Plant Diversity and Cover after Wildfire on Anthropogenically Disturbed and Undisturbed Sites in Subarctic Upland Picea mariana Forest

• Main Authors: Stephanie Nowak, G. Peter Kershaw, Linda J. Kershaw
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Published: 2001
• Subjects: Canada; Arctic; Subarctic; subarctique*
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.493.4827; http://pubs.aina.ucalgary.ca/arctic/Arctic55-3-269.pdf

ABSTRACT. Postfire development of cover and diversity was studied in an upland Picea mariana-dominated forest in the Canadian Subarctic. Short-term vegetation responses of 10- and 22-year-old cleared rights-of-way and a forest site were investigated two and three growing seasons after a wildfire. Prefire and postfire investigation of the study site allowed direct comparison of species cover and frequency values, as well as the Shannon-Wiener diversity index, before and after the fire. The fire considerably reduced diversity on all sites. Species diversity increased with the level of prefire disturbance. Prefire disturbance influenced the fire’s characteristics by altering the fuel load and soil moisture, which in turn affected the postfire revegetation through different soil and microclimatic conditions. The sites that were most severely disturbed before the fire experienced the most rapid revegetation, including the highest diversity index and highest plant cover. Of the sites that were undisturbed before the fire, the natural drainage swales offered the best growing conditions after the burn. Furthermore, prefire disturbance increased the patchiness of the burned area, and the residual flora of unburned patches added to postfire floristic diversity. Key words: Subarctic vegetation, wildfire, industrial corridor, postfire, boreal, succession RÉSUMÉ. On a étudié le développement du couvert et de la diversité après un incendie dans une forêt de haute terre dominée par Picea mariana, au Canada subarctique. Les réactions à court terme des plantes poussant dans les emprises dégagées vieilles de 10 et 22 ans, ainsi qu’un site forestier ont été l’objet de recherches deux et trois saisons de croissance après un incendie de forêt. Les travaux réalisés sur le site de l’étude avant et après le feu ont permis une comparaison directe du couvert et de la fréquence