Comparing long-term projected outcomes of adaptive silvicultural approaches aimed at climate change in red pine forests of northern Minnesota, USA

Abstract

The Adaptive Silviculture for Climate Change (ASCC) project was developed to test ecosystem-specific adaptation approaches. The first ASCC trial was installed on the Cutfoot Experimental Forest (CEF) in northern Minnesota, USA, in 2014. Three adaptation treatments (resistance, resilience, and transition), along with a no action control, were tested and compared using Forest Vegetation Simulator to determine their relative success. We compared mean annual increment (MAI) and mortality and determined how well each treatment achieved its species composition and stand structure targets. MAI was highest in the no action (3.77 ± 0.43 m3·ha–1·year–1) and lowest in the transition (1.72 ± 0.16 m3·ha–1·year–1). However, MAI for the transition treatment continually increased over time, which extended culmination age. The no action control had the highest mortality with 38.76 (±1.32) trees·ha–1 per 10-year timestep, while the resistance and transition treatments had the lowest levels at 9.36 (±0.49) and 4.19 (±0.35) trees·ha–1, respectively. Our findings highlight the relative success of the transition, which had lower mortality, greater structural diversity, and a future-climate-adapted species composition. The results from this study provide important context for adaptive silviculture aimed at climate change and offers an example of potential outcomes of these forest adaptation options.