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1. chinaXiv:202006.00217 [pdf]


梅高兴; 仇式明; 陈仕语
Subjects: Psychology >> Cognitive Psychology


submitted time 2020-06-22 Hits3624Downloads383 Comment 0

2. chinaXiv:202006.00222 [pdf]

Global Dryland Ecosystem Programme (G-DEP): Africa consultative meeting report

PENG Yu; FU Bojie; ZHANG Linxiu; YU Xiubo; FU Chao; Salif DIOP; Hubert HIRWA; Aliou GUISSE; LI Fadong
Subjects: Geosciences >> History of Geosciences

In order to enhance and restore the ecosystems of natural capital in African arid regions, the Global Dryland Ecosystem Programme (G-DEP) consultative meeting was hosted in Dakar, Senegal, from 23 to 25 September 2019. This paper details the first African meeting of the G-DEP. Consultative meeting reviewed preceding dryland ecosystems case studies, identified vulnerable arid and semi-arid regions, and proposed sustainable solutions to problems. It also identified the successes and failures of previous attempts to improve vulnerable ecosystems and ultimately formed an action plan to improve these attempts. Climate, ecosystems, and livelihoods for Sustainable Development Goals (SDGs), Great Green Wall Initiative (GGWI) for Sahara and Sahel, and China-Africa cooperation on science, technology, and innovation are three extra main sections concerned of the meeting. Separately, more specific topics as the complicated relationship between these natural processes and human activity, including pastoralism, soil restoration, and vegetation regenerate techniques, were fully discussed. Consultative meeting also identified the positive effects international collaboration can have on dryland regions, specifically in the capacity of sharing information, technology, and innovation on purpose to develop a joint proposal for long-term research programs in African arid and semi-arid areas. Moreover, meetings that review the progress made on ecosystem management for the sustainable livelihoods in Africa, identification of priority areas, and the development and implementation of ecosystem programs for proper research and collaboration in African arid and semi-arid zones, have been proposed as strategic recommendations to enhance the global partnership for sustainable development. Furthermore, as the outcomes of the workshop, there are three steps proposed to handle African dryland climate changes, several aspects suggested to solve current dilemmas of the GGWI, and a series of actions recommended for G-DEP related activities in Africa.

submitted time 2020-06-22 From cooperative journals:《Journal of Arid Land》 Hits4336Downloads265 Comment 0

3. chinaXiv:202006.00223 [pdf]

Market opportunities do not explain the ability of herders to meet livelihood objectives over winter on the Mongolian Plateau

BAI Haihua; YIN Yanting; Jane ADDISON; HOU Yulu; WANG Linhe; HOU Xiangyang
Subjects: Geosciences >> History of Geosciences

Drylands under pastoral land use are considered one of the most vulnerable social-ecological systems to global climate change, but the herders' abilities to adapt to the different extreme weather events have received little attention in the drylands. Herders on the Mongolian Plateau (MP; including Inner Mongolia Autonomous Region of China and Mongolia), have had a long history of adapting climatic variability and extreme weather events. However, it is unclear how changes such as increased levels of infrastructure and market integration affect the ability of herders to achieve the key livelihood objectives: the minimisation of the death and abortion rates of livestock in the winter. Here, we used remotely sensed and household survey data to map, model and explore the climate exposure and sensitivity of herders in the settled area (Inner Mongolia of China) and nomadic area (Mongolia) in the winter of 2012–2013. We aimed to quantify the multi-scaled characteristics of both climate exposure and sensitivity through the lens of key adaptive strategies utilized by herders. Our results showed that the higher levels of infrastructure and market integration, and the lower levels of remoteness on the MP did not increase the herders' ability to achieve the key livelihood objectives. Our results also suggested that exposure to the snow that is comparatively greater than the long-term average (cumulative exposure) may be more important in determining the social-ecological vulnerability than absolute exposure. We suggested that neither the risk management strategies available to these herders, nor the demographic variables, could compensate for the mode of production governing the pastoral systems. Our study could provide further evidence for the complex and scaled nature of climate exposure and sensitivity, and the results imply that any analysis of the relationship among exposure, sensitivity and vulnerability of pastoral households to climate change in the drylands will require a multi-scaled and interdisciplinary approach.

submitted time 2020-06-22 From cooperative journals:《Journal of Arid Land》 Hits4254Downloads272 Comment 0

4. chinaXiv:202006.00224 [pdf]

Effects of rodent-induced disturbance on eco-physiological traits of Haloxylon ammodendron in the Gurbantunggut Desert, Xinjiang, China

XIANG Yanling; WANG Zhongke; LYU Xinhua; HE Yaling; LI Yuxia; ZHUANG Li; ZHAO Wenqin
Subjects: Geosciences >> History of Geosciences

