Datos floristicos sobre la comarca de Las Corchuelas (Parque Natural de Monfragúe, Cáceres, España) IIi

Se comentan brevemente algunos taxones herborizados en la comarca de las Corchuelas (Parque Natural de Monfragúe), sector Toledano-Tagano, provincia corológica Luso-Extremadurense (RIVAS-MARTÍNEZ, S., Anal. Inst. Bot. Cavanilles, 30: 69-87. 1973).

Datos florísticos sobre la comarca de Las Corchuelas (Parque Natural de Monfragúe, Cáceres, España)

Se comentan brevemente algunos táxones interesantes herborizados en la comarca de Las Corchuelas (Parque Natural de Monfragiie).

La aplicación estratégica por escenarios en el medio natural. El caso del Nature Outlook 2050 del PBL.

La prospectiva es parte de la planificación estratégica. Es una herramienta habitual en la gestión y dirección de empresas. Algunos países europeos la incluyen dentro de sus trabajos de diseño de las políticas ambientales. La generación de escenarios es una técnica cualitativa de prospectiva apta para los entornos con alta variabilidad y complejidad. El artículo explica el modo de aplicar esta técnica poniendo en paralelo los pasos dados en el proyecto Nature Outlook 2050 que ha desarrollado la agencia de evaluación y prospectiva ambiental de los Países Bajos (PBL).

Effect of habitat fragmentation on levels and patterns of genetic diversity in natural populations of the peat moss Polytrichum commune

Peat bogs represent unique ecosystems that are under particular threat from fragmentation due to peat harvesting, with only 38% of the original peatland in Europe remaining intact and unaffected by peat cutting, drainage and silviculture. In this study, we have used microsatellite markers to determine levels and patterns of genetic diversity in both cut and uncut natural populations of the peat moss Polytrichum commune. Overall diversity levels suggest that there is more genetic variation present than had previously been assumed for bryophytes. Despite this, diversity values from completely cut bogs were found to be lower than those from uncut peatlands (average 0.729 versus 0.880). In addition, the genetic diversity was more highly structured in the cut populations, further suggesting that genetic drift is already affecting genetic diversity in peat bogs subjected to fragmentation.

Differential lifetime success and performance of native and non-native Atlantic salmon examined under communal natural conditions.

The lifetime success and performance characteristics of communally reared offspring of wild native Burrishoole (native), ranched native (ranched) and non-native (non-native) Atlantic salmon Salmo salar from the adjacent Owenmore River were compared. Non-native year parr showed a substantial downstream migration, which was not shown by native and ranched parr. This appears to have been an active migration rather than competitive displacement and may reflect an adaptation to environmental or physiographic conditions within the Owenmore River catchment where the main nursery habitat is downstream of the spawning area. There were no differences between native and ranched in smolt output or adult return. Both of these measures, however, were significantly lower for the non-native group. A greater proportion of the non-native Atlantic salmon was taken in the coastal drift nets compared to the return to the Burrishoole system, probably as a result of the greater size of the non-native fish. The overall lifetime success of the non-native group, from fertilized egg to returning adult, was some 35% of native and ranched. The ranched group showed a significantly greater male parr maturity, a greater proportion of 1+ year smolts, and differences in sex ratio and timing of freshwater entry of returning adults compared to native, which may have fitness implications under specific conditions.