Especies invasoras de alto impacto a la biodiversidad: prioridades en México

Ignacio José March Mifsut MARICELA MARTINEZ JIMENEZ (2007, [Libro])

El presente manuscrito constituye una primera aproximación a las prioridades que en materia de especies invasoras de alto impacto a la biodiversidad determinamos para México, con el propósito de motivar la implementación urgente de programas formales y sistemáticos de control, prevención, manejo y erradicación de especies invasoras. El documento presenta los resultados de un taller de expertos efectuado en mayo del 2006, en el que participaron especialistas mexicanos y extranjeros, teniendo los siguientes objetivos:

1. Determinar las prioridades a nivel nacional en materia de especies invasoras que impactan adversamente a la biodiversidad de México, tanto en sus ambientes terrestres como acuáticos (marinos y de agua dulce).

2. Iniciar el desarrollo de planes de acción viables y estratégicos para las prioridades identificadas que permitan evitar la entrada de nuevas especies invasoras de alto riesgo, y el control, contención y erradicación de aquellas que estén causando los mayores estragos a la biodiversidad en territorio nacional. Estos planes deben contemplar acciones a nivel local, nacional y regional, y considerando los distintos vectores y rutas de desplazamiento.

3. Identificar las actividades estratégicas que permitan fomentar condiciones favorables para iniciar programas formales y multi-institucionales para la prevención y control de especies invasoras de alto impacto a la biodiversidad.

4. Comenzar a conformar un grupo de trabajo que pueda enfocarse a impulsar proyectos y programas orientados a la prevención y combate de especies invasoras que afectan a la biodiversidad en México, con la cooperación de instituciones gubernamentales, centros académicos y organizaciones del sector civil.

Biodiversidad Desequilibrio ecológico Especies invasoras BIOLOGÍA Y QUÍMICA

Pathways from information to the adoption of conservation agriculture practices in Malawi and Tanzania

Paswel Marenya Dil Bahadur Rahut (2023, [Artículo])

To reduce agriculture's carbon, land and water footprint, the diffusion of conservation farming methods is one commonly cited proposition. Yet the process of translating available information on new conservation farming methods into farmers' practices is often a black box in many studies. This understanding is critical to inform strategies for scaling these complex, knowledge-intensive, but necessary practices for improving agriculture's resource and climate balance sheet. By implementing a series of mediation analysis using data from 700 households in Malawi and 930 households in Tanzania, this study examines how an improved understanding of conservation agriculture (CA) principles is an important mediator in the pathway from extension contact to the adoption of two of the CA practices examined. For the adoption of conservation tillage, the share of the mediated treatment effect was in the 31.5–34.4% range, while it was 31.6–46.9% for the adoption of soil cover (mulching). Our results suggest that unless learning from external sources strongly correlates with improved farmers' technical understanding of new farming practices, private learning by doing must be a critical adjunct to other avenues of learning. Beyond the basic promotional goals, improving farmers' technical know-how needs to be the centerpiece of holistic efforts in support of conservation farming and similar knowledge-intensive practices necessary for agriculture's sustinability goals.

CIENCIAS AGROPECUARIAS Y BIOTECNOLOGÍA CONSERVATION AGRICULTURE SMALLHOLDERS AGRICULTURAL PRACTICES FIELD EXPERIMENTATION

Nitrogen fertilizer application alters the root endophyte bacterial microbiome in maize plants, but not in the stem or rhizosphere soil

Alejandra Miranda Carrazco Yendi Navarro-Noya Bram Govaerts Nele Verhulst Luc Dendooven (2022, [Artículo])

Plant-associated microorganisms that affect plant development, their composition, and their functionality are determined by the host, soil conditions, and agricultural practices. How agricultural practices affect the rhizosphere microbiome has been well studied, but less is known about how they might affect plant endophytes. In this study, the metagenomic DNA from the rhizosphere and endophyte communities of root and stem of maize plants was extracted and sequenced with the “diversity arrays technology sequencing,” while the bacterial community and functionality (organized by subsystems from general to specific functions) were investigated in crops cultivated with or without tillage and with or without N fertilizer application. Tillage had a small significant effect on the bacterial community in the rhizosphere, but N fertilizer had a highly significant effect on the roots, but not on the rhizosphere or stem. The relative abundance of many bacterial species was significantly different in the roots and stem of fertilized maize plants, but not in the unfertilized ones. The abundance of N cycle genes was affected by N fertilization application, most accentuated in the roots. How these changes in bacterial composition and N genes composition might affect plant development or crop yields has still to be unraveled.

