Stand Dynamics and Stand Development of Conventional and Mixedwood Aspen Systems in Northern Minnesota

Abstract

In northern Minnesota, white spruce (Picea glauca (Moench) Voss) and aspen (Populus tremuloides Michx) mixedwood forests are important for timber production and ecological services. Traditionally grown in monoculture stands, little is known about the regeneration, growth, and yield of these species when managed in mixed compositions. 20 pure aspen and 20 mixedwood stands within a chronosequence of 0 – 23 years old in northern Minnesota were sampled to investigate stand differences. Forest inventory data were collected on seedlings, saplings, overstory trees, and non-tree understory cover, and forest modeling was conducted in Forest Vegetation Simulator (FVS) to simulate stand growth under different management scenarios. While aspen stands had higher density at regeneration and merchantable yield at harvest, mixedwoods maintained greater compositional and structural diversity throughout the rotation. Overall, white spruce-aspen mixedwood systems can provide opportunities for increased ecological services during early stand development without compromising on long-term timber-focused management goals.