From the kitchen and the field: Gender and maize diversity in the Bajío region of Mexico

The conservation of crop genetic diversity in farmers' fields is important for future food security. Recent research on women and biodiversity has emphasized the importance of women's knowledge in plant domestication and biodiversity conservation. This paper presents a case study of the differences in women's and men's knowledge of maize landraces in four different environments in the Bajío region of Mexico. We argue that research on crop diversity and conservation needs to include both men and women farmers' knowledge. Gendered knowledge results from men and women in a household being responsible for different tasks and sometimes for farming separate plots. In addition, as economic pressures increasingly force men to work away from their communities for extended periods, women become the primary agricultural decision-makers.     

Responding to the coffee crisis: a pilot study of farmers' adaptations in Mexico, Guatemala and Honduras

This article explores the impacts of market shocks and institutional change on smallholder livelihoods, and the challenge of adaptation in Mexico, Guatemala and Honduras. The rapid decline in coffee prices since the dissolution of the International Coffee Agreement in 1989 has had widespread and profound impacts across coffee-producing regions. The data collected in the three case studies of this project confirm the severity of the impact, particularly in the Mexican and Guatemalan communities. They also illustrate the importance of the historical relationship between farmers and public institutions in defining farmers' perception of risk, their awareness of the nature of the changes they face, and thus the flexibility of their responses to present and future uncertainty. The project's findings indicate that the existence and development of local networks among farmers, service providers and information sources may be critical for facilitating adaptation, particularly in the context of economic liberalization and globalized agriculture.     

Buying Development: Housing and Urban Growth in Guadalajara,Mexico

This study analyzes how Mexican federal housing policy affects the production of space and the housing landscape in Guadalajara, Mexico. Using a wide-ranging database of parcels developed in metropolitan Guadalajara, we map all housing developments from 1970 to 2000 and classify them into three categories that reflect different development processes. The greatly increased number of social-interest houses, and the large extension of land area developed since 1990 are explained by federal housing program reforms. Informal settlements remain a major path to home ownership, but the percentage of housing developments that are informal and the percentage of informally developed land have declined since the 1980s. We also discovered a trend of increasing land area devoted to low-density, élite enclaves, and analyzed marketing strategies and land use patterns that occurred in these newer developments. All of these outcomes reflect a neoliberal ideology that promotes consumption and the privatization of space, but largely excludes the urban poor. The result is higher rates of home ownership, but in an increasingly segregated and fragmented landscape poorly served by public infrastructure and lacking in amenities.     

Mapping land cover changes in Mexico, 1976–2000 and applications for guiding environmental management policy

Land use conversion typically implicates deforestation and fragmentation of primary land cover types, which invariably translates into impoverishment of both natural and cultural capital. Understanding where conversion is taking place crucially underpins sound environmental policy instruments to prevent these enormous social and economic costs. This paper examines 30 years of semi‐detailed (1:250 000) land cover mapping in Mexico. Pre‐existing analogue databases describing land cover patterns in the 1970s and 1990s were reviewed, corrected, reorganized and transformed into a digital format. Current land cover patterns were depicted by conducting updated reinterpretation on Landsat ETM+ imagery. Digital cartographic overlaying was performed and the results were used to construct a spatially explicit land use/land cover change (LULCC) database with an additional accuracy assessment procedure. The value of the results of this analysis is also seen in the light of their direct applications for identifying critical watershed trends, for guiding the allocation of financial funds for sound land use planning and for assessing the effectiveness of established protected areas. This effort highlights the importance of new and more effective geographical approaches to depict, understand and contribute to informed measures to mitigate ongoing negative trends in land cover and climatic changes.     

A late Holocene palaeolimnological record from central Mexico, based on faunal and stable-isotope analysis of ostracod shells

A late Holocene palaeolimnological record for central Mexico has been obtained from Lake Pátzcuaro, using recent and fossil ostracods. Lake Pátzcuaro, Michoacán, is a closed-basin lake which responds rapidly to changes in the ratio of precipitation/evaporation in the region. The record from a single lake-sediment core, dated by AMS radiocarbon method, covers the last ~3,530 yrs, and is based on ostracod faunal palaeoecology coupled with analysis of the stable-isotope (¹⁸O/¹⁶O and ¹³C/¹²C) composition of ostracod valves. The faunal distribution is determined by the presence or absence of aquatic vegetation and, to a lesser extent, salinity. The ¹⁸O/¹⁶O and ¹³C/¹²C ratios in ostracod calcite show good agreement with palaeolimnological inferences from the faunal assemblages, principally recording changing precipitation/evaporation and primary-productivity levels, respectively. Wetter conditions existed in central Mexico between approximately ~3,600 and ~2,390 yr BP, between ~1,330 to ~1,120 yr BP, and from ~220 yr BP to present, characterised by fluctuating lake levels. A dilution of the sediment load in the lake reduced turbidity levels allowing for a marked increase in productivity. During these phases, the combination of a deeper lake and increased macrophyte cover reduced the degree of mixing of the waterbody. In the earliest of these phases there was sufficient stratification of the waterbody for methanogenesis to occur in the sediment interstices. The wet phases were separated by prolonged dry periods, during which time the climatic conditions were relatively stable. Good agreement was found between the findings of this study and others from the central Mexican/Caribbean region suggesting that abrupt climate changes occurred at least at a regional scale.     

