Development of land desertification in Bashang area in the past 20 years

Natural conditions in Bashang area are characterized by zonal transitions which are liable to be impacted by natural disasters and intensified human activities. The extremely fragile eco-environment is also liable to have desertification formed and developed. In the 18 years from 1978 to 1996, the desertified land area of Bashang within the scope of the map nearly doubled, a total increase of 2199.11 km2, averaging an increase of 122.17 km2 per year. Moreover, the seriously desertified area increases rapidly. Land desertification in Bashang is the combined result of natural factors and irrational human economic activities. Cultivated land expansion, population growth, and overgrazing aggrevate desertification development.

Effect of land-use and land-cover change on nutrients in soil in Bashang area,China

The Bashang area is a water source area and ecological barrier zone for Beijing and Tianjin. The area is located at 200 km from Beijing and Tianjin and is a typical agriculture pasture interlacing zone, in which the eco environment is vulnerable and hence it is sensitive to environmental change. The area is relatively lagged in social and economic development, where the traditional cultivation mode is predominated in agriculture and animal husbandry, but the disturbance by human activity is relatively small. Therefore, in order to reveal the interrelation between eco environmental change in the area and environmental change in Beijing and Tianjin area, it is fairly necessary to study the effect of land use and land cover change on nutrients in soil in this area. According to the actual situation of changed land use for the limited time period, five series of changed land plots were selected and 4 samples were collected from each series for the study. The samples were collected from different soil forming levels at the same site in different time. Analysis of the collected samples indicates that in the process of change of land use and land cover, the nutrients in soil, such as organic matter, total N, total P, total K, and available N, P, K, and B, Mo, Mn, Zn, Cu, and Fe, have regularly changed. When the land had changed from grassland and non irrigated farmland into woodland, and from non irrigated farmland into irrigated field, the nutrients in soil totally increased. But there exists some exception, i.e. quick acting N, P, K, and some microelements have appeared to be inconsistent with the mentioned above regularity in some cases.

Planting Experiment of Five Quinoa Varieties in Bashang Area of Hebei Province

It is very suitable for planting quinoa in Bashang area of Hebei Province,but the local varieties of quinoa are disordered,which affects the development of quinoa industry.In this experiment,five quinoa varieties were selected and planted in Guyuan County.After two years of experiment,scientific conclusions were drawn on the yield,agronomic characters,economic characters,stress resistance and regional adaptability of these five varieties,and objective evaluation of variety characteristics and production and utilization value was conducted,which can provide scientific basis for variety identification,variety distribution and application of quinoa,and provide feedback information for promoting the development of quinoa industry.

Effects of Different Modes of Returning Farmland to Forest on Physicochemical Properties of Soil in Bashang Area of Northern Hebei Province

[Objective]The research aimed to understand the change rules of physicochemical properties of soil in the different modes of returning farmland to forest.[Method]The physicochemical properties of soil in three different types of returning farmland to forest(Hippophae rhamnoides Linn.forest,Caragana korshinskii forest and Ulmus pumila L.forest)were analyzed by taking the enclosed grassland as comparison in Bashang area of northern Hebei Province.[Result]The results showed that there were significant differences among different types.Order of the bulk density of soil:H.rhamnoides Linn.forest(1.17 g/cm^3)<U.pumila L.forest(1.24 g/cm^3)<C.korshinskii forest(1.26 g/cm^3)<enclosed grassland(1.61 g/cm^3);order of the total porosity of soil:H.rhamnoides Linn.forest(55.29%)>U.pumila L.forest(52.55%)>C.korshinskii forest(51.93%)<enclosed grassland(38.85%);order of the organic matter content of soil:H.rhamnoides Linn.forest(3.191%)>C.korshinskii forest(3.128%)>U.pumila L.forest(2.804%)>enclosed grassland(2.536%).[Conclusion]After returning farmland to forest,vegetation played a positive role in physicochemical properties of soil.There were significant differences in physicochemical properties of soil among different modes of returning farmland to forest,and the improvement effect of H.rhamnoides Linn.forest on physicochemical properties of soil was the best.

