Effects of ontogenetic stage and leaf age on leaf functional traits and the relationships between traits in Pinus koraiensis

Abstract

Investigating the effects of ontogenetic stage and leaf age on leaf traits is important for understanding the utilization and distribution of resources in the process of plant growth. However, few studies have been conducted to show how traits and trait-trait relationships change across a range of ontogenetic stage and leaf age for evergreen coniferous species. We divided 67 Pinus koraiensis Sieb. et Zucc. of various sizes (0.3–100 cm diameter at breast height, DBH) into four ontogenetic stages, i.e., young trees, middle-aged trees, mature trees and over-mature trees, and measured the leaf mass per area (LMA), leaf dry matter content (LDMC), and mass-based leaf nitrogen content (N) and phosphorus content (P) of each leaf age group for each sampled tree. One-way analysis of variance (ANOVA) was used to describe the variation in leaf traits by ontogenetic stage and leaf age. The standardized major axis method was used to explore the effects of ontogenetic stage and leaf age on trait-trait relationships. We found that LMA and LDMC increased significantly and N and P decreased significantly with increases in the ontogenetic stage and leaf age. Most trait-trait relationships were consistent with the leaf economic spectrum (LES) at a global scale. Among them, leaf N content and LDMC showed a significant negative correlation, leaf N and P contents showed a significant positive correlation, and the absolute value of the slopes of the trait-trait relationships showed a gradually increasing trend with an increasing ontogenetic stage. LMA and LDMC showed a significant positive correlation, and the slopes of the trait-trait relationships showed a gradually decreasing trend with leaf age. Additionally, there were no significant relationships between leaf N content and LMA in most groups, which is contrary to the expectation of the LES. Overall, in the early ontogenetic stages and leaf ages, the leaf traits tend to be related to a "low investment-quick returns" resource strategy. In contrast, in the late ontogenetic stages and leaf ages, they tend to be related to a "high investment-slow returns" resource strategy. Our results reflect the optimal allocation of resources in Pinus koraiensis according to its functional needs during tree and leaf ontogeny.

Influence of Leaf Age on the Scaling Relationships of Lamina Mass vs. Area

“…Photosynthetic rates of fully expanded leaves generally show a decline with increasing leaf age due to the reallocation of resources to young leaves to optimize the overall systemic photosynthetic returns of an individual plant, rather than resulting from leaf functional degradation (Field and Mooney, 1983;Hikosaka et al, 1994). Moreover, the photosynthetic capacity of young leaves has been shown to be significantly lower than mature leaves (Hikosaka and Shigeno, 2009;Liu et al, 2020;Ji et al, 2021). Although leaf functional traits have been regarded as important references for understanding plant ecological and growth strategies (Westoby et al, 2000(Westoby et al, , 2002, there are trade-offs among different leaf functional traits (e.g., lamina area, LMA) under the limitation of resources.…”

“…Mediavilla et al (2014) contended that the interspecific differences in leaf longevity, morphology, and chemical composition of mature leaves are more notable compared to immature leaves. Ji et al (2021) report that LMA and leaf dry matter content increase significantly during the development of leaves. In addition, previous studies have shown that leaf age is closely associated with photosynthetic capacity (Field and Mooney, 1983;Han et al, 2008).…”

“…However, prior research on the effects of leaf age on growth has mainly focused on conifers, e.g., Pinus pinaster Ait., Pinus koraiensis Sieb. et Zucc., and Picea rubens Sarg (Eimil-Fraga et al, 2015;Ji et al, 2021). To address this bias, we examined the shadetolerant evergreen shrub species Photinia × fraseri to determine the effects of leaf age on leaf functional traits and the leaf (lamina) mass vs. area scaling relationship Specifically, we addressed the following two questions: (i) Do leaf functional traits change with leaf age?…”

Leaf Nutritional Content, Tree Richness, and Season Shape the Caterpillar Functional Trait Composition Hosted by Trees

“…While more nutrient-rich, early-season leaves increase the growth rates of caterpillars [16,39], they have been found to particularly favor smaller herbivore species [4,40]. A decrease in content by leaf age has also been shown for other nutrients, such as magnesium (Mg), phosphorus (P), and potassium (K) [38,41,42] (but see opposing results for Ca [43]). N, P, K, Mg, and Ca are all essential nutrients for herbivorous insects [35,44], and micronutrients, such as Mg, have been shown to modify caterpillar species composition [45] and amplify the effect of macronutrients (N, P, K) on arthropod abundance [46].…”

Effects of growing position on leaflet trait variations and its correlations in <i>Fraxinus mandshurica</i>

“…©植物生态学报 Chinese Journal of Plant Ecology www.plant-ecology.com (Li et al, 2015;Griffith et al, 2016) (Funk et al, 2021), 但是单位质量氮的增加会使得气孔导 度增加, 从而丧失水分, 这可能是一、二级小叶的 LNC较小的原因 (Schulze et al, 1994)。 LPC整体随小 叶着生位置级别由小到大呈增大趋势(图2F), 与 LNC呈相反趋势, 这与前人LNC和LPC正相关的研 究结果 (Osnas et al, 2013;Guo et al, 2020;Ji et al, 2021) Griffith et al, 2016)。LT与LDMC在复叶 内部表现为同速生长关系(图4B), 由此推测对于外 界环境的响应二者同等程度改变, 叶片在增加其对 LT的投资时也使得LDMC增大, 这可能是LT增加, 叶肉组织增加, 叶片内空气含量降低导致的结果 (Poorter et al, 2019)。 SLA与LDMC显著负相关(图3), 这与先前一些 研究结果 (Wilson et al, 1999;Díaz et al, 2016;Anderegg et al, 2021)…”