北方冬小麦主产区的高产与稳产关联性及其影响因素

冬小麦产量高低及稳定性对于保障我国粮食安全同等重要。鉴于北方冬小麦主产区受气候变化的负面影响显著,有必要从高产—稳产关联特征入手,探究全面提升冬小麦产量及稳定性的途径。基于598个县1985—2014年的单产数据,分析了冬小麦高产与稳产关联性时空分异特征,并结合气象、物候观测、农业生产要素等数据,应用无序多分类Logistic模型揭示了冬小麦高产—稳产关联特征的影响因素。主要结论为：（1）冬小麦产量随时间不断提高的同时稳定性也增强,高产性和稳产性均呈东北向西南降低的特征。（2）冬小麦高产与稳产、低产与不稳产密切关联,在研究区占据主导地位,且这两种关联类型的分布区域相对稳定,空间聚集性强。（3）灌溉条件是促进冬小麦高产—稳产的关键因素,影响随时间逐渐增强;具备灌溉条件的情况下,研究区的光温水等气象条件均比较适合冬小麦生产,但不同物候期气象要素的波动对高产和稳产均有负向影响。研究结果可为划定冬小麦优质产区和制定气候变化应对策略提供依据。     

皖北地区旅游产业竞争力综合评价及聚类分析

基于旅游业的行业特点和产业竞争力理论,遵循统计学指标选取的科学性、系统性、可比性和可行性原则构建了区域旅游产业竞争力的评价指标体系,运用因子分析法对皖北地区6个地级市旅游产业竞争力进行了综合评价及排序,并做了聚类分析,给出了相关建议：打造淮河风情与历史文化旅游区、打造亳州古城与养生文化旅游区、打造黄河故道与楚汉文化旅游区.     

红色旅游发展效率评价及影响因素研究——以黔北黔西红色旅游区为例

红色旅游发展效率表征旅游区红色旅游高质量发展水平。以黔北黔西红色旅游区为研究对象,借助DEA模型及Malmquist指数对2014—2019年该区域17个县（市、区）的红色旅游发展效率进行测度,同时利用核密度函数和多元线性回归模型分别剖析了其空间演化特征与关键影响因素。研究发现：（1）研究区域内红色旅游发展效率整体偏低,受技术进步的积极影响,多数县（市、区）红色旅游发展效率呈稳步提升状态;（2）红色旅游发展效率具备空间集聚性和异质性的特征,整体呈现“M”型双峰分布,区域分布差异较大;（3）技术创新、红色旅游资源优势度、交通便利性是影响该区域红色旅游发展效率的主要因素,政府对旅游经济干预程度、经济发展水平和人才规模对该区域红色旅游发展效率的影响较小,产业结构对改善该区域红色旅游发展效率的积极影响尚未凸显。     

光腔衰荡光谱法走航连续观测海表大气中CH4

以基于高精度光腔衰荡光谱法(Cavity Ring-Down Spectroscopy,CRDS)的Picarro G2301型分析仪为核心,自主设计、组装,建立了适用于船载走航连续观测大气CH4的系统.采用可溯源至世界气象组织全球大气观测网(WMO-GAW)的标准气序列开展多次测试,并建立了外标法线性校正方程.测试表明,该系统对CH4响应精密度优于0.5 ×l0-9,准确度优于0.1％,5个月内漂移小于0.3 ×l0-9.同时,结合船载走航连续观测的特点,优化建立了观测数据处理与质量控制方法,以保证所获数据的高质量和国际可比性.分别于2011年7月和2012年5月,率先在北黄海及渤海海峡区域开展了海表大气CH4的走航连续观测.实践证明,该系统操作简便,运行稳定,适用于船载走航连续海表大气CH4的研究,可获取高精度高时空分辨的观测数据.其中,2011年7月观测到的CH4浓度范围为1823.8×10-9～2020.7×10-9,2012年5月为1887.2×10-9～ 2136.2×10-9,均呈渤海海峡区域浓度高,北黄海中部区域浓度低的分布特征.     

Ecological pressures on grassland ecosystems and their conservation strategies in Northern China

In this study,we identified ecological pressures on grassland ecosystems and adaptive countermeasures in Northern China.Our research revealed that the main sources of these pressures included population growth,economic development,resources exploitation,and global climate change,with human-related activities being overriding factors.Overgrazing was an important reason for grassland imbalance,causing soil erosion and desertification,especially during the sensitive spring greening phase.In steppe zones,commercial coal mining was destructive to the ecological environment.Regarding long-term strategies,we recommend that policy-makers devote more consideration to a new conceptual approach for transforming grasslands through shifting the focus from die grassland’s traditional production functions to meir ecological functions.Applying this concept,adaptive countermeasures should be developed to reduce human impacts based on the environmental capacities of grasslands.Moreover,we recommend the development of environment-friendly industries and reduction of pressures from human activities as effective measures for maintaining the balance between sustainable economic development and grassland conservation.Lastly,we suggest that restoration of degraded grasslands should conform to the principle of natural vegetation to further improve the ecological adaptability of plants and ecosystem stability.This study is expected to provide scientific support for policy-makers engaged in grassland protection.     

