Spatio-temporal Evaluation of Multi-scale Cultivated Land System Resilience in Black Soil Region from 2000 to 2019:A Case Study of Liaoning Province,Northeast China

It is of great significance to systematically analyze the cultivated land system resilience(CLSR) for the black soil protection and national food security.The CLSR is impacted by planting structure adjustment and cultivated land quality decline,posing major hidden dangers to food security.It is urgent to evaluate the CLSR at multiple spatio-temporal scales.This study took Liaoning Province in the black soil region of Northeast China as an example.Based on the resilience theory,this study constructed the CLSR evaluation system from the input-feedback perspective at the provincial-scale and the city-scale,and used the rank-sum ratio comprehensive evaluation method(RSR) to analyze the key influencing factors of CLSR in Liaoning Province and its 14 cities from 2000 to 2019.The results showed that:1) the time series changes of CLSR at the provincial-scale and the city-scale in Liaoning Province were similar,both showing an increasing trend.2) The CLSR in Liaoning Province presented a spatial pattern of ‘high in the west and low in the east’ at the city-scale.3) There were seven and six main influencing factors of CLSR at the provincial-scale and the city-scale,respectively.In addition to the net income per capita of rural households,other influencing factors of CLSR were different at the provincial-scale and the city-scale.The feedback factors were dominant at the provincial-scale,and the input factors and feedback factors were dominant at the city-scale.The results could provide a reference for the utilization of black soil and draw on the experience of regional agricultural planning and adjustment.

Dongbeititan dongi,the First Sauropod Dinosaur from the Lower Cretaceous Jehol Group of Western Liaoning Province,China

We herein describe a partial postcranial skeleton of a sauropod dinosaur recovered from the Lower Cretaceous Jehol Group in the Beipiao area of western Liaoning Province, northeastern China. A suite of features it possesses, including the camellate internal structure of its presacral elements, the existence of pneumatocoels on the proximal ends of the dorsal ribs, and especially the medially deflected proximal portion of the femur, definitively establish the titanosauriform affinities of the specimen. It differs from other titanosauriforms in having a craniocaudally elongate coracoid with a squared cranioventral extreme and a long, smooth, and slightly convex acetabular edge of the pubis. It represents a new taxon, Dongbeititan dongi gen. et sp. nov. Comparative studies suggest that Dongbeititan is a basal titanosauriform, more derived than Euhelopus, Fusuisaurus, and Huanghetitan, but less derived than Gobititan and Jiutaisaurus. Dongbeititan represents the first sauropod dinosaur reported from the Lower Cretaceous Jehol Group of western Liaoning Province.

The Evolution of Regional Economic Resilience in the Old Industrial Bases in China: A Case Study of Liaoning Province, China

The economic transformation of the old industrial bases is a key research topic among geographers in China.In this paper,we propose that the concept of regional economic resilience(RER)has unique theoretical value in analyzing the economic transformation of the old industrial bases.We constructed an analytical framework and an index system and applied the conceptual tools to study the evolution of RER in the old industrial base of Liaoning Province in China,which is currently subjected to not only sudden shocks but‘slow burn’—longer term processes of change that may nevertheless affect the regional economy.There are four main findings:first,the evolution of RER in Liaoning can be divided into four stages from 2000 to 2015.Liaoning is currently in its conservation-release period,and the next stage will be a release-reorganization period.Second,the RER of the majority of the studied cities is lower than the average value for Liaoning,and this is mainly attributed to the relatively weak vulnerability-resistance and adaptability-transformation capacity of these cities.Third,the RER levels of the 14 cities in Liaoning differ significantly.At the first level is Shenyang and Dalian,at the second level is Dandong and Yingkou,and the third level comprises the remaining cities.Fourth,regional economic resilience is mainly determined by vulnerability-resistance,which indirectly reflects Liaoning’s lack of adaptability-transformation capacity,and the ability of the region to renew or create a new development path is weak.

