生态脆弱区春季风沙成因及防治——以黑龙江西南部为例

黑龙江省西南部是我国著名的优良草地和商品粮基地,但作为生态脆弱区,其在春季有比较强烈的风沙天气,为该地区的生产和生活带来诸多的不便,同时给该地区的生态环境造成很大危害。本文论述了该地区春季风沙的现状、危害、成因和防治措施以及问题与对策,以期为今后防治风沙提供参考。

Sustainable Development of Agriculture in Northwestern Ecologically Fragile Desert Oasis——A case study of Guazhou County of Gansu Province

Guazhou County of Gansu Province is a typical ecological fragile area lying in the transition area of desert and oasis.The development of its agricultural economy is highly dependent on natural resources and environment.Contradiction of resources characterized agriculture and the fragile ecological environment has become one of the main barriers to log the impact of local agriculture to achieve sustainable development.Aiming at fragile ecological environment and limiting factors of agricultural sustainable development,thoughts and countermeasures of realizing agricultural sustainable development have been proposed.

Driving Analysis on Ecological Security in Vulnerable Transition Areas of Mountain and Plain

[Objective] This study aimed to investigate the driving mechanism of eco- logical security in vulnerable areas in mountain and plain. [Method] The ecological security evaluation index system of Lincheng County was established using PSR model. Driving mechanism was analyzed in total system and subsystems respectively by the principal components. The ecological safety driving factor was calculated through the total system and subsystem respectively. And the intersection was adopt- ed as dominant driving factor. [Result] A total of 10 indices including density index of rivers, land degradation index, farmland drought and flood insurance yield, human in- terference index, population density, the natural population growth rate, per capita GDP, the R＆D funds spending accounts for the proportion of GDP, laborer by edu- cation degree and three industry accounted for the proportion of GDP, are the domi- nant driving factors of the regional ecological security. [Conclusion] This study will pro- vide reasonable and feasible advice for the benign development of the area.

Application of Matter-element Model in Soil Nutrient Evaluation of Ecological Fragile Region

On the basis of the soil environment investigation in Da＇an City, Jilin Province, China, 40 soil samples from main land use types were obtained and tested by standard method. Soil organic matter （SOM）, total N （TN）, total P （TP）, total K （TK）, available N （AN）, available P （AP） and available K （AK） were chosen as the evaluation factors. A regional soil nutrient evaluation model was developed based on the matter-element model. The results show that the soil samples with nutrient grade Ⅱ-Ⅴ respectively account for 10%, 30%, 32.5% and 27.5%, and those with grade Ⅳ and Ⅴ account for 60% in all samples. The relationship between soil nutrients and land types indicates that the nutrients of farmland are relatively good, with 41.7% of soil samples with the nutrient grade Ⅳ and Ⅴ. The nutrients of saline-alkali land and sandy land are the worst, with 100% of soil samples with the nutrient grade IV and V. And the ratios of soil samples grade IV and V in grassland and wasteland are respectively 62.5 % and 54.55%. Generally speaking, the soil nutrients status in Da＇an City is poor, 60% of soil samples are in poor and extremely poor conditions, indicating that the soil has been severely eroded. Being a relatively superior evaluation method with more accurate resuits and spatial distribution consistency, matter-element analysis is more suitable for regional soil nutrient evaluation than previous models.

GIS-based Effect Assessment of Soil Erosion Before and After Gully Land Consolidation: A Case Study of Wangjiagou Project Region, Loess Plateau

The Loess Plateau is one typical area of serious soil erosion in the world. China has implemented ′Grain for Green′(GFG) project to restore the eco-environment of the Loess Plateau since 1999. With the GFG project subsidy approaching the end, it is concerned that farmers of fewer subsidies may reclaim land again. Thus, ′Gully Land Consolidation Project′(GLCP) was initiated in 2010. The core of the GLCP was to create more land suitable for farming in gullies so as to reduce land reclamation on the slopes which are ecological vulnerable areas. This paper aims to assess the effect of the GLCP on soil erosion problems by studying Wangjiagou project region located in the central part of Anzi valley in the middle of the Loess Plateau, mainly using the revised universal soil loss equation(RUSLE) based on GIS. The findings show that the GLCP can help to reduce soil shipment by 9.87% and it creates more terraces and river-nearby land suitable for farming which account for 27.41% of the whole study area. Thus, it is feasible to implement the GLCP in places below gradient 15°, though the GLCP also intensifies soil erosion in certain places such as field ridge, village land, floodplain, natural grassland, and shrub land. In short, the GLCP develops new generation dam land and balances the short-term and long-term interests to ease the conflicts between economic development and environmental protection. Furthermore, the GLCP and the GFG could also be combined preferably. On the one hand, the GFG improves the ecological environment, which could offer certain safety to the GLCP, on the other hand, the GLCP creates more farmland favorable for farming in gullies instead of land reclamation on the slopes, which could indirectly protect the GFG project.

