Trends in tree growth and intrinsic water-use efficiency in the tropics under elevated CO2 and climate change
Rahman M, Islam M, Gebrekirstos A, Bräuning A (2019)
Publication Type: Journal article, Review article
Publication year: 2019
Journal
DOI: 10.1007/s00468-019-01836-3
Abstract
Key message: Increasing water-use efficiency, due to rising atmospheric CO 2 , did not stimulate radial growth in tropical trees, probably because negative impacts of changing climate on tree growth have overridden the small positive influence of rising atmospheric CO 2 . Abstract: Global environmental changes affect tree growth and physiological behavior across the major biomes around the world. However, it is not yet clear how tree growth and physiology of tropical trees responded to global environmental changes in a long term, yet such information is critical to get insight into how tropical trees will respond to future global changes. The main objective of this review article is to explore the long-term trends in tree growth, carbon isotope discrimination (Δ 13 C), intercellular CO 2 concentration (C i ), and intrinsic water-use efficiency (iWUE) across the tropics and subtropics. We distinguished between data generated on plot levels or on species or tree individual levels. Stand-level growth trends were not consistent across the studies and plots, although recent studies indicated a declining growth trend. C i and iWUE consistently increased during the past decades, while Δ 13 C remained nearly constant. Increased iWUE either caused by higher photosynthetic capacity or reduced stomatal conductance did not translate into tree- and species-level radial growth, probably because assimilated carbon was allocated more to the root development to facilitate water absorption from moisture-limited soils rather than to basal area growth or xylem cell differentiation and maturation processess were impared by cavitation induced hydraulic limitations. Thus, higher temperature or drought-induced soil moisture deficit might have strongly impaired radial growth which has probably overridden the small positive effect of atmospheric CO 2 . Yet, disentangling the role of multiple drivers in explaining stem radial growth variation and their interactive effects on tropical trees under natural field conditions are not adequately studied and hence future research should focus on this aspect. Tree hydraulics should be taken into account in future research when predicting radial growth variability in tropical trees.
Authors with CRIS profile
Mizanur Rahman
Lehrstuhl für Geographie (Physische Geographie)
Mahmuda Islam
Institut für Geographie
Achim Bräuning
Lehrstuhl für Geographie (Physische Geographie)
Involved external institutions
Kenya (KE)How to cite
APA:
Rahman, M., Islam, M., Gebrekirstos, A., & Bräuning, A. (2019). Trends in tree growth and intrinsic water-use efficiency in the tropics under elevated CO2 and climate change. Trees-Structure and Function. https://dx.doi.org/10.1007/s00468-019-01836-3
MLA:
Rahman, Mizanur, et al. "Trends in tree growth and intrinsic water-use efficiency in the tropics under elevated CO2 and climate change." Trees-Structure and Function (2019).
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