Geochronology and Petrogenesis of Mesozoic Granitoids in the Geological Corridor of Western Liaoning Province, China

The geological corridor of Western Liaoning province is an area of length 100 km and width 20 km and located in the eastern segment of northern margin of North China Craton（NCC）,with the wide distribution of Mesozoic granitic magmatism.It is the ideal area to study the granitic petrogenesis,the nature of magma source and the tectonic attribute.In this paper,we do the systematic researchesaboutthepetrology,geochronology,geochemistry and Zircon Hf isotopic of granitic rocks.Based on the mentioned above,we have built the geochronological framework and have discussed the petrogenesis,the nature of magma source and the tectonic setting of granitic rocks.And according to the information about the crust-mantle interaction recorded in granitic rocks and the regional data,we also discuss the relationship between Mesozoic granitic magma activities and lithosphere thinning,destruction of Craton mechanism in the eastern segment of northern margin of NCC.The Mesozoic granitic magma activities in The geological corridor of Western Liaoning province are divided into four stages（Fig.1）:Late Triassic（230 Ma;28 Ma）,early-middle Jurassic（194 Ma;69 Ma）,Late Jurassic（161 Ma;55 Ma）and Early Cretaceous（139Ma;21 Ma）.The late Triassic granitic rocks are composed of adamellite,monzogranite and diorite.The samples have high Sr,Cr,Ni content and low Yb,Y content,and the sample have high Mg#and high ratio of Sr/Y and La/Yb.The characteristics of inhomogenous negative value ofεHf（t）(-6.40;0.19)in magmatic zircons and ancient crustal TDM2 values of 1.25 Ga;.67 Ga（Fig.2）,indicate that the Triassic granitic rocks were formed in a post-collisional extensional tectonic setting aftersubduction of Paleo-Asian Ocean and the subduction of Yangtze Craton,and they are the product of partial melting of ancient lower crust under the condition of the mantle-derived magma underplating,and geochemical features of the high Sr and low Y are inherited from the source of magma which is also enriched in Sr and depleted in Y.The geochemical features and assemblages of rocks formed during Jurassic-early Cretaceous are similar.The early-middle Jurassic granitic rocks are composed of syenogranite,monzogranite,quartz monzonite,granitic porphyry,granodiorite and quartz diorite.The late Jurassic granitic rocks are composed of monzogranite,granitic porphyry,and quartz diorite.The early Cretaceous granitic rocks are composed of monzogranite,quartz syenite,granitic porphyry,and quartz monzodiorite.The samples are characterized by the high SiO;content and total alkalis and are belonged to the high-K calc-alkaline series.And the characteristics of quasi-aluminous to weakly peraluminous（A/CNK<1.1,A/NK>1.0）and the negative relationship between P;O;and SiO;are similar to the characteristics of I-type granite.The samples are enriched in LREE contents and K,Pb and depleted in Nb,Ta,Ti and P.The characteristics of assemblage and geochemical features indicate the Jurassic-Cretaceous granitic rocks formed in the setting of active continental margin related to the subduction.The magmatic zircons of early-middle Jurassic granitic rocks have negativeεHf（t）(-16.60;4.15)and ancient crustal TDM2 values of 1.49 Ga;.28 Ga which indicates the primary magma is from the partial melting of ancient middle-lower crust（Fig.2）.These rocks formed in the setting of active continental margin of subduction of Paleo-Pacific plate.The magma source of granitic rocks is from partial melting of the ancient lower-middle curst caused by the underplating of mantle magma,which formed in the condition of fluid derived from the dehydration of subducted slab affected on the lithosphere mantle.The magmatic zircons of late Jurassic granitic rocks have negativeεHf（t）(-26.24;18.56)and ancient crustal TDM2 values of（2.39 Ga;.87 Ga）which indicates the primary magma is from the partial melting of ancient upper-middle crust（Fig.2）.And these rocks may be formed in the setting of active continental margin of intense subduction of Paleo-Pacific plate.In the intense subduction,the mantle magma is formed in the interaction of fluid derived from the dehydration of subducted slab with the lithosphere mantle,then further underplated the ancient middle-upper crust and make the ancient middle-upper curst partial melting.In this setting,the late Jurassic rocks are distributed widely in eastern North China.The samples in early Cretaceous have a wide range of values of Hf isotope:-24.92;20.88（139 Ma）,-4.72;6.22（130 Ma）,-17.30;11.56（125 Ma;21 Ma）,and the characteristics of Hf isotope indicate the source of earlyCretaceousmagma（middle-uppercrust,middle-lower crust or juvenile crust）is very complicated（Fig.2）.The early Cretaceous granitic rocks were formed in the lithosphere extensional environment when the Paleo-Pacific plate subducted/roll-backed quickly in the direction of NNW with high angle.The regional extension made the asthenosphere upwell and be unstable,and the magma of mantle was formed.Then wide mantle-crust interactions make the crust partial melt,as a result,the source of early Cretaceous igneous rocks which are distributed widely in eastern North China Craton.The participation of depleted mantle components in the process of Late Triassic rock formation in western Liaoning area indicate the time of the lithosphere thinning in the eastern segment of northern margin of NCC begin from the late Triassic（;30 Ma）.The double subduction of Paleo-Asian Ocean and Yangtze Craton in the early period is the reason of the lithosphere thinning.After the double subduction,the mantle-derived magma upwell and underplate the lithosphere mantle and lower crust in a post-collisional extensional tectonic setting.As a result,the lithosphere began to thin but the Craton destruction was not obviously in this period.The participation of depleted mantle components makes the continental crust slightly reforms and grows.The eastern segment of northern margin of NCC was in the setting of active continental margin in Jurassic,and the continuing dehydration and metasomatism of subduction slab changed the physical and chemical properties of the lithosphere mantle.The initial weak subduction in early-middle Jurassic makes the lithosphere become thin but no obvious destruction of Craton.And in this period,the continental crust reformed and grew slightly.As the subduction became stronger during late Jurassic,the thickness of lithosphere in eastern segment of northern margin of NCC become thinner and the destruction of Craton occurred locally and the continental crust reformed and grew to some extent.In early Cretaceous,the change of direction and angle of subduction of Paleo-Pacific led to the regional extension,which is the reason for massive mantle material upwelling and intense crust-mantle interaction.And the lithosphere thinning and destruction of Craton reached the peak.As a result,the effects of reconstruction and hyperplasia of continental crust are obviously.In our opinions,the underplating mechanism of mantle-derived magma occurred mainly in the initial stage（early Mesozoic）oflithosphere thinning,and the delamination of lithosphere mantle or lower crust coexisted while erosion action of mantle material occurred in the stage（late Mesozoic）of strong lithosphere thinning and destruction of Craton.

