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白桦响应盐胁迫的生理学机制及相关基因的鉴定
No full textBirches belong to the genus Betula in the family Betulaceae. Birch trees arefast-growing woody plants that adapt to adverse environments, and are widely distributedfrom north Europe to Russia, north of China, and Japan. Therefore, it is important tostudy the mechanism of salt stress tolerance in birch plants. Recently, the sequencingwhole-genome of Betula platyphylla Suk. has been completed. Therefore, it has laid asolid foundation for studying the Betula platyphylla Suk’s genetic resources. Here, we treated birch seedlings with a solution of 100 mM NaCl and studied thephysiological and related molecular response of white birch (Betula Platyphylla Suk.) tosalt stress. We found that abscisic acid and Ca2+level were induced in birch during theearly salt stress period, ABA was induced during early salt stress period, and thendecreased, and Ca2+level increased slowly but maintained at a high level for a long time. Under salt conditions, photosynthetic activity was inhibited; the Salt-Overly-Sensitive(SOS) pathway was activated in birch roots; reactive oxygen species (ROS) wasaccumulated, and superoxide dismutase is the main ROS scavenger in roots, whileperoxidase is the main ROS scavenger in leaves. Proline plays a role in stress tolerance inboth roots and leaves; however, soluble sugars and trehalose also have roles in salt stresstolerance, mainly in leaves. Additionally, the genes that might have essential roles incontrolling some of these physiological changes were identified. In leaves, the POD5 andPOD8 genes might play a main role in increase the POD activity. In roots, the SOD1 andSOD4 genes might make main contributions to the increased SOD activity during saltstress. P5CS1 is closely related to the biosynthesis of proline in roots, and P5CS2 mightplay a main role in proline biosynthesis in leaves; the TPS4 and TPP3 genes might playimportant roles in the biosynthesis of trehalose in birch during salt stress period. Therefore, they represent good candidate genes to characterize the salt tolerancemechanism of birch and to breed stress tolerant plants. Late Embryogenesis Abundant (LEA) proteins are accumulated during the last period of seed development, and also play important roles in abiotic stress tolerance of plants. Inthe present study, we studied the 13 LEA genes that are highly similar with the stresstolerance LEA genes in Arabidopsis, and they were cloned from B. platyphylla. Inaddition, the LEA genes that are in response to salt stress were further identified usingqRT-PCR. These LEA genes involving in salt stress response will be the good candidategenes in genetic approaches for breeding salt stress tolerance in plants
天山北坡三工河流域高时空分辨率气温与地表反照率数据构建与分析
No full textCurrently, the spatial resolutions of available temperature datasets such as ClimaticResearch Unit(CRU) 、 The Climate Forecast System Reanalysis(CFSR) 、 ModerateResolution Imaging Spectroradiometer(MODIS) are too coarse to efficiently characterizethe difference of heterogeneous hydrothermal pattern in medium-scale oasis-desertecosystem in arid regions. Therefore, the construction of mean air temperature dataset withhigh spatial and temporal resolution is crucial for investigating ecological interactionsbetween oasis and desert ecosystems. The human-induced land-use/land-cover changes areregarded as one of the main factors in affecting surface albedo and albedo affects the nearsurface air temperature through influencing the hydrothermal circulation between the landand atmosphere. Nowadays, studing the interactions between albedo and air temperature isbecoming a hot topic in the context of global climate change. Thus, the Sangong riverbasin which comprises a typical Mountains-Oasis-Desert System is selected as the studyarea. Based on Landsat TM/OLI images、meteorological datas and land use/land coverdatas, the relative change rates of air temperature (R-Rates) for different land-covers andthe daily mean air temperature dataset were retrieved. Moreover, the albedo datas withhigh spatial resulotion in August of year 1989、1998、2004、2014 were retrieved and alsoanalysed the land cover change features during the 25 years. Then the interactions betweenalbedo and air temperature were analysed. Results show that:(1) The regression coefficient between the instantaneous air temperature and daily meanair temperature perfomed well, R2=0.96，p0.90, RMSE=2.34℃,p soil desert > built-up> cropland >hill and the mean air temperature of oasis had a high fluctuation. The main factorwhich affects the interannual difference of albedo is land-cover change and affects theannual variance is the vegetation cover condition. The mean albedo and mean airtemperature of growing season had positive correlation, R2= 0.3, p < 0.01
