Changes in Ecosystem Service Values on the Loess Plateau in Northern Shaanxi Province,China

The Loess Plateau in northern Shaanxi Province of China covers Yulin, Yan＇an, and Tongchuan cities mainly. The kind of physiognomy is complicated and various, including the transitional region of the sand and wind, the hilly-gully fragile region, the pimple mound region from North to South. Large-scale land reclamation projects that are severely affecting these ecosystems have been implemented. In this paper, we reported an investigation to the changes in land use and ecosystem services on the Loess Plateau in northern Shaanxi Province from 1978 to 2000. We used three LANDSAT TM and/or ETM data sets to estimate the changes in the size of five land-cover/land-use categories, and we also used previously published value coefficients to estimate the changes in the value of ecosystem services delivered by each land category. Finally, we ranked the contribution of various ecosystem functions to the overall value of the ecosystem services, we have estimated that the annual value of the ecosystem services is 56.95 billon RMB yuan in the Loess Plateau in northern Shaanxi Province in 2000. In the region, from 1978 to 2000, the economic value of the fixing carbon was higher, the economic value of water conservation was the lowest, but the economic value of the NPP, fixing carbon, and supplying oxygen accounted for above ninety percent of the total value, obviously the vegetation created the biggest ecosystem service value. We can conclude that future land-use policy formulation should give precedence to the conservation of these ecosystems over uncontrolled reclamation, and that further land reclamation should be based on rigorous environmental impact analyses.

Quantitative analysis of the dynamic change and spatial differences of the ecological security: a case study of Loess Plateau in northern Shaanxi Province

Using the theory and method of the ecological footprint, and combining the changes of regional land use, resource environment, population, society and economy, this paper calculated the ecological footprint, ecological carrying capacity and ecological surplus/loss in 1986-2002 on the Loess Plateau in northern Shaanxi Province. What is more, this paper has put forward the concept of ecological pressure index, set up ecological pressure index models, and ecological security grading systems, and the prediction models of different ecological footprints, ecological carrying capacity, ecological surplus and ecological safety change, and also has assessed the ecological footprint demands of 10,000 yuan GDE The results of this study are as follows： （1） the ecological carrying capacity in northern Shaanxi shows a decreasing trend, the difference of reducing range is the fastest; （2） the ecological footprint appears an increasing trend; （3） ecological pressure index rose to 0.91 from 0.44 during 1986-2002 on the Loess Plateau of northern Shaanxi with an increase of 47%; and （4） the ecological security in the study area is in a critical state, and the ecological oressure index has been increasing rapidlv.

Change Characteristics and Cause Analysis of Summer Precipitation Anomaly in Loess Plateau of Northern Shaanxi Province

[ Objective] The research aimed to study change characteristics and formation cause of summer precipitation abnormality in Loess Plateau of northern Shaanxi Province. [ Method] Based on summer precipitation data at 15 observation stations in Loess Plateau of northern Shaanxi Province and NCEP/NCAR dataset from 1961 to 2008, change characteristics of summer precipitation in the region were investigated by using linear trend estimation and composite analysis. [Result] Summer rainfall had decrease trend in most parts of northem Shaanxi Province, but had increase trend in western and southern regions. The interannual and interdecadal variations were obvious. It had a large amount of precipitation from the mid- 1970s to the mid-1990s, while summer rainfall had decrease trend after the mid-1990s and increase trend in recent years. In wet years, it was a large positive anomaly zone from western Ural Mountains to northem Lake Baikal at middle and high latitudes, indicating that there was a blocking high over the Ural Mountains, while it was negative anomaly zone from northern Okhotsk Sea to Lake Baikal. From Northwest Pacific Ocean to Bo- hal Sea Bay and North China, it was a wide range of significant positive anomaly zone, which was favorable for Westem Pacific subtropical high ex- tending westward and northward. The analysis in dry years showed opposite circulation configuration. It was ＂ -, ＋, -＂ wave train distribution in middle and high latitudes and positive anomaly zone along the Sea of Okhotsk. Western Pacific subtropical high was also by south and east. Major water vapor was from southeast direction in wet years, and abundant water vapor caused more summer rainfall in northern Shaanxi. In dry years, water vapor was from westerly tuming southerly flow. It was weaker and by east. [ Conclusion] The research provided reference for reasonable utilization of summer precipitation in the zone.