Human health risk assessment of groundwater nitrate at a two geomorphic units transition zone in northern China

To assess groundwater nitrate contamination and its human health risks, 489 unconfined groundwater samples were collected and analyzed from Zhangjiakou, northern China. The spatial distribution of principle hydrogeochemical results showed that the average concentrations of ions in descend order was HCO₃^?, SO₄^2?, Na⁺, Ca²⁺, Cl^?, NO₃^?, Mg²⁺ and K⁺, among which the NO₃^? concentrations were between 0.25 and 536.73 mg/L with an average of 29.72 mg/L. In total, 167 out of 489 samples (~ 34%) exceeded the recommended concentration of 20 mg/L in Quality Standard for Groundwater of China. The high NO₃^? concentration groundwater mainly located in the northern part and near the boundary of the two geomorphic units. As revealed by statistical analysis, the groundwater chemistry was more significantly affected by anthropogenic sources than by the geogenic sources. Moreover, human health risks of groundwater nitrate through oral and dermal exposure pathways were assessed by model, the results showed that about 60%, 50%, 32% and 26% of the area exceeded the acceptable level (total health index>1) for infants, children, adult males and females, respectively. The health risks for different groups of people varied significantly, ranked: infants> children> adult males>adult females, suggesting that younger people are more susceptible to nitrate contamination, while females are more resistant to nitrate contamination than males. To ensure the drinking water safety in Zhangjiakou and its downstream areas, proper management and treatment of groundwater will be necessary to avoid the health risks associated with nitrate contamination.     

Influence of fur trade,famine, and forest fires on moose and woodland caribou populations in northwestern Ontario from 1786 to 1911

Hudson’s Bay Company records were used to estimate the 1786–1911 annual number of moose (Alces alces andersonii) and caribou (Rangifer tarandus caribou) involved in trade by northern Ojibwa natives to the company post at Osnaburgh House (51°10′N 90°15′W) in northwest Ontario, Canada. The human population for the early 19th century, and the number and severity of human starvations from 1786 to 1911 were estimated. The extent of forest fires in the region around Osnaburgh was documented using a “fire-day” index computed from Hudson’s Bay Company journals and using qualitative archival information. It is argued that the human population was too small to have caused the observed early 19th century moose and caribou population decline solely through predation. Likewise, severe early 19th century famines were caused by climatic factors rather than by declines in moose and caribou numbers. Habitat change caused by increased forest fires correlates with the observed decline of caribou, while moose increased and subsequently collapsed as winter shelter was destroyed. A burgeoning human population, sustained during winter food shortages on potatoes donated by the Hudson’s Bay Company, then kept ungulate populations to low levels until the late 19th century. Only then did maturing forests and a new outbreak of fires provide renewed habitat for resurgences of, respectively, caribou and moose.     

The Manchester earthquake of 14th September 1111: A re-appraisal of contemporary reports

In September 1777 a strong shock of earthquake was widely experienced in the Manchester area. Thanks largely to the density of population in this area and to the fact that the shock occurred on a Sunday morning when many people were in church, the earthquake attracted considerable attention; despite its modest size, it is one of the best documented earthquakes recorded before the 19th century. Analysis of contemporary literature of the event reveals something of the outlook of the society affected and suggests how circumstances of time and place influence the level of information available about early earthquakes. The earthquake caused minor damage but no loss of life. It is nevertheless shown to be a larger event than previously identified.     

Sustainable coasts? Perceptions of change and livelihood vulnerability in Nordland,Norway

ABSTRACT

Northern coastal regions are facing multiple challenges from accelerating global environmental and socioeconomic changes, such as ecosystem degradation, climate change, intensified resource extraction, land use change and declining populations. Based on interviews with 13 farmers, fishers and aquaculture employees from coastal Nordland, northern Norway, this study demonstrates how the local stakeholders’ perceptions of change and experiences of vulnerability are closely linked to their livelihood values and worldviews. What the informants consider a sustainable and meaningful way of coastal living does not coincide with national goals for sustainable, natural resource dependent development of the region. The article demonstrates the importance of attending to local values if policymakers and managers are to ensure successful local mobilisation, reduce vulnerability to ongoing and future processes of change, and ensure legitimacy and consistency in development goals of coastal zone management. Insights from this study are useful for local and regional decision makers with responsibility for natural resource policies and development efforts.     

Arctic Wilderness Policy in the United States and Finland

The United States and Finland have passed laws to classify and manage Arctic wilderness areas, but their national policies are based on different nature ideologies. Finns tend to perceive wilderness as a human-centered idea, while Americans are inclined to see the same land from a nature-based point of view. Rural residents in the Arctic, and especially indigenous peoples, use motorized vehicles for hunting and gathering in wilderness areas. Attempts of southern-based environmental groups to restrict motor use by imposing a nature-based ideology on rural residents in northern Alaska will result in high levels of political conflict. Alaska land managers need to respect the minority rights of rural residents and a study of wilderness policies in Finnish Lapland is instructive toward this end.