Bacterial Community Structure DArT-Seq Bacterial Community Functionality Genes Involved in N Cycling CIENCIAS AGROPECUARIAS Y BIOTECNOLOGÍA AGRICULTURAL PRACTICES MAIZE RHIZOSPHERE STEMS NITROGEN FERTILIZERS

Conservation agriculture practices towards regenerative agriculture

ML JAT (2021, [Objeto de congreso])

CIENCIAS AGROPECUARIAS Y BIOTECNOLOGÍA CONSERVATION AGRICULTURE AGRICULTURAL PRACTICES REGENERATION

Analyzing antifragility among smallholder farmers in Bihar, India: An assessment of farmers' vulnerability and the strengths of positive deviants

Roos Adelhart Toorop Santiago Lopez-Ridaura ML JAT Deepak Bijarniya Jeroen Groot (2023, [Artículo])

Farmers around the world are increasingly vulnerable: climate variability is identified as the primary stressor, but unfavorable biophysical circumstances and disturbances in the socioeconomic domain (labor dynamics and price volatility) also affect farm management and production. To deal with these disturbances, adaptations are recognized as essential. Antifragility acknowledges that adaptations and volatility are inherent characteristics of complex systems and abandons the idea of returning to the pre-disturbance system state. Instead, antifragility recognizes that disturbances can trigger reorganization, enabling selection and removal of weaker system features and allowing the system to evolve toward a better state. In this study, we assessed the vulnerability of different types of smallholder farms in Bihar, India, and explored the scope for more antifragile farming systems that can 'bounce back better' after disturbances. Accumulation of stocks, creation of optionality (i.e., having multiple options for innovation) and strengthening of farmer autonomy were identified as criteria for antifragility. We had focus group discussions with in total 92 farmers and found that most expressed themselves to be vulnerable: they experienced challenges but had limited adaptive capacity to change their situation. They mostly made short-term decisions to cope with or mitigate urgent challenges but did not engage in strategic planning driven by longer-term objectives. Instead, they waited for governmental support to improve their livelihoods. Despite being confronted with similar challenges, four positive deviant farmers showed to be more antifragile: their diverse farming systems were abundant in stocks and optionality, and the farmers were distinguished in terms of their autonomy, competence, and connectedness to peers, the community, and markets. To support antifragility among regular farmers, adaptations at policy level may be required, for example, by shifting from a top-down toward a bottom-up adaptation and innovation regime where initiative and cooperation are encouraged. With a more autonomous orientation, farmers' intrinsic motivation is expected to increase, enabling transitions at the farm level. In this way, connected systems can be developed which are socioeconomically and biophysically adaptive. When practices, knowledge, and skills are continuously developed, an antifragile system with ample stocks and optionality may evolve over time.

Autonomy Adaptive Capacity Smallholder Farmers CIENCIAS AGROPECUARIAS Y BIOTECNOLOGÍA POLICIES SMALLHOLDERS AGRICULTURAL PRACTICES

Bacterial communities in the rhizosphere at different growth stages of maize cultivated in soil under conventional and conservation agricultural practices

Yendi Navarro-Noya Bram Govaerts Nele Verhulst Luc Dendooven (2022, [Artículo])