Use of Intensity Analysis to Measure Land Use Changes from 1932 to 2005 in Zhenlai County, Northeast China

Analyzing spatiotemporal dynamics of land use and land cover over time is widely recognized as important to better understand and provide solutions for social, economic, and environmental problems, especially in ecologically fragile region. In this paper, a case study was taken in Zhenlai County, which is a part of farming-pastoral ecotone of Northeast China. This study seeks to use multi-temporal satellite images and other data from various sources to analyze spatiotemporal changes from 1932 to 2005, and applied a quantitative methodology named intensity analysis in the time scale of decades at three levels: time interval, category, and transition. The findings of the case study are as follows: 1) the interval level of intensity analysis revealed that the annual rate of overall change was relatively fast in 1932–1954 and 1954–1976 time intervals. 2) The category level showed that arable land experienced less intensively gains and losses if the overall change was to have been distributed uniformly across the landscape while the gains and losses of forest land, grassland, water, settlement, wetland and other unused land were not consistent and stationary across the four time intervals. 3) The transition level illustrated that arable land expanded at the expense of grassland before 2000 while it gained intensively from wetland from 2000 to 2005. Settlement targets arable land and avoids grassland, water, wetland and other unused land. Besides, the loss of grassland was intensively targeted by arable land, forest land and wetland in the study period while the loss of wetland was targeted by water except for the time interval of 1976–2000. 4) During the early reclamation period, land use change of the study area was mainly affected by the policy, institutional and political factors, followed by the natural disasters.

Impacts of Part-time Farming on Agricultural Land Use in Ecologically-vulnerable Areas in North China

Part-time farming has been increasing steadily in China. It is currently the largest segment among all the farm sectors in the country. Based on rural household survey data in Taipusi County as a case site ofecologically-vulnerable areas in North China, we firstly classify farm households into four types according to the proportion of non-farm income in total income, and then compare their agricultural land use patterns to empirically examine the impacts of part-time farming on agricultural land use in this area. The results suggest that non-farming households rent out all their land and give up farming, and this satisfies the expectation of other households to expand land area. The crop planting structure was not significantly different among the households, which reflected the farmers＇ will to pursuit labor productivity. Part-time farming households invest more capital and materials than full-time faming households because the income derived from non-farm employment relaxes the financial constraint of households. However, the amount of labor input of part-time farming households tends to be less, and farming practices are dominated by the elderly, female and laborers withrelative low educations.Yields of crops and the benefit of agricultural land use incline to reduce, which suggest that the potential of land use productivity is more elastic to labor inputs than capital inputs in the study area.

Agricultural Land Use Intensity and Its Determinants in Ecologically-vulnerable Areas in North China:A Case Study of Taipusi County,Inner Mongolia Autonomous Region

Based on rural household survey data in Taipusi County in Inner Mongolia Autonomous Region, this article analyzes agricultural land use intensity and its determinants. The results reveal marked differences of agricultural land use intensity among households with different ages of householders, proportion of non-farm participants, total agricultural land area, land fragmentation and land utilization capacity. （i） Households with older householders and households with a smaller proportion of non-farming laborers generally spend more time on managing their land and invest less capital and materials than other households. The proportion of non-farming laborers within younger households is relatively high, and they tend to invest more capital and materials because the income derived from non-farm employment relaxes their financial constraints. （ii） Land fragmentation is an important determinant of land use intensity. Households with a bigger land size per plot usually spend less time and invest more capital and materials on their land; （iii） Land with better quality is usually managed intensively. The results suggest that labor has become an important constraint for local agricultural production, and there is the potential to improve land management scale and increase machinery input to substitute for labor. Furthermore, the effects of non-farm employment on land use intensity indicate that the establishment of a coordination mechanism between non-farm employment and agricultural land use is an important way to solve the conflict between ecological security and agricultural production in ecologically-vulnerable areas.

Overview of Ecological Restoration Technologies and Evaluation Systems

Ecological degradation is a global problem, and ecological restoration technologies have played and will continue to play an important role in its mitigation. However, the lack of systematic research and evaluations of ecological technologies has thus far affected their effective application in vulnerable ecological regions. This study therefore provides an overview of the main technologies for remediating soil and water erosion, desertification, and rock desertification in China and throughout the world. It addresses key issues and recommends approaches for evaluating ecological restoration technologies. Restoration technology emerged as early as 1800. Over the years such technology has changed from single objective applications to multi-purpose, multi-objective applications employing strategies that take into account ecosystem rehabilitation and integrated ecological and socioeconomic development. Along with this technological evolution, different countries have taken pertinent actions as part of their restoration initiatives. However, key issues remain, including the lack of location-specific restoration technologies and a methodological strategy to assess and prioritize existing technologies. This study proposes a four-level analytical hierarchical framework in conjunction with an indicator system that highlights the establishment and adaptation of associative indicators, while also recommending a three-phase evaluation method（The Mert）, targeting The Mert to qualitative（quick and extensive） and quantitative（detailed） evaluations in order to select the most appropriate restoration technologies available. This study can also be used as a basis for understanding the evaluation and prioritization of restoration technologies, while increasing the awareness of decision makers and the public on the role of technology in restoring degraded ecosystems.

