Trade-offs between fire suppression and biodiversity: vegetation recovery in burnt grasslands and firebreaks under different restoration treatments

[摘要] BackgroundWildfire is an important component of many grassland ecosystems, but it is often suppressed in modern landscapes to protect infrastructure and human safety. Disk-harrowed firebreaks are frequently used to stop wildfire spread; however, this method represents a severe soil disturbance that may alter grassland species composition and structure. We studied the effects of a low-intensity growing-season wildfire on the vegetation of pristine and restored Central European dry grasslands, and evaluated vegetation recovery on firebreaks for 3 years post-fire. Firebreaks were subjected to passive restoration (disk-harrowing), assisted natural regeneration (rolling) or active restoration (rolling combined with grass seed sowing). In total, 180 permanent vegetation plots were surveyed for 3 years.ResultsSeveral grassland specialist species were associated with burnt grasslands during the first two post-fire years, but these patterns disappeared by the third year and did not affect overall specialist richness or cover. Fire did not promote disturbance-tolerant or weed species in the long run. Grassland specialists were able to re-establish in disk-harrowed and rolled firebreaks from the seed bank and seed rain; however, their cover remained substantially lower than in reference grasslands. Sowing seeds of the competitive perennial grass Festuca rupicola accelerated the development of a continuous grass cover and substantially reduced the proportion of weeds. Even in the third year after disturbance, firebreak vegetation remained dominated by disturbance-tolerant and weed species. Recovery of specialists was faster in restored grasslands, characterized by species typical of mid-successional stages, than in pristine grasslands.ConclusionLow-intensity growing-season wildfire had moderate and temporary effects on dry grasslands, indicating that fire represents an endogenous disturbance to which these communities respond with a short-term internal reorganization. In contrast, mechanical soil disturbance associated with firebreak establishment represented an exogenous disturbance with longer-lasting effects on vegetation composition and structure. Although species richness of target grassland species recovered quickly, their cover remained lower than in reference grasslands even for the third year. Sowing a dominant perennial grass effectively suppressed weeds, but increased competition may limit the establishment of other grassland species. Our results highlight a trade-off between short-term fire safety and long-term biodiversity conservation, suggesting that firebreak establishment should be cautiously applied and accompanied by appropriate monitoring and targeted management.

[发布日期] 2026-09-10

[关键词] Assisted natural regeneration;Fire suppression;Grassland specialists;Loess grassland;Nature conservation;Passive restoration;Seed sowing;Soil disturbance;Wildfire