基于近景多角度摄影图像的高精度三维模型构建——以交河故城东门为例
No full text是否能利用一个廉价的工具和方法，快捷、高效、准确地获取物体表面特征的高精度三维模型数据并满足研究课题或者用户要求的精度要求一直是三维建模技术研发中的热点问题。目前三维模型的构建以三维扫描技术和基于图像的三维建模技术最为流行。三维扫描技术利用三维激光扫描仪自主获取物体体表的三维几何信息，主要特点是效率高、精度高，但是仪器设备比较昂贵，成本很高，无法广泛使用。基于图像的三维建模技术依据给定的一张或多张二维图像获取整个待测目标物的几何和纹理信息等三维特征信息。本文所试验的是基于图像的建模技术，即借助普通数码相机、工作站等工具，以运动恢复结构(Structure from Motion，SfM）方法来从图像中提取高精度三维特征信息，对选定目标物进行三维模型的构建。这个过程是以 SfM 方法为基础，通过数码相机对目标物进行近景多角度拍摄获取数字图像数据，摄像机标定结合人工处理方法对数据进行预处理，通过特征点匹配算法获取相机位置以及提取图像中重叠部分的点云模型；TIN 模型；最后完成纹理填充。图像数据是基于图像的三维建模方法最不可缺少的，使用常见的数码相机采集建模区域内的图像，借助全站仪、激光测距仪、GPS、卷尺等工具采集控制点数据，构建高精度三维模型，并从点、线、面三种空间特征几何形状数据评价模型精度。文中构建的模型无论从视觉还是精度方面验证了使用这种方法建模的可行性与适用性，充分展现文中使用方法在构建三维模型中的优势
尼龙网方格沙障防护效应研究
No full textThe mechanical sand barrier increases the surface roughness, absorbs and disperses thewind momentum within a certain height above the groundby changing the nature of theunderlying surface to reducethe momentum transfer between the airflow and the groundmaterial. In response to the change of the underlying surface, the effect of airflow onsurface sand, the bed on the airflow and the adjustment of wind speed profile have changed.In this paper, wind tunnel simulation and field observation experiments have been carriedout to study the flow field structure with different sizes of nylon sand barrier. Meanwhile,the morphological characteristics, sand cutoff, sand flow structure with different sizes ofnylon sand barrier and the spatial distribution characteristics of sand grain size in the sandbarrier in the hinterland of Taklimakan Desert were analyzed and explored respectively. Insummary, the reasonable pattern of nylon sand barrier was determined. The paper aim toprovide a basis for rational setting of sand barrier in desert areas and the result will providetheoretical and practical meanings respectively for further understanding the sand preventiontechniques on wind erosion protection. The main conclusions of this paper are as follows:（1）The sand barrier of nylon has a distinct districts feature. The flow field structure ofsand barrier is divided into four flow field area. Which is A（A1.A2.A3）,B,C(C1.C2.C3),D.With the increase of wind speed, the deceleration zone of A1 is reduced, the contours aremore intensive and the vortex is stronger, the area of B has increased and reduced, thedegree of deceleration of C1,C2,C3,C4 has gradually reduced, the wind speed contours atD become straight gradually, respectively. The acceleration rate increased and graduallyrestored to the level before the barrier when the airflow is farther away from the sandbarrier. Apart from 14m·s-1, the greater the experimental wind speed, the more obvious thechange. With the sand barrier specifications gradually increased, the number of zones hasnot changed but the range and the vortex strength.（2）In the form of sand barrier morphology, with the increase in wind speed, Maximum sediment height has reduced. The width of the sand peak is widened. Sediment thickness isalso getting thinner. Contours are becoming more and more intensive. The smaller thespecification, the more smooth the concave surface. Which facilitates the formation ofstable concave surface. In terms of sediment transport rate, the sediment transport rate isdecreasing at the vertical height when the wind speed is small. Sediment transportincreased firstly and then reduced. When the wind speed is great. The greater the windspeed, the more trapped sand material, the greater the fluctuation of the curve, the betterthe retention effect of the nylon sand barrier. The larger the specifications, the less thetrapped sand material, the worse the protective effect.(3)The spatial differentiation characteristics of sand particle size on the surface ofnylon mesh were analyzed by field experiment. 1 m×1 m and 1.5 m×1.5 m sand grainaverage particle size along the main wind gradually increased. 