Governing intensification: the influence of state institutions on smallholder farming strategies in Calakmul,Mexico

ABSTRACT

In forest frontiers, smallholder agrarian livelihoods remain uneasily juxtaposed with conservation interests. Agricultural intensification is often considered a viable means of reconciling competing environmental and livelihood objectives given its potential to concentrate production on less land. However, intensification may have unintended consequences, including loss of resilient agricultural systems. The risks of smallholder agricultural intensification warrant a better understanding of its drivers. This study uses the case of Calakmul, Mexico, to examine the critical role of the state in intensification processes. Drawing on household surveys and key-informant interviews, it traces the linkages between state institutions and local farming practices. Statistical and qualitative analyses reveal how intensification is both incentivized and imposed by prevailing policies, the former via subsidies and the latter via regulations against field rotations. The outcome – increased external inputs and longer cultivation periods between fallows – may undermine the sustainability of smallholders’ agroecosystems, an undesirable consequence amid limited livelihood alternatives.     

冀中南平原区气溶胶标高变化及估算模型研究

作为反映大气气溶胶垂直分布的重要参量,气溶胶标高被广泛应用于气溶胶反演及模型订正研究中.为研究气溶胶标高时空变化规律并构建其简易计算模型,基于2009～2016年气象站点观测资料及MODIS卫星反演数据,利用Peterson模型及多元回归分析对冀中南平原区气溶胶标高进行了估算分析.研究结果表明:区域气溶胶标高夏季最高,...     

Land use change in Southern Romania after the collapse of socialism

The drastic socio-economic and political changes that occurred after the breakdown of socialism in Eastern Europe triggered widespread land use change, including cropland abandonment and forest cover changes. Yet the rates and spatial patterns of post-socialist land use change remain largely unclear. We used Landsat TM/ETM+ images to classify land cover maps and assess landscape pattern changes from 1990 to 2005 in Argeş County, Southern Romania. Cropland abandonment was the most widespread change (21.1% abandonment rate), likely due to declining returns from farming, tenure insecurity, and demographic developments during transition. Forest cover and forest fragmentation remained remarkably stable during transition, despite widespread ownership transfers. Cropland abandonment provides opportunities for increased carbon sequestration, but threatens cultural landscapes and biodiversity. Continued monitoring is important for assessing whether abandoned croplands will eventually reforest or be put back into production and to better understand the consequences of post-socialist land use change for ecosystems and biodiversity.     

Temporal signatures of advective versus diffusive radon transport at a geothermal zone in Central Nepal

Temporal variation of radon-222 concentration was studied at the Syabru-Bensi hot springs, located on the Main Central Thrust zone in Central Nepal. This site is characterized by several carbon dioxide discharges having maximum fluxes larger than 10 kg m⁻² d⁻¹. Radon concentration was monitored with autonomous Barasol™ probes between January 2008 and November 2009 in two small natural cavities with high CO₂ concentration and at six locations in the soil: four points having a high flux, and two background reference points. At the reference points, dominated by radon diffusion, radon concentration was stable from January to May, with mean values of 22 ± 6.9 and 37 ± 5.5 kBq m⁻³, but was affected by a large increase, of about a factor of 2 and 1.6, respectively, during the monsoon season from June to September. At the points dominated by CO₂ advection, by contrast, radon concentration showed higher mean values 39.0 ± 2.6 to 78 ± 1.4 kBq m⁻³, remarkably stable throughout the year with small long-term variation, including a possible modulation of period around 6 months. A significant difference between the diffusion dominated reference points and the advection-dominated points also emerged when studying the diurnal S₁ and semi-diurnal S₂ periodic components. At the advection-dominated points, radon concentration did not exhibit S₁ or S₂ components. At the reference points, however, the S₂ component, associated with barometric tide, could be identified during the dry season, but only when the probe was installed at shallow depth. The S₁ component, associated with thermal and possibly barometric diurnal forcing, was systematically observed, especially during monsoon season. The remarkable short-term and long-term temporal stability of the radon concentration at the advection-dominated points, which suggests a strong pressure source at depth, may be an important asset to detect possible temporal variations associated with the seismic cycle.     

Public participation mechanisms and sustainable policy-making: a case study analysis of Mexico City's Plan Verde

Mexico City has gained an international reputation for its ground-breaking approach to sustainability as a result of policies implemented during the Marcelo Ebrard administration (2006–2012). In this paper, we examine the development and implementation of the Plan Verde de la Ciudad de México (Green Plan), the 15-year policy aimed to transform Mexico City into the most progressive and sustainable city in Latin America. Key to the plan's success, it was claimed, would be the active participation of stakeholders from all levels of society. Drawing on documentary material and interviews, we argue that whilst the plan did have a significant impact on the environmental sustainability of the megacity, it failed to include effective citizen participation mechanisms. As predicted by several members of the Green Plan Monitoring and Assessment Board, this lack of representation, alongside other failures, appears to have facilitated the premature demise of the plan under the new administration.     