Carrying Capacity of Marine Region in Liaoning Province

Carrying capacity is one of important studies on coordinating development of population,resources,and environment.At present,the researches on it mainly concentrate on the carrying capacity for population and economy,such as the water resources carrying capacity,the land resources carrying capacity,the environment carrying capacity,etc.Based on the related theories and methods,this paper creatively proposed the concept and meaning of carrying capacity of marine region,and formed the appraisal system.According to the developing situation of marine economy of Liaoning Province in recent years,and by employing the method of the state space,this paper also measured the carrying capacity and carrying state of marine region and discussed the sustainable problems of marine economy of Liaoning.The research results show that the carrying state of marine region of Liaoning is in the state of overloading at present,but taking a favorable turn.

Temporal and Spatial Variation Characteristics of Soil Organic Carbon Content in Cultivated Land of Black Soil Region in Liaoning Province

[Objectives]To study the temporal and spatial variation of SOC content in cultivated land in black soil region in Liaoning Province.[Methods]Through the evaluation and analysis of the research data of this project and the data of the second national soil census,and using GIS technology,this paper studied the temporal and spatial variation characteristics of SOC in the black soil region of Liaoning Province,and provided a basis for improving cultivated land carbon storage and soil organic matter content.[Results]Since 1980,the SOC content in cultivated land in the black soil region in Liaoning Province has generally declined,and the spatial distribution difference has gradually decreased.From 1980 to 2018,the homogeneity of SOC distribution weakened,and the variation in a small range strengthened.The SOC content generally showed the characteristics of increase and decrease,and the changes in the area were scattered.[Conclusions]This study is of great significance to the sustainable utilization of land resources.

