Winter habitat use by female caribou in relation to wildland fires in interior Alaska Kyle Joly, Bruce W. Dale, William B. Collins, and Layne G. Adams Abstract: The role of wildland fire in the winter habitat use of caribou (Rangifer tarandus) has long been debated. Fire has been viewed as detrimental to caribou because it destroys the slow-growing climax forage lichens that caribou utilize in winter. Other researchers argued that caribou were not reliant on lichens and that fire may be beneficial, even in the short term. We evaluated the distribution of caribou relative to recent fires (<50 years old) within the current winter range of the Nelchina caribou herd in east-central Alaska. To address issues concerning independence and spa- tial and temporal scales, we used both conventional very high frequency and global positioning system telemetry to es- timate caribou use relative to recent, known-aged burns. In addition, we used two methods to estimate availability of different habitat classes. Caribou used recently burned areas much less than expected, regardless of methodologies used. Moreover, within burns, caribou were more likely to use habitat within 500 m of the burn perimeter than core ar- eas. Methods for determining use and availability did not have large influences on our measures of habitat selectivity. RØsumØ : Le rle des feux de toundra sur lutilisation de lhabitat par le caribou (Rangifer tarandus) en hiver fait lobjet de longs dØbats. Le feu est considØrØ comme nuisible au caribou, car il dØtruit les lichens  croissance lente du climax que le caribou utilise en hiver. Dautres chercheurs pensent que le caribou nest pas dØpendant des lichens et que le feu peut Œtre bØnØfique, mŒme  court terme. Nous avons ØvaluØ la rØpartition des caribous en fonction des feux rØcents (<50 ans) dans les aires dhivernage actuelles du troupeau de caribous Nelchina dans le centre-est de lAlaska. Pour rØsoudre les questions relatives  lindØpendance et aux Øchelles spatiales et temporelles, nous avons utilisØ  la fois la tØlØmØtrie conventionnelle  trLs haute frØquence et la tØlØmØtrie basØe sur le systLme de positionnement global pour estimer lutilisation par les caribous de surfaces rØcemment brßlØes dge connu. De plus, nous avons utilisØ deux mØthodes pour estimer la disponibilitØ des diffØrentes classes dhabitat. Les caribous utilisent les surfaces rØcemment incendiØes beaucoup moins que prØvu, quelle que soit la mØthodologie employØe. De plus, sur les surfaces incendiØs, les caribous sont plus susceptibles dutiliser les habitats situØs  moins de 500 m du pØrimLtre de la surface brßlØe que la rØgion centrale. Les mØthodes employØes pour dØterminer lutilisation et la disponibilitØ nont pas dinfluence impor- tante sur nos mesures de sØlectivitØ de lhabitat. [Traduit par la RØdaction] Joly et al. 1201 Introduction Recurrent and often expansive wildland fires are a natural component of boreal forest ecosystems (Lutz 1956). Indeed, wildland fire is the dominant ecological process determining the vegetative landscape of interior Alaska. Fire recurrence is related to age of vegetation, physiography, and local envi- ronmental conditions (Rowe et al. 1974). Patterns of postfire succession (Van Cleve and Viereck 1981, 1983) and fire cy- cle effects on the forest mosaic are well described for boreal forests (Bergeron and Dansereau 1993). Although wildland fires increase overall vegetative diversity and productivity, they destroy fruticose lichens. These lichens, if available, are major constituents of winter diets of caribou (Rangifer tarandus; Boertje 1984; Thomas 1998). Forage lichens are associated with late successional seres of boreal forest (Klein 1982) and require long periods of recovery following fire or other disturbance (Viereck and Schandelmeier 1980; Thomas and Kiliaan 1998). Since at least the 1920s, it has been suggested that wildland fires are harmful to caribou populations (Klein 1982). Early research suggested that fires had negative ef- fects on caribou populations because of losses of mature for- est stands with substantial lichen biomass (Kelsall 1960; Scotter 1965, 1970; Thomas 1969). However, other studies indicated little or no impact of fire on the population dynam- ics of caribou (Skoog 1968; Bergerud 1972; Johnson and Rowe 1975). These divergent findings precipitated research in Canada to evaluate the influences of fire history on winter habitat use of caribou (Miller 1976, 1980; Schaefer and Pruitt 1991; Thomas 1991; Thomas et al. 1998). The re- search revealed that caribou avoided recent fires (up to 60 years) and that caribou herds may expand their ranges to compensate for burned portions of wintering areas. Klein (1982) and Schaefer and Pruitt (1991) concluded that al- though wildland fire may be detrimental to caribou popula- tions in the near term by destroying forage lichens, fire might be requisite in the long term to maintain high lichen productivity by destroying competing mosses and rejuvenat- Can. J. Zool. 81: 11921201 (2003) doi: 10.1139/Z03-109 ' 2003 NRC Canada 1192 Received 9 January 2003. Accepted 30 May 2003. Published on the NRC Research Press Web site at http://cjz.nrc.ca on 31 July 2003. K. Joly 1 and L.G. Adams. U.S. Geological Survey, Alaska Science Center, 1011 East Tudor Road, Anchorage, AK 99503, U.S.A. B.W. Dale and W.B. Collins. Alaska Department of Fish and Game, 1800 Glenn Highway, Suite 4, Palmer, AK 99645, U.S.A. 1 Corresponding author (e-mail: Kyle_Joly@usgs.gov).