Subjects: Geosciences >> Geography submitted time 2024-06-12 Cooperative journals: 《干旱区研究》
LEI Feiya
LI Xiaoshuang
TAO Ye
YIN Benfeng
RONG Xiaoying
ZHANG Jing
LU Yongxing
GUO Xing
ZHOU Xiaobing
ZHANG Yuanming。
Abstract： Biological soil crusts (BSCs) are the main active groundcover community in arid regions. BSCs can significantly affect the material cycle and energy exchange, improve the physical, chemical, and biological properties of surface soil, and influence the soil multifunctionality (SMF). Moss crust is an important type of BSCs. This study investigates the SMF variability of moss crust-covered and bare sand in the deserts of northwestern arid regions, and explored the main drivers of the variability. We analyzed eight crucial ecosystem function indicators. SMF was calculated by applying the mean method and factor analysis approach. We used the ordinary least square and structural equation modeling to explore the drivers of SMF changes. The results show that: (1) soil monofunctionality and SMF under moss crust cover were higher than those in bare sand (P<0.05). (2) The drivers of the SMF change in bare sand and under moss crust cover were very different. The main drivers of SMF in bare sand were aridity and soil water content, whereas the driver of SMF under moss crust cover was soil sand content(Sand). (3) The mean annual temperature had the largest indirect effect on changes in SMF for both soil in bare sand and under moss crust cover. Therefore, the development of moss crust significantly increased SMF and, in addition, modulated the relevant drivers of SMF. Our results are important for a deep understanding of the differences and drivers of SMF in desert soil with bare sand and under moss crust cover
Subjects: Geosciences >> Geography submitted time 2024-03-01 Cooperative journals: 《干旱区研究》
Abstract： Xylem structure traits are the basis for plant adaptation to different water conditions and are core planttraits in response to changes in environmental conditions. The typical shrubs Reaumuria soongarica andCalligonum mongolicum in the northwest desert region were selected as the subjects for comparison betweenstem xylem structure and functional traits to understand the differences or similarities of different species in thesame habitat and the xylem structure plasticity of the same species under different environmental conditions. Theresults showed that (1) Xylem structure traits of R. soongarica and C. mongolicum were significantly different.The mean vessel diameter and vulnerability index of C. mongolicum were significantly higher than those of R.soongarica, whereas the opposite was true for vessel density and vessel grouping index. (2) The patterns ofxylem structure traits in response to climate change differed between R. soongarica and C. mongolicum. Themean vessel diameter and vessel thickness-to-span ratio of C. mongolicum significantly reduced with increasingmean annual precipitation and aridity index, whereas that of R. soongarica were unrelated, and only thetheoretical hydraulic conductivity had a significant positive correlation with the mean annual precipitation andaridity index. (3) There was a trade-off between efficiency and safety in the xylem hydraulic conductivity systemof R. soongarica, whereas none was observed in C. mongolicum. (4) The trait network analysis results indicatedthat the central traits of both R. soongarica and C. mongolicum were mean vessel diameters. Changes in meanvessel diameter mediate changes in the trait network. Xylem structure traits between R. soongarica and C.mongolicum were significantly different, with R. soongarica having a more conservative water use strategy thanC. mongolicum.
Subjects: Geosciences >> Geography submitted time 2024-03-01 Cooperative journals: 《干旱区研究》
Abstract： Ecological assets refer to ecological systems that provide benefits and services to human beings.Assessing changes in ecological assets can objectively reveal the effectiveness of ecological protection efforts.Situated in the transition area between the Qinghai-Tibet Plateau and the Loess Plateau, the Huangshui RiverBasin has a fragile and sensitive ecological environment. It also has the highest population density andsocioeconomic intensity in the region, making it the key area for implementing ecological protection policies andprojects. By calculating the stock and discharge of ecological assets in the Huangshui River Basin, wecomprehensively analyze the spatiotemporal dynamic changes in ecological assets in the watershed, investigatethe driving factors behind the gains and losses in ecological assets using the geographical detectors model, andexplore the ecological protection benefits in combination with different ecological protection measures. Theresults are as follows: (1) The comprehensive index of ecological assets in the Huangshui River Basin in 2020was 30.98, showing a distribution pattern of low ecological assets in the southeast plain and high ecologicalassets in the northwest mountains. From 2000 to 2020, the comprehensive index of ecological assets increased by6.71%, indicating an overall improvement in the quality of ecological assets. (2) In 2020, the ecological assetflow value of the Huangshui River Basin was approximately 107.374 billion yuan, with the regulation servicevalue accounting for 69.50%. Over the past 20 years, ecological assets have increased by 83.116 billion yuan, ofwhich 57.123 billion yuan was attributed to regulating services. The regulation of grassland ecological resourcesprimarily contributed to the flow value, which is also influenced by the stock quality of ecological assets. (3)There was a notable spatial difference in the driving influence of ecological asset profit and loss in the HuangshuiRiver Basin. Socioeconomic factors (average contribution of 12.95%) impacted ecological asset profit and lossmore than natural factors (average contribution of 10.54%). (4) Ecological assets in the Huangshui River Basinhave shown steady improvement, and considerable success has been achieved in ecological protection andrestoration. However, the region faces challenges due to the imbalance between natural background restrictionsand economic development, leading to significant spatial differentiation in ecological assets and continuedpressure on local ecological protection. This study is of great significance for understanding the ecological statusof the Huangshui River Basin and guiding the protection of its ecological assets. Overall, the ecological assets ofthe Huangshui River Basin have improved steadily.
Subjects: Geosciences >> Geography submitted time 2024-01-28 Cooperative journals: 《干旱区地理》
Abstract：利用2012年1月至2021年12月青海省50个国家气象站和39个公路沿线交通气象站地面气象观测中的逐日降水量数据、地理信息数据、社会经济数据，在分析公路沿线暴雨洪涝发生发展规律、时空分布特征和不同强度降雨日数空间分布特征的基础上，采用层次分析法、自然断点法等方法对暴雨洪涝致灾因子风险指数、孕灾环境风险指数、承灾体风险指数、防灾减灾能力风险指数及风险综合指数空间特征进行了总结，并运用公路沿线暴雨洪涝灾害风险的孕灾环境、气象风险及防灾减灾能力等因子，构建了公路沿线暴雨洪涝灾害风险模型。结果表明：（1） 青海省公路沿线不同强度降雨日数空间分布总体呈由东南向西北递减，致灾因子危险性最高风险区至次高风险区路段包括国道G315线的西宁-天峻路段和G227线的西宁-峨堡岭等路段。（2） 暴雨洪涝孕灾环境脆弱性风险自东南、东北向西逐渐降低，孕灾环境脆弱性风险较高的路段包括国道G227线的祁连路段和G214线的共和-囊谦等路段。（3） 承灾体暴露性的最高风险区主要集中在国道G109线的民和-共和路段和G227线的西宁-峨堡岭等路段。（4） 防灾减灾能力较高的区域主要分布在青海省西宁、海东、海北东部和海西西部等路段。（5） 青海省公路沿线暴雨洪涝灾害风险模型等级划分为暴雨洪涝最低风险（1级）、次低风险（2级）、中等风险（3级）、次高风险（4级）和最高风险（5级）。该风险模型可在气象灾害风险管理业务中进行应用，为地方交通运输部门防灾减灾救灾工作提供科学依据。
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