Tree growth responses to temporal variation in rainfall differ across a continental-scale climatic gradient.

Autor: Alison J O'Donnell, Michael Renton, Kathryn J Allen, Pauline F Grierson
Jazyk: angličtina
Rok vydání: 2021
Předmět:
Zdroj: PLoS ONE, Vol 16, Iss 5, p e0249959 (2021)
Druh dokumentu: article
ISSN: 1932-6203
DOI: 10.1371/journal.pone.0249959
Popis: Globally, many biomes are being impacted by significant shifts in total annual rainfall as well as increasing variability of rainfall within and among years. Such changes can have potentially large impacts on plant productivity and growth, but remain largely unknown, particularly for much of the Southern Hemisphere. We investigate how growth of the widespread conifer, Callitris columellaris varied with inter-annual variation in the amount, intensity and frequency of rainfall events over the last century and between semi-arid (800 mm mean annual rainfall) biomes in Australia. We used linear and polynomial regression models to investigate the strength and shape of the relationships between growth (ring width) and rainfall. At semi-arid sites, growth was strongly and linearly related to rainfall amount, regardless of differences in the seasonality and intensity of rainfall. The linear shape of the relationship indicates that predicted future declines in mean rainfall will have proportional negative impacts on long-term tree growth in semi-arid biomes. In contrast, growth in the tropics showed a weak and asymmetrical ('concave-down') response to rainfall amount, where growth was less responsive to changes in rainfall amount at the higher end of the rainfall range (>1250 mm annual rainfall) than at the lower end (
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