Survey and Countermeasures on Current Status of Farmer Training and Education Informatization in Western Liaoning Province

This study summarized the main achievements of farmers’training and rural informatization construction in the past few years,and explored the needs of rural informatization in western Liaoning Province.The current status of agricultural development in western Liaoning and farmers’needs for education and training and rural education informatization were surveyed.The construction of an education and technical support service platform for scientific and technological farmers in western Liaoning was proposed,aiming to use information technology to train modern professional farmers.Through independent and self-learning education and training methods,it is expected to promote great improvement in the scientific and technological quality and moral level of farmers in western Liaoning and cultivate professional farmers who are educated and understand both agricultural techniques and business management.

A Mesozoic Pompeii: History of the Jehol Biota's Rise and Fall

The Jehol fauna was initially represented by a bony fish, concostracan and an insect, as a Lycoptera davidi-Eosestheria-Ephemeropsis trisetalis association,but since the researches of recent decades, the Jehol Biota is now completely different from the past low-diversity, and encompasses a native terrestrial biota that includes many well-preserved vertebrates, invertebrates and plants. There are more than 20 important biological categories, thousands of taphonomically unusual fossils, especially noted for the wide variety of biological tissues. The Jehol Biota has caused a sensation in the world with its wide distribution, large quantity, great variety, fine preservation and detailed information, which records the rise and fall of the numerous taxa, and provides significant evidence for three origins： of birds, eutherian mammals, and angiosperms. The Jehol Biota is a highlight of basic scientific research in China, and we honor it as a world-class fossil treasury and ＂a Mesozoic Pompeii＂.

Characteristics of mantle branch structure in western Shandong and its roles in minerogenesis and ore-controlling

This work deals with the characteristics of mantle branch structure in western Shandong Province, China, with respect to the distribution characteristics and ages of the regional strata, the development of ring-like and radial faults, the development of gently inclined detachment-slip structures in the axial part, mantle-source magmatic activities, regional petrology, petrochemistry and isotope geology. The study indicated that the N-W sharply plunged ductile shear zone in the region of western Shandong cuts through the mantle rocks detached from the deep-seated North China mantle sub-plume, hence leading to unloading in response to depressurization and thereafter the formation of anatexis magma. The intense and complete magmatic evolution series not only manifests a variation trend of alkalinity of magma from high to low and its intrusive depth from deep to shallow, but also reflects that the wall-rock alteration shows a general evolution trend from strong to weak. The evolution of mantle structure played an important role in controlling endo-mineralogenesis, accompanied with the rise of the country rocks. As a result, typical mantle branch structures were formed as observed in western Shandong. At the top of the mantle branch structure was developed an obvious detachment-tilt fault block, and some endogenic ores, at the same time, were uplifted onto the shallow levels.

Effect of Mesozoic volcanic eruptions in the western Liaoning Province, China on paleoclimate and paleoenvironment

Well-preserved Mesozoic vertebrate fossils were found from lacustrine deposits inter-bedded with tuff and tuffites in the lower part of the Yixian Formation, western Liaoning Province, China. The fossil-rich layers were preserved in the intermediate-acid volcanic deposits in Sihetun excavating profile. Based on the petrographic studies of samples of the tuff and tuffites collected from the profile, this paper determines major element concentrations and volatile compositions of the melt inclusions in phenocrysts and matrix glasses with electron microprobe analysis. Volatile (S, F, Cl and H2O) contents emitted into the atmosphere were estimated by comparing pre- and post-eruptive volatile concentrations. Amount of volatiles (except for water) emitted in western Liaoning are much higher than those in the historic eruptions which had a substantial effect on climate and environment. Based on the nature and amount of the gases emitted in the eruptions of western Liaoning, we present a hypothesis that volatile-rich volcanism could result in mass mortal-ity of vertebrates in the study area by injecting a large amount of volatiles (e.g., SO2, H2S, HCl, HF and H2O) into the stratosphere that would have triggered abrupt environmental and climate changes and altered lake chemistry. In terms of contents of volatile emissions, the eruptions in western Liaoning can be subdivided into the following three categories. The first group is domi-nated by HF emission, which had a fatal but possibly short-lived effect on paleoclimate and pa-leoenvironment and finally caused the mass mortality of the primitive birds. The second group presents the highest halogen concentrations emitted. However, contents of chlorine erupted is higher than those of fluorine emitted. The reactive chlorine compounds probably led to the ozone layer depletion and, therefore, caused mass mortality of most of all vertebrates including fishes, turtles and dinosaurs. The third one consists mainly of sulfur gases (primarily SO2 and H2S) re-leased. They declined the surfaces temperatures and formed large-scale toxic acid rains. Eventu-ally, such environmental trauma killed many land- and freshwater-based vertebrates and formed vertebrate (including feathered theropod dinosaurs) fossil-rich layers. The results show that the Mesozoic volcanic activities on either a large scale or frequent moderate scales in western Liao- ning could lead to mass mortality of the vertebrates.