The Ecological Water Demand of Different Vegetation Types in the Bashang Area,Northwest Hebei Province

In order to construct stable vegetation for reducing wind and sand disasters and soil erosion in the Bashang Area of Northwest Hebei Province in China,it is very important to understand the ecological water demand of different vegetation types in this area.Based on observed data and the Irmak-Allen formula,we investigated the ecological water demand and ecological water shortage of arbor,shrub and grassland in Bashang Area of northwestern Hebei province.The results showed that the actual evapotranspiration values of the three vegetation types in the growing seasons in the study area from high to low were arbor forest(401.81 mm),shrub(358.78 mm)and grassland(346.02 mm).The minimum ecological water requirements of arbor forest,shrub and grassland in the growing season were 243.96 mm,218.35 mm and 211.36 mm,respectively,and the optimal ecological water requirements were 472.99 mm,423.34 mm and 409.77 mm,respectively.In addition,the optimal ecological water shortage values were 198.56 mm for arbor forest,148.91 mm for shrub and 135.34 mm for grassland.The ecological water shortage of vegetation has obvious seasonality,with the largest water shortage in May and June,and a lower and steady water surplus in July to October.Therefore,an artificial water supplementation in May and June would alleviate the drought stress of the vegetation.The rainfall in Bashang Area of Northwest Hebei Province can meet the requirements of minimum ecological water demand for arbor forest,but the gap between the rainfall and the optimal ecological water requirement is too large to support good growth of an arbor forest,which could explain why the degradation of poplar protective forests has occurred in Bashang Area.

坝上地区莜麦秸秆热解特性研究

为实现高寒坝上地区农作物秸秆高效清洁燃烧,文章选取典型莜麦秸秆作为研究对象,通过混合气体模拟烟气燃烧过程中的热解气氛环境,采用热重分析仪研究空气和N_(2),CO_(2),O_(2)不同比例组成的混合气体氛围下热失重特性以及升温速率对其影响,采用AKTS软件进行动力学分析。结果表明:莜麦秸秆热解过程可分为干燥(30~140℃)、挥发(140~370℃)、炭化(370~900℃)3个阶段;气体氛围主要影响热解的炭化阶段,对干燥和挥发阶段影响较小;升温速率影响挥发和炭化阶段,升温速率越快,反应速率越大;当热解气氛为15%O_(2)-5%CO_(2)-80%N_(2)混合气体(气体2)时,热解过程所需活化能最少,平均活化能为139.86 kJ/mol。研究结果可为高寒坝上地区生物质秸秆能源化利用提供一定理论依据。

绿肥对河北坝上错季蔬菜地土壤的改良效果

以北方常见不同科属的4种绿肥作物为试材,采用2年定位改良试验方法,研究了绿肥作物不同生育期的土壤化学性质变化,以期为解决当地错季蔬菜种植所造成的环境问题提供参考依据。结果表明:在绿肥生长过程中,其土壤有机质和养分含量增减变化存在差异。相比于第1年,绿肥种植第2年有机质含量提高了10.7%。相较于基础地力而言,种植并翻压绿肥显著降低了土壤有效磷和硝态氮含量,分别降低了34.8%和74.6%,对菜地氮磷累积有显著的削减效果。不同品种绿肥作物对土壤养分含量的影响也存在差异,主成分分析结果表明毛叶苕子处理对土壤养分含量影响最大,春油菜处理次之。

