Climatic Stress during Stand Development Alters the Sign and Magnitude of Age-Related Growth Responses in a Subtropical Mountain Pine

Abstract

The modification of typical age-related growth by environmental changes is poorly understood, In part because there is a lack of consensus at individual tree level regarding age-dependent growth responses to climate warming as stands develop. To increase our current understanding about how multiple drivers of environmental change can modify growth responses as trees age we used tree ring data of a mountain subtropical pine species along an altitudinal gradient covering more than 2,200 m of altitude. We applied mixed-linear models to determine how absolute and relative age-dependent growth varies depending on stand development; and to quantify the relative importance of tree age and climate on individual tree growth responses. Tree age was the most important factor for tree growth in models parameterised using data from all forest developmental stages. Contrastingly, the relationship found between tree age and growth became non-significant in models parameterised using data corresponding to mature stages. These results suggest that although absolute tree growth can continuously increase along tree size when trees reach maturity age had no effect on growth. Tree growth was strongly reduced under increased annual temperature, leading to more constant age-related growth responses. Furthermore, young trees were the most sensitive to reductions in relative growth rates, but absolute growth was strongly reduced under increased temperature in old trees. Our results help to reconcile previous contrasting findings of age-related growth responses at the individual tree level, suggesting that the sign and magnitude of age-related growth responses vary with stand development. The different responses found to climate for absolute and relative growth rates suggest that young trees are particularly vulnerable under warming climate, but reduced absolute growth in old trees could alter the species’ potential as a carbon sink in the future.

Climate‐ and successional‐related changes in functional composition of European forests are strongly driven by tree mortality

“…Overall, the importance of the interaction between climate and forest development agrees with previous studies that identified similar strong interactions for tree growth (e.g. Gómez‐Aparicio, García‐Valdés, Ruiz‐Benito, & Zavala, ; Ruiz‐Benito et al., ), tree mortality (e.g. Ruiz‐Benito et al., ; Vilà‐Cabrera, Martínez‐Vilalta, Vayreda, & Retana, ), recruitment (e.g.…”

Age-Effect Radial Growth Responses of Picea schrenkiana to Climate Change in the Eastern Tianshan Mountains, Northwest China

“…in northeast Hamburg of northern Germany, Pinus taiwanensis Hayata. in Taiwan, and Pinus cooperi Blanco in the Sierra Madre Occidental of northern Mexico [57][58][59][60]. As shown by a controlled experiment on cambial cell sensitivity to rising temperature of Cryptomeria japonica (L. f.) D. Don from different ages, the young tree growth trend would more easily be limited by long-term drought [61].…”

Age‐mediation of tree‐growth responses to experimental warming in the northeastern Tibetan Plateau

“…To date, comparative studies have investigated on phenology patterns of young and mature growth as well as the environmental sensitivities (Esper et al, ; Li et al, ; Ruiz‐Benito et al, ). Compared to adult trees of deciduous species, seeding and saplings have been found to be characterized by an earlier flushing, an earlier xylem formation, a longer growth season and a growth rate (Augspurger & Bartlett, ; Li et al, ; Vitasse, ).…”

“…Indeed, this trajectory can be complex, because tree performance in response to climate warming may be mediated by traits related to resource acquisition (Chen, An, Inouye, & Schwartz, 2015;Dorji et al, 2013;Estiarte & Peñuelas, 2015;Schwartz, Hanes, & Liang, 2014), such as life-history phases (juvenile vs. mature forest). However, variability in phenological plasticity and sensitivity to elevated temperature over the plant life cycle is not well known; we lack the insight on how age structure affects tree growth in the future warmer world (Esper, Niederer, Bebi, & Frank, 2008;Ruiz-Benito et al, 2015;Xu, Yin, Xiong, Wan, & Liu, 2012).…”