The Australian plants facing a bleak future due to climate change
Native Australian alpine plants may not be able to adapt or migrate quickly enough to survive rapid changes in climate change, a UNSW study has found.
The study of 21 plants from Kosciuszko National Park found that 20 were not responding to warming conditions.
Only one species – the Star Plantain (Plantago muelleri) - showed that it was adapting to warmer conditions by displaying an increase in plant size.
The second plant that showed evidence of a change in plant traits was the Cascade Everlasting (Ozothamnus secundiflorus), but it decreased in leaf thickness over a 125-year time period.
“We predicted leaves would become thicker, as this would be advantageous if plants were facing longer growing seasons and increasing temperatures,” lead author Meena Sritharan said.
“Our findings suggest that native alpine plants may not be adapting to the substantial local climate change occurring in Australian alpine regions.
“Australian native alpine plants face a bleak future in the face of rapid climate change.”
The point of the study was to gauge whether alpine plants in the southern hemisphere had changed in morphology, or their physical form, over time in response to recent climate warming.
Ms Sritharan said the 21 alpine plants exist in one of the ecosystems known to be least resistant to the effects of climate change.
“Alpine environments are facing higher-than-average increases in temperature in the last century,” Ms Sritharan said.
“But rapid changes in the environment can promote rapid changes in species.”
“Consequently, we expected that a rapid increase in temperature would result in a change in the plant traits we measured, such as size and leaf shape. These changes in plant traits would suggest that alpine plants may be changing in response to a changing climate.”
Previous studies have also shown that both native and invasive plants are capable of rapid changes in their morphology.
The researchers used herbarium (preserved) plant specimens collected between 1890 and 2016, and modern specimens collected in February, 2017.
Examples of the alpine plants they studied included Cushion Caraway (Oreomyrrhis pulvinifica), Alpine Rice flower (Pimelea alpine), Carpet Heath (Pentrachondra pumila) and Snow Aciphyll (Aciphylla glacialis).
The researchers measured five different plant traits: plant size, leaf shape, leaf area, leaf width and specific leaf area (the ratio of the leaf area to leaf dry mass).
Ms Sritharan said the study findings are surprising as the results were contrary to what they expected and what species in the northern hemisphere are facing.
She said plants in the northern hemisphere are changing substantially and adapting to changed environmental conditions brought by climate change.
“For instance, some British plant species (such as White Nettle (Lamium album) and Kenilworth ivy (Cymbalaria muralis) are flowering earlier than expected in the past decade compared to the previous four decades,” Ms Sritharan said.
“The plant height of species growing in tundra ecosystems (treeless regions in cold climates) have also increased with warming over the past three decades."
Scientists also forecast that plant species will migrate to higher elevations to escape the effects of climate warming.
But Ms Sritharan was surprised to find that a shrub – Cascade Everlasting (Ozothamnus secundiflorus) - had moved downslope over time rather than to a higher elevation.
“This indicates that we should look into if, and where, other native Australian alpine species may be migrating to, in the face of climate change,” she said.
Ms Sritharan’s supervisor, the director of UNSW’s Evolution & Ecology Research Centre, Professor Angela Moles, is currently investigating whether Australian alpine plants are shifting their distributions uphill.
“This summer we will be doing heatwave experiments to measure how Australian alpine plants respond to an increased duration of heatwaves, which is what climate researchers forecast for the future,” Prof. Moles said.
Are you worried about the plants Australia could lose as a result of climate change? What have you noticed happening in your own garden?
Climate change is a natural cycle that has been happening since time immemorial. Some plants will thrive, others will not and that is a natural result of the changing climate. There has been too much publicity about climate change, especially by those who benefit from the misinformation that has been promoted in the past. Man has had a very small effect on the climate regardless of what has been said and published. Politicians don't help as they are the ones who have always told us that there is a problem and they are the only ones who can fix it.
We have been told that the rainfall will not be sufficient to fill our dams and we will run out of water by 2012. Even if the rain did fall, the ground would be so parched and dry that the rain wouldn't penetrate. Warragamba Dam has had overflows three times since that forecast. We have been told that Pacific islands would disappear because of melting ice and sea level rises yet a family which has been oyster farming in the Cooks River, which is tidal, for over 80 years has never lifted the oyster racks which means that the level has not risen. Schoolchildren are being taught that climate change can be fixed and march with placards and slogans because they have also been told that unless climate change can be fixed by 2030 that the world will end. They want the PM to do something but when quizzed about what the PM must do, they have no idea.
We have been told that we must send money to Paris to stop climate change but nobody has been able to tell us how that money will be used nor by how much the Earth's temperature will drop. In Australia we are told to stop mining, reduce the national herd by 2/3rds, close down power stations and build more wind turbines as well as installing solar panels. This will be a disaster for workers in this country. Even if we do all of these things, nobody has ever answered the question: "By how much will this reduce the Earth's temperature.
I am a strong believer in climate change, geologists have proved that climate change has been happening for centuries and is cyclical. We are currently in a warming cycle and it is noted that the temperature has remained reasonably stable for the past 20 years which suggests that we may be at the peak of the warming cycle. Scientists are using current figures to extrapolate what the future may hold but this is not an exact science and whilst they may be right, the other theory that warming has peaked may also be right.