Sensitivity of height growth response to climate change does not vary with age in common garden among Norway spruce populations from elevational gradients

Abstract

Tree populations are typically adapted to their local environments, and this adaptive ability is crucial for the maintenance of resilient forest ecosystems. Norway spruce is an important tree species in temperate and boreal forests in Europe, but it is highly vulnerable to climate change-associated risks. The aim of this study was to investigate associations between growth, phenology and climate in a 33-year-old common garden experiment testing progeny of 48 Norway spruce populations from elevational gradients within two European mountain ranges - the Carpathian and Sudeten Mountains. We also investigated whether sensitivity of height growth to a climatic transfer changed with age.Tree growth and phenology significantly varied among studied populations, and variation pattern reflected adaptation to the environment of their origin. However, contrary to our expectation, the slopes of height growth rate vs. climatic transfer did not vary among the four analyzed time periods, implying that populations did not show an increasing maladaptation to climate change with age. Our results indicate that existing spruce populations from both examined mountain ranges are likely to show a decreasing productivity with warming and drying climate. Unexpectedly though, spruce populations from Suteden Mts. were more vulnerable than populations from Carpathians in terms of precipitation transfer. The ecotype of planting material will remain relevant for management decisions with regard to planting new forests adapted to changing climate in the future.