Table of Content

15 October 2024, Volume 41 Issue 10 Previous Issue    Next Issue

Weather and Climatee

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Raindrop spectral characteristics of an autumn convective precipitation on the north slope of the Qilian Mountains FU Shuangxi, WANG Fucong, LI Baozi, FANG Chungang, CHEN Tianyu 2024, 41 (10):  1615-1626.  doi: 10.13866/j.azr.2024.10.01 Abstract ( 207 )   HTML ( 34 )   PDF (9715KB) ( 209 )   This study analyzed the influence system, characteristics of the raindrop spectrum of a convective precipitation process that occurred on September 21, 2020, in the northern slopes of the Qilian Mountains using upper-air and ground data, Doppler weather radar products, and Parsivel2 laser raindrop spectrometer observation data. Results demonstrated that precipitation was affected by a short-wave trough moving eastward over the plateau and the northern border region. Liquid water content W was consistent with rain rate R, and the corresponding raindrop diameter D was <1 mm when the particle number concentration N(D) was maximum at each site, which occurs during stratiform precipitation. The raindrop diameter increased rapidly during the maximum rain intensity of convective precipitation, with the maximum diameter D being in the range of 2.75-3.75 mm at each site. The mean raindrop number concentration NT was larger at higher elevation sites than at lower elevation sites, whereas the mean mass weighted average diameter Dm was larger at lower altitude sites than at higher altitude sites. The Dm of convective precipitation was significantly larger than that of stratiform precipitation. The distributions of Dm and logNw were relatively concentrated for convective precipitation, whereas they showed larger spectral width for stratiform precipitation. The gamma function could better fit the average raindrop spectrum of convective precipitation and stratiform precipitation in the Qilian Mountains. The shape parameter µ and the slope parameter λ of the gamma fitting function satisfied the good fitting relationship in convective precipitation and stratiform precipitation. Positive fitting coefficient and exponent were observed in the relationship of Dm-R. Dm increased with the improvement of R and stabilized after the rain rate reached a certain value. The logNw of stratiform precipitation changed faster with improvement of R, and the logNw of convective precipitation increased slowly with improvement of R. The precipitation estimates of convective precipitation and stratiform precipitation were lower in the Qilian Mountains when the default Z-R relationship was used to estimate precipitation in the operational radar application. Figures and Tables | References | Related Articles | Metrics

Weather and Climate

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Climate characteristics and variation in the Qilian Mountains from 1961 to 2022 YANG Fei, ZHANG Wentao, ZHANG Feimin, WANG Chenghai 2024, 41 (10):  1627-1638.  doi: 10.13866/j.azr.2024.10.02 Abstract ( 215 )   HTML ( 31 )   PDF (15154KB) ( 167 )   Global warming has resulted in the phenomenon of warming and wetting in northwest China. The Qilian Mountains is located in the arid region of northwest China, which spans the arid, semi-arid, and extremely arid climate zones from east to west. The climate has also obviously changed, which exerts a significant effect on the regional ecology and hydrological process. Based on the data of air temperature and precipitation in the Qilian Mountains and its surrounding areas from 1961 to 2022, this study analyzed the temporal and spatial variations of air temperature and precipitation in the Qilian Mountains and the relationship between precipitation and changes in precipitation with altitude. Results demonstrated a significant increase in temperature and precipitation in the Qilian Mountains in the past 60 years. The variation in temperature was the largest in the middle part of the Qilian Mountains, and the variation in precipitation was the largest in the east part of the Qilian Mountains, whereas the variation in precipitation was the smallest in the western part. The interannual variation in precipitation was the largest in August. The tendency rate of temperature increase in the Qilian Mountain area was approximately 0.36 ℃·(10a)-1, which was higher than the national level of 0.21 ℃·(10a)-1. The maximum temperature increase rate was observed in winter [0.45 ℃·(10a)-1], particularly in the western region where it was 0.5 ℃·(10a)-1. The maximum increase rate of precipitation was found in the middle region [11.86 mm·(10a)-1]. Precipitation in the Qilian Mountains and surrounding areas increased with altitude, showing two peaks. One peak was located at an altitude of 2600-2800 m, and the other was located at an altitude of 3600-3800 m. However, the relationship between precipitation and altitude was generally unimodal for each mountain. Among the mountains, the windward slope of Daban Mountain had the largest precipitation, and Qinghai Nanshan Mountain had the smallest precipitation. The climate in the Qilian Mountains exhibited warming and humidification. The annual mean minimum temperature increased faster than the maximum temperature, and the minimum temperature increased most obviously in the western part of the Qilian Mountains. The rapid increase in the minimum temperature will exert an impact on the glaciers and ecosystems of the Qilian Mountains. Figures and Tables | References | Related Articles | Metrics