Division of diagenesis reservoir facies and its control——Case study of Chang-3 reservoir in Yangchang formation of Fuxian exploration area in northern Shaanxi

By dividing the diagenetic reservoir facies and studying its distribution,we can effectively evaluate reservoirs.Using an analytical method for mutual relationships among diagenesis of reservoirs,structural characteristics and the origin of types of sand,we classified the diagenetic reservoir of the Yanchang formation Chang-3 oil layer into different types and analyzed the factors controlling this high quality reservoir.The results show that:1) the catagenesis of the Chang-3 oil layer in the Fuxian region is complex and variable;2) mechanical compaction,pressure solutions and cementation of all kinds of authogenous minerals decreases porosity by 28.13% and 3) corrosion increases porosity by 3.39%.Cementation and corrosion of laumontite is a kind of catagenesis which makes this region different from other exploratory regions.The original amount and rate of corrosion of laumontite are the main factors for the increase in laumontite porosity.The Chang-3 oil layer developed four kinds of diagenetic reservoir facies,of which the weak compaction facies,i.e.,laumontite corrosion and overgrowth,of the original pore reservoir facies has the most promising diagenesis.Its distribution is controlled by a sedimentary facies zone and is widely developed in the original truncated tributary channel facies belt of the delta plain.The development of this high quality reservoir is controlled by the distribution of sedimentary sand bodies and secondarily-eroded porosity of laumontite in the Chang-3 oil layer of the Fuxian exploratory region.

秦岭北麓筠竹种子育苗试验

因气候条件的限制,秦岭北麓很难获得竹子种子,因而难以通过播种育苗获得造林绿化所需要的大量苗木。2019年7月在秦岭北麓陕西省楼观台国有生态实验林场辖区的森林公园内发现了一株筠竹开花并结实,遂采集种子,开展了播种试验,以期探讨秦岭北麓竹种子育苗的可行性。结果显示,筠竹采种后在室温下贮藏,第2年播种的出苗率为25.4%;实生苗前3年的生长状况优于秦岭北麓优势竹种淡竹的生长。该研究表明,在秦岭北麓筠竹通过播种进行繁殖是可行的,并探索了一套实生苗繁育的管理经验,可在一定范围内推广,为绿化造林和生态建设提供大量苗木。

陕北富油煤地下原位热解先导试验

【目的】陕北富油煤地下原位热解先导试验在国内外尚属首次,开创了富油煤、油页岩等原位转化新方向,引起了行业内外广泛关注。富油煤地下原位热解的研究尚处于起步阶段,缺少现场工程数据的系统研究。【方法】通过现场先导试验,明确富油煤地下原位热解的地质条件和工程难点,总结陕北富油煤地下原位热解开采进展,探讨下一步技术攻关方向。【结果和结论】结果表明:(1)先导试验区具有煤层稳定、煤质条件好、煤焦油产率高、生油潜力大、煤系富水性弱、隔水层厚度大等优越的原位热解地质条件,但煤层孔隙连通性差、导流能力低、煤层导热能力差、高效加热难度大、煤层改造难度大、体积造缝要求高等因素影响到工程效果。(2)开展综合地质评价有利于规避地层水、断层等不利因素对地下热解过程的影响,可控冲击波致裂技术有助于地下煤层裂缝连通,井下高效电加热器稳定运行是高效产油的关键。(3)经过一个月加热运行,成功提取出全球第一桶地下原位热解油,初步打通了富油煤地下原位热解开采技术路径,获取了产油的地下温度、压力等工艺参数。先导试验存在加热周期短、产油量低、耗能高,缺少项目运行的系统性技术评价,需从研发高效井下电加热器、地下煤层体积造缝、热解−气化一体化、热能综合利用及集成CCS等方面继续升级技术,实现降本增效,综合提高富油煤地下原位热解开采的经济性、安全性和可靠性。