Zircon isotopic ages from magnetite quartzites of the Jianping metamorphic complex, western Liaoning Province

Using the zircon Pb evaporation method and high precise ion microprobe analyses, zircon isotopic ages in supracrustal magnetite quartzites from Jianping metamorphic complex have been obtained. The results show that the deposition of the supracrustal rocks occurred around 2 552-2 520 Ma and the peak of granulite facies metamorphism reached at about 2 487 Ma; about (1 806±16) Ma, i.e. Mid-Proterozoic, the other possible metamorphic event with relatively low intensity happened in the study area. it is speculated that a likely tectonic setting where the Jianping metamorphic complex formed is an active Continental margin that is involved in Continental collision and crustal thickening shortly after its formation.

基于空间文化传承下的传统村落研究与保护——以瓦房店许屯村和东马屯村为例

辽南地区自古以来屡经战乱之患,致使历史遗迹损毁严重,当前遗存的传统村落亟需得到有效保护,然而并未获得足够的关注与重视。在第六批中国传统村落评选中,位于辽宁省大连市瓦房店许屯镇下的许屯村和东马屯村的入选,将辽南地区传统村落保护重新拉回到公众视野。该文选取许屯村与东马屯村作为研究个案,借助空间句法、实地调研和文献分析等多元化方法与理论,对两村的街巷空间特征进行定量化研究,深入剖析并归纳传统村落街巷空间的共性与差异。在此基础上,以空间句法所得村落指标为依据,进一步提出针对性的保护策略,旨在为辽南地区传统聚落的保护与发展提供有益的参考与借鉴。

晋西黄土区典型人工林土壤水分的垂直分布特征

【目的】探究晋西黄土区人工林恢复过程中0~500 cm土层土壤含水量垂直特征,为改善人工林土壤水环境,实现林水平衡提供理论依据。【方法】以晋西黄土区蔡家川流域5种典型人工林(刺槐Robinia pseudoacacia、侧柏Platycladus orientalis、油松Pinus tabuliformis、刺槐-侧柏、刺槐-油松)为研究对象,通过土钻烘干法测定0~500 cm土层土壤含水量,分析人工林土壤含水量的垂直特征。【结果】研究区典型人工林平均土壤含水量由大到小依次为侧柏、刺槐-侧柏、油松、刺槐-油松、刺槐,5种人工林土壤含水量差异显著(P<0.05),降水量及土壤质地是影响人工林土壤含水量的主要因素;在垂直方向上,人工林土壤含水量变异程度均为中等变异,变异系数随土层深度的增加呈减小趋势,约在360 cm土层形成稳定变化,人工植被主要影响0~360 cm土层内的土壤水,5种人工林中刺槐林地土壤水分变异程度最大,侧柏林地土壤水分最为稳定;采用有序聚类法将人工林土壤水分垂直层次划分为交换层、利用层、调节层和稳定层,不同林分间层次划分深度存在一定差异。【结论】研究区人工林可导致土壤含水量一定程度的减少,刺槐、油松、刺槐-油松林会加剧对深层土壤水分的消耗,其中刺槐林对深层土壤水分的消耗最为明显,建议在林业生态工程建设时,适当减少刺槐林面积,提高侧柏栽植比例。对现存土壤含水量较低的刺槐林,通过间伐降低林分密度,或将其改造为混交林,以期改善土壤水环境,实现林水平衡。

