Assessing and modeling total height and diameter increment of ponderosa pine planted in Minnesota, USA

Forest managers are increasingly planting non-native tree species that are adapted to anticipated future conditions such as increased droughts. This work quantified individual tree growth patterns of ponderosa pine (Pinus ponderosa P. & C. Lawson), a western US species, planted outside of its natural range in Minnesota, USA. After 50 years, survival was as high as 69% for some ponderosa pine seed sources, and individuals from the Black Hills, Eastern High Plains, and South and East Montana regions of the western US were some of the tallest and largest diameter trees grown in Minnesota. Predictions of total tree height and diameter increment displayed the lowest bias when equations for ponderosa pine in the western US were used rather than equations for red pine (Pinus resinosa Ait.) in Minnesota, a species that occupies a similar ecological niche. These results indicate that using existing growth and yield equations from a species’ native range may provide a suitable representation of growth and yield patterns if observations from outside the species’ native range are lacking. Historical data from provenance trials such as these can provide a long-term record to quantify the growth potential of non-native species in anticipation of future climate scenarios.