Disturbance by rodents alters the morphologies and nutrients of plants as well as the physical-chemical properties of the soils. Changes in plants are considered to be mechanisms of defense against the disturbance by rodents. Rodents gnaw on the assimilating branches of Haloxylon ammodendron (CA Mey.) Bunge and burrow under the bushes in the desert ecosystems of Xinjiang, China. However, eco-physiological responses of different age groups of H. ammodendron to the disturbance by rodents are not well understood. In this study, soil physical-chemical properties under the shrubs and the above-ground morphological, physiological and biochemical features of assimilating branches of H. ammodendron of different age groups (i.e., young, 30?100 cm; middle-aged, 100?200 cm; and mature, >200 cm) in burrowed and non-burrowed (control) areas were studied in 2018. We found that disturbance by rodents significantly increased the crown width and total branching rates of young and middle-aged H. ammodendron. Photosynthetic pigment contents of assimilating branches of H. ammodendron were significantly reduced under the disturbance by rodents. In term of plant nutrients, the main differences among different age groups of H. ammodendron under the disturbance by rodents occurred in the total soluble sugar and reducing sugar contents that decreased in young plants, increased in middle-aged plants, and did not affect in mature plants. Crude protein and phosphorus contents significantly increased, while crude fiber and calcium contents significantly decreased in young plants. Crude fat and calcium contents significantly decreased in middle-aged plants. Soil organic matter (SOM), total nitrogen (TN), available nitrogen (AN) and available potassium (AK) contents in the topsoil (0–20 cm), which are conducive to forming ''fertile islands'', also increased under the disturbance by rodents. In particular, soil AN and AK were the major factors affecting the above-ground morphological characteristics of H. ammodendron in burrowed areas. Overall, the response and defense strategies of H. ammodendron to the disturbance by rodents differed among different age groups, and the effect of the disturbance by rodents on H. ammodendron gradually weakened with the increasing plant age.

submitted time 2020-06-22 From cooperative journals:《Journal of Arid Land》 Hits4353Downloads302 Comment 0

5. chinaXiv:202006.00234 [pdf]

Does cotton bollworm show cross-resistance to the Bacillus thuringiensis toxins Cry1Ac and Cry2Ab? A mini review

MA Jihong; TIAN Changyan; LYU Guanghui; MAI Wenxuan
Subjects: Geosciences >> History of Geosciences

Since 1996, transgenic Bacillus thuringiensis (Bt) cotton has been commercially grown in numerous countries in an effort to stem the losses caused by key lepidopteran pests. However, the development of pest resistance to Bt toxins has jeopardized the continued utilization of Bt cotton. As a strategy designed to circumvent the development of resistance, Bt cotton varieties expressing two or more toxins targeting the same pest have been introduced. Nevertheless, from the perspective of long-term planting of Bt cotton, the potential risk of cross-resistance to these Bt toxins is a threat that cannot be ignored. In this paper, we review current research (including that based on the analysis of protein binding sites and resistance genes) on the resistance of cotton bollworm (Helicoverpa armigera) to the Bt toxins Cry1Ac and Cry2Ab and the interrelationship between these toxins. On the basis of existing evidence, we assume that the actions of Cry1Ac and Cry2Ab against cotton bollworm are not completely independent, and then propose the ''resistance-associated gene mutation potential hypothesis''. Although the mechanisms underlying the resistance of pests to Bt toxins are yet to be comprehensively elucidated, this hypothesis could undoubtedly have important implications for adopting ''pyramid'' strategy in the future. Further research is recommended to devise strategies to retard the development of H. armigera resistance to Bt cotton, either using different Bt toxins or their various combinations.

submitted time 2020-06-22 From cooperative journals:《Journal of Arid Land》 Hits868Downloads139 Comment 0

6. chinaXiv:202006.00235 [pdf]

Origin and circulation of saline springs in the Kuqa Basin of the Tarim Basin, Northwest China

SHAN Junjie; WANG Jianping; SHAN Fashou; TENG Xueming; FAN Qishun; LI Qingkuan; QIN Zhanjie; ZHANG Xiangru
Subjects: Geosciences >> History of Geosciences