农村社区农户互动效应的定量评估——来自河南省杞县孟寨村的实证

信息流动会使农户产生互动学习效应,进而影响农户的农业生产率。基于河南省孟寨村第8小组农户的普查,获得有关农户亲戚、邻居和与之地块邻近农户的社会经济特征和大蒜产量的信息,对这些群组内部的互动学习效应进行检验,并识别不同类型的互动效应。结果表明:内生互动效应仅存在于亲缘群组;情境互动效应存在于地邻群组和邻里群组,但在两个群组中存在一定的差异;关联效应在三个群组均存在,与亲缘群组相比,邻里群组和地邻群组中关联效应更大,但在亲缘群组中,关联效应远小于内生互动效应,在邻里群组和地邻群组中也远小于情境互动效应。研究结论对国外学者的发现进行了修正。这种理论研究具有重要的政策含义。     

Making the Subterranean Visible: Security,Tunnels, and the United States–Mexico Border

The number of unauthorized tunnels discovered through the U.S.–Mexico border has risen dramatically since the mid‐1990s. These tunnels are problematic for the state because the subterranean border is both less visible and more difficult to monitor and control than is the surface border. In this era of heighten security, the debate on secure borders has intensified. As a result, the need to demonstrate security success at both the national and the agency level has risen. Efforts to make tunnel discoveries (and security) visible are made within border‐security agencies and within national discourse and legislation. These efforts spatially fix tunnels to the border in ways that obscure fuller a understanding of drug trafficking in general. This paper employs archival research, content analysis, and informal interviews with security‐enforcement agents to consider the material presence of tunnels within border landscapes.     

Gendered production spaces and crop varietal selection: Case study in Yucatán, Mexico

This paper examines the influence of gender relations and gendered domains on maize and squash varietal selection in a village in Yucatán State, southeast Mexico. Results of the exploratory study indicate that the traditional production spaces of homegardens and agricultural fields are complementary gendered domains of varietal maintenance for both crops although with different cropping patterns, while a 'new' space, of land allocated to some families for future residential construction ( terreno ) is in the meantime a jointly worked agricultural domain. Women's labour, knowledge and preferences predominate in post-harvest processes. Fieldwork revealed that neither men nor women are independent decision-makers, planning what to grow, where and in what amounts, but that in most aspects of farming the interests of both are accommodated within the household's production spaces.     

The Zihuatanejo, Mexico, earthquake of 1994 December 10 (M= 6.6): source characteristics and tectonic implications

An analysis of the Zihuatanejo, Mexico, earthquake of 1994 December 10 ( M = 6.6), based on teleseismic and near-source data, shows that it was a normal-faulting, intermediate-depth ( H = 50 ± 5 km) event. It was located about 30 km inland, within the subducted Cocos plate. The preferred fault plane has an azimuth of 130°, a dip of 79° and a rake of −86°. The rupture consisted of two subevents which were separated in time by about 2 s, with the second subevent occurring downdip of the first. The measured stress drop was relatively high, requiring a Δσ of about a kilobar to explain the high-frequency level of the near-source spectra. A rough estimate of the thickness of the seismogenic part of the oceanic lithosphere below Zihuatanejo, based on the depth and the rupture extent of this event, is 40 km.
This event and the Oaxaca earthquake of 1931 January 15 ( M = 7.8) are the two significant normal-faulting, intermediate-depth shocks whose epicentres are closest to the coast. Both of these earthquakes were preceded by several large to great shallow, low-angle thrust earthquakes, occurring updip. The observations in other subduction zones show just the opposite: normal-faulting events precede, not succeed, updip, thrust shocks. Indeed, the thrust events, soon after their occurrence, are expected to cause compression in the slab, thus inhibiting the occurrence of normal-faulting events. To explain the occurrence of the Zihuatanejo earthquake, we note that the Cocos plate, after an initial shallow-angle subduction, unbends and becomes subhorizontal. In the region of the unbending, the bottom of the slab is in horizontal extension. We speculate that the large updip seismic slip during shallow, low-angle thrust events increases the buckling of the slab, resulting in an incremental tensional stress at the bottom of the slab and causing normal-faulting earthquakes. This explanation may also hold for the 1931 Oaxaca event.     