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Response of NDSI in the Tarim River Basin mountainous areas to climate change over the past 20 years ZHANG Yin, SUN Congjian, LIU Geng, CHAO Jinlong, GENG Tianwei 2024, 41 (10):  1639-1648.  doi: 10.13866/j.azr.2024.10.03 Abstract ( 156 )   HTML ( 7 )   PDF (12063KB) ( 69 )   NDSI is used to evaluate the degree of surface snow cover, which plays a vital role in exploring snow cover changes in mountainous areas. In this study, remote sensing data and reanalysis data from 2001 to 2022, trend analysis, and multiple linear regression were used to analyze the spatiotemporal changes and attribution of NDSI in the mountainous areas of the Tarim River Basin over the past 20 years. Results indicated a downward trend of NDSI in the mountainous areas of the Tarim River Basin from 2001 to 2022, with significant spatial heterogeneity. The seasonal variation of NDSI was similar in the northern and western mountainous areas, with the average NDSI ranking from high to low in winter>spring>autumn>summer. However, the average NDSI in the southern mountainous areas was higher in summer than in autumn. The average annual actual evapotranspiration in the mountainous areas of the Tarim River Basin showed an increasing trend. Precipitation in the northern mountainous areas exhibited a slight downward trend, whereas that in the western and southern mountainous areas showed an upward trend. The difference in saturated water vapor pressure showed an upward trend in all mountainous areas. The downward surface solar radiation exhibited a decreasing trend. The minimum temperature in the northern and western mountainous areas showed an increasing trend, whereas that in the southern mountainous areas showed a slightly decreasing trend. The maximum temperature in all regions exhibited an upward trend. Among these variables, temperature and saturated water vapor pressure exerted a significant impact on NDSI. This study can provide a scientific basis for policy decision-making. Figures and Tables | References | Related Articles | Metrics

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Impact of land cover variations on surface albedo in Xinjiang and its surrounding Central Asian region XU Yunhong, LIU Qiong, CHEN Yonghang, WEI Xin, LIU Xin, ZHANG Taixi, SHAO Weiling, YANG Hequn, ZHANG Chengming 2024, 41 (10):  1649-1661.  doi: 10.13866/j.azr.2024.10.04 Abstract ( 129 )   HTML ( 11 )   PDF (42366KB) ( 125 )   Based on MODIS MCD12C1 land cover and MCD43C3 surface albedo data, we investigated the spatial and temporal distribution characteristics of land cover and surface albedo in Xinjiang and its surrounding Central Asian region from 2002 to 2021. We also discuss the impact of land cover change on surface albedo. Results demonstrated that (1) The net change of land cover was primarily characterized by the decrease of barren land and cropland and the increase of woodland and grassland, and the largest change was in grassland. The change of barren land around the Tarim Basin into grassland was obvious, and the problem of shrub encroachment in the arid area of Central Asia was serious. (2) The conversion of barren land into grassland and grassland into woodland resulted in a decrease of surface albedo by 0.006 and an increase of surface albedo by 0.009, respectively. The conversion of shrub encroachment resulted in an increase of surface albedo by 0.012. The conversion of grassland into barren and exerted the largest impact on surface albedo, with a change of 0.015. The mutual transformation of cropland and grassland exerted the least impact on surface albedo, with a change of <0.001. (3) The change in surface albedo was the most obvious from 2006 to 2011, with the proportion of significant change being 34.87%. (4) The change in surface albedo in the arid area was significantly higher than that in other regions, and the surface albedo in woodland was higher than that in grassland and cropland, due to which the change trend in the three land types was different from that in other regions. Figures and Tables | References | Related Articles | Metrics

