Impact of Vegetation Restoration on Soil Fungal Community Structure in Karst Rocky Desertification Areas

In this paper,managed forest(MF)and natural forest(NF)in the Huajiang Demonstration Zone of Guanling,Guizhou were selected as research objects,and cropland(CL)was taken as control.High-throughput sequencing technology was used to study the characteristics of fungal community composition and species diversity in the surface(0-10 cm)soil of each restoration measure,in order to reveal the dominant soil fungal groups and fungal community composition in karst rocky desertification areas,which was conducive to a more comprehensive understanding of the soil conditions of different vegetation restoration measures.Research has shown that vegetation restoration significantly affected the diversity of soil fungal community,with significant increases in Sob index,Ace index,and Chao index.The vegetation restoration has significantly changed the composition of fungal community.The dominant fungi in the CL topsoil are Sordariomycetes(62.28%),Dothideomycetes(12.34%),and Eurotiomycetes(9.12%);the dominant fungi in the MF soil are Sordariomycetes(45.05%),Dothideomycetes(14.74%),and Mortierellomycetes(10.40%);the dominant fungi in the NF soil are unclassified fungal community(26.38%),Sordariomycetes(19.78%),and Agaricomycetes(13.82%).Vegetation restoration has changed the key fungal groups in the soil.Sordariomycetes,Fusarium,and Setophoma are the key dominant fungal groups in CL soil;Dioszegia is key dominant fungal group in MF soil;c_unclassified_k_Fungi,p_unclassified_k_Fungi,o_unclassified_k_Fungi,f_unclassified_k_Fungi,g_unclassified_k_Fungi,Teichospora,and Diaporthe are key dominant fungal groups in NF soil.

Remote sensing monitoring of the recent rapid increase in cultivation activities and its effects on desertification in the Mu Us Desert, China

The recent ecological improvement in the Mu Us Desert of China, largely attributed to large-scale afforestation projects, has created new opportunities for cultivation activities. However, the subsequent rapid increase in reclamation on desertification land and its impact on desertification have raised concerns. In this study, we first extracted data on cultivated land and desertification land in 1975,1990, 2000, 2005, 2010, 2015, and 2020 through the human-computer interaction visual interpretation method. By overlaying the cultivated land dynamics and desertification land, we subsequently explored the effect of cultivation activities on desertification in the Mu Us Desert during the six periods from 1975 to 2020(1975–1990, 1990–2000, 2000–2005, 2005–2010, 2010–2015, and 2015–2020). The results showed that cultivated land in the Mu Us Desert showed a fluctuating and increasing trend from 3769.26 km~2 in 1975 to 4865.73 km~2 in 2020, with 2010 as the turning point for the recent rapid increase. The main contributors included the large and regular patches distributed in Yuyang District and Shenmu of Shaanxi Province, and relatively smaller patches concentrated in Inner Mongolia Autonomous Region. The increased cultivated land from the reclamation on desertification land was dominated by moderate and severe desertification lands, and the decreased cultivated land that was transferred into desertification land as abandoned cultivated land was dominated by slight and moderate desertification lands. The effect of cultivation activities on desertification reversal(average area proportion of 10.61% for reversed desertification land) was greater than that of the development of desertification(average area proportion of 5.82% for developed desertification land). Nevertheless, compared to reversed desertification land,both the significant increase of developed desertification land during the periods of 2000–2005 and 2005–2010 and the insignificant decrease during the periods of 2005–2010, 2010–2015, and 2015–2020 implied a potential remobilization risk. Therefore, this study provides a significant theoretical reference for the formulation of ecological restoration projects and regional macroeconomic development policies by considering the influence of cultivation activities, to ensure the overall environmental stability and sustainability in desertification land where reclamation and abandonment activities have taken place.

