%,而FM处理增加幅度分别为10.68%和17.85%。不同处理之间穗长、穗粗和穗行数差异不明显。穗粒数顺序为FM>FG>CK,籽粒含水量顺序为FG>CK>FM;产量顺序为FM>FG>CK,FM和FG处理分别较CK增产5.20%和3.20%。 展开更多
关键词 半干旱地区 秸秆还田 颗粒有机碳 水溶性有机碳 产量
下载PDF
上一页 1 2 31 下一页 到第
使用帮助 返回顶部