Land and Water Resources

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Analysis of driving forces and dynamic evolution of water ecological security in the Gansu section of the Yellow River Basin DAI Wenyuan, MA Jiucao, CHEN Yichen, ZHENG Zhixiang, ZHANG Rui, ZHANG Jiangke 2024, 41 (10):  1662-1671.  doi: 10.13866/j.azr.2024.10.05 Abstract ( 123 )   HTML ( 11 )   PDF (7047KB) ( 46 )   This study constructed a water ecological security evaluation index system based on the W-SENCE perspective (a complex ecosystem integrating economy, society, and nature with water as the mainstay). Using statistical data from the Gansu section of the Yellow River Basin from 2003 to 2022, the Entropy-TOPSIS method, M-K analysis, and ARIMA model were used to analyze the driving forces and dynamic evolution trends of water ecological security in the Gansu section of the Yellow River Basin. The following results were obtained: (1) The ratio of runoff to pollution; reservoir regulation and storage capacity; the proportion of water consumption for forestry, animal husbandry, and fisheries; and the proportion of water consumption for farmland irrigation were the major driving factors for water ecological security in the basin. The social subsystem and ecological subsystem were the key driving factors for water ecological security. (2) From the perspective of spatial differences, the overall water ecological security status in the Gansu section of the Yellow River Basin was relatively poor (<Grade III), with the upstream consistently performing better than the downstream. The area from Lanzhou to Hekou is a key regulation zone. (3) In terms of dynamic evolution, a mutation occurred in the water ecological security status around 2013, followed by an improving trend. The section from Longyangxia to Lanzhou was a focus of attention. (4) The water ecological security status will continue to improve steadily from 2023 to 2034, with the risk of water ecological security being higher in the middle and downstream than in the middle and upstream. The area from Lanzhou to Hekou remains a key regulation zone. Figures and Tables | References | Related Articles | Metrics

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Characteristics of ecology and water resource changes in the Shiyang River Basin under the background of climate change and human activities CHENG Qian, QI Yue, LIU Mingchun, ZHANG Peng, DING Wenkui, LI Xingyu, REN Liwen, YANG Hua 2024, 41 (10):  1672-1684.  doi: 10.13866/j.azr.2024.10.06 Abstract ( 164 )   HTML ( 6 )   PDF (7760KB) ( 60 )   This study investigated the characteristics of climate factors and ecological environment changes in the Shiyang River Basin and discusses the impact of climate change and human activities on the ecological environment of the basin based on meteorological data, remote sensing data, and human data of the Shiyang River Basin. Results demonstrated that the air temperature of the Shiyang River Basin significantly increased in the past 60 years, with a warming rate of 0.40 ℃·(10a)-1. The abrupt change occurred in 1998, and the significance test of 0.05 level was passed. Annual precipitation exhibited an increasing trend, with an increase of 7.3 mm·(10a)-1, and the difference between years was large. From the perspective of spatial distribution, annual precipitation decreased from the south to the north of the basin. Dryness index revealed a decreasing trend since 1961 from the northern basin to the southern decline. The runoff of Jiutiaoling station at the exit of Xiying River in the upper reaches of the basin exhibited a weak upward trend, with an increase rate of 0.037×108 m³·(10a)-1, which was primarily affected by precipitation. Since the implementation of the 2007 Shiyang River Basin Management Plan, there have been significant changes in water resources and vegetation areas in this basin, the water discharge of Caiqi section, the average annual flow of the Shiyang River, and the area of the Qingtu Lake and its surrounding waters, wherein the vegetation increased significantly, and the groundwater level increased steadily. Under the dual influence of climate change and human activities, the ecological environment of the Shiyang River Basin has been effectively improved, which provides a scientific basis for the protection and construction of ecological environment and the rational utilization and protection of water and soil resources. Figures and Tables | References | Related Articles | Metrics

