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A method to better monitor landscape-level fire characteristics is presented. Three study areas in southern Ohio oak-hickory (Quercus-Carya) forests were established with four treatment areas of ~20 ha each: control (C), burn only (B), thin only (T) or thin plus burn (TB). Two independent measures useful for qualitatively characterising fire intensity were established on a 50-m grid, resulting in over 120 sampling locations at each site, in the burned areas: aluminum tags painted with temperature-sensitive paints, and logger-probe units that logged probe temperature every 2 s during burns. Fires were conducted in spring 2001. The logger-probe units allowed five measures qualitatively related to fire intensity or timing to be calculated at each grid point: maximum probe temperature; duration of probe temperature above 30°C; a heat index, defined as the summed temperatures above 30°C; time of maximum temperature; and estimated rate of spread. Maximum temperatures recorded by the two measuring systems were highly correlated (r2 = 0.83). Relative to painted tags, logger-probe units provide information useful for assessing some other components of fire behaviour. The temporal recording of temperatures allowed us to prepare a web-based simulation of the fires. Heat index and rate of spread estimates provided additional fire information. The TB units consistently burned cooler than the B units, perhaps because of uncured slash and a disrupted fuel bed in those units.

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The response of black cherry (Prunusserotina Ehrh.), sugar maple (Acersacchárum Marsh.), and yellow-poplar (Liriodendrontulipifera L.) seedlings after being exposed to two seasons of ozone ranging from subambient to twice ambient (exposures ranged from 16 to 107 ppm•h in 1990 and 31 to 197 ppm•h in 1991) was studied in standard 3-m diameter open-top chambers. All three species responded differently to ozone. After one season of exposure, black cherry growth and biomass decreased with increasing ozone exposure; yellow-poplar growth and biomass increased with increasing ozone exposure; and sugar maple growth and biomass were not significantly affected by ozone. After two seasons of exposure, few to no effects from ozone were observed in either sugar maple or yellow-poplar. However, total plant and root biomass of black cherry exposed to twice ambient ozone were reduced 32 and 39%, respectively, when compared with those grown in charcoal-filtered air. Exposure–response relationships were either linear or quadratic for most of the growth and biomass parameters measured.

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