Tropical dry forest trees and lianas differ in leaf economic spectrum traits but have overlapping water-use strategies

Abstract

Tree species in tropical dry forests employ a wide range of strategies to cope with seasonal drought, including regulation of hydraulic function. However, it is uncertain if co-occurring lianas also possess a diversity of strategies. For a taxonomically diverse group of 14 tree and 7 liana species, we measured morphological and hydraulic functional traits during an unusual drought and under non-drought conditions to determine (i) if trees have different water-use strategies than lianas and (ii) if relationships among these traits can be used to better understand how tree and liana species regulate diurnal leaf water potential (Ψdiurnal). In this Costa Rican tropical dry forest, lianas and trees had overlapping water-use strategies, but differed in many leaf economic spectrum traits. Specifically, we found that both lianas and trees employed a diversity of Ψdiurnal regulation strategies, which did not differ statistically. However, lianas and trees did significantly differ in terms of certain traits including leaf area, specific leaf area, petiole length, wood vessel diameter and xylem vessel density. All liana and tree species we measured fell along a continuum of isohydric (partial) to anisohydric (strict or extreme) Ψdiurnal regulation strategies, and leaf area, petiole length, stomatal conductance and wood vessel diameter correlated with these strategies. These findings contribute to a trait-based understanding of how plants regulate Ψdiurnal under both drought stress and sufficient water availability, and underscore that lianas and trees employ a similarly wide range of Ψdiurnal regulation strategies, despite having vastly different growth forms.

Effects of dry‐season irrigation on leaf physiology and biomass allocation in tropical lianas and trees

“…, Werden et al. ). However, more conservative resource‐use strategies, such as higher water use efficiency, denser wood, and lower leaf turgor loss points are associated with greater drought resistance (Bartlett et al.…”

Effect of lianas on forest‐level tree carbon accumulation does not differ between seasons: Results from a liana removal experiment in Panama

“…Lianas may have a competitive advantage over trees by maintaining their ability to grow during the dry season (Cai, Schnitzer, & Bongers, ; Sánchez‐Azofeifa et al, ; Schnitzer, ; Schnitzer & van der Heijden, ). Lianas differ from trees in foliar nutrients, hydraulic traits and allocation to defence, especially in tropical dry forests (Asner & Martin, ; Collins, Wright, & Wurzburger, ; Werden, Waring, Smith‐Martin, & Powers, ), which may augment carbon fixation during seasonal drought (Collins et al, ; Wyka, Oleksyn, Karolewski, & Schnitzer, ; Zhu & Cao, ). In addition, lianas are able to uptake water from deeper soil layers (Andrade, Meinzer, Goldstein, & Schnitzer, ; Chen et al, ) and/or different water sources during the dry season (De Deurwaerder et al, ).…”

Edaphic factors, successional status and functional traits drive habitat associations of trees in naturally regenerating tropical dry forests

“…To link functional trait data with tree species occurring in the plots, we used previously published databases of functional traits (Powers & Tiffin, ), seed mass (Smith‐Martin et al, ) and wood anatomy traits (Werden, Waring, Smith‐Martin, & Powers, ) all collected in the same region using standard methods (Pérez‐Harguindeguy et al, ). From (Powers & Tiffin, ), we collated mean species‐level values of specific leaf area (SLA; cm 2 /g), leaf area (cm 2 ), leaf dry matter content (LDMC; g/g), wood density (g/cm 3 ), foliar δ 13 C (‰), foliar phosphorus (P; %), nitrogen (N; %) and carbon (C; %), leaf type (simple or compound) and habit (deciduous, semi‐deciduous and evergreen).…”

“…Additional trait data were gathered for mean seed mass (g; Smith‐Martin et al, ), maximum adult tree height (m; J.S. Powers, unpublished), wood vessel diameter (mm) and xylem vessel density (# vessels/cm 3 ; Werden, Waring, et al, ). Finally, we considered species‐level dispersal syndrome (animal, wind or gravity, both; Powers et al, ; Hilje, Calvo‐Alvarado, Jiménez‐Rodríguez, & Sánchez‐Azofeifa, ).…”