坝上地区典型防护林水源涵养功能对林分结构的响应

【目的】坝上是京津冀地区重要的生态屏障和水源涵养地,探究典型防护林林分结构对枯落物层和土壤层水源涵养功能的影响,为该地区防护林的抚育管理与林分优化提供科学依据。【方法】选取坝上地区御道口林场3种典型防护林(樟子松林、华北落叶松林、樟子松华北落叶松混交林)为研究对象,调查胸径、树高、林龄、密度、郁闭度和叶面积指数等林分结构指标,通过室内浸水法和环刀法进行枯落物层和土壤层持水性能的测定,运用冗余分析探究防护林结构对枯落物层和土壤层持水性能的影响机制。【结果】(1)樟子松华北落叶松混交林的枯落物层厚度、蓄积量、枯落物最大持水量和有效拦蓄量均大于纯林,其中总枯落物厚度差异显著(P<0.05)。(2)土壤总孔隙度、含水量和最大持水量都随着土层的增加而减小。其中土壤总孔隙度和最大持水量在0~30 cm土层表现为华北落叶松林>樟子松华北落叶松混交林>樟子松林,在30~60 cm土层表现为华北落叶松林>樟子松林>樟子松华北落叶松混交林。(3)冗余分析表明,林分结构与水源涵养功能密切相关,林分密度和树高对不同防护林枯落物层水源涵养能力影响显著,而树高和林龄对不同防护林土壤层水源涵养能力影响显著(P<0.05)。【结论】3种防护林中枯落物层和土壤层水源涵养能力最好的分别是樟子松华北落叶松混交林和华北落叶松林,林分密度、树高和林龄可以较好地解释水源涵养功能的变化。本研究对坝上地区生态平衡维护与可持续发展具有积极意义。

生物法去除坝上地区生活污水中氮磷的试验研究

以张家口坝上地区生活污水为研究对象,采用微藻水棉与微生物EM菌剂协同作用处理坝上地区生活污水,探究坝上生态环境脆弱地区污水中EM菌群和微藻水棉的脱氮除磷能力以及在藻菌共生系统中EM菌群对微藻水棉生长的影响。结果表明:微藻水棉与EM菌群共生系统在处理坝上地区污水中氮磷过程中存在协同作用,且体系中EM菌群的加入量与微藻水棉的生物量增长在一定区间内呈正相关。生活污水经离心稀释后调节初始pH为7.5,装液量为10 L,接入6%的微藻水棉藻悬液,6%EM菌液,于25℃,光照16h/d条件下培养5d。污水中总氮降解率达到89.2%,总磷降解率达到84.4%,好于微藻水棉单独作用污水效果,结果符合地表水环境质量Ⅴ类标准。

坝上地区园林绿化大树移植技术浅谈

大规格园林树木的应用在保持自然资源特色和体现城市化特点中起到了重要作用。笔者结合多年实践工作经验,针对张家口坝上地区气候等特点,就大树移植中存在的问题、移植时间和方法、具体的移植技术和移植后的养护管理等进行详细的介绍,以期为高寒地区园林绿化的大树移植及养护工作提供借鉴和参考。

张家口坝上地区影响杨树根蘖苗发生和生长的关键因素探讨

以河北省张家口坝上地区退化杨树林为研究对象,采用林地开沟促萌的方法,探讨了距母树行距离、林分密度以及萌蘖根粗度对根蘖苗发生和生长的影响。结果显示:(1)距母树行距离显著影响根蘖苗的发生和生长。当距母树行距离超过6 m时,将不会有根蘖苗的发生。而当距母树行距离在6 m以下时,随着距母树行距离的增大,根蘖苗的发生以及高径生长呈现出下降的趋势。在距母树行距离2~3 m处开沟促萌对于杨树根蘖苗更新是较为适宜的;(2)随着林分密度的降低,根蘖苗的发生数量显著降低,但根蘖苗的高、径生长却显著增大。低密度林分内发生的根蘖苗的数量和生长情况,完全能满足退化杨树林分的更新所需;(3)随着萌蘖根粗度的增大,发生在其上的根蘖苗的数量和生长状况均显著增加。综合分析认为:对于张家口坝上地区退化杨树林而言,发生于粗度1.0~1.5 cm以上的根蘖苗更适宜用于萌蘖更新。

