TY - JOUR

T1 - The hydraulic efficiency–safety trade-off differs between lianas and trees

AU - van der Sande, Masha T.

AU - Poorter, Lourens

AU - Schnitzer, Stefan A.

AU - Engelbrecht, Bettina M. J.

AU - Markesteijn, Lars

N1 - © 2019 The Authors. Ecology published by Wiley Periodicals, Inc. on behalf of Ecological Society of America.

PY - 2019/5

Y1 - 2019/5

N2 - Hydraulic traits are important for woody plant functioning and distribution. Associations among hydraulic traits, other leaf and stem traits, and species' performance are relatively well understood for trees, but remain poorly studied for lianas. We evaluated the coordination among hydraulic efficiency (i.e., maximum hydraulic conductivity), hydraulic safety (i.e., cavitation resistance), a suite of eight morphological and physiological traits, and species' abundances for saplings of 24 liana species and 27 tree species in wet tropical forests in Panama. Trees showed a strong trade-off between hydraulic efficiency and hydraulic safety, whereas efficiency and safety were decoupled in lianas. Hydraulic efficiency was strongly and similarly correlated with acquisitive traits for lianas and trees (e.g., positively with gas exchange rates and negatively with wood density). Hydraulic safety, however, showed no correlations with other traits in lianas, but with several in trees (e.g., positively with leaf dry matter content and wood density and negatively with gas exchange rates), indicating that in lianas hydraulic efficiency is an anchor trait because it is correlated with many other traits, while in trees both efficiency and safety are anchor traits. Traits related to shade tolerance (e.g., low specific leaf area and high wood density) were associated with high local tree sapling abundance, but not with liana abundance. Our results suggest that different, yet unknown mechanisms determine hydraulic safety and local-scale abundance for lianas compared to trees. For trees, the trade-off between efficiency and safety will provide less possibilities for ecological strategies. For lianas, however, the uncoupling of efficiency and safety could allow them to have high hydraulic efficiency, and hence high growth rates, without compromising resistance to cavitation under drought, thus allowing them to thrive and outperform trees under drier conditions.

AB - Hydraulic traits are important for woody plant functioning and distribution. Associations among hydraulic traits, other leaf and stem traits, and species' performance are relatively well understood for trees, but remain poorly studied for lianas. We evaluated the coordination among hydraulic efficiency (i.e., maximum hydraulic conductivity), hydraulic safety (i.e., cavitation resistance), a suite of eight morphological and physiological traits, and species' abundances for saplings of 24 liana species and 27 tree species in wet tropical forests in Panama. Trees showed a strong trade-off between hydraulic efficiency and hydraulic safety, whereas efficiency and safety were decoupled in lianas. Hydraulic efficiency was strongly and similarly correlated with acquisitive traits for lianas and trees (e.g., positively with gas exchange rates and negatively with wood density). Hydraulic safety, however, showed no correlations with other traits in lianas, but with several in trees (e.g., positively with leaf dry matter content and wood density and negatively with gas exchange rates), indicating that in lianas hydraulic efficiency is an anchor trait because it is correlated with many other traits, while in trees both efficiency and safety are anchor traits. Traits related to shade tolerance (e.g., low specific leaf area and high wood density) were associated with high local tree sapling abundance, but not with liana abundance. Our results suggest that different, yet unknown mechanisms determine hydraulic safety and local-scale abundance for lianas compared to trees. For trees, the trade-off between efficiency and safety will provide less possibilities for ecological strategies. For lianas, however, the uncoupling of efficiency and safety could allow them to have high hydraulic efficiency, and hence high growth rates, without compromising resistance to cavitation under drought, thus allowing them to thrive and outperform trees under drier conditions.

KW - P-50

KW - Panama

KW - drought tolerance

KW - functional traits

KW - hydraulic architecture

KW - hydraulic conductivity

KW - lianas

KW - plant-water relations

KW - species abundance

KW - tropical forest

UR - https://esajournals.onlinelibrary.wiley.com/action/downloadSupplement?doi=10.1002%2Fecy.2666&file=ecy2666-sup-0001-AppendixS1.pdf

U2 - 10.1002/ecy.2666

DO - 10.1002/ecy.2666

M3 - Article

C2 - 30801680

VL - 100

SP - e02666

JO - Ecology

JF - Ecology

SN - 0012-9658

IS - 5

ER -