1 m×2 m and 2 m×2 m sandgrain average particle size increases firstly and then decreases. Sorting factor is a goodsorting and sorting better range, the larger the specification, the better the sorting. Theoverall degree of skewness is positive and positive, the larger the specification, the greaterthe skew value. In addition to a few points, the front is a very wide peak. The averageparticle size of the four kinds of sand barrier is not correlated with the sorting coefficient,skewness and kurtosis. The kurtosis of sand grains in sand barrier is positively correlatedwith skewness and separation coefficient. The positive correlation coefficient between theskewness and the sorting coefficient is above 0.92. The vertical distribution of sedimenttransport of coarse-grained sand grains follows the decreasing law of exponential, With thedeepness of the sand barrier, the vertical distribution of sand and the amount of sedimentare affected by sand barrier. The horizontal distribution of sand grains is related to themovement mode of sand and flow field, and it has different distribution characteristics inhorizontal direction. After sand barrier, the horizontal distribution of silver sand is the mostsignificant. In the vertical direction, the degree of separation from L1-L2-L3 is slightlyworse, the skewness is very positive, the skewness coefficient is slightly larger but notsignificant. From wide to narrow, the kurtosis gradually increases. The average particle size increases with height. In the horizontal direction, from the T1-T2-T3 process, theaverage particle size of the sand increased firstly and then decreased; the best sorting at T2,the degree of skewness and kurtosis minimum. In the vertical direction, the average grainsize (Ф) at the L1 and L2 is positively correlated with the sorting coefficient, kurtosis andskewness. In the horizontal orientation, the grain size parameters of the three views (T1, T2and T3) have no significant correlation with the average particle size
阿尔泰山边境铁丝网及对野生动物影响
No full textBorder fences impact on wildlife migration, such as large mammals, geese andduckes.So the purpose of this study is to understand the status of wild animalresources in the Altay Prefecture, to investigate the situation of border fences at theAltay Mountains, to make clear the border fences impacted on animals, to putforward to restore or build biological corridor proposals, and come up with atransboundary protected area idea in the border area. The main results are as follows:1）Wildlife resources in the Altay Prefecture.The Altay Prefecture had 7 orders, 13 families, 31 genera and 35 - 42 species offish, 1 order, 2 families, 2 genera and 2 species of amphibians, 2 orders, 4 families,and 5genera and 11 species of reptiles, 20 orders, 61 families, 171 genera and 350species of birds, 7 orders, 20 families and 64 species of mammals.2）The status of border fences of the Altay Mountains.Border fences of the Altay Mountains involves China, Kazakhstan, Russia andMongolia, with the length of 1 205 km. The border fences height is 2.0 - 2.8 m,single door width is 1.2 - 1.3cm and height is 1.9 - 2.0 m. double doors width is 3.4 -3.6 m and height is 2.0 m. flood discharge culvert width is 98.2 cm and height is81.3 cm while length is 493.0 cm along the border fences.3）Border fences impacted on wildlife at Altay Mountains.We found wild animal corpses and furs, such as Red deer（Cervus elaphus），Siberian ibex（Capra sibirica）and Goitered gazelle (Gazella subgutturosa) on theborder fences at the Altay Mountains. Death rate was approximately 0.74 individuals/ km in the Aketasibulake regional.Using camera trap to monitor results showed wildlife movement around theborder fences, such as Wolverine, Red deers and Siberian ibexes. Some infraredcameras monitored wild animal prowl back and forth near the border fences in winter. Many experiments showed that the border fences of the Altay Mountains hasno effect on reptiles, amphibians and small mammals, but the large andmedium-sized mammals, birds that in the wetlands were greatly impacted by theborder fences. It was estimated that 32.81% mammals and 16.57% birds may beaffected by the border fences in the Altay Prefecture.4）How did the local people know border fences?Survey results indicated that building border fence made wild animalspopulation decrease,and affected their activities and behaviors. Border fencesbecome the main factors that threatening the existence of wild animals at AltayMountains. Most interviewees considered that it was necessary to open wildlifecorridors in the border areas, they were willing to take part in protecting