It is widely accepted that hydrogeochemistry of saline springs is extremely important to understand the water circulation and evolution of saline basins and to evaluate the potential of potassium-rich evaporites. The Kuqa Basin, located in the northern part of the Tarim Basin in Northwest China, is a saline basin regarded as the most potential potash-seeking area. However, the origin and water circulation processes of saline springs have yet to be fully characterized in this saline basin. In this study, a total of 30 saline spring samples and 11 river water samples were collected from the Qiulitage Structural Belt (QSB) of the Kuqa Basin. They were analyzed for major (K+, Ca2+, Na+, Mg2+, SO42?, Cl? and HCO3?) and trace (Sr2+ and Br?) ion concentrations, stable H-O-Sr isotopes and tritium concentrations in combination with previously published hydrogeochemical and isotopic (H-O) data in the same area. It is found that the water chemical type of saline springs in the study area belonged to the Na-Cl type, and that of river water belonged to the Ca-Mg-HCO3-SO4 type. The total dissolved solid (TDS) of saline springs in the QSB ranged from 117.77 to 314.92 g/L, reaching the brine level. On the basis of the general chemical compositions and the characteristics of the stable H-O-Sr isotopes of saline springs, we infer that those saline springs mainly originated from precipitation following river water recharging. In addition, we found that saline springs were not formed by evapo-concentration because it is unlikely that the high chloride concentration of saline springs resulted in evapo-concentration and high salinity. Therefore, we conclude that saline spring water may have experienced intense evapo-concentration before dissolving the salty minerals or after returning to the surface. The results show that the origin of salinity was mainly dominated by dissolving salty minerals due to the river water and/or precipitation that passed through the halite-rich stratum. Moreover, there are two possible origins of saline springs in the QSB: one is the infiltration of the meteoric water (river water), which then circulates deep into the earth, wherein it dissolves salty minerals, travels along the fault and returns to the surface; another is the mixture of formation water, or the mixture of seawater or marine evaporate sources and its subsequent discharge to the surface under fault conditions. Our findings provide new insight into the possible saltwater circulation and evolution of saline basins in the Tarim Basin.

submitted time 2020-06-22 From cooperative journals:《Journal of Arid Land》 Hits2660Downloads140 Comment 0

7. chinaXiv:202006.00236 [pdf]

Prediction of meteorological drought in arid and semi-arid regions using PDSI and SDSM: a case study in Fars Province, Iran

Subjects: Geosciences >> History of Geosciences

Drought is one of the most significant environmental disasters, especially in arid and semi-arid regions. Drought indices as a tool for management practices seeking to deal with the drought phenomenon are widely used around the world. One of these indicators is the Palmer drought severity index (PDSI), which is used in many parts of the world to assess the drought situation and continuation. In this study, the drought state of Fars Province in Iran was evaluated by using the PDSI over 1995–2014 according to meteorological data from six weather stations in the province. A statistical downscaling model (SDSM) was used to apply the output results of the general circulation model in Fars Province. To implement data processing and prediction of climate data, a statistical period 1995–2014 was considered as the monitoring period, and a statistical period 2019–2048 was for the prediction period. The results revealed that there is a good agreement between the simulated precipitation (R2>0.63; R2, determination coefficient; MAE<0.52; MAE, mean absolute error; RMSE<0.56; RMSE, Root Mean Squared Error) and temperature (R2>0.95, MAE<1.74, and RMSE<1.78) with the observed data from the stations. The results of the drought monitoring model presented that dry periods would increase over the next three decades as compared to the historical data. The studies showed the highest drought in the meteorological stations Abadeh and Lar during the prediction period under two future scenarios representative concentration pathways (RCP4.5 and RCP8.5). According to the results of the validation periods and efficiency criteria, we suggest that the SDSM is a proper tool for predicting drought in arid and semi-arid regions.

submitted time 2020-06-22 From cooperative journals:《Journal of Arid Land》 Hits1430Downloads129 Comment 0

8. chinaXiv:202006.00237 [pdf]


邹慧; 高光耀; 朱斌; 刘丹一; 杨文斌
Subjects: Environmental Sciences, Resource Sciences >> Basic Disciplines of Environmental Science and Technology

降水是干旱半旱地区土壤水分的主要来源,对该区植被恢复具有重要意义。本文采用EC-5土壤水分传感器对2014—2015年0~120 cm土壤水分进行连续监测,研究了退耕后不同恢复年限草地土壤水分动态变化及其0~40 cm土壤10 min时间尺度土壤水分对降水的响应。结果表明:土壤水分从恢复5 a草地向恢复15 a草地逐渐降低,这种降低趋势在恢复30 a草地减弱。恢复5 a草地土壤水分增幅最小,响应次数最少。单次降雨事件中,土壤水分增长过程和衰减过程均符合Logistic模型。恢复5 a草地相对稳定期(平台期)历时最长;恢复15 a草地土壤水分在表层(0~5,5~10 cm)增速最快,而在下层(20~40 cm)增速减慢且响应时间滞后;恢复30 a草地在下层(20~40 cm)增速最快。建议对恢复草地应适当采取措施,促进降雨向深层土壤水分转化,并减少恢复初期平台期历时。

submitted time 2020-06-22 From cooperative journals:《干旱区研究》 Hits1454Downloads117 Comment 0