Soil quality assessment for desertification based on multi-indicators with the best-worst method in a semi-arid ecosystem

Since there are some signs of land degradation and desertification showing how soil sustainability is threatened, it is crucial to create a soil quality index(SQI) model in the semi-arid ?orum Basin, situated between the Black Sea and Anatolia Region, Central Turkey. The primary aims of the study are:(1) to determine SQI values of the micro-basin in terms of land degradation and desertification.Moreover, the best-worst method(BWM) was used to determine the weighting score for each parameter;(2) to produce the soils' spatial distribution by utilizing different geostatistical models and GIS(geographic information system) techniques;and(3) to validate the obtained SQI values with biomass reflectance values. Therefore, the relationship of RE-OSAVI(red-edge optimized soil-adjusted vegetation index) and NDVI(normalized difference vegetation index) generated from Sentinel-2A satellite images at different time series with soil quality was examined. Results showed that SQI values were high in the areas that had almost a flat and slight slope. Moreover, the areas with high clay content and thick soil depth did not have salinity problems, and were generally distributed in the middle parts of the basin. However, the areas with a high slope, poor vegetation, high sand content, and low water holding capacity had low SQI values.Furthermore, a statistically high positive correlation of RE-OSAVI and NDVI indices with soil quality was found, and NDVI had the highest correlative value for June(R~2=0.802) compared with RE-OSAVI.

An Inspiring Triumph Ethiopia can learn from China’s reversing desertification and promoting a green future

Minqin County,located in the arid Gansu Province of northwest China,has a remarkable story of hope and triumph.The residents of the region faced challenges due to the unrelenting expansion of desertification,which led to the degradation of their land.Determined to fight against the invading sand,the people of Minqin embarked on a great journey to reclaim their land from the desert and prevent the sand dune expansion.Despite the rapid desertification and land degradation that Minqin was facing,with unfaltering determination and well-implemented strategies,it has emerged as a shining example of how countries facing similar environmental issues,such as Ethiopia,can tackle desertification.Minqin’s desertification drive rests on its commitment to reverse the adverse impacts of desert expansion through afforestation.

云南省岩溶地区石漠化土地治理分区研究

根据云南省岩溶地区石漠化土地空间分布特征和各区域地质地貌、气候、水文、岩溶土壤和森林植被分布,结合碳酸盐岩的类型、岩性组合特征、不同岩溶地貌对区域环境和水土资源的制约、石漠化在不同地貌条件下的形成和发育特征,统筹考虑岩溶生态系统的完整性、地理单元的连续性和经济社会发展的可持续性等因素,将全省88个岩溶监测县划分为6个治理区,并就各分区地理区位、地质地貌、成土母岩、水文、气候类型、森林植被类型分布以及各石漠化区不同类型岩溶土地面积占比等进行描述。

提示对学习者自我生成教学过程和学习效果的作用

研究主要探讨了自我生成教学中不同类型的提示对学习效果和学习感知的影响。实验1发现自我生成教学的学习效果好于重复学习。实验2对比了图片、文字、关键词三种提示和无提示的效果。结果发现图片和关键词提示具有更好的学习效果。实验3设置了关键词提示组、生成提示组和无提示组。结果发现关键词提示和生成提示的保持成绩好于无提示,生成提示的迁移成绩好于无提示。此外,关键词提示和生成提示可以促进学习者产生更多的概念单元。结论认为:(1)在自我生成教学时获得图片提示能促进知识保持,获得关键词提示能促进知识保持和迁移。(2)相比于被动获得提示,学习者主动生成提示更能促进知识迁移。(3)概念单元数量在提示影响学习效果中起中介作用。

石漠化地区不同配方施肥下九叶青花椒产量与生长和养分储存的关系

【目的】揭示配方施肥下九叶青花椒产量与枝梢和根系生长、养分积累之间的关系,为提高花椒幼年期的经济产量及提前进入丰产期提供依据。【方法】在赤水河流域的遵义市播州区三合镇人工种植九叶青花椒林地设置样地,设置N、P和K共3个肥料因素,各因素均设置4个施肥水平,分析不同施肥处理对幼年期九叶青花椒枝梢和根系生长、非结构性碳水化合物含量、花芽分化率、结果枝率、穗粒数和产量等的影响。【结果】以尿素590 g/株、过磷酸钙1335 g/株、硫酸钾480 g/株、硼肥10 g/株、有机肥10 kg/株处理促进效果最佳,可显著提升九叶青花椒的花芽分化率、结果枝率、穗粒数、千粒重、坐果率和产量,其中,产量在各处理中最高,达1.088 kg/m^(2),比不施肥对照高73.49%。施肥改变养分在生长、养分贮藏以及生殖(开花结实)间的资源分配,施肥促进枝梢和根系生长,有利于植株获取养分,进而促进结实。产量与穗粒数显著相关,表明施肥能促进花芽分化且减少落花落果。施肥也促进枝条和根系可溶性糖含量积累,进而提高植株抗逆性。【结论】施肥可促进九叶青花椒养分积累、抗逆性提高(主要是对冬季低温),减少落花落果,进而提高产量。