animals..5）Biological corridor recommends.In the border area, the influence of border fences on the migration of wildanimals is remarkable, especially the migration, hatching, changing hair, hiding,mating, calving, spreading, foraging and licking salt. The restoration orestablishment of biological channels in the border area of the Altay Mountains andthe construction of Transboundary Protected Area are conducive to improving theliving conditions of wild animals. Opening methods of biological corridor were (1)migration passage opening, （2）target species of biological corridor opening, （3）phased in stages opening, (4) alpine areas, depopulated zone or seasonal opening.We must take effective measures to ensure the safety of the border area after openingthe border fences
全球变暖背景下 1960-2014 年中国降水时空变化特征
No full text降水是水循环过程中最基本的环节，是地表径流的本源，也是地下水的主要补给来源，降水在时空分布上的不均匀是引起洪涝和旱灾的直接原因。降水的过程伴随着能量的转换过程，雨滴的凝结是吸热过程，而地表降水的蒸发又是散热过程。总之，降水是连接天气、气候和水循环等方面的关键物理过程，也是生态系统清洁水的最终来源，是关系到国计民生的重要气象要素之一。中国降水量的分布极不均匀，且洪涝干旱灾害频发。IPCC 第五次评估报告指出，近百年来全球气候变暖毋庸置疑，气温升高使得大气中水汽增多，水循环加快，极端降水事件增加，在此背景下，开展中国降水变化趋势的研究，有助于理解中国降水变化的特征和机制，并对提高相应地区水资源管理和调控能力，对洪涝干旱的防灾减灾具有借鉴意义。本文以中国大陆为研究区，并划分了西部、北方、青藏和南方四个区域，以国家气象局发布的气象站台逐日降水观测数据为主要研究数据，采用自定义和国家气象局的通用标准分别将降水划分为小、中和大雨。本文重点分析了在气候变暖背景下1960-2014 年间不同强度降水的时空变化趋势和特征，最后通过综合比较，总结出了降水的时空变化规律，并深入探究了影响小雨降水频率的因素以及大雨（极端降水）与局地气温的关系，比较了不同强度降水与总降水量的相关性，量化了不同强度降水量、频率和强度在总降水变化中的贡献，以及不同强度降水频率和强度在降水量变化中贡献，展示了小雨和大雨降水量在总降水量中比例的变化特征，分析了降水量变化与地形的关系，本文的主要结论如下：（1）1960-2014 年间，总降水、小、中和大雨的降水量、频率和强度的空间分布和时空变化趋势因地而异，区域性差异明显。全国平均降水量没有表现出显著变化趋势，降水频率显著减少而强度显著增强，且强降水事件明显增多，而小雨降水事件显著减少。（2）小雨降水频率减少量在总降水频率的减少趋势中起主要作用，而且，小雨降水频率的减少是整个中国小雨降水量减少的主要原因。低空大气的气温和比湿和夏半年小雨降水频率的减少有着密切关系。气温的升高被认为是对整个中国小雨降水频率有减少作用，而比湿变化的地域性差异决定了小雨降水频率变化的地域性差异，这也导致了在中国西部地区小雨降水频率呈显著增加趋势，而在东部地区呈显著减少趋势。（3）只有南方地区的大雨降水量、频率和强度均呈显著增加和增强趋势，而且局地气温的升高对大雨（极端降水）降水有一定的增强作用，包括降水量、频率和强度三个方面，而且，大雨阈值越高，气温的增强作用越明显，在其他地区没有发现该特征。（4）在全国和区域尺度上，总降水量的增加趋势中，大雨降水量的增加量最多，起主要作用；总降水频率的减少趋势中，小雨降水频率的减少量最大，起主要作用。同时，降水量和频率有从小雨、中雨转移到大雨的趋势，并且，小雨的降水量在总降水量中所占比例显著减少，而大雨的降水量在总降水量中所占比例显著增大。（5）降水频率和强度的变化均对降水量的变化起作用，在中国以及各区域中，降水频率的变化在总降水、小、中和大雨降水量的变化均起主要作用。（6）关于降水量与海拔的关系，在西北地区，年均降水量、频率和强度均随着海拔的升高而逐渐增大，而且大雨变化量在总降水量变化量中的比例随着海拔的升高而增加
古尔班通古特沙漠南缘梭梭群落水分来源
No full textHaloxylon ammodendron is a dominant plant species in the Gurbantünggüt Desert. The study of the water source of H. ammodendron community under natural conditions is helpful to understand the water consumption mechanism more deeply. And it’s also in favor of exploring the change of the water use pattern of H. ammodendron dynamic and adaptation strategies under the condition of the change of hydrological characteristics on the ecological process. Then, providing scientific basis for the study of the protection and restoration of plant diversity in arid area under the condition of climate change. To investigate the dynamics of water usage of these plants, we used the direct comparison method, Iso-Source model and the mean depth of water uptake model. The main results were as follows: （1）The water source characteristics of H. ammodendron H. ammodendron as one of the main species of the Gurbantunggut desert, the root system has the characteristics of "two states", and there are obvious seasonal differences in water use. During April to May, the main water source of Haloxylon ammodendron were shallow soil water, deep soil water and groundwater. As the temperature increased, because of the strong evaporation and plant water effect, shallow soil water moisture content decreased obviously, H. ammodendron mostly use of soil water soil depth gradually move down. During April to September, the average depth of H. ammodendron using soil water also moved along with the changing seasons.The growth and development of root system resulted in the difference of water use among H. ammodendron. The root system of young H. ammodendron was immature, so its root system was more active than middle-aged H. ammodendron and mature H.ammodendron, and the utilization of surface soil water was significantly lower than the later two. In June, the main water source of moddle-aged H. ammodendron was 250-350 cm layer soil water, the main water source of mature H. ammodendron was 180-250 cm layer soil water. From July to September, mature H. ammodendron was the most concentrated soil layer of soil water, followed by middle-aged, the most extensive range was young H. ammodendron. Deep soil water and groundwater have been the main source of water for mature H. ammodendron, and deep soil water is the main source of water for middle-aged and young H. ammodendron.