Elevated night-time temperatures increase growth in seedlings of two tropical pioneer tree species

Journal Publication ResearchOnline@JCU
Cheesman, Alexander W.;Winter, Klaus
Abstract

Increased night-time temperatures, through their influence on dark respiration, have been implicated as a reason behind decreasing growth rates in tropical trees in the face of contemporary climate change. Seedlings of two neo-tropical tree species (Ficus insipida and Ochroma pyramidale) were grown in controlled-environment chambers at a constant daytime temperature (33°C) and a range of increasing night-time temperatures (22, 25, 28, 31°C) for between 39d and 54d. Temperature regimes were selected to represent a realistic baseline condition for lowland Panama, and a rise in night-time temperatures far in excess of those predicted for Central America in the coming decades. Experiments were complemented by an outdoor open-top chamber study in which night-time temperatures were elevated by 2.4°C above ambient. Increasing night-time temperatures resulted in >2-fold increase in biomass accumulation in growth-chamber studies despite an increase in leaf-level dark respiration. Similar trends were seen in open-top chambers, in which elevated night-time temperatures resulted in stimulation of growth. These findings challenge simplistic considerations of photosynthesis-directed growth, highlighting the role of temperature-dependent night-time processes, including respiration and leaf development as drivers of plant performance in the tropics.

Journal

New Phytologist

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Volume

197

ISBN/ISSN

1469-8137

Edition

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Issue

4

Pages Count

8

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Publisher

Wiley-Blackwell

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EISSN

N/A

DOI

10.1111/nph.12098