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Simulation of rainfall and snowmelt runoff on the daily scale of the Kuwei Station in the Irtysh River ZHAO Wenlong, LYU Haishen, ZHU Yonghua, LIU Han, WU Zhuojun 2024, 41 (10):  1685-1698.  doi: 10.13866/j.azr.2024.10.07 Abstract ( 117 )   HTML ( 14 )   PDF (2368KB) ( 103 )   Due to geographical conditions, there are limited hydrometeorological stations and a lack of basic data in the Irtysh River Basin, and the snowmelt flood exerts a considerable effect on the flood season and water resources management in the basin. In this study, precipitation and temperature reanalysis products and AVHRR snow cover data were applied, the K-means clustering method was used to divide the characteristics of different runoff periods, the corresponding SRM+LSTM model in different periods was constructed, and the runoff data observed in the field in 2023 were used. Results showed that the reanalysis product CMFD can be well applied to the Irtysh River Basin according to precipitation and temperature. The relationship between snow cover and runoff was divided into different runoff periods, as follows: December 11th to April 10th of the following year was the snow retreat period, April 11th to August 10th was the snowmelt precipitation runoff period, and August 11th was the precipitation runoff period. The simulation effect of the SRM model was poor, and the Nash efficiency coefficient of most runoff was<0. The SRM+LSTM model could better simulate the runoff in different periods of the basin, the deterministic coefficient could reach>0.5, and the Nash efficiency coefficient NSE could also reach>0.5, which confirms that the SRM+LSTM model can be better applied to the area with high accuracy. Figures and Tables | References | Related Articles | Metrics

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Research on the extraction method of Tianshan glacier lake based on decision tree LI Mengfan, ZHENG Jianghua, QIAN Anliang, LI Jiahui, Adiljan PARHAT, WANG Zhe, MA Lisha, WANG Nan 2024, 41 (10):  1699-1707.  doi: 10.13866/j.azr.2024.10.08 Abstract ( 107 )   HTML ( 5 )   PDF (13459KB) ( 31 )   The Tianshan region, located in the middle of the Eurasian continent, is a major distribution area of modern glaciers, and its glacial meltwater has formed a large number of and widespread glacial lakes. Glacial lakes are vital indicators of climate change and an important source of surface and groundwater supply in arid and semi-arid regions of Northwest China. The impact of topographic factors and spectral characteristics of ground objects makes it difficult to distinguish between glacial lakes, mountain shadow, and snow cover when extracting glacial lakes from remote sensing images using a single water index. In this study, based on the Google Earth Engine platform and Landsat 8 remote sensing images as the data source, a decision tree extraction method of the glacial lake was constructed according to the topographic characteristics (slope, elevation, and buffer analysis) and spectral characteristics of the glacial lake. This method was compared with the NDWI and MNDWI threshold methods. Experimental results demonstrated that the decision tree method can effectively reduce the impact of mountain shadow and snow cover and accurately extract glacial lake information. The overall accuracy of the extraction results was 89.14%, the Kappa coefficient was 0.783, and the F1 score was 87.85%. The decision tree method, which combines spatial topographic features and spectral features, is a relatively efficient extraction method for dynamic monitoring and research analysis of glacial lakes. Figures and Tables | References | Related Articles | Metrics

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Ecological stoichiometry of soil carbon, nitrogen, and phosphorus in six grassland types in northern Xinjiang LIANG Yuanye, FAN Lianlian, MA Xuexi, MAO Jiefei, HUI Tingting, LI Yaoming 2024, 41 (10):  1708-1718.  doi: 10.13866/j.azr.2024.10.09 Abstract ( 136 )   HTML ( 6 )   PDF (3535KB) ( 56 )   Spatial variations in soil carbon, nitrogen, and phosphorus concentrations, as well as their ecological stoichiometry, in grasslands are related to the function and stability of grassland ecosystems. The Irtysh River Basin exhibits a significant disparity in altitude, remarkable climate variation, and diverse grassland types that display a vertical zonal distribution. Nevertheless, there are no clear data on the influence of altitude, climate, soil properties, and vegetation on the spatial patterns of soil carbon, nitrogen, and phosphorus stoichiometry in the Irtysh River Basin, which is a typical pastoral area in Xinjiang. Therefore, this study investigated 65 sample points from six main grassland types (temperate desert, temperate desert steppe, temperate steppe, temperate meadow steppe, mountain meadow, and alpine meadow) in the Irtysh River Basin at depths of 0-10 and 10-20 cm. The following results were obtained: (1) The soil organic carbon (39.06-62.59 g·kg-1), total nitrogen (3.87-6.95 g·kg-1), and total phosphorus (0.53-1.59 g·kg-1) concentrations of alpine meadow, mountain meadow, and temperate meadow steppe were higher than the average concentrations of Chinese soil. However, the soil C:N (5.03-9.97) and C:P (7.50-52.38) ratios, as well as the soil N:P (1.53-3.72) ratios of temperate steppe, temperate desert steppe, and temperate desert, of the six grassland types were lower than the average ratios of Chinese soil (2) The concentrations of soil carbon, nitrogen, and phosphorus, as well as the C:N and C:P ratios, increased significantly with increasing altitude (328-2655 m) and precipitation and decreasing temperature. These parameters also exhibited significant correlations with soil physicochemical properties and vegetation characteristics. With increasing altitude and precipitation and decreasing temperature, the differences in soil carbon and nitrogen concentrations and soil C:P ratios gradually increased among soil layers. (3) The structural equation model revealed that altitude and climate exerted the highest impact on soil carbon, nitrogen, and phosphorus concentrations, as well as on their ecological stoichiometry. Altitude affected soil carbon, nitrogen, and phosphorus concentrations by changing the temperature, precipitation, vegetation characteristics, and soil physicochemical properties, ultimately affecting ecological stoichiometry. Future research should further explore the impact of climate change on soil carbon, nitrogen, and phosphorus concentrations, as well as on their ecological stoichiometry, at a regional scale. This study provides basic data and a theoretical basis for estimating soil nutrient storage, as well as for protecting and utilizing grassland ecosystems in the Irtysh River Basin. Figures and Tables | References | Related Articles | Metrics