Ecological Rehabilitation Measures in Civil Airport Construction Projects in Different Ecologically Vulnerable Regions in China

Numerous airports have been constructed based on the Twelfth Five-Year Plan for Civil Aviation Development of China. We collected relevant data on the number and distribution of civil airports, the construction of which had started or that had been assessed and approved. Based on a comparative analysis of the limits of ecological restoration in different ecologically vulnerable areas from the perspective of space, as well as an examination of ecological sensitivity factors in the ecosystems surrounding airport construction projects, suggestions concerning key ecological control techniques to be employed in airport construction projects in different ecologically vulnerable areas are put forward. The results showed that the airport construction projects recently approved by the Ministry of Water Resources and the Environmental Protection Agency are mainly distributed in the ecologically vulnerable areas of the Red Soil Hilly Area in southern China, the Karst Rocky Desertification Area in southwest China, the Agro-pastoral Ecotone in the southwestern mountain region, and the Desert-Oasis Connecting Belt in northwest China. The airport construction projects in the southwest mountain area, the hilly areas of southern China, and in the Qinghai-Tibetan Plateau are mainly based on the ecological technologies of slope protection, interception and drainage management, and vegetation restoration, respectively. In the arid and semi-arid areas, the ecological control technology employed in airport construction is mainly the rational utilization of water resources and reduction or mitigation of the effects of sandstorms. This study aims to serve as basis for soil and water conservation plans in airport construction projects and accelerate ecosystem restoration within the vicinity of airport construction sites.

The Effects of Eco-Compensation in the Farming-Pastoral Transitional Zone of Inner Mongolia,China

Ecological compensation or eco-compensation has been implemented mainly through institutional arrangement in China. In the farming-pastoral transitional zone of Inner Mongolia, eco-compensation has been implemented in two modes, one for land use abandonment and the other for productionstructure adjustment. Based on a detailed field survey, this study performs a comparative analysis of the willingness of households to accept economic compensation and consequently evaluates the effects of the two eco-compensation modes. The mode of eco-compensation for land use abandonment lacks a mechanism for generating employment opportunities and so is unsustainable. In contrast, ecocompensation for production-structure adjustment makes the pastoral and farming scales of households decrease significantly and most importantly helps to generate more job opportunities. Although this mode faces households with more market risk, it provides an effective means for resolving conflicts between ecosystems restoration and regional socio-economic development.

Ecological Restoration Strategies in Fragile Subtropical Mountain Ecosystems in China Based on Long-term Research in Changting County

Changting County is located in western Fujian province. Natural, social and economic aspects of ecolog- ical restoration were studied in this area from 2000 to 2011, and the results are widely representative of subtropical mountain ecosystem fragility across China. Great attention should be paid to the application of system theory and the harmony of human-nature relationships. This paper aims to provide the scientific theory to support strategies known as ＇harmony of man with nature＇, which means exerting natural regenesis potential by following natural law, transferring runoff from harm to benefit by operating on the ground and making material and economic virtuous cir- cles in land utilization by arousing human initiatives. It is necessary to transform ideas, tactics and technology and break technological bottlenecks, space limitations and systemic obstacles.

The Evolution of Desertification Control and Restoration Technology in Typical Ecologically Vulnerable Regions

Global economic development and increasing human activities have brought great challenges to fragile ecosystems.In order to avoid,reduce,and reverse desertification,Chinese and foreign scientists and ecological governance institutions have developed a series of ecological restoration technologies(ERTs)and models in the past few decades.These technologies can improve residents’livelihoods,strengthen disaster resilience,and launch a comprehensive review of degraded ecosystems in desertification regions.However,some studies and practices have limited the selection and promotion of good technologies and the assessments of these technologies,resulting in the waste and loss of funds and manpower.The objective of this study is to identify desertification control and restoration technologies and models,summarize the evolutionary features and trends of these technologies under different natural conditions,and evaluate the various ERTs that are now available.The data sources of this study include the databases of international organizations,CNKI,related literature and reports,and questionnaires from institutions and experts.First,the three stages of ERTs evolution were summarized,and the key events and social-economic developments were identified as the driving forces of evolution.Then,the four categories of ERTs were identified as biological,engineering,agricultural,and management ERTs.Finally,the key ERTs were evaluated in the five dimensions of the degree of difficulty,the degree of maturity,effectiveness,suitability,and potential for transfer.The management ERTs scores for the degree of difficulty,the degree of maturity,and potential for transfer are higher.This study provides a reference for adapting to local conditions,the comprehensive management,rational development,and utilization of dryland resources,improving the application of ecological technologies,and promoting the export and import of the excellent technologies.