Cambio climático y algunas estrategias agrícolas para fortalecer la seguridad alimentaria de México

This essay explores the possible security with food sovereignty of Mexico in the first half of the century XXI, given the impending climate change. The initial conditions include a national population growth, increasing food dependence, and a model of exploitation of natural resources extractive historically, which has led to its significant degradation. It is assumed, that agricultural technology available to the field will be obsolete within the first half of the century due to climate change, with the availability of water for crops and their genetic tolerance to drought and extreme temperatures core variables food production. The fragility of half the arable land in hillside climate change, due to its exposure to soil erosion due to lack of protection is highlighted. The urgent to resource management are discussed to correct deferred investment accumulation of protective adaptations. The research plans intermediate-term (5-10 years) and long term (20 to 40 years) is analyzed. The first to develop transition technologies and the second to develop appropriate advanced stages of climate change technology. The need is observed 1) multiobjective technologies as a MIAF for agricultural management slopes observed; 2) recirculation of elite germplasm of annual crops within and between regions; 3) real-time search and use of native germplasm with genetic adaptation to drought and extreme temperatures; and 4) the development of perennity in the cultivation of corn. Keywords: climate change; food security with sovereignty; technologies adapted to extreme environmental stressesEn este ensayo se explora la posible seguridad con soberanía alimentaria de México en la primera mitad del siglo XXI, dado el cambio climático inminente. Las condiciones iniciales incluyen una población nacional en crecimiento, una dependencia alimentaria creciente, y un modelo de aprovechamiento de los recursos naturales históricamente extractivista, que ha conducido a su degradación significativa. Se da por hecho, que la tecnología agrícola de que dispone el campo será obsoleta dentro de la primera mitad del siglo debido al cambio climático, siendo la disponibilidad de agua para los cultivos y su tolerancia genética a la sequía y a temperaturas extremas las variables centrales de la producción de alimentos. Se resalta la fragilidad de la mitad de la tierra de labor en ladera al cambio climático, debido a su exposición a la erosión del suelo por falta de protección. Se discuten adaptaciones urgentes al manejo de los recursos para corregir la acumulación diferida de inversión protectora. Se analiza planes de investigación de plazo intermedio (5 a 10 años) y de plazo largo (20 a 40 años). El primero para desarrollar tecnologías de transición y el segundo para desarrollar tecnología adecuada a etapas avanzadas de cambio climático. Se observa la necesidad 1) de tecnologías multiobjetivo como el MIAF para el manejo agrícola de laderas; 2) la recirculación de los germoplasmas élite de cultivos anuales dentro y entre regiones; 3) la búsqueda en tiempo real y aprovechamiento del germoplasma nativo con adaptación genética a la sequía y a temperaturas extremas; y 4) el desarrollo de perennidad en el cultivo del maíz. Palabras clave: cambio climático; seguridad con soberanía alimentaria; tecnologías adaptadas a tensiones ambientales extrema

Dune and Beach Morphodynamics at Cabo Falso, Baja California Sur, Mexico: Response to Natural, Hurricane Juliette (2001) and Anthropogenic Influence

Cabo Falso is located on the southern coast of the Baja California peninsula. The beach is broad and wide with a steep face and tall foredunes on the backshore. Landwards, an active, predominantly parabolic dune field has developed with average heights of 30 m. Part of the field is used by recreational all-terrain vehicles. The main goal of this study was to identify the principal morphodynamic characteristics of the deposits influenced by these recreational activities and affected by Hurricane Juliette in 2001. The morphology of the study area was monitored using seasonal topographic profiles, examination of aerial photographs from 1972 and 1993, and on-site photographs (November 1999 to April 2002). The topographic profiles indicated that the erosion period for both the beach and the dunes was June to December. Hurricane Juliette was the responsible for most of the observed erosion. The greatest sediment accumulation occurred between December 2001 and February 2002, associated with the onset of the natural recovery process of the beach–dune system. The photographs revealed that the dunes have lost vegetation cover because of the activities of all-terrain vehicles, which erode paths perpendicular to the dune crests. This in turn allows increased sediment movement, resulting in instability of the dune field system

