Wood Nutrient-Water-Density Linkages Are Influenced by Both Species and Environment

Abstract

Tropical trees store a large amount of nutrients in their woody tissues, thus triggering the question of what the functional association of these elements with other wood traits is. Given the osmotic activity of mineral elements such as potassium, sodium, and calcium, these elements should be strong candidates in mediating the water storing capacity in tropical trees. We investigated the role of wood nutrients in facilitating wood water storage in trees by using branch samples from 48 tropical tree species in South America and examined their associations with wood density (ρ). Wood density varied from 316 kg/m3 in Peru plots, where the soil nutrient status is relatively higher, to 908 kg/m3 in Brazil plots, where the nutrient availability is lower. Phosphorus content in wood varied significantly between plots with lowest values found in French Guiana (1.2 mol/m3) and plots with highest values found in Peru (43.6 mol/m3). Conversely, potassium in woody tissues showed a significant cross-species variation with Minquartia guianensis in Brazil showing the lowest values (8.8 mol/m3) and with Neea divaricata in Peru having the highest values (114 mol/m3). We found that lower wood density trees store more water in their woody tissues with cations, especially potassium, having a positive association with water storage. Specific relationships between wood cation concentrations and stem water storage potential nevertheless depend on both species’ identity and growing location. Tropical trees with increased water storage capacity show lower wood density and have an increased reliance on cations to regulate this reservoir. Our study highlights that cations play a more important role in tropical tree water relations than has previously been thought, with potassium being particularly important.

Functional traits and water‐transport strategies of woody species in an insular environment in a tropical forest

“…Interestingly, T. guianensis had higher trait variation in RES (Figure 3, Table 1), a more stressful environment than DOF. Stressing environments act as filters constraining trait variation and functional diversity (Lira-Martins et al, 2022). However, the wider trait variation of T. guianensis in RES suggests that this species is well adapted to these conditions and that foliar adjustment in SD and G max are important for coping with limiting water availability.…”

“…T. guianensis and E. pulchrum showed an adaptive response in wood traits with variation in environmental conditions. We were not able to separate soil or climatic effects in these differences, but soil and climate represent central ecological influences on wood and leaf trait variations (Heineman et al, 2016;Cosme et al, 2017;Oliveira et al, 2019Oliveira et al, , 2021Bittencourt et al, 2022;Lira-Martins et al, 2022). The parenchyma arrangement, and more specifically the axial parenchyma, is one important characteristic that varies significantly across different taxonomic groups (Carlquist, 2018).…”

“…T. guianensis and E. pulchrum showed an adaptive response in wood traits with variation in environmental conditions. We were not able to separate soil or climatic effects in these differences, but soil and climate represent central ecological influences on wood and leaf trait variations (Heineman et al, 2016; Cosme et al, 2017; Oliveira et al, 2019, 2021; Bittencourt et al, 2022; Lira‐Martins et al, 2022).…”

“…Thus, determining the intraspecific variability in plants of different physiognomies from the hydraulic architecture (Poorter et al, 2014; Messier et al, 2017; Lira‐Martins et al, 2022) will help us to understand the mechanistic process between resistance to embolism and hydraulic efficiency, in addition to providing fundamental data on the species in different environments (Méndez‐Alonzo et al, 2012; Rosas et al, 2019; Guillemot et al, 2022). Studies have shown that trade‐offs between secondary xylem and leaf structure promote adjustments concerning rates of water supply, hydraulic conductivity (Cosme et al, 2017; Olson, 2020), and embolism resistance (Lens et al, 2011; Li et al, 2016; Skelton et al, 2018).…”

Competition and site weakly explain tree growth variability in undisturbed Central African moist forests

“…Heineman et al (2016) showed in Panama that wood P concentration decreased with increasing wood density. Lira-Martins et al (2022) showed in the Amazon that lower wood density trees store more water in their woody tissues and have high K concentrations, certainly to regulate this reservoir. As Heineman et al (2016) also showed a good correlation between soil nutrients and wood nutrients, these results could in turn explain why lower wood density trees are limited by P and K soils, in contrast to higher wood density trees.…”