9. chinaXiv:202006.00238 [pdf]

Assessing the collapse risk of Stipa bungeana grassland in China based on its distribution changes

QIAO Xianguo; GUO Ke; LI Guoqing; ZHAO Liqing; LI Frank Yonghong; GAO Chenguang
Subjects: Geosciences >> History of Geosciences

The criteria used by International Union for Conservation of Nature (IUCN) for its Red List of Ecosystems (RLE) are the global standards for ecosystem-level risk assessment, and they have been increasingly used for biodiversity conservation. The changed distribution area of an ecosystem is one of the key criteria in such assessments. The Stipa bungeana grassland is one of the most widely distributed grasslands in the warm-temperate semi-arid regions of China. However, the total distribution area of this grassland was noted to have shrunk and become fragmented because of its conversion to cropland and grazing-induced degradation. Following the IUCN-RLE standards, here we analyzed changes in the geographical distribution of this degraded grassland, to evaluate its degradation and risk of collapse. Past (1950–1980) distribution areas were extracted from the Vegetation Map of China (1:1,000,000). Present realizable distribution areas were equated to these past areas minus any habitat area losses. We then predicted the grassland's present and future (under the Representative Concentration Pathway 8.5 scenario) potential distribution areas using maximum entropy algorithm (MaxEnt), based on field survey data and nine environmental layers. Our results showed that the S. bungeana grassland was mainly distributed in the Loess Plateau, Hexi Corridor, and low altitudes of the Qilian Mountains and Longshou Mountain. This ecosystem occurred mainly on loess soils, kastanozems, steppe aeolian soils and sierozems. Thermal and edaphic factors were the most important factors limiting the distribution of S. bungeana grassland across China. Since 56.1% of its past distribution area (4.9×104 km2) disappeared in the last 50 a, the present realizable distribution area only amounts to 2.2×104 km2. But only 15.7% of its present potential distribution area (14.0×104 km2) is actually occupied by the S. bungeana grassland. The future potential distribution of S. bungeana grassland was predicted to shift towards northwest, and the total area of this ecosystem will shrink by 12.4% over the next 50 a under the most pessimistic climate change scenario. Accordingly, following the IUCN-RLE criteria, we deemed the S. bungeana grassland ecosystem in China to be endangered (EN). Revegetation projects and the establishment of protected areas are recommended as effective ways to avert this looming crisis. This empirical modeling study provides an example of how IUCN-RLE categories and criteria may be valuably used for ecosystem assessments in China and abroad.

submitted time 2020-06-22 From cooperative journals:《Journal of Arid Land》 Hits2580Downloads144 Comment 0

10. chinaXiv:202006.00239 [pdf]

Snow resisting capacity of Caragana microphylla and Achnatherum splendens in a typical steppe region of Inner Mongolia, China

YAN Min; ZUO Hejun; WANG Haibing; DONG Zhi; LI Gangtie
Subjects: Geosciences >> History of Geosciences

Snow resisting capacity of vegetation is important for secondary distribution of water resources in seasonal snow areas of grassland because it affects the regeneration, growth and nutrient circulation of vegetation in grassland. This study investigated vegetation characteristics (canopy height, canopy length and crown width) of Caragana microphylla Lam. (shrub) and Achnatherum splendens (Trin.) Nevski. (herb), and snow morphologies (snow depth, snow width and snow braid length) in a typical steppe region of Inner Mongolia, China in 2017. And the influence of vegetation characteristic on snow resisting capacity (the indices of bottom area of snow and snow volume reflect snow resisting capacity) was analyzed. The results showed that snow morphology depends on vegetation characteristics of shrub and herb. The canopy height was found to have the greatest influence on snow depth and the crown width had the greatest influence on snow width. The canopy length was found to have little influence on morphological parameters of snow. When the windward areas of C. microphylla and A. splendens were within the ranges of 0.0–0.5 m2 and 0.0–8.0 m2, respectively, the variation of snow cover was large; however, beyond these areas, the variation of snow cover became gradually stable. The potential area of snow retardation for a single plant was 1.5–2.5 m2 and the amount of snow resistance was 0.15–0.20 m3. The bottom area of snow and snow volume (i.e., snow resisting capacity) of clumped C. microphylla and A. splendens was found to be 4 and 25 times that of individual plant, respectively. The results could provide a theoretical basis both for the estimation of snow cover and the establishment of a plant-based technical system for the control of windblown snow in the typical steppe region of Inner Mongolia.

submitted time 2020-06-22 From cooperative journals:《Journal of Arid Land》 Hits864Downloads112 Comment 0

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