Spatial variation in soil inorganic nitrogen across an arid urban ecosystem

We explored variations in inorganic soil nitrogen (N) concentrations across metropolitan Phoenix, Arizona, and the surrounding desert using a probability-based synoptic survey. Data were examined using spatial statistics on the entire region, as well as for the desert and urban sites separately. Concentrations of both NO₃-N and NH₄-N were markedly higher and more heterogeneous amongst urban compared to desert soils. Regional variation in soil NO₃-N concentration was best explained by latitude, land use history, population density, along with percent cover of impervious surfaces and lawn, whereas soil NH₄-N concentrations were related to only latitude and population density. Within the urban area, patterns in both soil NO₃-N and NH₄-N were best predicted by elevation, population density and type of irrigation in the surrounding neighborhood. Spatial autocorrelation of soil NO₃-N concentrations explained 49% of variation among desert sites but was absent between urban sites. We suggest that inorganic soil N concentrations are controlled by a number of ‘local’ or ‘neighborhood’ human-related drivers in the city, rather than factors related to an urban-rural gradient.     

回纥与漠北草原诸族关系初探

古代回纥作为我国维吾尔族的祖先,其起源同漠北草原其他各族之间有着错综复杂的关系。本文在充分吸收前人成果的基础上,经过对诸多文献的梳理论证,对于同回纥有渊源的丁零、敕勒、铁勒、九姓乌护、九姓乌古斯,以及突厥之间的关系进行了系统探索,全面论证了回纥如何在与周邻各族的密切交往过程中不断发展壮大的历史过程。     

Desire for the desert: racialising white teachers’ motives for working in remote schools in the Australian desert

Abstract

Distinct from rurality, the Australian desert has long functioned as a signifier of remoteness in the dominant imagination; a product of spatialised binary relations between ‘progressive’ (white) mainstream or idealised white countryside, and disordered/dangerous Aboriginal periphery. Remoteness constitutes a complex racial dynamic that has historically mediated white teachers’ and missionaries’ desires to travel to the social margins. This article adopts a discursive understanding of remoteness to examine contemporary white teachers’ decisions to work in Aboriginal schools in the desert – decisions that are often articulated through unwitting recourse to the ‘three Ms’ or ‘tourist’. The article explores these identity constructs and how they enable different performances of whiteness. It examines how white people’s desires are often covertly raced but does not however, position the teacher as a priori racist. Rather, desire is theorised as a social construct in which subjects invest, which may at times contribute toward processes of decolonisation. This rendering moves beyond a logic of individualism and underpins the argument that recognising how these dynamics play out is vital with respect to understanding the place of white teachers inside remote Indigenous Education. Moreover, such insights are valuable for appreciating how whiteness continues to be reproduced in White Australia under a guise of good intentions.     

以色列对荒漠的开发治理及其主要经验

面对紧张的人地关系,以色列对占有国土面积一半以上的荒漠地区进行了开发治理,并积累了大量经验:保护与开发并重;政策倾斜引导;重视科研开发;完善社会化服务体系;加强国际合作等,为我国开发治理土地贫瘠地区,实现人口、资源与环境的可持续发展提供了借鉴。     

环境退化地区家庭人口对土地利用的影响研究——以中国西北毛乌素沙地为例

微观层面模型对于区分不同的人口群体以更好地明确环境退化的责任主体及其原因具有重要价值,对不同的土地利用方式进行经济区分是联接家庭人口特征与土地覆盖结果的重要手段。基于扩展的恰亚诺夫理论框架,文章利用2007—2008年两次调查所获293个农户样本数据,采用OLS和logit多变量模型实证分析毛乌素沙地家庭人口和其他因素对土地利用的影响。研究结果表明:(1)家庭人口因素对毛乌素沙地农户的土地利用产生重要影响;(2)毛乌素沙地主要土地利用的环境影响也遵循家庭生命周期的过程;(3)毛乌素沙地农户在减少有助于土壤修复利用活动的同时面临上升的退化风险。     

探索人类灵魂的艰难旅程——对帕特里克·怀特在《沃斯》中象征手法的解读

帕特里克.怀特的《沃斯》一直是西方文学评论界的热点。有人赞扬它是"天才之作",也有人指责它晦涩难懂,高深莫测。本文试图对《沃斯》一书的象征手法进行解读,以进一步探讨作品的深层意义。在物质丰富、精神贫乏的现代社会中,基督教为人们超越自我、净化心灵提供了一条可靠途径。     

新疆南疆地区社会经济发展面临的问题、对策及其意义--新疆维吾尔自治区南疆地区实地调查

本文根据对新疆维吾尔自治区南疆地区部分农村进行实地调查所获取的第一手资料和所了解到的情况,对长期以来制约南疆地区经济发展的客观的和主观的原因,进行了实事求是的分析,提出了存在的问题和解决这些问题的措施及设想,阐述了西部大开发及发展南疆地区社会经济的重大的经济意义和政治意义.     

开发西部沙漠的全新理论——论钱学森的沙产业理论

钱学森首倡的知识密集型沙产业理论是开发西部沙漠的全新理论。它在防沙治沙用沙的关系、开发西部沙漠的思路创新和指导原则等方面对传统治沙理论有了全新突破,呈现出战略性和前瞻性的特色。它对于我国西部开发、构建社会主义新农村和落实科学发展观具有重要的理论指导意义。     

论荒漠治理的制度安排

荒漠化是我国经济社会可持续发展所面临的一个严峻问题。由于制度原因,我国荒漠化治理的进展相当缓慢,因此必须对荒漠化治理的制度进行变革。治理荒漠必须完善产权制度以及补偿制度,重新设计激励制度。     

对沙产业科学内涵的认识——纪念钱学森沙产业论述发表20周年

沙产业理论是以太阳能为直接能源利用技术装置靠植物的光合作用来进行产品生产的体系,要求生产技术现代化,生产过程组织严密,生产工序配合紧密,为创建新的农业文明提供了指导和依据,这已被实践证明,但沙产业特定的发展空间是沙漠戈壁脆弱的生态环境,保持生态与经济效益的双赢是永恒的主题,是在技术的发展和实践中逐步完善和壮大,实现"变不毛之地为沃土"的理念.