Broncano M.J., Rodrigo A., Retana J. (2008) Post-dispersal seed predation in Pinus halepensis and consequences on seedling establishment after fire. International Journal of Wildland Fire. 17: 407-414.EnllaçDoi: 10.1071/WF07095
In the present study, we analyse the spatiotemporal patterns of seed predation and the consequences of this predation in the establishment of new Pinus halepensis individuals. Rodents were the main predators of P. halepensis seeds in burned areas, while predation by ants was considerably lower. Concerning spatiotemporal patterns of seed predation, the results obtained indicate that, although there were some small differences among distances or among seasons, removal of P. halepensis seeds was consistently very high in all situations, whether close to or far from the unburned margins, in pine or mixed forests, in different sites and in all sampling periods throughout the year. We analysed the role of seed predation on the modulation of post-fire regeneration of P. halepensis. Just after fire, no differences in seedling density were found between plots with or without rodent exclusion, probably owing to the high density of seeds on the ground and the low density of rodents affected by fire. One year after fire, when rodent populations had recovered in burned areas and seeds were much less abundant, the combination of addition of seeds and rodent exclusion led to an increase in pine seedling establishment. © IAWF 2008.
Pausas J.G., Llovet J., Rodrigo A., Vallejo R. (2008) Are wildfires a disaster in the Mediterranean basin? A review. International Journal of Wildland Fire. 17: 713-723.EnllaçDoi: 10.1071/WF07151
Evolutionary and paleoecological studies suggest that fires are natural in the Mediterranean basin. However, the important increase in the number of fires and area burned during the 20th century has created the perception that fires are disasters. In the present paper, we review to what extent fires are generating ecological disasters in the Mediterranean basin, in view of current fire regimes and the long-term human pressure on the landscapes. Specifically, we review studies on post-fire plant regeneration and soil losses. The review suggests that although many Mediterranean ecosystems are highly resilient to fire (shrublands and oak forest), some are fire-sensitive (e.g. pine woodlands). Observed erosion rates are, in some cases, relatively high, especially in high fire severity conditions. The sensitive ecosystems (in the sense of showing strong post-fire vegetation changes and soil losses) are mostly of human origin (e.g. extensive pine plantations in old fields). Thus, although many Mediterranean basin plants have traits to cope with fire, a large number of the ecosystems currently found in this region are strongly altered, and may suffer disasters. Post-fire disasters are not the rule, but they may be important under conditions of previous human disturbances. © IAWF 2008.
Rodrigo A., Sardà-Palomera F., Bosch J., Retana J. (2008) Changes of dominant ground beetles in black pine forests with fire severity and successional age. Ecoscience. 15: 442-452.EnllaçDoi: 10.2980/15-4-3117
This study analyzes the effect of fire on the composition and abundance of ground beetles in Pinus nigra forests. We used pitfall traps to sample beetles in burned P. nigra forests in Catalonia (Spain). Since fire dramatically alters forest structure and composition and beetles follow vegetation changes, we expected drastic changes in beetle composition and abundance immediately after fire. Because P. nigra forests do not recover after fire, we also expected beetles in burned and unburned areas to differ along a chronosequence. Beetle abundance per plot increased in canopy-fire-burned areas, but per plot species richness, diversity, and dominance were not affected by fire. Species composition varied depending on fire intensity. Some species were associated with canopy fire and low vegetation cover. Other species were associated with shrub cover and time since fire. Finally, some species were not dependent on fire or vegetation cover. Beetle abundance in burned areas was independent of time since fire. This lack of medium-term convergence between burned and unburned P. nigra forests agrees with our second hypothesis. Given the increase in fire frequency and size in submediterranean areas and the observed slow recovery of beetle species, a decline in beetle diversity at a regional scale is expected.
Dona't d'alta al Newsletter per rebre totes les novetats del CREAF al teu e-mail.
AMB EL SUPORT DE
© 2016 CREAF | Avís legal