Under the influence of multiple factors such as climate change and human activities, the frequency, intensity, and destructiveness of forest fires are increasing, which may trigger multiple ecological crises. Forest fires can be scientifically prevented, and their risks can be mitigated through specific approaches, particularly by managing forest combustible materials. Common methods include mechanical clearance, prescribed burning, and the establishment of biological firebreak belts, along with the application of grazing to regulate forest fuels. This paper presents a review of studies on grazing and fire risk, both domestically and internationally. Research indicates that livestock grazing has complex effects on forest fire risk: appropriate grazing can manage fuels and modify ecosystem structure to reduce fire hazards—for instance, by decreasing the accumulation of surface flammable materials and promoting the regeneration of fire-resistant tree species. Conversely, overgrazing may disrupt ecological balance and increase fire risk, such as by exacerbating soil erosion and encouraging the invasion of flammable weed species. Case studies from different ecological regions worldwide demonstrate varied effects of grazing on fire prevention, though research in this area exhibits geographical disparities. Adaptive management should integrate targeted grazing, prescribed burning, and mechanical treatments in a synergistic manner. Future efforts should prioritize cross-scale studies, investigate the mechanisms of woody fuel modulation, and refine fire ecology models to enhance the precision and global applicability of grazing-based fire management.
The characteristics of litter combustion have a significant impact on the spread of surface fires in the central Yunnan Province, a high-risk forest fire zone. The burning behavior of individual and mixed-species litter samples from five dominant tree species (Pinus yunnanensis Franch., Keteleeria evelyniana Mast., Quercus variabilis Blume., Quercus aliena var. acutiserrata, and Alnus nepalensis D. Don.) was assessed in this study using cone calorimeter tests. Fern fronds and fine branches were included in additional tests to evaluate their effects on specific combustion parameters, such as Fire Performance Index (FPI), Flame Duration (FD), Time to Ignition (TTI), Mass Loss Rate (MLR), Residual Mass Fraction (RMF), Peak Heat Release Rate (PHRR), and Total Heat Release (THR). There were remarkable differences in the burning properties of the three types of litter (broadleaf, pine needles, and short pine needles). The THR and PHRR values of P. yunnanensis were the highest, whereas the PHRR of the other species varied very little. Short pine needle litter showed incomplete combustion and a long flame duration. When measured against pure pine needle litter, mixtures of P. yunnanensis and broadleaf litter showed lower PHRR. When set side by side to pure pine needle litter, P. yunnanensis and broadleaf litter showed lower PHRR. THR rose when fine branches were included, underlining the significance of fine woody fuels in fire behavior. The insertion of ferns increases the percentage of unburned biomass, prolongs TTI, and dramatically reduces PHRR.