Relevance of wood anatomy and size of Amazonian trees in the determination and allometry of sapwood area

Abstract

Hydrological processes in forest stands are mainly influenced by tree species composition and morpho-physiological characteristics. Few studies on anatomical patterns that govern plant hydraulics were conducted in tropical forest ecosystems. Thus, we used dye immersion to analyze sapwood area patterns of 34 trees belonging to 26 species from a terra firme forest in the central Brazilian Amazon. The sapwood area was related with wood anatomy and tree size parameters (diameter-at-breast-height - DBH, total height and estimated whole-tree volume). Exponential allometric equations were used to model sapwood area using the biometrical variables measured. Sapwood area traits (cross-section non-uniformity and heartwood visibility) varied significantly among and within species even though all were classified as diffuse porous. DBH was strongly and non-linearly correlated with sapwood area (R 2 = 0.46, P < 0.001), while no correlation was observed with vessel-lumen diameter (P = 0.94) and frequency (P = 0.58). Sapwood area and shape were also affected by the occurrence of vessel obstruction (i.e., tyloses), hollow stems and diseases. Our results suggest that sapwood area patterns and correlated variables are driven by intrinsic species characteristics, microclimate and ecological succession within the stand. We believe that individual tree sapwood characteristics have strong implications over water use, hydrological stand upsaling and biomass quantification. These characteristics should be taken into account (e.g., through a multi-point sampling approach) when estimating forest stand transpiration in a highly biodiverse ecosystem.

Allometric Relationships for Predicting Aboveground Biomass and Sapwood Area of Oneseed Juniper (Juniperus monosperma) Trees

“…We examined the relationship between diameter and SWA at the stem level using wet diameter measurements for maximum relevance to nondestructive field applications. Our 200 observations were described well by a two-parameter power function (Figure 3; Table 2), which is consistent with the model form reported for many other tree species (Vertessy et al, 1995;Jung et al, 2011;Brantley et al, 2016;Aparecido et al, 2019).…”

“…Results were visualized using ggplot2 (Wickham, 2018 v3.1.0). We used power models to describe AGB as a function of ESD and maximum height (Ansley et al, 2012) and SWA as a function of stem diameter (Köstner et al, 1998;Pangle et al, 2015;Aparecido et al, 2019). We believe that power models have a stronger biological basis than the logarithmic models previously used to predict biomass from ESD [sensu (West et al, 1997)].…”

Dry Season Transpiration and Soil Water Dynamics in the Central Amazon

“…To do so, we first modeled tree-level SA as a function of DBH. We pooled data from our eight trees with additional allometry data collected by Aparecido et al (2019) at the same site. In Aparecido et al (2019) , the relationship between SA and DBH was limited to trees with DBH < 40 cm.…”

“…Differences in access to and use of water are often dependent on tree height and diameter ( West et al, 1997 ; Meinzer et al, 2005 ). Diameter can be used to predict characteristics related to hydraulic capacity, such as sapwood area ( Aparecido et al, 2019 ), which can then be used to estimate whole tree water use if sap velocity is known. In the tropics, the largest, emergent trees are subject to greater evaporative demand than other shorter canopy trees ( Motzer et al, 2005 ; Kunert et al, 2017 ) and are a major source of stand-level T ( Brum et al, 2018 ).…”

Bark characterization of Tachigali guianensis and Tachigali glauca from the Amazon under a valorization perspective

“…Studies on Tachigali species are scarce. Wood anatomy has been studied for species of Sclerolobium and species of Tachigali (Loureiro et al 1983;Pernía and Melandri 2006;Gasson et al 2003;Reis et al 2011;Macedo et al 2014), S. chrysophyllum and T. paniculata (Aparecido et al 2019), and T. glauca (=T. myrmecophila) (Fedalto et al 1989).…”