晋西黄土区不同密度刺槐林土壤有机碳组分及碳库特征

明晰不同林分密度下土壤有机碳组分含量及碳库特征,以期为确定刺槐林适宜人工造林密度和评价水土保持效益提供科技支撑。设置不同密度(700、1 500、1 800、2 400、3 000、3 500 plant·hm^(-2))刺槐样地,以荒草地为对照,分析0-40 cm土层土壤有机碳组分及变化规律,计算碳库活度指数(CPAI)、碳库指数(CPI)以及碳库管理指数(CPMI),解析不同密度刺槐林地土壤碳库变化,并探讨土壤理化性质对土壤有机碳及其组分变化的影响。结果表明:不同密度刺槐林地土壤有机碳及其组分的含量均随着土层深度的增加而减少,平均土壤有机碳(SOC)含量为:6.80 g·kg^(-1)(1 800 plant·hm^(-2))>5.01 g·kg^(-1)(1 500 plant·hm^(-2))>4.73 g·kg^(-1) (2 400 plant·hm^(-2))>4.17 g·kg^(-1) (3 000 plant·hm^(-2))>2.78 g·kg^(-1) (700 plant·hm^(-2))>2.68 g·kg^(-1) (3 500plant·hm^(-2))>0.52 g·kg^(-1) (CK)。随着刺槐人工林密度的增大,土壤有机碳组分及CPMI呈先增大后减小的趋势,中密度刺槐林分土壤有机碳组分含量及CPMI最大。与对照相比,0-40 cm土层,6种林分密度的土壤易氧化有机碳、稳定态有机碳含量、可溶性有机碳、颗粒有机碳和矿质结合态有机碳分别提高了77.3%-94.9%、55.8%-91.3%、86.0%-94.2%、81.4%-93.5%和79.8%-91.2%。6种林分密度土壤碳库管理指数均高于100%。相关关系分析表明土壤总有机碳含量与各有机碳组分均呈极显著正相关(P<0.010);冗余分析表明土壤全氮对土壤有机碳及其组分变化的解释率最大。因此,从森林土壤固碳功能而言,晋西黄土区刺槐人工林的适宜林分密度为1 800 plant·hm^(-2),该林分密度能较好提高土壤碳养分供给水平与碳库稳定性。

辽宁省半干旱区乡土草生态修复能力综合评价

辽西北地区气候干旱,土壤贫瘠,水土流失严重。现有研究尚未筛选出适合区域生态修复应用的草种,亟待建立科学的评价技术体系。本研究利用层次分析法构建了辽西北乡土草生态修复能力综合评价模型,并对15种优势乡土草种进行生态修复能力的评价。根据专家打分结果,选择环境适应性、水土保持能力和繁殖能力作为3个一级指标,选择抗旱性、抗寒性、广布性、耐盐性、根系生物量等14个指标作为二级指标。一级指标中,环境适应性权重最高,为0.4881,水土保持能力次之,繁殖能力最低;二级指标中,抗寒性、抗旱性、生长速度、分蘖/分枝数等的权重较高。基于待评乡土草各指标的表现,带入评价模型,筛选出铁杆蒿(Artemisia stechmanniana)、野古草(Arundinella hirta)、黄背草(Themeda triandra)、白羊草(Bothriochloa ischaemum)和羽茅(Achnatherum sibiricum)为较好的生态修复用草,为辽西北地区的生态修复提供了科学的草种选择依据。

基于MaxEnt模型的辽西地区亚洲狗獾生境适宜性分析

为掌握亚洲狗獾(Meles leucurus)生境利用及适宜生境分布格局,本研究利用2018年和2022年辽西地区的132个亚洲狗獾有效分布点,基于MaxEnt模型进行研究。结果表明:(1)地形、气候、植被和水源是影响辽西地区亚洲狗獾分布的主要环境因素。(2)辽西地区亚洲狗獾在海拔1150 m、坡度40°、归一化植被指数85%、最热月最高温24.5℃、气温年较差39℃、距河流距离100 m左右的生境出现概率最高。(3)潜在适宜生境面积约12051.13 km^(2),占研究区总面积的41.63%。高适宜生境分布较为集中,主要分布在研究区西南部的凌源、建昌、绥中和中部的喀左、朝阳等地区;低适宜生境分布较为分散,在整个研究区均有分布;中适宜生境则环绕高适宜生境,成为高、低适宜生境间的过渡区。本研究明确了辽西地区亚洲狗獾适宜生境的分布格局和限制其分布的主导环境因子,这将有助于研究亚洲狗獾在辽西地区的生态适应性,为该地区亚洲狗獾的保护和管理提供更精细的生境分布规律参考资料。

