OPORTUNIDADES DE CONSERVACIÓN DEL BOSQUE DE NIEBLA A TRAVÉS DE TECNOLOGÍA AGROALIMENTARIA CON SISTEMAS SILVOPASTORILES

The Mountain Mesophyll Forest (MMF) in the central region of Veracruz presents a complex problem, because it is the only one in the country with urban settlements. This entails the development of economic activities that place the ecosystem at risk; and the change in land use for livestock production which has generated its fragmentation. The integrated agricultural and livestock systems, through practices of diversification and interaction between their components, foster the emergence of new properties of the system that help to counteract the environmental impact that livestock production activities currently generate. An example of this are Forest Grazing Systems, which can be a source of wealth and social development for MMF inhabitants, reducing the environmental impact that the livestock activity generates and promoting the regeneration of the landscape. Ways to implement this are suggested.Bosque Mesófilo de Montaña (BMM) de la región centro de Veracruz posee una problemática compleja, debido a que es la única en el país con asentamientos urbanos. Lo anterior conlleva al desarrollo de actividades económicas que ponen en riesgo al ecosistema; y el cambio de uso de suelo para uso ganadero ha generado su fragmentación. Los sistemas agropecuarios integrados, por medio de prácticas de diversificación e interacción entre sus componentes, propician el surgimiento de nuevas propiedades del sistema que ayudan a contrarrestar el impacto ambiental que las actividades ganaderas generan en la actualidad. Ejemplo de esto son los Sistemas Silvopastoriles, que pueden ser fuente de riqueza y desarrollo social para los habitantes del BMM, reduciendo el impacto ambiental que la actividad ganadera genera y promoviendo la regeneración del paisaje. Se plantean formas de cómo hacer su implementació

Stretched exponential relaxation for growing interfaces in quenched disordered media

We study the relaxation for growing interfaces in quenched disordered media. We use a directed percolation depinning model introduced by Tang and Leschhorn for 1+1-dimensions. We define the two-time autocorrelation function of the interface height C(t',t) and its Fourier transform. These functions depend on the difference of times t-t' for long enough times, this is the steady-state regime. We find a two-step relaxation decay in this regime. The long time tail can be fitted by a stretched exponential relaxation function. The relaxation time is proportional to the characteristic distance of the clusters of pinning cells in the direction parallel to the interface and it diverges as a power law. The two-step relaxation is lost at a given wave length of the Fourier transform, which is proportional to the characteristic distance of the clusters of pinning cells in the direction perpendicular to the interface. The stretched exponential relaxation is caused by the existence of clusters of pinning cells and it is a direct consequence of the quenched noise.Comment: 4 pages and 5 figures. Submitted (5/2002) to Phys. Rev.

Hatchery production of the greater amberjack (Seriola dumerili)

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