Plant Ecology

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Prediction of potential suitable distribution area of Pinus bungeana in China under the background of climate change FAN Yuke, REN Ju, WANG Runlong, ZHOU Dongdong, PAN Zikai, ZHANG Xiaowei, ZHOU Xiaolei 2024, 41 (10):  1719-1730.  doi: 10.13866/j.azr.2024.10.10 Abstract ( 131 )   HTML ( 12 )   PDF (6660KB) ( 62 )   This study was conducted to predict the distribution of potential suitable area and the impact of climate change and to determine the appropriate distribution range in the future, which could provide a reference for the protection of Pinus bungeana and its utilization in ecological engineering construction. Based on 83 wild distribution sites of P. bungeana and climate factor data, the MaxEnt model and ArcGIS software were used to simulate the potential suitable zone distribution of P. bungeana under the present and three climate change scenarios (SSP126, SSP370, and SSP585) (2080-2100, low-level, medium-level, and high greenhouse gas emission scenarios). In the MaxEnt model simulation, the AUC (area value under the subject operating characteristic curve) was >0.973, and the prediction results were highly accurate. Under the present climate conditions, the potential suitable areas of P. bungeana were primarily distributed in Shaanxi Province, southern Shanxi Province, southeastern Gansu Province, northwestern Henan Province, and northwestern Hubei Province, with a total area of approximately 74.5×104 km2, under the background of future climate change. The core suitable distribution areas were reduced to different degrees, with temperature being the primary limiting factor for the distribution of the potential growth zones of P. bungeana. Under low and medium greenhouse gas emission scenarios, temperature still remained the limiting factor for the distribution of the potential growth zones of P. bungeana. Under the high greenhouse gas emission scenario, the global temperature increased faster, and rainfall was the major limiting factor affecting the distribution of the suitable area of P. bungeana. The centroid of the suitable area of P. bungeana shifted eastward, especially being more sensitive under the high emission concentration of greenhouse gases, and the migration distance was farther. This study proposes the protection of P. bungeana, and the results provide a reference for ecological engineering construction using P. bungeana. Figures and Tables | References | Related Articles | Metrics

