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Summary1. Upland heaths in the UK are of significant conservation importance. Large areas are managed through prescribed burning to improve habitat and grazing for red grouse Lagopus lagopus scoticus, deer Cervus elaphus and sheep Ovis aries. Previous research has identified trends in vegetation development following burning, but has not linked this to variation in fire behaviour and severity. 2. We burned 15 experimental fires on an area of Calluna vulgaris-dominated moorland, and recorded pre-and post-fire vegetation structure and composition, fire behaviour characteristics, and several 'proxy measures' of fire severity. 3. We distinguished measures of fire severity, describing the immediate physical effects of burning, from the long-term ecosystem responses of substrate development and Calluna regeneration. Proxy measures of fire severity did not relate strongly to fire behaviour or ecosystem response. 4. Post-fire regeneration was strongly linked to stand age and post-fire substrate type. Fire behaviour and severity had little effect, though fire-induced ground-surface heating may promote Calluna seedling establishment. Vegetative regeneration of Calluna was extremely poor in older stands, as was seedling establishment in areas where the post-fire substrate was dominated by live or dead pleurocarpous moss mats. 5. Synthesis and applications. Significant nonlinearities exist in fire severity on heathlands, with step changes related to the depth and moisture content of moss ⁄ litter layers and peat. Younger stands, less than c. 30 cm tall, should be the focus of management if the objective is to maximize Calluna regeneration. Burning older and uneven-aged stands is discouraged except for the purposes of fire hazard management. Managers should develop landscape-level burn plans to target burning effectively and create diverse fire regimes.

1. Calluna-dominated heaths occur throughout Europe but are in decline across their range. There is growing interest in using prescribed burning for their management, but environmental and social change will impact future fire regimes. Understanding fire behaviour is vital for the sustainable use of fire, but no robust models exist to inform management. 2. Shrub fuels display complex fire behaviour. This is particularly true in UK moorlands which are unusual in their fuel structure and moisture regime, being dominated by live fuel and an oceanic climate. 3. We burnt 27 experimental fires in the Scottish uplands during the legal burning season using a replicated experimental design. Plots were assigned to one of three commonly identified growth phases. We estimated a range of prefire fuel characteristics, including heterogeneity in fuel structure. We recorded wind speed and direction and estimated rate of spread (RoS). 4. Redundancy analysis was used to investigate the relationship between fire behaviour parameters as a whole and control variables. Fuel structure and heterogeneity, wind speed and canopy fuel moisture content were strongly related to variation in fire behaviour. 5. Best subsets regression was used to generate models of fire spread based on wind speed, vegetation height, canopy fuel moisture and an index of fuel heterogeneity. RoS was determined largely by wind speed, but this interacted strongly with vegetation structure. Changes in fuel horizontal continuity and vertical structure reduced rates of spread in low wind speeds. 6. Synthesis and applications. Live fuel moisture and fuel heterogeneity play an important role in dampening fire behaviour, aspects of shrub fuels that have previously not been examined in detail. Careful use of fire for moorland management increases habitat diversity and creates fire-safe landscapes. Escaped prescribed fires burn large areas, homogenize landscapes and have severe impacts on ecosystem services. The complex relationship between fuel structure and wind speed implies that changes in behaviour can be rapid and unexpected. Models can be used to assess fire hazard prior to prescribed burning and to choose fuels that can be burnt safely under prevailing or forecast conditions.

The popular, but rarely documented, view in Britain is that ticks have increased in distribution and abundance over recent years. To assess this, we gathered evidence for changes in tick distribution and abundance by distributing a survey questionnaire throughout Britain and by analysing trends in the prevalence of tick infestation on red grouse chicks Lagopus lagopus scoticus Latham (Galliformes: Tetranoidae), gathered over 19 years at three Scottish sites, and on deer (Cetartiodactyla: Cervidae) culled over 11 years on 26 Ministry of Defence (MoD) estates. Based on the survey, the current known distribution of Ixodes ricinus Linnaeus (Acari: Ixodidae) has expanded by 17% in comparison with the previously known distribution. The survey indicated that people perceive there to be more ticks today than in the past at 73% of locations throughout Britain. Reported increases in tick numbers coincided spatially with perceived increases in deer numbers. At locations where both tick and deer numbers were reported to have increased, these perceived changes occurred at similar times, raising the possibility of a causal link. At other locations, tick numbers were perceived to have increased despite reported declines in deer numbers. The perceptions revealed by the survey were corroborated by quantitative data from red grouse chicks and culled deer. Tick infestation prevalence increased over time on all grouse moors and 77% of MoD estates and decreased at six locations.