Assessing ecological barriers to black spruce regeneration and forest management in Terra Nova National Park, NL

Abstract

Terra Nova National Park (TNNP) is dominated by black spruce, which relies on fire to release its seeds and reduce soil organic matter (SOM) thickness for successful regeneration; however, active fire suppression in TNNP has greatly reduced black spruce regeneration over the last century. As a result, TNNP has few young stands and a significant representation of over-mature stands. Additionally, Kalmia angustifolia establishes without fire and actively excludes black spruce via various competitive mechanisms, which has caused several areas in TNNP to convert from black spruce stands to Kalmia heaths. TNNP has attempted to introduce prescribed fire as one of their management strategies to resolve these issues; however, there are limitations to this management. TNNP is highly interested in alternative management considerations to promote black spruce regeneration; however, to make informed management decisions, TNNP must determine the spatial distribution of two key ecological factors, black spruce seed viability and seedbed quality. We investigated 28 sites and evaluated tree age, seed viability, seedbed quality (i.e., SOM and seedbed type), natural black spruce regeneration, and Kalmia presence. Our results identified a strong age-reproduction relationship, an influence of seedbed quality on black spruce regeneration, and the potential for Kalmia to interfere with black spruce establishment. By assessing these relationships, we geographically mapped the reproductive potential of black spruce in TNNP. The information collected and analyzed in this project provides a more in-depth understanding of TNNP’s black spruce regeneration, directly contributing to TNNP’s boreal forest management.