Intraspecific responses to climate change in Cunninghamia lanceolata (Lamb.) Hook.: Local may not be the best

Abstract

The response of tree growth to ongoing climate change has significant implications for sustainable forest management. An analysis of 10-year diameter at breast height, height, individual stem volume, and volume per hectare was conducted for 43 populations of Chinese fir (Cunninghamia lanceolata (Lamb.) Hook.) grown in 32 common gardens across southern China. Population-specific performance under contemporary and future climate conditions was examined using response function and transfer projection. Findings indicated that mean temperature in the coldest month was the most influential variable in predicting population growth-related traits. Adaptation lags were more pronounced in populations at the climatic margins compared to core populations. On average, provenances from cooler climates benefited from long southward transfers (3.9–4.0 °C warmer), while warm-origin provenances responded favorably to shorter northward transfers (2.7–3.0 °C cooler). Calculated transfer limits were substantial, indicating populations could tolerate significant climatic shifts before experiencing a decline below 90 % of the local seed source's growth. The moderate climate model (SSP119) predicted minimal declines, whereas the extreme scenario (SSP585) projected significant growth reductions in southern populations. Other nonmarginal populations in near-optimal climates were also expected to be negatively affected, whereas most northern populations were projected to benefit from climate warming. These findings indicate that the response of Chinese fir to climate variation varies according to genetic differences between populations. These valuable insights are essential for the strategic selection of seed sources in reforestation initiatives.