Farmers in Mexico till soil intensively, remove crop residues for fodder and grow maize often in monoculture. Conservation agriculture (CA), including minimal tillage, crop residue retention and crop diversification, is proposed as a more sustainable alternative. In this study, we determined the effect of agricultural practices and the developing maize rhizosphere on soil bacterial communities. Bulk and maize (Zea mays L.) rhizosphere soil under conventional practices (CP) and CA were sampled during the vegetative, flowering and grain filling stage, and 16S rRNA metabarcoding was used to assess bacterial diversity and community structure. The functional diversity was inferred from the bacterial taxa using PICRUSt. Conservation agriculture positively affected taxonomic and functional diversity compared to CP. The agricultural practice was the most important factor in defining the structure of bacterial communities, even more so than rhizosphere and plant growth stage. The rhizosphere enriched fast growing copiotrophic bacteria, such as Rhizobiales, Sphingomonadales, Xanthomonadales, and Burkholderiales, while in the bulk soil of CP other copiotrophs were enriched, e.g., Halomonas and Bacillus. The bacterial community in the maize bulk soil resembled each other more than in the rhizosphere of CA and CP. The bacterial community structure, and taxonomic and functional diversity in the maize rhizosphere changed with maize development and the differences between the bulk soil and the rhizosphere were more accentuated when the plant aged. Although agricultural practices did not alter the effect of the rhizosphere on the soil bacterial communities in the flowering and grain filling stage, they did in the vegetative stage.

Community Assembly Functional Diversity Intensive Agricultural Practices Plant Microbiome CIENCIAS AGROPECUARIAS Y BIOTECNOLOGÍA SUSTAINABLE AGRICULTURE TILLAGE SOIL BACTERIA MAIZE

Diagnóstico integral de planeación y modelación hidráulica de la Comisión de Agua Potable y Alcantarillado de Cancún (CAPA)

RODRIGO ULISES SANTOS TELLEZ (2017, [Documento de trabajo])

Con el propósito de fortalecer la recuperación ecológico-ambiental de la Península de Yucatán, el proyecto ha tenido como objetivo elaborar un programa jerarquizado de acciones e inversiones, para la gestión y mejora de eficiencias del sistema de abastecimiento de agua potable de la ciudad de Cancún, en el estado mexicano de Quintana Roo, proyectado a corto y mediano plazo. Lo anterior, con el fin de modernizar los servicios de agua potable, alcantarillado y saneamiento en un marco de autosuficiencia técnica, financiera y ambiental. Para lograrlo, se realizó un diagnóstico integral de planeación, así como un modelo de simulación hidráulica de la red de abastecimiento con el que se obtiene un programa de acciones jerarquizado, para orientar la gestión y mejora de eficiencias e inversiones del organismo operador.

Organismos operadores Organización y administración Protección ambiental Cancún, Quintana Roo INGENIERÍA Y TECNOLOGÍA

The Mexican environmental flow standard: scope, application and implementation

MARIA ANTONIETA GOMEZ BALANDRA MARIA DEL PILAR SALDAÑA FABELA MARICELA MARTINEZ JIMENEZ (2014, [Artículo])

With the implementation of the Official Mexican Standard NOM-011-CONAGUA-2000, the water balance of 730 basins has been calculated and its water availability agreement is published. This rule points out to allocate water for the environment only as an annual volume since methods for estimating environmental flows were not standardized in the country. In this paper, an analysis of the environmental flow standard and examples of the suggested hydrological methods are presented. For its implementation, some steps are taking place, mainly establishing environmental water reserves and building capacities. In addition, environmental allocations are becoming a common practice for all water projects, as well as setting limits to hydrological alterations by hydroelectric dams. The standard promotes the use of technical integration tools to analyze the responses of ecosystems to changes in the flow regime and adaptive management under different scenarios of water use. Although the main steps have been taken, its implementation as mandatory rule will take time.

Flujos ambientales Modelos hidrológicos Normas técnicas BIOLOGÍA Y QUÍMICA

Distribución de la variación genética de insectos asociados a Hesperoyucca whipplei en la península de Baja California

Distribution of genetic variation of insects associated with Hesperoyucca whipplei in the Baja California peninsula

Roberto Suárez Hernández (2024, [Tesis de maestría])

