University of Tasmania

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Seasonal changes in plant-water relations influence patterns of leaf display in Miombo woodlands: evidence of water conservative strategies

journal contribution
posted on 2023-05-19, 22:06 authored by Vinya, R, Malhi, Y, Brown, N, Fisher, JB, Timothy BrodribbTimothy Brodribb, Aragao, LEOC
Water availability has frequently been linked to seasonal leaf display in seasonally dry ecosystems, but there have been few ecohydrological investigations of this link. Miombo woodland is a dominant seasonally dry tropical forest ecosystem type in southern Africa; however, there are few data on the relationship between seasonal dynamics in plant–water relations and patterns of leaf display for Miombo woodland. Here we investigate this relationship among nine key Miombo woodland tree species differing in drought tolerance ability and leaf phenology. Results of this study showed that seasonal patterns of leaf phenology varied significantly with seasonal changes in stem water relations among the nine species. Leaf shedding coincided with the attainment of seasonal minimum stem water potential. Leaf flush occurred following xylem rehydration at the peak of the dry season suggesting that endogenous plant factors play a pivotal role in seasonal leaf display in this forest type. Drought-tolerant deciduous species suffered significantly higher seasonal losses in xylem hydraulic conductivity than the drought-intolerant semi-evergreen tree species (P < 0.05). There was a significant and positive correlation between species drought tolerance index and species’ seasonal loss in hydraulic conductivity (P < 0.05), confirming the ecological role of long-distance xylem transport in this seasonally dry tropical forest. Our results reveal that water stress in seasonally dry tropical forests selects for water conservative traits that protect the vulnerable xylem transport system. Therefore, seasonal rhythms in xylem transport dictate patterns of leaf display in seasonally dry tropical forests.


Australian Research Council


Publication title

Tree Physiology








School of Natural Sciences


Heron Publishing

Place of publication

202, 3994 Shelbourne St, Victoria, Canada, Bc, V8N 3E2

Rights statement

Copyright 2018 The Authors

Repository Status

  • Restricted

Socio-economic Objectives

Terrestrial systems and management not elsewhere classified; Climate change adaptation measures (excl. ecosystem)