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Spatial-temporal dynamics of vegetation light use efficiency and its driving factors on the Qinghai-Xizang Plateau QIMEI Lamu, ZHENG Cheng, YUAN Liuhuan, WU Peitong, TAN Kai, SHEN Qiaotian, SHI Haijing 2024, 41 (10):  1731-1739.  doi: 10.13866/j.azr.2024.10.11 Abstract ( 100 )   HTML ( 4 )   PDF (11262KB) ( 37 )   Investigating the spatial-temporal variation characteristics of vegetation light-use efficiency on the Qinghai-Xizang Plateau has important ecological value and practical significance for determining the carbon sink and future function maintenance of terrestrial ecosystems. This study was conducted to explore the interannual dynamic variation characteristics of vegetation light-use efficiency on the Qinghai-Xizang Plateau and its relationship with temperature, rainfall, VPD, and solar radiation using GLASS data and climate data from 1982 to 2018 and trend analysis and partial correlation analysis methods. Results showed that (1) From 1982 to 2018, the LUE of the Qinghai-Xizang Plateau vegetation ecosystem generally exhibited a significant linear growth trend, with a growth rate of 3.16×10-3 g C·MJ-1·a-1. (2) The spatial distribution of LUE in the Qinghai-Xizang Plateau vegetation ecosystem had strong spatial heterogeneity, exhibiting an increasing spatial trend from west to east. The trend analysis revealed an obvious interannual growth trend of LUE in the central and northeastern regions. (3) Temperature was more closely related to interannual changes in the LUE of vegetation than factors such as precipitation and VPD. This study provides a basis for revealing the response of the Qinghai-Xizang Plateau vegetation ecosystem to climate change. Figures and Tables | References | Related Articles | Metrics

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Study on the characteristics of changes in vegetation cover and its driving forces in the Three-North Shelterbelt program regions: Taking Ningxia as example QI Ronglian, LI Qingbo, REN Jia, ZOU Miao, YANG Haopeng, WEI Yaofeng, TANG Qiong 2024, 41 (10):  1740-1752.  doi: 10.13866/j.azr.2024.10.12 Abstract ( 126 )   HTML ( 10 )   PDF (4305KB) ( 68 )   Ningxia as the only province whose entire territory is included in the “Three-North project,” has an extremely important ecological location. This study investigated the temporal-spatial variation in the normalized difference vegetation index (NDVI) and quantified the impact of climate variations (CV) and human activities (HA) on NDVI based on various datasets (e.g., NDVI and meteorological dataset) and methods(e.g., trend analysis and residual trend analysis). The trend of future NDVI in the Ningxia was also determined using the Hurst index. Results demonstrated that (1) NDVI fluctuated, showing an increase at a rate of 7.6×10-3 a-1 during the study period. The spatial distribution of NDVI was heterogeneous, showing the characteristics of “Yellow River diversion irrigation area and southern mountainous area high and central-arid zone low.” NDVI in the Ningxia generally belonged to low-level vegetation cover (0.2<NDVI≤0.4) with a proportion of >50%. (2) NDVI exhibited an overall increasing trend across 94.94% of the total Ningxia from 2001 to 2020. Furthermore, 65.23% of vegetation of the study area in the future may be at potential risk of degradation. (3) Both CV and HA exerted a positive effect on the amelioration of NDVI, and increases in NDVI in 89.49% of the total Ningxia were controlled by the interactive effect of CV and HA. Among the climate factors, precipitation played a major role in promoting the change of NDVI. (4) The relative contribution rates of CV and HA to changes in NDVI were 43.79% and 56.21%, respectively. Overall, in future programs on vegetation restoration and ecological construction, the primary role of human activities in increasing vegetation cover should be actively exploited, and monitoring and management of the existing vegetation should be strengthened to avoid its degradation trend. Figures and Tables | References | Related Articles | Metrics

