The reproductive periods of brown trout (Salmo trutta) populations in 12 rivers in the Baetic Mountains in southern Spain were studied from 2008 to 2013. This area is an ecological and geographical limit for the distribution of this species in Europe. We found that the spawning period has been markedly extended in these fish. The mean spawning dates in the studied populations are consistent with the European trend at this latitude, but our data suggest that females from most of the populations that we studied are able to produce eggs from early October through late April or early May, yielding a reproductive period of between 150 and 170 days, the longest and most delayed brown trout reproduction periods that have been reported in the literature. We believe that such expanded spawning periods result primarily from the unpredictability of the Mediterranean climate, although it is possible that other factors may have contributed to the development of this reproductive behaviour. This hypothesis is discussed in the context of a comparison of our results with those found for other European S. trutta populations.

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The impact of erosion on soil productivity was assessed for a Typic Hapludox on the Eastern Plains of Colombia (EPOC). An experiment was initiated in 1997 on a site with a known history of prior erosion in order to determine primarily the effect of differing degrees of soil erosion on the current soil quality status and to assess the impact on soil productivity through its effect on current yield of an upland rice crop (Oryza sativa). The results demonstrate that the influence of erosion on crop productivity is complex and simple relationships with changes in soil quality variables and with crop yields may often be confounded by other factors. Yet, EPOC's Oxisols are still shown to be extremely vulnerable to water erosion and illustrate the risk of converting savannas to croplands without appropriate soil management practices.