Diminishing returns: A comparison between fresh mass vs. area and dry mass vs. area in deciduous species

Abstract

“Diminishing returns” in leaf economics occurs when increases in lamina mass (M), which can either be represented by lamina dry mass (DM) or fresh mass (FM), fail to produce proportional increases in leaf surface area (A), such that the scaling exponent (α) for the M vs. A scaling relationship exceeds unity (i.e., α > 1.0). Prior studies have shown that FM vs. A is better than DM vs A in assessing diminishing returns in evergreen species. However, the superiority of FM vs. A over DM vs. A has been less well examined for deciduous species. Here, we applied reduced major axis protocols to test whether FM vs. A is better than DM vs. A to describe the M vs. A scaling relationship, using a total of 4271 leaves from ten deciduous and two evergreen tree species in the Fagaceae and Ulmaceae for comparison. The significance of the difference between the scaling exponents of FM vs. A and DM vs. A was tested using the bootstrap percentile method. Further, we tested the non-linearity of the FM (DM) vs. A data on a log-log scale using ordinary least squares. We found that (i) the majority of scaling exponents of FM vs. A and DM vs. A were >1 thereby confirming diminishing returns for all 12 species, (ii) FM vs. A was more robust than DM vs. A to identify the M vs. A scaling relationship, (iii) the non-linearity of the allometric model was significant for both DM vs. A and FM vs. A., and (iv) the evergreen species of Fagaceae had significantly higher DM and FM per unit area than other deciduous species. In summary, FM vs. A is a more reliable measure than DM vs. A when dealing with diminishing returns, and deciduous species tend to invest less biomass in unit leaf light harvesting area than evergreen species.

Leaf-age and petiole biomass play significant roles in leaf scaling theory

“…The same is true for the petiole fresh mass vs. lamina area scaling relationship compared to that of petiole dry mass vs. lamina area. This phenomenon highlights the superiority of fresh mass over dry mass in describing leaf biomass allocation with the scaling approach, as previously demonstrated (see Huang et al., 2019 ; Liu et al., 2020 ; Guo et al., 2022 ).…”

“…The difference in the results emerging from the use of the ratio and scaling approaches should be a key consideration when designing a research program ( Cheng et al., 2015 ; Li et al., 2022 ). The ratio-based approach has the advantage that it reveals plant biomass allocation as a simple proportion or percentage between any two variables of interest ( Wright et al., 2005 ; Poorter et al., 2012 ), whereas the scaling approach has the advantage of capturing any non-linear or linear relationship between two variables while adjusting for size or age, i.e., provides a simple way of summarizing proportional and size-dependent phenomena ( Niklas, 1994 ; Milla and Reich, 2007 ; Niklas et al., 2007 ; Guo et al., 2022 ).…”

Comparison of four performance models in quantifying the inequality of leaf and fruit size distribution

“…Meanwhile, fruits, particularly fleshy ones, play a key role in seed dispersal by providing nourishment for various frugivorous animals (Willson, 1994). Literature has consistently emphasized the importance of leaf and fruit size, including parameters such as area, volume, and mass, in analyzing scaling relationships between these sizes (Guo et al, 2021(Guo et al, , 2022Milla & Reich, 2007;Niklas & Christianson, 2011;Pan et al, 2013;Shi, Miao, et al, 2022;Sun et al, 2017;Wang et al, 2023).…”

“…Meanwhile, fruits, particularly fleshy ones, play a key role in seed dispersal by providing nourishment for various frugivorous animals (Willson, 1994). Literature has consistently emphasized the importance of leaf and fruit size, including parameters such as area, volume, and mass, in analyzing scaling relationships between these sizes (Guo et al., 2021, 2022; Li, Shi, et al., 2022; Milla & Reich, 2007; Niklas & Christianson, 2011; Pan et al., 2013; Shi, Miao, et al., 2022; Sun et al., 2017; Wang et al., 2023). Moreover, several mathematical models have been proposed and refined to describe leaf or fruit shape (Dornbusch et al., 2011; Gielis, 2003; Li, Niklas, et al., 2022; Li, Quinn, et al., 2022; Li, Zheng, et al., 2022; Lin et al., 2016; Schrader et al., 2021; Shi et al., 2015, 2020, 2021; Wang et al., 2023).…”

“Diminishing returns” and leaf area-biomass scaling of ferns in subtropical ecosystems

“…The relationship between leaf (lamina) biomass and area not only reflects the light-harvesting capability of most land plants, but also their environmental adaptability ( Kleiman and Aarssen, 2007 ; Huang et al., 2020 ; Guo et al., 2022 ). Therefore, this scaling relationship has important implications for plant growth and community productivity ( Liu et al., 2020 ).…”