Data from: Climate change and the northern elephant seal (Mirounga angustirostris) population in Baja California, Mexico

The Earth′s climate is warming, especially in the mid- and high latitudes of the Northern Hemisphere. The northern elephant seal (Mirounga angustirostris) breeds and haul-outs on islands and the mainland of Baja California, Mexico, and California, U.S.A. At the beginning of the 21st century, numbers of elephant seals in California are increasing, but the status of Baja California populations is unknown, and some data suggest they may be decreasing. We hypothesize that the elephant seal population of Baja California is experiencing a decline because the animals are not migrating as far south due to warming sea and air temperatures. Here we assessed population trends of the Baja California population, and climate change in the region. The numbers of northern elephant seals in Baja California colonies have been decreasing since the 1990s, and both the surface waters off Baja California and the local air temperatures have warmed during the last three decades. We propose that declining population sizes may be attributable to decreased migration towards the southern portions of the range in response to the observed temperature increases. Further research is needed to confirm our hypothesis; however, if true, it would imply that elephant seal colonies of Baja California and California are not demographically isolated which would pose challenges to environmental and management policies between Mexico and the United States

Data from: Climate change and the northern elephant seal (Mirounga angustirostris) population in Baja California, Mexico

The Earth′s climate is warming, especially in the mid- and high latitudes of the Northern Hemisphere. The northern elephant seal (Mirounga angustirostris) breeds and haul-outs on islands and the mainland of Baja California, Mexico, and California, U.S.A. At the beginning of the 21st century, numbers of elephant seals in California are increasing, but the status of Baja California populations is unknown, and some data suggest they may be decreasing. We hypothesize that the elephant seal population of Baja California is experiencing a decline because the animals are not migrating as far south due to warming sea and air temperatures. Here we assessed population trends of the Baja California population, and climate change in the region. The numbers of northern elephant seals in Baja California colonies have been decreasing since the 1990s, and both the surface waters off Baja California and the local air temperatures have warmed during the last three decades. We propose that declining population sizes may be attributable to decreased migration towards the southern portions of the range in response to the observed temperature increases. Further research is needed to confirm our hypothesis; however, if true, it would imply that elephant seal colonies of Baja California and California are not demographically isolated which would pose challenges to environmental and management policies between Mexico and the United States

Nutrient input from the Colorado River to the northern Gulf of California is not required to maintain a productive pelagic ecosystem

The high phytoplankton production (PP) of the northern Gulf of California (NGC) supports a rich biodiversity and fisheries with high yields. The NGC is the habitat of the vaquita (Phocoena sinus), the cetacean most at risk of extinction in the world. The objective of this study is to demonstrate that the NGC is a healthy system at the level of primary producers despite the lack of nutrient input from the Colorado River, and that the small size of the vaquita population is not attributable the collapse of its pelagic ecosystem. Information derived from satellite sensors (CZCS, SeaWiFS, and Aqua-MODIS) was used to explore the possibility of a negative tendency in phytoplankton biomass and PP in the NGC during the last ~35 years. Temporal and spatial variations in sea surface temperature (SSTsat), chlorophyll concentration (Chlsat), and PP were analyzed. Times series were generated for four coastal quadrants, two in the western part and two in the eastern part of the NGC. The NW quadrant covers the vaquita habitat, and it had higher Chlsat and PP values than the others. This may be due to advection of turbid Upper Gulf waters into the NW quadrant. Semiannual and interannual changes in Chlsat and PP occurred, but the seasonal signal was dominant in the whole region. SSTsat maxima occurred in August and September (30–31 ºC) and minima in January and February (16–17 ºC). Chlsat and PP maxima were recorded in March and April (2–3 mg m–3, 2–3 g C m–2 day–1, respectively) and minima in August and September (0.2–0.9 mg m–3, 0.5–1.1 g C m–2 day–1, respectively). These values indicate that the pelagic ecosystem of the NGC is very productive (mesotrophic in summer-autumn and eutrophic in winter-spring).

mean air temperature (month)

monthly average mean air temperature on Cedros Island, 1957-199