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Effects of precipitation and nitrogen deposition on transgenerational plasticity in alternate generations of Erodium oxyrhinchum SHA Tao, ZHANG Lingwei, LIU Huiliang, ZHANG Lan, LU Yuting, ZHOU Xinyu, WEN Xiaohu, ZHANG Yuanming 2024, 41 (10):  1753-1766.  doi: 10.13866/j.azr.2024.10.13 Abstract ( 90 )   HTML ( 8 )   PDF (5216KB) ( 41 )   Transgenerational plasticity is an effective method to protect offspring from environmental stress, buffering the impact of environmental changes on the offspring by increasing the probability of matching the offspring with the environment and improving the adaptability of the offspring to the environment in which they live. Therefore, this study was conducted to analyze the transgenerational differences in the response of ephemeral plants to climatic factors from the perspective of their physiological and biochemical indexes and to elucidate the effects of climatic factors on the physiological plasticity of desert ephemeral plants in transgenerational periods. For this purpose, we used Erodium oxyrhinchum, a dominant species of annual ephemeral plants with rapid growth and development and sensitive response to the environment, in combination with water and nitrogen increase treatments. We also clarified the effect of climatic factors on the physiological plasticity of desert ephemeral plants across generations. Results showed that (1) the water addition treatment significantly increased the soluble sugar (SS) content of two generations of plants, the remaining physiological indexes exhibited transgenerational differences, and the soluble protein (SP), SS, and peroxidase (POD) exhibited transgenerational adaptations under the water addition treatment. (2) The nitrogen enrichment treatment significantly inhibited the production of superoxide dismutase (SOD), POD, catalase (CAT), and malondialdehyde (MDA) in the parental plants and inhibited the production of CAT and reactive oxygen species (ROS) in the offspring plants, and the contents of SP, SOD, and POD exhibited transgenerational adaptations. (3) The water-nitrogen interaction treatment significantly promoted the production of POD, CAT, and ROS in the progeny plants but significantly suppressed the production of SOD. The production of SOD and POD was promoted, and that of CAT, MDA, and ROS was inhibited in offspring plants. SP and POD were spaced-adapted under the water-nitrogen interaction treatment. Overall, precipitation and nitrogen deposition exerted a significant effect on the transgenerational physiological plasticity of E. oxyrhinchum, and the physiological and biochemical indexes of E. oxyrhinchum exhibited different response differences to the treatment of water increase, nitrogen increase, and water-nitrogen interactions. Increased precipitation and nitrogen deposition in the future may alter the ecological adaptive capacity and strategy of the descendants of E. oxyrhinchum, which may in turn alter the future development trend of their populations. Figures and Tables | References | Related Articles | Metrics

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Effects of water and salt stress on the physiological growth characteristics of Atriplex canescens ZHANG Lingxue, LI Xiaofeng, QU Jun, MA Meiyu, ZHANG Jianbin, LI Yaoming 2024, 41 (10):  1767-1777.  doi: 10.13866/j.azr.2024.10.14 Abstract ( 115 )   HTML ( 14 )   PDF (6704KB) ( 93 )   In arid regions, soil salinity and moisture are the major factors that limit plant growth and development. Through the course of evolutionary processes, plants have evolved a myriad of physiological and ecological adaptation mechanisms to mitigate the detrimental effects of such stressors. Considering the prevalent aridity and medium soil salinity characteristic in Xinjiang, investigating plant adaptive strategies under drought and salinity stress conditions presents significant potential for advancing ecological restoration efforts within arid landscapes. Atriplex canescens, a perennial semi-evergreen shrub belonging to the Quinoa family, naturally thrives in the semi-arid regions of the Midwestern Plateau in the United States. It exhibits remarkable resilience to arid and saline environments. This study explored the physiological and growth responses of A. canescens seedlings to salt (low salt: 6.4 g·kg-1, medium salt: 13.3 g·kg-1) and water (W1: 3% soil moisture content; W2: 6% soil moisture content; W3: 9% soil moisture content; W4: 12% soil moisture content) stress using pot experiments. Results showed that (1) salt and water stress exerted a significant effect on the physiological and growth indicators of A. canescens. (2) Under different salt treatments, the levels of antioxidant enzymes (superoxide dismutase and peroxidase) and osmotic adjustment substances (starch, soluble sugars, and proline) significantly increased in W1 treatment compared with those in W4 treatment; in particular, proline and soluble sugars were more sensitive. A. canescens exhibited increased root-to-shoot ratio, specific root length, specific root area, and volume with increasing drought severity, whereas root, stem, and leaf biomass showed the opposite trend. A. canescens exhibited robust regulatory capabilities to tolerate drought stress through improvements in osmoregulation, antioxidant mechanisms, water absorption efficiency, and regulation of resource allocation. (3) The relative leaf water content significantly decreased in W1 treatment compared with that in W2 treatment. Moreover, the levels of chlorophyll a and chlorophyll b decreased in W1 treatment compared with those in W4 treatment across all salt treatments, with the exception of chlorophyll b in the medium salt treatment, where the decrease was not statistically significant. With an increase in water stress, the photosynthetic and water-retaining capabilities of A. canescens gradually weakened. (4) Correlation and principal component analyses indicated that osmotic adjustment substances and morphological indicators of A. canescens responded together to adapt to water and salt stress, explaining 31.92% of the variation in physiological and growth indicators. Thus, A. canescens demonstrates medium salt tolerance and strong physiological and ecological regulatory characteristics. Altogether, A. canescens exhibits robust salt tolerance and profound physiological and ecological regulatory traits, rendering it a viable candidate for restoration initiatives of desert vegetation. Figures and Tables | References | Related Articles | Metrics