辽西半干旱区玉米花生间作对不同降水年型下产量与水分利用效率的影响

针对辽西半干旱地区降雨不足、水资源分布不均等问题,筛选出更具有韧性的适应气候变化的种植模式,通过田间试验,以玉米(MS)和花生(PS)单作为对照,研究玉米花生2行/2行(M2P2)、玉米花生4行/4行(M4P4)和玉米花生8行/8行(M8P8)这3种间作种植模式对不同降水年型下的产量和水分利用效率的影响。结果表明:不同降水年型中玉米花生间作LER均大于1,3年M2P2、M4P4和M8P8处理土地当量比(land equivalent ratio,LER)分别为1.02~1.08,1.10~1.15,1.07~1.08,表明能够提高农田的生产力。随着间作条带宽度增加,玉米的间作优势和花生的间作劣势均减弱。玉米具有边行优势,花生则存在边行劣势,同一间作处理中边1行玉米产量显著高于其他边行和玉米单作,边1行花生产量则显著低于其他边行和花生单作。发挥玉米的边行优势,降低花生的边行劣势,是实现玉米花生间作高产高效的重要途径。玉米花生间作具有稳产性,其主要原因是不同降水年型的间作玉米产量以及收获指数差异不显著。随着间作带幅变小间作玉米收获指数、单位面积穗数、穗粒数和百粒重有增加趋势,而间作花生则下降。不同降水年份间,玉米单位面积穗数和穗粒数、花生单位面积荚数和荚粒数差异显著,玉米和花生百粒重差异不显著。不同降水年型中M4P4的LER和WER均最高(1.09~1.15),是适宜在辽西半干旱地区的间作种植模式。

“候鸟式”养老模式下辽西地区乡村养老空间设计研究

辽西地区自古以来便以农业为主。进入到21世纪后,由于城市化的快速发展,辽西广袤的乡村也出现了中青年人口流失和空心化严重的现象;近年来,随着老龄化问题的加剧,这一地区的城市养老也出现了新的需求。在二者的耦合作用下,“候鸟式”养老模式应运而生。文章以此为基础,从辽西地区“候鸟”人群的特点和需求出发,总结这一新兴养老模式的空间设计原则,以居住空间、交往交流空间和康养空间的设计为主要研究方向,从细节入手,寻求适用于辽西地区乡村养老的发展之路。

辽西勿兰乌苏磷矿床地质特征及控矿因素

勿兰乌苏磷矿是辽宁省西部重要的磷矿床之一,资源储量达到大型规模,同时伴生有益组分(磁铁矿).磷矿体赋存于新太古界小塔子沟岩组,控矿因素主要为绿岩型含磷磁铁建造.矿石矿物组合为磷灰石+磁铁矿+钛磁铁矿+角闪石+黑云母+斜长石.磷灰石含量与铁钛锰等暗色组分含量呈正相关,显示了磷的亲铁性.矿床成因属于变质型磷灰石矿床.

基于信息量和机器学习的滑坡灾害易发性分析——以湖南省中西部地区为例

以湖南省中西部地区为研究区,选取地形地貌、地质条件、环境条件和人工活动4个方面15个因子构成滑坡易发性评价体系。首先,以2015—2022年发生的1 017个历史滑坡灾害数据为样本数据,采用信息量模型统计和分析影响该区域的滑坡因子重要度,结果表明该区域内地形湿度指数、土地利用类型、距道路距离、距河流距离和植被覆盖指数是影响滑坡发生的因子。然后,结合因子相关性分析,筛选其中14个因子纳入滑坡易发性分区分析,基于5种机器学习方法进行滑坡易发性建模和对比,结果表明随机森林方法在该区域针对相关的因子体系表现出的精度相对较高。最后,采用随机森林方法,按照低易发、较低易发、中易发、较高易发和高易发5个等级对研究区进行易发性分区制图,并与历史滑坡记录进行比对,结果表明易发性等级划定结果与滑坡密度基本吻合。该研究结果可以为湖南中西部地区滑坡灾害预测预报提供技术参考。