Identifying the potential of governance regimes to aggravate or mitigate local water conflicts in regions threatened by climate change

There is a need for specific knowledge of what people can do to mitigate harmful water conflicts. This need is evident in the rural dry tropics of Central America where people face climate change impacts, inefficient water management, and social tension. To address this need, we investigated why some local water conflicts escalated to violence and why other potential conflicts were avoided in Guanacaste Province, Costa Rica. We used interviews, focus groups, and a stakeholder workshop to analyse five cases. We found that violent actions only occurred when rural groups opposed government agencies in settings without mediating leadership. With one exception in a circumstance aggravated over many years, water users did not take violent action against competing water users. Distrust, which has been formed by legacies of ineffective rural stakeholder engagement, diminished the credibility of water-related information used in decision processes and thus prolonged conflicts. Active community-based groups respected by both rural constituencies and government agencies helped some people avoid difficult conflicts. Self-organised groups in other areas struggled to address disputes in settings with contested property rights, high socio-economic inequality, and low human capital. Using insights from Guanacaste, we outline practical conflict mitigation strategies fitted to a range of local water governance contexts found in rural Central America. Results suggest the need for incorporating certain types of peace-building processes in water management and development. The study provides a foundation for policy-makers, water managers, and other stakeholders to more effectively manage water disputes and avoid harmful conflicts in challenging regions.     

Polychlorinated biphenyls (PCBs) residues in milk from an agroindustrial zone of Tuxpan, Veracruz, Mexico

The coasts of the Gulf of Mexico are zones exposed to the exploration and exploitation of petroleum sources, and the products generated in agricultural zones may become contaminated by persistent organic pollutants (POPs). The objective of the present study was to evaluate the presence of polychlorinated biphenyl compounds (PCBs) in milk from dairy production units near sources of environmental pollutants. It was confirmed that the seven congeners of nondioxin-like PCBs (NDL-PCBs) are present in milk where compounds PCB101, PCB118, PCB153 and PCB180 appear in 100% of the samples analyzed, the rank of concentration for the sum of the seven congeners fluctuating between 2.6 and 26 ng g⁻¹ with a median of 6 ng g⁻¹. None of the samples surpassed the provisional value established by the EU of 40 ng g⁻¹ of milk fat for the sum of the seven congeners, indicator that was not affected by the season of the year (p < 0.05), whose median of 8.6 ng g⁻¹ and 6.3 ng g⁻¹ for rain and drought respectively. The concentrations of NDL-PCBs found in milk do not represent a problem for human health; however, they alert the existence of spontaneously generated, uncontrolled sources that may represent a potential danger for human and animal health.     

Climate and Freshwater Resources in Northern Mexico: Sonora, a Case Study

An analysis of current trends in water availability in the Mexican border state of Sonora is presented to illustrate what may be faced under climate change conditions. Precipitation, streamflow and even dam levels data are examined to estimate what changes have been experienced in recent decades. There are indications that the more frequent occurrence of El Niño/Southern Oscillation (ENSO) events have resulted in more winter precipitation and consequently in a slight increase in water availability in northwestern Mexico. However, water demands grow much faster than such trends in water availability, mainly due to a rapid increase in population in urban areas and in socio-economic activities such as those related to agriculture, industry and power generation. Some strategies to adapt or mitigate climate change conditions are proposed.     

The Effects of a Dredge Excavation Pit on Benthic Macrofauna in Offshore Louisiana

Over two years after the original creation of a sand excavation pit 8 km off the Louisiana coast, benthic macrofauna communities and sedimentary characteristics are still effected. Macrofaunal communities inside the pit had lower abundance, biomass, and diversity than communities outside the pit. This difference, however, was only significant with some of the stations outside the pit. Results from multi-dimensional scaling and cluster analysis showed that macrofaunal communities were less than 32% similar inside the pit to communities outside the pit. The polychaete Mediomastus ambiseta was the most abundant species outside the excavation pit, but the species was only counted once inside the pit. The most dominant species, which made up over 90% of organisms inside the pit, was the pioneer polychaete Paraprionospio pinnata. Only three species were found at each station inside the pit as opposed to 9–27 species at stations outside the pit. All species inside the pit were also found outside the pit; thus, change was due to a loss of species rather than replacement by different species. Sediment inside the pit contained more silt and clay; however, no difference in water quality was detected compared with outside the pit. Hurricanes Katrina and Rita passed near the dredge pit in 2005 and could have effected sediment transport in the region. Because the macrofaunal community inside the pit has not recovered within 38 months, it is likely that it will require more time before it resembles the surrounding conditions.     

Another outlook into energy-growth nexus in Mexico for sustainable development: Accounting for the combined impact of urbanization and trade openness

This study corroborates the importance of United Nations Sustainable Development Goal 7 (SDG-7), intended to ensure access to affordable, reliable, sustainable energy for all, and SDG-8, designed to promote decent work and sustainable economic growth. This article is motivated by the highlighted SDGs and empirically explores the long-run and causality relationship between energy consumption, urbanization, trade openness, and economic growth for annual frequency data from 1965 to 2021 for the case of Mexico. To this end, we leverage the use of fully modified ordinary least squares, dynamic ordinary least squares, and canonical regression estimation methods, while for the direction of causality, the gradual shift and wavelet coherence methods are used. According to the Autoregressive distributed lag (ARDL), the bounds test traces a long-run relationship between the outlined variables over the sampled period. Empirical evidence validates the energy-induced growth hypothesis. This result resonates with the causality analysis, where energy consumption drives economic growth one way in Mexico. This suggests that Mexico cannot embark on energy-conservative policies, as such actions will hurt economic progress. In addition, unidirectional causality is seen between urbanization, trade openness, and economic growth. These findings have far-reaching implications for economic growth and macroeconomic indicators in Mexico. More insights are highlighted in the concluding section.