（2）The water source characteristics of H. ammodendron community The main soil water of Erodium oxyrrhynchum, Sisymbrium polymorphum, Seriphidium santolinum and Suaeda glauca was 8-65 cm layer soil water, there were still some differences in soil water use, and the seasonal variation of soil water use of Seriphidium santolinum and Suaeda glauca was significant. In May, The main water source of Suaeda glauca grown in the space was concentrated in 0-10 cm soil layer, the average depth of soil water use was 8.43 cm. In August, the depth of soil water that used moved down, and the average depth of soil water utilization was 41.2 cm. On the ground, Seriphidium santolinum and Suaeda glauca mainly use the 20-40 cm soil layer, and the depth of soil respectively were 22.3 cm and 57.6 cm in May. In August, which make use of soil water depth increased, focused on 0-20 cm soil layer soil water, the average depth was 12.2 cm.H.ammodendron did not affect the water use characteristics of Sisymbrium polymorphum. The results showed that the soil moisture utilization of Erodium oxyrrhynchum and Seriphidium santolinum in May and Suaeda glauca in August were less affected by H. ammodendron. The soil water use of Suaeda glauca in May and Seriphidium santolinum in August greatly affected by H.ammodendron. Sisymbrium polymorphum, Seriphidium santolinum and Suaeda glauca under the canopy had a competition about soil moisture, while the plants in the space area had no competition
准噶尔西部农业开发区表层土壤盐分时空变化
No full textSoil salinization directly threatens the stability of desert oasis ecological environmentand the sustainable development of agricultural production. It is of great significance forthe prevention and control of soil salinization, the rational use of cultivated land resourcesin arid area and the maintenance of oasis agroecosystem in exploring the spatial andtemporal pattern of salinization after cultivated land reclamation in inland arid area. Basedon soil sampling data and remote sensing images, combined with field investigation,statistics, remote sensing and geographic information system, this paper quantitativelyanalysis the spatial and temporal distribution and change characteristics of soil salinizationin the Karamay Agricultural Development Zone before and after reclamation, revealing thedistribution characteristics and changes of soil salinization under different reclamationyears and different groundwater levels. The main conclusions are as follows:(1) The soil salinization in the study area has a tendency to decrease, but there aredifferences in different stages and different regions. The results of soil sampling in 1996,2006 and 2016 indicate that the salinization in the southern part of the study area is higherthan that in the northern region, and change range of the salinization in the southern area isgreater than that in the north. Severe and moderate salinization is mainly distributed in thesouthern region, non-salinization and mild salinization is mainly distributed in the northernregion.(2) During the period from 1996 to 2016, More than 45% of the areas of soilsalinization were changed in different ranges. The degree of soil salinization is mainlymanifested as an increase in non-salinized soil area and a decrease in mild, moderate andsevere salinized soil area. Non-salinization is mainly from the transfer of mild salinizedsoil, mild, moderate and severe salinization were transferred to the soil type, which waslighter than the level of their salinization, and shifted from the soil type, which was severerthan the level of their salinization. Different salinized soil types varied from 1996 to 2006and 2006 to 2016.(3) The study area is basically in accordance with the order from north to south development, in 2001 for the first time a large-scale cultivation, 2014, all reclamation iscompleted. With the increase of reclamation period, the total salt content of soil samplingpoints showed a decreasing tendency, but the fluctuation of change gradually increasedwith the passage of time. The sampling point of soil total salt content large fluctuation in2016 is mainly located in the southwest of the study area, and it is not reclaimed in thesampling area in 2006, which indicates that the degree of salinization in this area isrelatively heavy and the change is complicated.