Postfire Burnt-Wood Management Affects Plant Damage by Ungulate Herbivores

Abstract

I analyze the effect of post-fire burnt wood management on herbivore attack on a woody plant species (Ulex parviflorus). Two experimental plots of ca. 20 hectares were established at two elevations in a burnt area in a Mediterranean mountain (Sierra Nevada, Spain). Three replicates of three treatments differing in post-fire burnt wood management were established per plot: "no intervention" (NI, all trees remained standing), "partial cut plus lopping" (PCL, felling the trees, cutting the main branches, and leaving all the biomass in situ), and "salvage logging" (SL; removal of logs and elimination of woody debris). Risk of herbivory and damage intensity were monitored for two years. The pattern of attack by ungulate herbivores varied among treatments and years. In any case, there was an overall reduction in the risk of herbivory in the PCL treatment, presumably because the highest habitat complexity in this treatment hampered ungulate movement and foraging. As a result, the burnt logs and branches spread over the ground acted as a physical barrier that protected seedlings from herbivores. This protection may be used for the regeneration of shrubs and trees, and it is of interest for the regeneration of burnt sites either naturally or by reforestation.

Precision restoration: a necessary approach to foster forest recovery in the 21st century

“…2B). As they are not living items, dead logs and branches are not a source of competition, but improve the microclimate for the focal plants, provide nutrients through decomposition, and may reduce herbivory by acting as a physical barrier (Castro 2013; Marañón‐Jiménez & Castro 2013; Marcolin et al 2019; Fig. 2B).…”

Tamm review: Does salvage logging mitigate subsequent forest disturbances?

“…However, deadwood elements can act as physical impediments for large animals (Fig. 2), and thus as browsing refugia for regeneration (Castro, 2013). By opening space, salvage logging may increase browsing pressure and eventually reduce regeneration.…”

“…Despite the above, several studies have questioned the actual efficacy of salvage logging in reducing the risk of subsequent disturbances, such as wildfire (Donato et al 2006) and insect outbreaks (Grodzki et al 2006). Other studies indicate that salvage logging may trigger other interaction chains, including a higher risk of erosion (Wagenbrenner et al, 2016), avalanches (Wohlgemuth et al, 2017), herbivory (Castro, 2013), and windthrow (Dobor et al, 2019). Several mechanisms may influence the risk of various subsequent disturbances depending on how, and over what timeframes, the logging intervention affects disturbance legacies and forest recovery.…”

Salvage logging effects on regulating and supporting ecosystem services — a systematic map

“…(c) Forest regeneration capacity -Salvage logging has the potential to alter residual growing stock, soil seed bed, canopy and soil seed banks, and species interactions such as competition, seed dispersal, seed predation, and herbivory (Greene et al 2006;Collins et al 2010;Puerta-Piñero et al 2010;Castro et al 2012;Castro 2013).…”