Palaeolimnology of the Upper Lerma Basin,Central Mexico: a record of climatic change and anthropogenic disturbance since 11 600 yr BP

The Upper Río Lerma valley, Estado de México, is a high-altitude (2575 m a.s.l.) basin floored by Quaternary alluvial, lacustrine and pyroclastic deposits. Two pits were dug in the swampy bed of the recently drained L. Chiconahuapan. Ten ¹⁴C dates have been obtained from these profiles, which consist of diatomaceous organic lake muds and peats with intercalated tephras. The oldest unit is the Upper Toluca Pumice (Tripartite Ash), dated 11 580±70 yr BP. Analyses of sediment chemistry, loss-onignition, mineral-magnetic variations and subfossil diatom assemblages provide evidence of environmental changes since this date. Alkaline ponds or freshwater lakes developed during the intervals 9000–6000, 6000–5500, 3600–1400 and 800–0 yr BP, and acidic marshes or bogs during the intervening dry episodes. An important phase of accelerated erosion, beginning around 3100 yr BP and culminating around 1400–700 yr BP, appears to have been associated with human disturbance of the basin soils.     

Shifting approaches to slums in Chennai: Political coalitions,policy discourses and practices

Slums pose a persistent challenge for fast growing urban areas in the global South, despite several decades of policy intervention. While Chennai has adopted several strategies ranging from upgrading to reconstruction, the city has been unable to deliver its target of ‘clearing’ slum settlements. Through an analysis of four enumeration reports and a look at the evolving political contexts and subsequent practices, we illustrate the evolution of slum policy approaches in Chennai since the 1970s. The analysis shows slum practices in Chennai continue to be characterized by an underlying continuity, with relocation as the dominant mode of operation since the nineties. However, approaches to slums have also evolved from paternalistic socialism with in‐situ development in the seventies, to approaches characterized by affordability and cost recovery in the eighties, to the aesthetics of global cities in the nineties, to the technology driven, to slum‐free ‘smart city’ discourse currently in vogue.     

基于生态系统的适应(EBA)——概念、工具和案例

生物多样性公约将基于生态系统的适应(Ecosystem-Based Adaptation)(简称EBA)定义为:在总体适应战略中,利用生物多样性和生态系统服务,帮助人类适应气候变化的不利影响。随着气候变化对当今社会可持续性的影响不断增加,EBA正在成为国际社会适应气候变化的政策和行动支柱之一。介绍国际上EBA概念的历史由来、相关定义与特点进行,阐述了EBA的应用原则和相关分析工具,简要分析总结了国际上实施EBA项目取得的经验教训。     

技术关联性、复杂性与区域多样化——来自中国地级市的证据

忽视现实基础,盲目追求新兴产业的现象普遍存在于当前中国的一些城市。基于国家知识产权局的专利数据,描绘1987—2016年中国地级市技术关联性和复杂性的时空演化特征,探讨两者对区域技术进入和增长的影响。结果表明：① 新技术的本地关联度越高,就越有可能进入该地区;现有技术的本地关联度越低,就越容易退出该地区;② 中国城市的技术发展总体上呈现路径依赖特点。其中,东部地区的技术关联性和复杂性变化较大,中西部地区变化较小;③ 技术关联性对新技术的进入和增长起到显著的促进作用。在引入复杂性较高的技术时,只有存在较高关联性才会促进区域的技术进步。最后提出的区域多样化发展框架,可为决策者权衡选择技术发展道路提供参考。     

Science,local knowledge and exclusionary practices: Lessons from the Alta Dam case

The Alta Dam project in Norway is used to illustrate how state control of information may result in environmental injustice through a process of closed decision-making and political marginalization. By closing the decision-making process and related research from stakeholders, a state can attempt to insulate itself from criticism and contrary opinion, even if such practices run contrary to the traditions of inquiry. The exclusionary practices at Alta are examined in relation to the environmental justice literature and history of the Alta dam.     

转型期广州市居民职住模式的群体差异及其影响因素

职住关系是城市研究领域重要的议题之一。体制改革后中国社会分层结构特殊,检验不同阶层居民在职住地选择偏好的差异,有助于理解居民职住格局形成的内部机制。利用广州市入户问卷调查、建成环境和人口普查等数据,采用两步聚类和多项logistic回归,对广州市居民进行阶层划分,对比居民职住模式的群体差异及其影响因素。结果表明：职住决策时,体制外工薪阶层追求低生活成本,受职住地建成环境影响显著;体制内阶层习惯于传统单位制下社会关系密切的社区,受邻里环境影响显著,还受个人属性影响;无固定工作者决策自由和平衡程度高,受少量建成环境因素影响。研究有助于了解居民职住格局形成的制度性机制,为优化居民职住格局提供思路。