Four Australian Plant Species respond positively to declining Rainfall

A new paper published by Royal Society Open Science:

D'Agui, H., Fowler, W., Lim, S.L., Enright, N. and He, T. 2016. Phenotypic variation and differentiated gene expression of Australian plants in response to declining rainfall. Royal Society Open Science 3: 160637. (Link)
Banksia Hookeriana

Abstract

Declining rainfall is projected to have negative impacts on the demographic performance of plant species. Little is known about the adaptive capacity of species to respond to drying climates, and whether adaptation can keep pace with climate change. In fire-prone ecosystems, episodic recruitment of perennial plant species in the first year post-fire imposes a specific selection environment, offering a unique opportunity to quantify the scope for adaptive response to climate change. We examined the growth of seedlings of four fire-killed species under control and drought conditions for seeds from populations established in years following fire receiving average-to-above-average winter rainfall, or well-below-average winter rainfall. We show that offspring of plants that had established under drought had more efficient water uptake, and/or stored more water per unit biomass, or developed denser leaves, and all maintained higher survival in simulated drought than did offspring of plants established in average annual rainfall years. Adaptive phenotypic responses were not consistent across all traits and species, while plants that had established under severe drought or established in years with average-to-above-average rainfall had an overall different physiological response when growing either with or without water constraints. Seedlings descended from plants established under severe drought also had elevated gene expression in key pathways relating to stress response. Our results demonstrate the capacity for rapid adaptation to climate change through phenotypic variation and regulation of gene expression. However, effective and rapid adaptation to climate change may vary among species depending on their capacity to maintain robust populations under multiple stresses.
As they start their study, they announce that
 Little is known about the adaptive capacity of species to respond to drying climates, and whether adaptation can keep pace with climate change. 
Their study revealed:
We show that offspring of plants that had established under drought had more efficient water uptake, and/or stored more water per unit biomass, or developed denser leaves, and all maintained higher survival in simulated drought than did offspring of plants established in average annual rainfall years. 
And in the discussion:
Our glasshouse experiment revealed that climate changes (declining rainfall in this case) can drive adaptive morphological change in a single generation. Despite such morphological changes not being consistent across all studied species, our results provide evidence of general presence of positive adaptation to drought. 
Adaptive changes to declining rainfall in a single generation;  general presence of positive adaptation to drought.


CO2 science reported on the study:
D'Agui et al. write that their results demonstrate a capacity for "rapid adaptation to climate change through phenotypic variation and regulation of gene expression," which findings further suggests that "some species and ecosystems might be more resilient to climate change than we currently believe," with "adaptive evolution through natural selection and/or heritable phenotypic plasticity as results of epigenetic processes within a relatively short time frame," which in their case was but a single plant generation. 




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