Temporal and Spatial Evolution of Lakes in the Bashang Plateau for Nearly Recent 30 Years

Lakes are important ecological water sources in the Bashang Plateau. Its expansion or shrinkage directly affects the ecological security of the plateau and its surrounding areas. In this study, Landsat images from 1984 to 2015 were selected to monitor the area of lakes in the Bashang Plateau and to analyze the spatiotemporal evolution and driving forces of lakes in the Bashang Plateau. The results showed that there were 47 lakes in the Bashang Plateau in 2015, with a total area of 37.63 km2, mainly distributed in the central and western regions of the region. From 1984 to 2015, the lakes in Bashang Plateau showed a shrinking trend. At the same time, there are obvious stage differences in lake changes. During 1984-1996, the number of lakes increased by 99 and the total area increased by 124.43 km2. From 1996 to 2015, the number of lakes decreased by 142, and the total area decreased by 183.96 km2. Before 1996, climate change was the dominant factor. However, the shrinkage of lakes after 1996 is the result of climate change and human activities. Among them, the large-scale planting of water consuming crops such as vegetables is the main human activity mode leading to lake shrinkage. This study will help to understand the expansion and contraction factors of the Bashang Plateau lakes in Hebei province and provide a reference for the future protection and management of the lakes.

冀北坝上地区营造樟子松人工林对植被群落特征与土壤理化性质的影响

为明确在冀北坝上地区营造樟子松人工林对植被群落特征与土壤理化性质的影响,本研究将冀北坝上地区划分为坝西、坝中、坝东3个区域,以樟子松人工林为研究对象,以天然草地为对照,分析同一植被类型不同区域以及同一区域不同植被类型间植被物种组成、物种多样性和土壤理化性质的差异。结果表明:(1)营造樟子松人工林后,坝西植被物种数量明显增加,喜阴植物重要值和增加,Margalef丰富度指数(DM)显著增大,Pielou均匀度指数(Jsw)显著减小;坝中植被物种数量几乎不变,喜阴植物重要值增加,Simpson指数(DS)和Shannon-Wiener指数(H′)以及Pielou均匀度指数(Jsw)均显著减小;坝东植被物种数量明显减少,喜阴植物重要值和几乎不变,物种多样性与均匀度指数变化不显著。(2)坝西土壤容重显著减小,大团聚体含量和非毛管孔隙度显著增加;坝东土壤毛管孔隙度均显著减小,土壤容重均显著增加。(3)坝西和坝中土壤的酸碱性显著减小至中性,坝中土壤全氮含量、坝东土壤全氮和碱解氮含量显著减小。综上所述,在冀北坝上地区不同区域营造樟子松人工林效果并不相同,在坝西营造樟子松人工林对植被群落和土壤理化性质积极效果明显。

冀北坝上地区榆树和樟子松人工林降雨再分配特征研究

为明确冀北坝上地区主要人工林降雨再分配特征,在河北省承德市丰宁满族自治县大滩镇以林分结构相似的榆树(Ulmus pumila)和樟子松(Pinus sylvestris var.mongolica)人工林为研究对象,测定每场降雨2种人工林林冠截留各水文分量,分析其降雨再分配特征及影响因素。结果表明:(1)榆树和樟子松人工林的林冠截留量与林外降雨量分别呈指数关系和对数关系。(2)郁闭度较小的情况下,2种人工林的林内降雨量与林外降雨量都呈线性关系。(3)榆树和樟子松人工林分别在林外降雨量为0.25 mm和4.58 mm时开始产生树干茎流,且与林外降雨量均呈线性关系;榆树树皮对树干茎流的阻拦和吸收作用大于樟子松。(4)2种人工林的林内降雨量均显著大于林冠截留量和树干茎流量;在降雨量较小时,林冠截留量显著大于树干茎流量,随着雨量级的增加,树干茎流量会超过林冠截留量。(5)风增大了榆树人工林的林内降雨量并减小了林冠截留量和树干茎流量,对樟子松人工林林冠截留各水文分量影响不大。综上所述,不同人工林对降雨再分配作用会受到降雨量、树干、林冠等特征和风的影响,樟子松人工林的林冠截留作用更为稳定。