El tipo de interacción ecológica obligada entre plantas hospederas y sus insectos asociados ha demostrado tener un impacto en la diversidad genética de las especies involucradas. La yuca de chaparral, Hesperoyucca whipplei, presenta una relación de mutualismo obligado con la polilla polinizadora Tegeticula maculata, y de comensalismo obligado con la polilla Prodoxus marginatus. Ambos insectos depositan sus huevos en estructuras de la flor y se alimentan del fruto en desarrollo. Con el fin de determinar el efecto de la interacción ecológica sobre la diversidad genética de los insectos, en este estudio se evaluó el nivel de variación y estructura genética de ambas polillas a lo largo de la península de Baja California. Se amplificó el gen mitocondrial COI en 86 individuos de T. maculata y 120 individuos de P. marginatus. La diversidad haplotípica fue menor en T. maculata (Hd = 0.601) en comparación con P. marginatus (Hd = 0.966) mientras que la diversidad nucleotídica fue baja en ambas especies (Pi= 0.0018 y 0.007 respectivamente). Las redes haplotípicas, el AMOVA, la prueba mismatch y los valores D de Tajima en T. maculata indican un patrón de expansión poblacional, mientras que en P. marginatus indican una estabilidad demográfica. Estos hallazgos sustentan que el mutualismo obligado entre H. whipplei y T. maculata, en contraste con el comensalimo obligado con P. marginatus, tiene un impacto directo en el nivel de la diversidad genética de las polillas, más que en su estructura a lo largo del área de distribución.

The type of obligate ecological interaction between host plants and their associated insects has been showing to have an impact on the genetic diversity of the species involved. The chaparral yuca (Hesperoyucca whipplei) presents a relationship of obligate mutualism with the pollinating moth Tegeticula maculata, and obligate commensalism with the moth Prodoxus marginatus. Both insects deposit their eggs in flower structures and feed on the developing fruit. To determine the effect of ecological interactions on insects’ genetic diversity, this study evaluated the level of variation and genetic structure of both moths throughout the Baja California peninsula. The mitochondrial COI gene was amplified in 86 individuals of T. maculata and 120 individuals of P. marginatus. Haplotypic diversity was lower in T. maculata (Hd = 0.601) compared to P. marginatus (Hd = 0.966) while nucleotide diversity was low in both species (pi = .0018 and 0.007 respectively). Haplotype networks, AMOVA, mismatch test and Tajima’s D values in T. maculata indicate a pattern of population expansion, whereas in P. marginatus they indicate demographic stability. These findings support that obligate mutualism between H. whipplei and T. maculata, in contrast, to obligate commensalism with P. marginatus, has a direct impact on the level of genetic diversity of the moths, rather than on their structure across the distribution.

mutualismo, comensalismo, filogeografía comparativa, polillas mutualism, commensalism, comparative phylogeography, moth BIOLOGÍA Y QUÍMICA CIENCIAS DE LA VIDA BIOLOGÍA DE INSECTOS (ENTOMOLOGÍA) ECOLOGÍA DE LOS INSECTOS ECOLOGÍA DE LOS INSECTOS

Perspectiva sobre la sequía actual en México

RENE LOBATO SANCHEZ PAMELA ISKRA MEJIA ESTRADA (2021, [Artículo])

DOI: 10.24850/b-imta-perspectivas-2021-16

Las condiciones de sequía en México son recurrentes, aunque irregulares, y están normalmente regidas por la fluctuación de patrones climáticos, como variaciones en la actividad solar, o por la influencia tanto de fenómenos globales como de patrones atmosféricos de gran escala que son influenciados por variaciones de temperatura oceánica de baja frecuencia, como El Niño o La Niña. Actualmente se presentan condiciones de sequía importantes en el país, probablemente las más severas desde los últimos diez años. El escenario actual corresponde a los escenarios climáticos derivados de La Niña y está influenciado, sobre todo en el norte del país, por el déficit de precipitación de 2020, del cual no se ha visto una completa recuperación. Finalmente, dado que las sequías —a diferencia de otras amenazas— no tienen epicentro o trayectoria, sino una progresión lenta, es difícil determinar su inicio y, por ende, su término. Sin embargo, el mes de abril es parte de la temporada de estiaje, durante la cual se ven condiciones de precipitación reducida. Para superar estas dificultades, el monitoreo y diagnóstico de la sequía se realiza con ayuda de índices cuantitativos, que describen el comportamiento e interacción de variables meteorológicas e hidrológicas con condiciones de vegetación y humedad del suelo. Estos parámetros sirven como información de referencia sobre las anomalías climáticas, tanto para el público en general como para la investigación científica, y sobre la intensidad y el alcance espacial de las sequías.

Sequías Impacto ambiental INGENIERÍA Y TECNOLOGÍA