土壤侵蚀原理课程思政建设与思考

在课程思政建设背景下,以专业课程思政建设、改革与人才培养质量提升为目的,分析土壤侵蚀原理课程思政建设的价值,确立土壤侵蚀原理课程思政建设的原则与目标,探讨土壤侵蚀原理课程思政建设的内容、建设环节与方式等,并提出对土壤侵蚀原理课程思政建设的思考。以期推动土壤侵蚀原理课程思政建设与改革的同时,促进水土保持与荒漠化防治专业知识传授、学生能力培养和思政教育全面协同发展。

云南省岩溶地区石漠化草原现状及分区保护与修复策略

据最新调查数据,云南省石漠化草原主要分布于曲靖、昆明、红河等5个州(市),总面积37.97万hm2,占岩溶土地面积的3.53%,其分布最广的海拔区间为1 500~2 500 m,占比47.85%,基岩裸露度分布区间为30%~94%,以植被盖度为10%~19%的分布区间面积最广,占比37.85%,绝大部分分布于土层薄甚至极薄区域,占比达92.10%。根据石漠化草原空间分布特征,在充分衔接各大生态保护和修复工程建设规划基础上,统筹考虑岩溶生态系统的完整性、地理单元的连续性和经济社会发展的可持续性,将云南省石漠化草原区划为6个分区,分区阐述石漠化草原生态保护与修复策略。

云南省岩溶地区石漠化耕地现状及治理策略

云南省石漠化土地面积212.85万hm^(2),占岩溶土地面积的19.81%,其中石漠化耕地面积46.36万hm^(2),占石漠化土地面积的21.78%,石漠化耕地以轻度石漠化和中度石漠化土地为主,集中分布在人口稠密、经济欠发达地区。目前云南省石漠化治理存在着投资标准低,投入不足,治理需求大,成果巩固压力大,管理体制不顺,地方配套资金筹措困难等问题。藉此,提出遵循水土保持原则,因地制宜,改善农业条件,大力发展林禽林下经济模式,持续推进石漠化综合治理工程,节约集约用地,严把耕地红线关,降低石漠化区域耕地承载压力,遏制石漠化耕地发生等治理策略。

剑麻专用肥对石漠化山区剑麻生长及产量的影响

石漠化山区自然条件恶劣,剑麻具备耐瘠薄、耐旱、综合利用价值高、发展前景广阔等特点,成为石漠化山区产业扶贫的较好选择。试验结果表明,剑麻新增叶片数、叶长和鲜叶产量随专用肥施入量增加而增加,每株剑麻施用专用肥量为200 g时,鲜叶产量、经济效益最高。该结论为石漠化山区剑麻高产栽培技术提供技术参考。

基于TF-IDF算法的运营商客户投诉原因研究

针对运营商人工处理客户投诉工单高成本低效率问题,提出了一种基于TF-IDF算法的定量研究方法,旨在高效精准地识别客户投诉原因。选用Jieba分词,导入自定义词典和停用词列表,对运营商客户投诉工单进行关键词抽取,获取各类问题中TF-IDF值排名前6的关键词,输出关键词集。提高了关键词抽取的准确性和效率。此外,对比仅对文档集使用TF进行统计和使用TextRank算法的情况,突显了IDF的重要性及算法原理的差异。实验结果表明,光猫、路由器、机顶盒问题广泛存在于各类投诉中。针对这三类问题,为运营商提供了改进产品、服务的相关建议,对运营商集中治理、解决问题具有一定的实用价值。

“四大奇书”连称的关键词批评及阅读史意义

作为古代通俗章回小说一类重要的接受现象,历代读者尝试将《三国演义》《水浒传》《西游记》《金瓶梅》连称为“四大奇书”。基于特定的社会情境,“四大奇书”的连称往往会限定通俗章回小说各种意义符号被诠释的可能性与可行性,既限定世人批评行为的介入方式,亦影响世人诠释实践的逻辑。“四大奇书”的关键词批评不仅是一个批评论断,而且作为一类认知视角而存在,更是一种批评行为。它促成了一定的群体习惯,改变了读者阅读的理解途径与意见生成,最终形成一种阐释范式,反过来制约读者的自由阅读。探讨“四大奇书”连称的阅读史意义,既要注意历代文教生态之于文本阐释的群体性表达,亦应重视读者个体建构的艰难努力。