坝上地区人工林和草地生长季土壤水势动态

为研究坝上地区人工林土壤水势动态,以结缕草(Zoysia japonica)为对照,选取坝上地区典型人工林小叶杨(Populus simonii Carr.)和樟子松(Pinus sylvestris var.mongolica),研究其生长季不同时间、空间土壤水势和变异系数及晴天和降雨下土壤水势变化。结果表明:(1)人工林和草地土壤水势变化趋势相同,在生长季前期和后期土壤水势较高,中期土壤水势进入波动下降期,但不同植被进入波动期时间不同,樟子松晚于小叶杨和结缕草。小叶杨、樟子松、结缕草土壤水势最低值分别出现在70,10,30 cm处,最低值分别为-1257.24,-747.97,-830.11 kPa。小叶杨、樟子松和结缕草土壤水势变异系数最大值分别在9月10 cm、7月10 cm、7月30 cm处,其值分别为-155.9%,-208.0%,-183.6%。总体上,变异系数生长季中期大于前期和后期,表层大于深层。(2)晴天人工林和草地土壤水势差的最大值与日均温度之间存在显著的相关关系,随着日均温度升高,水势差最大值也增大。典型晴天大气温度在日内上下波动,土壤水势呈现滞后波动,在生长季浅层土壤最为明显。(3)不同降雨量与土壤水势差呈现相关关系,随着降雨量升高,土壤水势差也随之升高。典型降雨事件下,中雨和大雨剖面土壤水势迅速上升,小雨事件下主要呈现波动变化。从不同植被来看,草地土壤水势较人工林波动更为剧烈。综上,生长季樟子松土壤水势进入波动期最晚,波动幅度最大。而土壤水势对于大气温度和降雨的响应方面,结缕草最为敏感。研究结果对于指导当地人工林建设与水资源高效管理具有重要意义。

河北坝上林田湖草土壤水盐氮分布与累积特征

[目的]探索干旱半干旱区土壤水盐氮的分布规律,为防治地下水面源污染和实现水土资源可持续利用提供依据。[方法]选取河北坝上地区4种典型的土地利用类型(林、田、湖、草),分析土壤水分、盐分以及硝态氮的变化特征,阐明不同土地利用类型土壤剖面的水盐氮分布规律。[结果]①不同土地利用方式中,安固里淖干涸湖底的土壤水盐含量最高,平均含水率达60.18%,且土壤水盐分布均表现出中等变异性,含水率变异程度更大。②林地、旱作农田和安固里淖干涸湖底0—220 cm土壤水盐分布规律基本一致,分别呈振荡型、均匀型和底聚型,而草地的水盐分布存在差异。③盐分离子在4种土地利用类型间均具有显著差异(p<0.05),其构成以SO_(4)^(2-)为主,K^(+),Mg^(2+)和Ca^(2+)普遍缺乏。④安固里淖干涸湖底土壤剖面平均硝态氮含量高达134.18 mg/kg,在林地和旱作农田分布呈表聚型,在安固里淖干涸湖底呈中间少、上下多的特征。草地硝态氮上层土壤累积明显。⑤林田湖草土壤硝态氮均与K^(+)存在显著或极显著正相关,K^(+)是控制区域硝态氮变化的主要因子。[结论]河北坝上林田湖草土壤水盐氮分布具有明显的差异性,安固里淖干涸湖底土壤水盐氮含量显著高于其他3种土地利用类型,对地下水造成严重的潜在污染。

