Postfire seedling recruitment at the southern limit of lichen woodland

• Published in: Canadian Journal of Forest Research
• Main Authors: Moss, Melissa, Hermanutz, Luise
• Format: Article in Journal/Newspaper
• Language: English
• Published: Canadian Science Publishing 2009
• Subjects: Ecology; Forestry; Global and Planetary Change; Canada; Newfoundland
• Online Access: http://dx.doi.org/10.1139/x09-150; http://www.nrcresearchpress.com/doi/full-xml/10.1139/X09-150; http://www.nrcresearchpress.com/doi/pdf/10.1139/X09-150

Although fire is the primary mechanism driving regeneration in open black spruce ( Picea mariana (Mill.) BSP) lichen woodland, there are limited data concerning the sources of seedling mortality across the range of burn severity. We monitored planted seedlings in areas of high and low burn severity in Terra Nova National Park (Newfoundland, Canada) to determine sources and patterns of mortality of black spruce seedlings among burn treatments following a recent burn (2002). The importance of herbivory by small mammals as a source of seedling mortality was evaluated using small cages that excluded voles and non-native snowshoe hare. Overall seedling mortality was high (79%) in all areas; mortality was similar in areas of low (73%) and high (76%) burn severity, and highest in edge areas adjacent to closed-canopy forest (90%). Drought, rather than herbivory, was the most common cause of mortality during the first two seasons following germination. Seedling mortality at the southern edge of the lichen woodland was comparable to that found in other studies, but sources differed, emphasizing the spatially variable nature of mortality. Based on the level of seedling recruitment, our results suggest lichen woodland will return at this site.