Should I stay or should I go? Meteorological effects on radial growth in introduced lodgepole pine provenances

Climate change poses significant challenges to tree survival and productivity, necessitating the introduction of non-native species to enhance forest resilience. This study examines the sensitivity of different lodgepole pine (Pinus contorta) provenances to meteorological conditions in Latvia compared to native Scots pine (Pinus sylvestris). The study was carried out in lodgepole pine provenance trials at two locations in Latvia. It analyzed 12 provenances of Pinus contorta from Canada, one Pinus contorta grown in Latvia, and one Pinus sylvestris grown in Latvia. The age of the experimental trials ranged from 29 to 38 years. Data analysis involved climate sensitivity analysis, including cluster analysis, correlation analysis and linear-mixed effects model, to examine the relationship between radial growth patterns and meteorological variables. Complex meteorological influences on TRW were revealed, identifying eight significant predictors primarily associated with spring and summer conditions. The most substantial effects were linked to climatic water balance in spring, winter temperatures, and summer precipitation. Site conditions significantly influenced growth more than genetic effect between provenances. The Lacobie Creek provenance, originating from the central part of the natural distribution area demonstrated lower sensitivity to climatic variables and was the most productive, indicating a lower risk from climate-related challenges and promising future growth potential. In general, the variation in weather sensitivity across provenances was similar. Testing under local site conditions is essential to evaluate the potential for introducing non-native provenances, as their performance compared to native species can vary depending on the specific environmental conditions.