Assessing red spruce (Picea rubens Sarg.) restoration potential under current and future predicted climate change in Virginia

Global climate change threatens many species across the planet. High-elevation species, such as red spruce (Picea rubens), face significant and immediate threats from climate change. Red spruce has faced anthropogenic disturbances for over a century and is only recently beginning to recover across its range. Ecological niche modeling has become a common method of identifying the suitable habitat of a species, providing vital information to land managers carrying out restoration efforts. In this study, ecological niche models were used in a novel way, predicting distribution and habitat suitability separately and simultaneously to determine the spatial extent to which red spruce forests can be restored. In addition to models, surveys were conducted to elucidate the current regeneration trends of red spruce. Furthermore, climate projections were used to determine how restoration potential may change over the course of the twenty-first century. Comparisons between distribution and habitat suitability models indicate that there is additional habitat available for red spruce expansion. Regeneration surveys show that there is positive regeneration both within and beyond red spruce canopies, validating model comparisons. Climate change projections indicate total elimination of suitable habitat in Virginia by 2100. However, these projections likely predict increased competition for red spruce from low elevation competitors as opposed to physiological limitations imposed by climate change. It is therefore prudent to protect established populations and encourage further regeneration within and beyond current red spruce stands in anticipation of future ecological shifts.

Automated summary

Global climate change poses significant threats to high-elevation species like red spruce. This study used ecological niche models to predict the distribution and habitat suitability of red spruce, revealing the potential for expansion. Surveys confirmed the accuracy of the models. Climate projections suggest the loss of suitable habitat for red spruce in Virginia by 2100, likely due to increased competition rather than physiological limitations from climate change. Protecting existing populations and encouraging regeneration is crucial in anticipation of future ecological shifts.