(4) The background conditions of soil salinization in the study area have somedifferences in spatial distribution, and this difference always exists at different times afterreclamation. In areas with long reclamation periods, soil salinization is relatively light andthe reclamation period is shorter, and soil salinization is relatively heavy. Reclamationresulted in a decrease in the degree of salinization in the study area and a decrease insalinization between different sub-areas.(5) From 2006 to 2015, the groundwater level inside and outside the study areashowed an increasing trend, and the distribution pattern of high groundwater level centeredon the southwest was formed in the study area by 2015. The internal groundwater level issignificantly higher than the external area, the groundwater level rises more than theexternal area. There are significant differences in the groundwater level in the differentseasons in the study area. The summer and autumn water levels are higher than those in thespring, and the seasonal variation of the groundwater level in the external area is small.There was no significant relationship between the water depth and soil total salt content in2006, mainly due to the lower groundwater level in the study area in 2006, and the input ofirrigation water was mainly salt washing. In 2016, the groundwater level was higher, andwith the increase of water depth, the total soil content of soil showed a decreasing trend.Moderate and severe salinization distribution area is basically located in 2006 ~ 2015groundwater level less than 2.5 meters in the area
模拟水、氮脉冲变化对两种荒漠一年生植物生长和物种竞争的影响
No full textWater in desert areas is the most important factor limiting plant growth. Innatural conditions, the availability of moisture and nitrogen is dependent on thedynamic changes in the environment, the fluctuation of precipitation and resourcepulse greatly impact the germination, individual growth and reproduction of differentdesert plants. Spring annual plants, also called ephemerals, and summer annual plantshave significant different water and nutrient use efficiency. Therefore, we infer thatthe seasonal variation of water and N availability will change the growth dynamicsand interspecific relationship of these two different life forms of plants, and it willalso affect their relationship in community phenology. This study examined anephemeral (Malcolmia Africana) plant’s characteristics in terms of floweringphenology, individual growth, biomass distribution and interspecific competition withan annual grass specie known as Descuminia Sophia with a long life cycle response toseasonal nitrogen availability. Plants received the same amount of water in threedifferent patterns according to the real water and N deposition in study area. The mainresults are as follows:Nitrogen application patterns have a significant effect on the process of M.african’s flowering phenology with a typical single-peak curve under the even modeland spring-dominated model, and a trend of two-peak curve under summer-dominatedmodel. The final plant height of M. African under spring-dominated model is thehighest in three treatments in individual growth.Different water application patterns significantly changed the flowering curve ofthe flowering grain. Compared to the average model of water addition, the index andthe single-peak water patterns make the flowering peak in advance. Compared to theindividual growth environment, under the competition with D. sophia, the ratio offlowering of M. africana changed a lot in different time. The flowering of M. Africanaunder the average water pattern is more dispersed in individual growth environmentbut more concentrated in intergrowth environment.The competition for water is more intense in individual growth environment thanthat in intergrowth environment. The M. africana is sensitive to precipitation and itcan use the short-term sufficient water to grow but with lower drought resilience thanD. sophia with the longer life history. Under the background of increasing spatial-temporal distribution of precipitation in arid area, the amount and pattern ofprecipitation variability will make an important effect on desert plants’ growth,phenology and even community composition
南疆地区就业情境模拟与政策优化研究
No full text就业问题首先受到人口劳动力和产业发展的直接影响，在生态脆弱地区，产业发展又受到区域资源环境的直接约束。本研究在之前研究成果的基础上，将资源环境约束纳入就业约束条件，通过资源环境约束、人口与劳动力、产业发展与就业相互关系中的直接关系，建立典型生态脆弱地区的区域就业理论模型，因而具有更为普遍的指导意义