陕北榆林滴灌春玉米不同生育期适宜土壤水分控制界限研究

【目的】确定陕北榆林滴灌春玉米各生育期适宜的土壤水分界限,得到该地区滴灌春玉米的灌溉制度。【方法】采用正交试验设计方法,在春玉米苗期、拔节期、抽雄期、灌浆期、成熟期5个生育期设置4种灌溉水平,探究不同灌水方案对滴灌春玉米的生长及水分利用效率的影响。【结果】(1)陕北榆林滴灌春玉米关键生育期为拔节期、抽雄期。苗期、灌浆期及成熟期为非关键期。在拔节期和抽雄期适当降低灌溉水平更有利于春玉米后续生长发育;(2)综合各灌水方案对春玉米株高、茎粗、叶面积指数和产量的影响,最优的田间土壤水分控制界限为:苗期适宜土壤水分界限为59%~79%FC(FC代表土壤田间持水率),拔节期为70%~90%FC,抽雄期为68%~88%FC,灌浆期为56%~76%FC,成熟期为49%~69%FC。【结论】最优的灌溉制度为全生育期灌水9次,即苗期2次(m=20 mm),拔节期3次(m_(1)=20 mm,m_(2)=m_(3)=30 mm),抽雄期3次(m_(1)=m_(2)=m_(3)=30 mm),灌浆期1次(m=25 mm),成熟期不灌水,综合灌溉定额为235 mm。该制度下春玉米产量为14664 kg/hm^(2),水分利用效率达3.01 kg/m^(3)。较对照组产量提高15.56%,WUE提高19.19%。该研究结果对陕北榆林滴灌春玉米田间水分管理具有重要指导意义。

红色陕北形象的三维叙事书写——以抗战前后美中苏记者陕北访问为对象

抗战前后,访问陕北的记者们以自身观察展现红色陕北的多元形象。梳理美中苏三国记者埃德加·斯诺、陈学昭、罗曼·卡尔曼等人的陕北访问书写,可以发现斯诺、陈学昭、卡尔曼分别关注革命与现代化建设的独立,主体人格与生活的独立,中国民族国家独立,陕北访问对其而言具有必然性。通过解放区与国统区对比,记者们既展现红色陕北对中国民族国家建设的必要意义,又在访问中完善认知、重塑生活、积淀经验。围绕国际视野,记者们从现代建设、个体尊严、世界性与民族性等角度发现陕北争取民族解放,摆脱他者地位,融入世界格局的努力。三者的陕北访问源自不同经历体验,又展现多元统一的红色陕北面孔。

Quantifying the vertical distribution pattern of land-use conversion in the loess hilly region of northern Shaanxi Province 1995–2015

The mountainous and hilly region plays an important role in ecological safety and production in China. However, recent studies have poorly characterized the parallel structure of land use in the valleys of the mountainous and hilly region using topographic factors(e.g.elevation, slope, aspect). Here, the loess hilly region of northern Shaanxi Province is used as a representative case area to analyze the vertical distribution pattern of land-use conversion using the relative elevation concept and the HAND index. The differences in the vertical structure of land-use conversion between absolute elevation and relative elevation were compared. We found that the classifications of absolute and relative elevation had similar proportions of each relative elevation grade in each absolute elevation grade. Cropland,woodland, and grassland were distributed evenly in each grade of absolute/relative elevation,while water body, built-up land and unused land were more likely to spread in low grades of relative elevation than those of absolute elevation. The land-use conversion(i.e. loss of cropland and gain in woodland and built-up land) showed an apparently stepped distribution with relative elevation classification, suitable for revealing vertical distributions of land-use conversion in the loess hilly region. Cropland transformed to woodland was mainly distributed in high grade of relative elevation, decreasing with a decrease in grades, while built-up land transformed from cropland and grassland was mainly distributed in low grade of relative elevation, decreasing with increases in grades. The grade of relative elevation where cropland transformed to woodland descended with the implementation of the Grain for Green Project. Our results suggest that it is better to analyze the vertical distribution of land-use conversion with relative elevation classification in hilly regions.