Agricultural Ecology

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Characteristics of spatial and temporal changes and zoning of cultivated land resilience in Xinjiang JIN Chenyang, DU Hongru 2024, 41 (10):  1778-1788.  doi: 10.13866/j.azr.2024.10.15 Abstract ( 146 )   HTML ( 5 )   PDF (2867KB) ( 67 )   Based on the occurrence of resilience and the ability of cultivated land system to improve resilience, this study established a set of cultivated land system resilience evaluation index systems applicable to arid areas, with an aim to apply the resilience theory to the cultivated land system, evaluate the cultivated land system resilience and the spatiotemporal evolution characteristics of Xinjiang in the past 20 years, and propose policy suggestions on the sustainable use of cultivated land in Xinjiang from the perspective of resilience. Using grid as a scale, the resilience level of the cultivated land system in Xinjiang was measured using the comprehensive index method. Results showed that (1) The cultivated land area of Xinjiang increased during 2000-2020, and it was primarily distributed in areas with abundant water resources. (2) The resilience of the cultivated land system in Xinjiang increased slightly, but the overall level was still low, and the spatial heterogeneity was strong. In the past 20 years, the area with high value exhibited a trend of shifting to the south, primarily distributed in the valley delta area formed by the alluvial river. (3) In the past 20 years, the resilience and adaptability of the Xinjiang cultivated land system have increased, but the transformation ability has decreased. Regarding spatial distribution, the resilience and transformation ability of the cultivated land system in southern Xinjiang continuously improved, and the adaptive ability basically demonstrated a distribution pattern of “high in the north and low in the south.” Due to the different factors affecting the resilience of the cultivated land system in different regions, the cultivated land-use system was divided into five zones according to the resilience of the cultivated land system in 2020, and the specific optimization plan was proposed to improve the corresponding ability. Figures and Tables | References | Related Articles | Metrics

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Effects of different land-use methods on the organic carbon composition and soil microbial biomass carbon of farmland soil LI Na, XIN Huinan, LAI Ning, LI Yongfu, LYU Caixia, GENG Qinglong, DUAN Jingjing, CHEN Shuhuang 2024, 41 (10):  1789-1796.  doi: 10.13866/j.azr.2024.10.16 Abstract ( 138 )   HTML ( 7 )   PDF (3253KB) ( 86 )   Investigating the content characteristics of organic carbon components and microbial biomass carbon in farmland soil under different land-use methods is of considerable significance for guiding the rational utilization and management of soil resources in the Ili River Valley. By combining field investigations, sample collection, indoor analysis, and geostatistics, this study explored the content characteristics of soil SOC, POC, DOC, LFOC, EOC, and MBC in five land-use types, including dryland, irrigated land, paddy field, orchard, and abandoned land in the Ili River Valley. This study compared and analyzed the effects of land-use changes on soil organic carbon components and microbial biomass carbon in farmland in the Ili River Valley. Results showed that the contents of TN, AN, AP, and AK in soil were in the order of paddy field>irrigated land>dryland>orchard>fallow land. The nutrient content of paddy soil was significantly higher than that of the other four land-use types. The soil SOC content showed significant differences, primarily reflected in paddy fields (25.62 g·kg-1)>dryland (13.80 g·kg-1)>irrigated land (12.19 g·kg-1)>orchards (11.58 g·kg-1)>abandoned land (8.81 g·kg-1), and all reached a significant difference level (P<0.05). The contents of soil SOC, DOC, POC, LFOC, and MBC showed the characteristics of paddy field>dryland>irrigated land>orchard>abandoned land, with significant differences. The EOC content showed the characteristics of paddy field>irrigated land>dryland>orchard>abandoned land, with significant differences. The contents of SOC, DOC, POC, LFOC, MBC, and EOC in paddy soil were significantly higher than those in the other four land-use types. A highly significant positive correlation was detected between soil SOC and POC, LFOC, and DOC in the five land-use types, with the correlation coefficients being 0.622, 0.36, and 0.489, respectively (P<0.01), indicating that soil SOC content is an important factor affecting soil particulate organic carbon, light organic carbon, and soluble organic carbon contents. Figures and Tables | References | Related Articles | Metrics