基于信息可视化的非线性超声研究现状及成熟度分析

基于信息可视化分析,对非线性超声的研究现状进行分析。检索Web of Science数据库,得到非线性超声相关文献4061篇。对关键词进行可视化分析及聚类分析,非线性超声领域关键词主要涉及6个方面,目前主要侧重于理论研究。对于应用范围,在微裂纹、结构监测等方面具有应用前景。对非线性超声的论文数及专利数进行技术成熟度分析,结果表明其处在技术发展的增长期。

胃肠间质瘤影像诊断及病理分析研究热点可视化分析

目的对比分析中外数据库中有关胃肠间质瘤(GIST)影像诊断及病理分析研究的侧重点和学科发展情况。方法本研究以GIST影像诊断及病理分析研究为例,统计了中国知网(CNKI)和Web of Science(WOS)数据库有记录以来至2023年6月的文献发表、关键词等情况,利用趋势分析、关键词统计、基于文献可视化软件(VOSviewer)的热点分析等方法,对比分析两个数据库的文献研究热点。结果有关GIST的影像诊断及病理分析的研究自1993年出现,2010年以后研究热度在不断提高;CNKI数据库中的文献研究热点较为集中,主要为案例分析和诊断方法比较,而WOS数据库中的文献思路和关键词涉及领域则较为开阔,通常涉及较多医学相关领域,且包含大量病情分析、模型模拟、患病机制等研究难点。结论相较于WOS数据库,CNKI数据库中的相关文献在研究深度和主要关键词方面还存在一定的滞后性和局限性,有待进一步提升。

基于CiteSpace的河洛文化研究态势分析

河洛文化是中华民族的根文化和中国传统文化的源头。研究解读河洛文化,对于建设新时代中华民族精神家园,实现中华民族伟大复兴意义重大。基于SiteSpace科学文献计量知识图谱研究方法,以1984~2023年间中国知网收录的757篇河洛文化论文为研究对象,从“发文时间分布”“关键词共现”“关键词聚类”“关键词突显”4个方面,探究其发展历程与现状。目前,河洛文化研究虽然取得了一系列丰硕成果,但仍有需要深入拓展的学术领域。

模拟干旱条件对重度石漠化土壤易提取态腐殖质光化学行为的影响

为探讨光照对土壤腐殖质直接光反应的影响,采集重度石漠化土壤模拟干旱条件,探讨不同波段紫外线(长波黑斑效应紫外线(UVA)、中波红斑效应紫外线(UVB)、短波灭菌紫外线(UVC))照射对重度石漠化土壤腐殖质易提取态光化学行为的影响。结果表明:(1)土壤有机碳质量分数无明显变化,UVA和UVB组全氮质量分数随照射时间逐渐增加,而UVC组逐渐减小,碳氮质量分数比与全氮质量分数变化相反;(2)由于氮损失造成含氮水溶性的芳香类物质减少,导致UVC组水提液整体呈现疏水组分减少的状态,而脂肪链类的疏水官能团整体均呈增加趋势,A_(250)/A_(365)值同样支持上述结论;(3)以甲醇为提取剂时,UVA、UVB、UVC组的芳香性及相对分子质量均减小,且变化程度明显大于水提液的变化,均以腐殖酸为主且有向富里酸转化的趋势,S_(254)、S_(260)、A_(253)/A_(203)值均表明不溶于水的极性物质的芳香性和疏水组分均减少;(4)以正己烷为提取剂时,S_(254)、S_(260)、A_(253)/A_(203)值均表明不溶于水的非极性物质的芳香性和疏水组分均减少。故增加甲醇和正己烷的提取能够印证结论(2),并补充水提液无法提取非水溶性物质的不足,同时拓展了紫外光谱技术在腐殖质表征技术方面的应用。综上所述,不同波段紫外线光照能对重度石漠化地区土壤腐殖质组成及相关性质产生不同程度改变,并且可以通过改变氮素的固定与释放,影响石漠化土壤生态的碳氮循环过程。