陕北沙区长柄扁桃害虫种类及危害调查

【目的】长柄扁桃是陕北沙区重要生态树种和经济树种,在区域经济和生态建设中发挥着重要作用。近年来受到多种害虫侵扰,受害面积不断增加且日益严重。为此进行了该研究,以明确陕北沙区长柄扁桃害虫种类及害虫危害情况,为今后长柄扁桃害虫监测和科学防控提供基础资料。【方法】于2017年3月至2020年10月,采用人工采集法和黑光灯诱法对陕北沙区长柄扁桃害虫进行采集,对采集到的标本进行了鉴定、整理和区系分析;随后采用标准地调查法对害虫的危害程度做了系统的调查。【结果】共计调查到陕北沙区长柄扁桃害虫35种,隶属3个目19科,鞘翅目害虫种类为15种,占害虫种类的42.86%;半翅目害虫种类为11种,占害虫种类的31.43%;鳞翅目害虫种类为9种,占害虫总数的25.71%。区系分析表明,长柄扁桃的鞘翅目害虫古北种最多,占73.33%,鳞翅目害虫和半翅目害虫广布种最多,分别占88.89%和81.82%。危害程度研究表明,危害严重的害虫有5种,危害中度的害虫有8种,危害轻的害虫有22种。【结论】陕北沙区长柄扁桃害虫主要分布在鞘翅目和半翅目,鞘翅目害虫以古北种为主,半翅目和鳞翅目害虫以广布种为主。长柄扁桃害虫的优势种为华北大黑鳃金龟、苹毛丽金龟、阿拉善舌喙象、李小食心虫和桃蚜。

陕北退耕区域“两山论”的实现路径——商品型生态农业

[目的]促进区域资源循环再利用,提高资源利用率,形成生态产业化、产业生态化良性发展格局,推动区域经济与生态协同发展。[方法]通过理论分析明确了“绿水青山就是金山银山”,揭示了生态资源与生产力耦合过程,揭示了生态保护与经济发展之间的辩证关系。[结果]依据陕北退耕区域资源特征,确定了生态林资源、林果资源、高效设施农业资源为主的3种资源类型下商品型生态农业的发展模式,即生态林资源为主的区域形成以“特色种植+休闲旅游+服务业”为核心的循环链网结构,林果资源为主的区域形成以“果业+食用菌+加工业”为核心的循环链网结构,耕地(川、梯、坝)资源为主的区域形成以“果业+食用菌+种植业+养殖业+休闲旅游”为核心的循环链网结构。[结论]在陕北退耕区域建设商品型生态农业满足了“两山论”的需求,成为后退耕时代这一区域实现“两山论”的重要路径。

基于贝叶斯网络的生态系统服务权衡协同关系及其驱动因子分析——以陕北黄土高原为例

了解生态系统服务的权衡协同关系及其驱动因子效应是实现生态系统有效管理和改善人类福祉的基础。以陕北黄土高原为例,定量评估其2018年土壤保持、产水服务、粮食供给和固碳服务,在构建贝叶斯网络生态系统服务模型的基础上,通过节点的重要性分析识别影响生态系统服务的关键节点,利用联合概率分布、概率推理和情景模拟探讨生态系统服务权衡协同关系及其驱动因子效应。结果表明:(1)陕北黄土高原各类生态系统服务空间异质性较强。其中,土壤保持、产水服务和固碳服务的空间分布情况较为一致,高值区集中在东南部,低值区在西北部,呈“南高北低”的分布特征;粮食供给呈“中部高、南北低”的分布特征。(2)土壤保持、产水服务和固碳服务之间互为协同关系,粮食供给分别与土壤保持、产水服务、固碳服务为权衡关系。其中,产水服务与固碳服务的协同关系、产水服务与粮食供给的权衡关系较强。(3)土地利用、降水和NPP(Net primary production)是影响生态系统服务权衡协同关系的主要驱动因子,其中土地利用主要影响生态系统服务的协同关系,而降水和NPP在影响协同关系的同时对权衡关系也有一定的制约作用。研究发现:不同驱动因子在不同状态下产生相同的协同(或权衡)方式,相同驱动因子在不同状态则会造成协同(或权衡)方式的差异。研究对于认识多种生态系统服务间的复杂关系及其驱动因子差异,为后续提出改善生态系统管理和提高人类福祉的对策与措施,具有重要的理论和实践价值。

