Report on field experiments in Northumberland, March 2010: a multidiscipinary approach to assess fire behaviour and effects in a humid temperate climate.

A moorland site in Northumberland in the northeast of England was used for a series of experimental burns in heather-dominated vegetation (Calluna vulgaris) and one burn in a stand of gorse (Ulex europaeus) towards the end of March 2010. This article summarises the main aspects of the exercise, its context and objectives, methods used and some of its findings. These experimental burns were part of an ongoing programme of such tests to be carried out in the UK for studying rural vegetation fires or bushfires. Participants from eight academic groups were involved in this first exercise, in partnership with fire services, deploying a range of scientific instrumentation, sampling and burn strategies.Although the UK can experience long dry periods that create ideal conditions for severe rural vegetation fires (as in the spring and summer of 2003, for example), the weather during the experimental period was less ‘ideal’. Conditions were dry enough for burning on only one and a half days over the planned five day period. The burns carried out were closer to marginal than severe conditions for flammability of the heather, although the small-scale gorse plot was found to be highly flammable in spite of rain a few hours earlier. The techniques put to use in the burns, although not at all plots, included: (1) terrestrial LiDAR before and after the burns for mapping topography and structure of vegetation, as well as changes in structure; (2) destructive sampling of biomass, before and after the fires, to examine fuel load, type and proportion burnt; (3) fuel moisture content sampling of fine fuels; (4)characterising smoke emissions using Fourier transform infrared measurements; (5)helicopter-borne infrared imaging of fire spread; (6) aircraft mounted LiDAR and hyperspectral reflectance imaging; (7) field spectroradiometry of pre-fire and post-fire reflectance; (8) thermocouple temperature measurements at points in the vegetation and the soil; (9) soil sampling for analysis of fire-effects;o (10) use of different ignition patterns. The objectives of this and future exercises range from fundamental understanding of rural fire spread and its effects on vegetation, soil and the environment, along with the development and use of remote sensing techniques for analysis of vegetation, fire damage, emissions, etc., to managed burning for vegetation or fuel-load control and the development of a knowledge base for practical fire suppression tactics and techniques in the UK.