可持续发展实验区石漠化时空演变及其驱动机制研究——以广西恭城县为例

西南喀斯特地区是我国实施可持续发展战略的重要地区,同时也是生态环境极为脆弱、石漠化集中分布的地区,但有关可持续发展实验区石漠化的内在演化机制研究还较少涉及。以广西恭城县国家可持续发展实验区为例,利用2000年、2005年、2010年、2015年和2021年遥感影像为数据源,采用人机交互解译法进行石漠化信息提取,定量分析了恭城县石漠化的时空演变规律及其成因机制。结果显示,恭城县石漠化主要经历了2000-2005加速恶化、2005-2015年快速改善和2015-2021年缓慢恶化三个阶段,石漠化总面积在88.96~229.55 km^(2);2000-2005年,恭城县石漠化表现为无石漠化向轻度和中度石漠化转移,2005-2021年呈逆向改善。西岭镇、莲花镇、平安镇是石漠化发生的主要地区,占全县石漠化总面积的55.47%~61.31%。灰岩区发生的石漠化面积为104.03 km^(2),占石漠化总面积的72.91%;园地内发生的石漠化面积为56.26 km^(2),占比为38.12%。结果表明:灰岩区强烈的岩溶作用,以及长期种植的单一经济果林遭大面积砍伐,是导致近年恭城县石漠化加重的主要原因。

经济林生态种植对石漠化区土壤细菌群落的影响

为探究经济林生态种植对石漠化区土壤细菌群落的影响,选取滇东南石漠化地区两种自然修复样地(灌草自然修复地和乔灌草自然修复地)和两种经济林生态种植修复样地(猕猴桃种植修复地和核桃种植修复地)进行土壤细菌群落结构和多样性实验。结果表明:灌草自然修复地和乔灌草自然修复地土壤细菌群落丰富度和多样性低于猕猴桃种植修复地以及核桃种植修复地,在灌草自然修复地、猕猴桃种植修复地和核桃种植修复地土壤细菌群落中以变形菌门、放线菌门、酸杆菌门和绿弯菌门最丰富,乔灌草自然修复地土壤细菌群落主要以变形菌门、放线菌门、酸杆菌门以及拟杆菌门最丰富。乔灌草自然修复地主要作用菌种是酸杆菌属;灌草自然修复地主要作用菌种是放线菌门和嗜热油菌纲;猕猴桃种植修复地和核桃种植修复地主要作用菌种则分别是芽单胞菌门和绿弯菌纲。将不同修复样地下的土壤细菌与环境因子作相关性分析,结果表明土壤全钾和速效钾浓度随植被由猕猴桃种植修复地、核桃种植修复地到灌草自然修复地和乔灌草自然修复地的变化呈下降趋势,相比之下,土壤氮、磷、有机质、pH值在自然恢复后呈现出微弱的恢复趋势。

小生境尺度下喀斯特弃耕地植物多样性、生物量及其影响因素

深入探讨小生境尺度下物种多样性及其影响因素,可以为弃耕地演替早期群落恢复提供理论依据。本研究以重庆喀斯特典型弃耕地(弃耕年限为4~6年)为研究对象,根据地下特征选出均质浅土、均质深土、异质梯型和异质漏斗型4种小生境并对其进行植物群落调查,分析不同小生境的土壤理化性质、生物量和物种多样性变化及其之间的关系。结果表明:1) 4种小生境中土壤含水量随着土壤深度的增加呈增加趋势,但总氮含量和碳氮比随着土壤深度的增加呈降低趋势;在2种异质生境中,土壤深度、土壤含水率的变异系数相差不大,均属于高等变异强度。2)不同小生境之间的物种丰富度指数、香农-维纳指数和均匀度指数无显著差异。3)各小生境的地上生物量之间无显著差异,异质性生境的地下生物量和总生物量均高于均质性生境。4)不同小生境中仅异质漏斗型的生物量与多样性存在显著负相关关系(P<0.05)。资源异质性对喀斯特弃耕地演替早期群落生物量产生了积极影响,但物种多样性在该阶段受生境的影响不大。中等厚度土壤促进了植物的生长、有利于生产力的维持。因此在植被恢复的早期阶段,应充分利用各生境类型特点,维持植物的多样性及其生长。