陕北黄土区不同林地土壤有机碳含量研究

为探究黄土高原植被恢复对深层土壤碳库的影响,选取退耕还林第一县陕北吴起县金佛坪流域5种植被恢复类型(山杏林(Armeniaca sibrica),油松林(Pinus tabulaeformis)、沙棘林(Hippophae rhamnoides)、刺槐林(Robinia pseudoacacia)、小叶杨林(Populus simonii))和以自然恢复为主的荒草地为研究对象,通过调查0~1000 cm土层土壤有机碳含量,并计算土壤有机碳储量,分析不同植被类型的土壤有机碳剖面分布和差异。结果表明:在总体上,土壤有机碳在0~60 cm出现快速下降,60~1000 cm出现不明显的波动变化,其中40~260 cm土层,小叶杨林地土壤有机碳含量明显最高。不同植被恢复都具有固碳效益,且不同植被土壤有机碳含量差异显著(P<0.05)。不同植被土壤有机碳储量:小叶杨(18年)(301.51 t·hm^(-2))>刺槐(19年)(249.86 t·hm^(-2))>沙棘(18年)(242.14 t·hm^(-2))>山杏(8年)(226.08 t·hm^(-2))>油松(5年)(182.91 t·hm^(-2))>荒草地(160.45 t·hm^(-2)),这可能是由于不同树龄和植被类型导致的结果。深层(100~1000 cm)土壤有机碳储量占0~1000 cm剖面有机碳储量的73%~84%。深层土壤有机碳含量颇丰,在今后碳汇评估中不容忽视。

陕北浅埋煤层一体化漏风通道探查技术

以陕北侏罗纪煤田浅埋煤层受火灾威胁矿井为研究对象,应用高分辨率无人机可见光与热红外双光低空遥感、手持红外热成像仪、风速测量仪、球胆采样器、束管检测和采样、气相色谱仪、钻孔测温、钻孔窥视等技术手段,综合开展天空、地面、孔中与井下综采工作面、密闭墙、巷道等潜在漏风通道隐蔽致灾因素的快速探查;系统归纳陕北侏罗纪煤田浅埋煤层地面、孔中、井下漏风通道隐蔽致灾因素的类型和特征,构建“空-地-孔-井”四位一体的浅埋煤层煤矿漏风通道隐蔽致灾因素的快速排查技术体系,并以受火灾威胁的德泉煤矿为对象应用该技术体系进行了探查,快速确定了漏风通道类型、空间分布特征,结合防灭火工程实现了对火区的快速熄灭和煤矿隐蔽高温区温度的整体快速控制,保障了矿井的安全、绿色、高效开采。

北朝邑义考略——以陕西地区石刻造像为中心

本文以陕西地区的95件石刻造像为中心,综合考察了北朝的佛教邑义、道教邑义及佛道混合邑义;考证分析了邑义名称、宗教属性、造像题材与流行时限等问题。本文尝试利用考古发现的实物资料与间接文献中寻得的蛛丝马迹,为史料相较匮乏的早期地方宗教研究提供一个超越文字记载的视角,庶几可补史籍、经典之阙。

陕北地区小杂粮产业发展情况调研报告

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