Title: The effects of fire on ecosystem functions: A study with the purpose of improving fire management in Lesotho

Rangeland burning is common in Lesotho during the dry season, though illegal. This practice has negative consequences as biodiversity is lost, and human well-being is negatively affected. The present study was primarily conducted as a desk study with focus on factors that affect fire behaviour; effects of fire on ecosystems and ecosystem functions; and fire management in Lesotho. The desk study was supported by a field study on the effects of fire on pine and birch ecosystems in Iceland. The field study focused on the effect of fire on vegetation composition; regrowth of burned areas; and cover of bare patches. Sixteen plots were established, eight for each ecosystem, equally divided between burned and unburned areas. The desk study showed that topography, weather, and fuel load influence the behaviour of fire. Fire severity, frequency, and duration influence the magnitude of the impact of fire on ecosystem components. It was also shown that the effects of fire on herbaceous vegetation, woody vegetation, soil nutrients, soil physical properties, animals and their habitats, differ according to the frequency, severity, and duration of fire experienced. The field study showed that the effect of fire is more severe on birch trees than pine trees as pine trees are taller and less flammable. Low shrubs and mosses were totally eradicated by the fire, while some herbaceous plants came back immediately afterwards. Certain species seemed to benefit from fire, while others take a long time to come back. Wildfires are a significant contributor to land degradation in Lesotho. For this reason, fires have not been used in rangeland management, but illegal rangeland burning is common. Therefore, there is a need to limit unprescribed fire. Prescribed fires are recommended in the management of rangelands in Lesotho.