品种多样性对冀北坝上地区燕麦种子产量稳定性的影响

[目的]冀北坝上地区燕麦产量较低且年际间波动剧烈,探究品种多样性对燕麦种子产量稳定性的影响,对保证燕麦高产和稳产具有重要意义。[方法]选择坝莜3号、蒙燕1号、坝燕6号、甜燕麦、白燕18号和KONA(美国)6个品种为试验材料,研究2017-2019年不同品种的生育期和产量变化,并揭示燕麦产量变异的气象决定因子。[结果]不同燕麦品种生育期在78~99 d之间,其中坝莜3号生育期最长。同一品种生育期年际间变异较高。2017年、2018年和2019年6个品种的产量分别为2872.51~5860.55 kg·hm^(-2)、3194.70~4841.50 kg·hm^(-2)和3117.50~5193.75 kg·hm^(-2),年际间变异为11.7~29.2%。6个品种的平均产量分别为4424.61、4158.46和3865.71 kg·hm^(-2),干旱年份(2019年)品种多样性的产量优势更加明显。品种多样性显著降低年际间产量的变异,6个品种平均产量的年际间变异率仅为6.7%。出苗-孕穗期降水量(PE-B)、抽穗-开花期降水量(PB-F)、开花-乳熟期最低温度(TminF-MR)和孕穗-抽穗期总辐射(SB-H)4个因子决定冀北坝上地区燕麦产量变异的70%。[结论]品种多样性提高冀北坝上地区燕麦种子产量和年际间产量稳定性,并且品种多样性的产量优势在干旱年份更加明显。

河北张家口坝上地区退化林修复碳排放估算

基于河北张家口坝上地区退化林修复各机械设备的燃料品种、基本燃料消耗量,肥料种类、肥料施用量等活动水平数据,以及相应的排放因子等参数,采用IPCC法(一种以详细技术为基础的部门方法),分别估算了油锯伐木、油锯造材、汽车运材、机械整地、汽车运苗、汽车运肥、洒水车运水和复合肥等各排放源的碳排放量,然后相加得出碳排放总量。再由碳排放总量除以修复面积,得出单位面积碳排放量。结果表明,河北张家口坝上地区退化林修复项目CO_(2)排放总量为182315.1 t,单位面积CO_(2)排放量为2.2 t/hm^(2)。研究成果有助于森林经营活动的碳汇计量与监测,以及省级乃至国家级温室气体清单的编制。通过研究,建议各地在退化林修复过程中应充分利用自然,选择自然恢复为主的修复方式开展修复。在辅以补植等人工措施时,还要采取科学设计栽植密度、选择更为节水的灌溉方式等措施,以减少对化石燃料的消耗,降低碳排放量,促进节能减排工作。

坝上乡村景观初探——以河北省张北县为例

文章研究了农牧文化影响下中国坝上地区乡村的景观建设,以河北省张北县为例,梳理了张北县乡村景观特征,并从“自然地形”“植被格局”“农牧智慧”“乡村游径”“村庄布局和风貌”五个方面分析其乡村景观的形成。最后,结合张北县乡村发展现状,提出未来坝上地区乡村景观发展的建议。

坝上地区紫花苜蓿氮、磷、钾肥料效应与推荐施肥量

采用"3414"试验设计,进行田间试验,研究了坝上地区紫花苜蓿氮、磷、钾肥料效应及推荐施肥量。结果表明:在偏干旱条件下,施氮提高紫花苜蓿产量8%～25%,施磷增产率在122%～172%之间,施钾降低紫花苜蓿产量0～12%;与无肥处理相比,缺磷处理减产38.24%,其余处理增产26%～68%,高磷处理增产率最高(67.94%);氮钾互作效应降低紫花苜蓿产草量,而磷钾和磷氮互作效应为提高;缺氮、缺磷和缺钾处理的相对产量分别为75.02%、36.78%和91.60%,土壤速效氮、速效磷和速效钾的丰缺状况依次为中等、极缺和丰富。结合肥料效应函数法和养分丰缺指标法,得出坝上地区旱作条件下紫花苜蓿推荐年施氮(N)、磷(P2O5)和钾(K2O)量分别为80、50和60kg/hm2。