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Land use and land cover changes (LUCC) are recognized as one of the most relevant drivers of biodiversity loss in ecosystems. Through the analysis of satellite images, this article quantifies the LUCC that occurred between 1985 and 2008 in the Colombian Andes. Four submodels of changes were analyzed: deforestation, crop intensification, conversion to pastures, and abandonment. We associated these changes with demographic, socioeconomic, and abiotic variables and to some attractors of landscape change, and finally we have considered three scenarios of change: reference, increase in pasture, and crop intensification. The dynamics of LUCC were dominated by systematic transitions between crops, pastures, and secondary vegetation. Of all the submodels, pasture conversion has an important contribution in terms of accuracy rate (84%), and the most relevant variables for explaining land cover changes in the region were elevation, soil type, and distance to roads, cities, and pastures. Our simulations suggest that the pasture conversion scenario would have the biggest impact in natural ecosystems and could cause the loss of 28–30% of the cover area by 2050. The results indicate some that these hotspots of change are currently still under a good conservation state with large extension of forests. [ABSTRACT FROM PUBLISHER]

We examined the density and composition of the immediate seed supply (i.e. instant potential post-fire germination from soil seed bank and off-site seed rain) after a large wildfire in a sub-Mediterranean pine forest. We also tested the effects of fire severity and distance from unburned edges on the density and composition of the seed bank and the immediate off-site seed rain. Our results showed that although seed density did not differ between them, their composition was markedly different. The soil seed bank was dominated by species from the Fabaceae family with limited dispersal mechanisms such as autochory and barochory, whereas the seed rain was mainly composed of species from the Asteraceae family with wind-dispersed seeds. These patterns were not affected either by fire severity or distance from the fire edge. The main conclusion of the study is that both the soil seed bank and the seed rain play an important role in providing seeds for immediate regeneration after a large wildfire throughout the burned area. We suggest that the role of seed rain on immediate post-fire recovery of Mediterranean plant communities might be more important than has previously been thought. However, the effective role of this group of species on the longer term should be evaluated. We examined the immediate seed supply after a large wildfire by comparing soil seed bank and off-site seed rain. Although seed density did not differ between them, their species composition was markedly different, and these patterns were not affected either by fire severity or distance from the fire edge. [ABSTRACT FROM AUTHOR]

This study relates the spatial variability in tree regeneration generated by fire with topography and pre-fire vegetation composition, and analyses how the pattern of fire severities determines post-fire regeneration of the dominant tree species (Pinus halepensis and Quercus ilex) in a large fire that occurred in north-eastern Spain in summer 1994. At the fire level, the proportion of the different fire severities in the burned area was characteristic of large fires that burn with high severity. At the level of plot, the variability of fire severity in the study site depended on two topographic characteristics: elevation and aspect. Plots burned with high fire severity were distributed at higher altitude than less severely burned plots, which were mainly distributed in south- and east-facing slopes. Fire severity also increased with Q. ilex density in the stand. The mosaic of fire severities determined both plant mortality and seedling regeneration. Mortality of stems caused by fire was very high in both species, but many Q. ilex individuals resprouted after fire. Seedling regeneration of P. halepensis showed large differences among plots in the burned area, reflecting large spatial variability due to the elevation gradient, the variation in density of adult pine trees, and the spatial variability created by fire. [ABSTRACT FROM AUTHOR]