How climate change is shifting time for animals and plants

January 19, 2015 by Marie Keatley, Lynda Chambers And Paul Beggs, The Conversation
Wine grapes are now maturing earlier than they used to, thanks to climate change. Credit: Peter Werkman –, CC BY

Every Spring, the blanket of Australian alpine snow starts to melt, and the Mountain Pygmy Possum wakes up from its seven-month-long hibernation.

Naturally after so long under the snow, its first thought is to find food. But over the last few years, the snow's been melting earlier, and an important food source – the Bogong moth – is arriving later on its yearly migration, leaving these endangered possums to go hungry.

In Australia, spring-time events on the land, as well as in freshwater and marine systems are now generally occurring earlier than they used to.

The time at which certain events happen in the lives of animals or plants – such as when moths or birds start their annual migration, or when plants flower – is mostly influenced by temperature, although day length and rainfall can also play a part.

The timing of these life cycle events and their interaction with the seasonal climate is called phenology.

Since phenology is sensitive to small changes in the environment, any changes in timing can help highlight the impact of climate change on natural and managed systems. You can help record these changes through the ClimateWatch app developed by the Bureau of Meteorology, Earth Watch Institute and the University of Melbourne.

Starting early

The life cycles of many plants and animals affect our day-to-day lives, and understanding these cycles is important for our survival. To successfully produce food or hunt, we need to understand animal behaviour and plant growth – and how these are linked to the environment.

In Australia, the breeding season and migration of many birds is beginning earlier by an average of 2.6 days per decade.

For many Australian plants, flowering, fruiting and harvesting is starting earlier by an average of 9.7 days per decade.

Flowering also means the presence of pollen in the air. What was once thought of as the "" is also changing as the climate changes.

For many people, airborne pollen is a source of suffering – for asthma sufferers who are allergic to pollen, and for those with , pollen can mean sneezing and wheezing.

In North America the length of the ragweed pollen season, one of the biggest causes of hay fever, is now 13-27 days longer than in 1995 (depending on location). The longer pollen season is linked to recent warming, delays in the first frost of Autumn, as well as the number of frost-free Autumn days.

Similar changes have also been found in Europe. Researchers in Italy found that the pollen season for several allergenic plants was up to 85 days longer in recent decades, with the pollen season starting earlier now than in the 1980s.

Wine grapes in southern Australia are also maturing earlier – on average eight days earlier per decade than they were in 1985. These changes are related to increasing air temperatures and decreasing moisture in the soil.

The grape growing season is likely to shorten which will mean changes to the areas suitable for particular varieties. At least one winery has already bought vineyards in Tasmania as a way of dealing with a warming climate.

A Northern Hemisphere bias

Most of the reports of changes in species phenology have come from the Northern Hemisphere. This may be partly due to the dramatically visible seasonal changes over this region (first snow for example).

"Firsts" in these regions, such as the arrival of migratory birds or flowering, are very obvious and easy to record.

Some phenological events are also documented because of cultural significance. In Japan, the date of the first bloom of cherry blossoms is known from as far back as the ninth century.

Changing species relationships

Box-ironbark forests are unusual in that they have trees which flower during winter. These flowers are a vital food source for nectar-dependent woodland birds.

Occasionally, these ironbarks fail to flower, leaving dependent woodland birds short of a vital food supply.

Historical records from 1945 to 1970 of red ironbark flowering in the Rushworth Forest in Victoria, indicate that no flowering occurred in only four of the 26 years.

However, a more recent study from 1997 to 2007 of red ironbark flowering found that the number of years with no flowering had increased. Over the 11-year study, there were four years with no flowering, with three of the failures occurring in the final six years. These flowering failures may have contributed to recent declines in the number of in that forest.

Despite these snapshots, an Australia-wide understanding of the impacts of is needed, including records of phenology from many more regions.

A new app means you can now contribute to recording species phenology in Australia. The Bureau of Meteorology, Earth Watch Institute and the University of Melbourne have developed ClimateWatch, where you can record the life cycle events of plants and birds, spiders and whales and more.

Explore further: Rocky Mountain wildflower season lengthens by more than a month

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Display comments: newest first

1.8 / 5 (5) Jan 19, 2015
The 7 highest recorded Global temperature readings from 1998 to 2014 (NOAA) are within a range of 14.51 and 14.58 degree C . All these high readings are only 0.07 or 7/100's of 1.0 degree difference.

These are not separate records these are ALL the same readings and certainly within the ability of determining the real planet's global temperature each year.

The 20th Century average was 13.90 degrees C. The current 21st Century average is 14.44 or a 0.54 degree C increase to date.

I would dare say 13.9 to 14.4 is within the yearly error in measuring the Global temperature, as well.

A human living on a 13.9 degree planet or a 14.44 degree planet would not be able to tell the difference.
1.8 / 5 (5) Jan 19, 2015
Since the 1998 NOAA global temperature was/is 14.51 Degrees C

and the 2014 NOAA global temperature was/is 14.58 and

since the average from 1998 through 2014 is 14.44

That these figures show no additional warming since 1998, only fluctuations

That since its been claimed that human Co2 emissions from burning fossil fuels is causing global warming, that that claim is not substantiated due the observed atmospheric temperature at a time when human Co2 emissions have been at the most maximum amount and most accelerated rate of introduction to the atmosphere during this non-warming 21st Century.
1.8 / 5 (5) Jan 19, 2015
Keeping in mind that:

Since the 1998 NOAA global temperature was/is 14.51 Degrees C

and the 2014 NOAA global temperature was/is 14.58 and

That there has been 5 other global temperatures measuring between 14.51 and 14.58 as well.

Yet the average from 1998 to 2014 is only 14.44 degrees C.
2.3 / 5 (3) Jan 19, 2015

After 33 years of science's "could be" warnings the world now needs science to say it's "PROVEN" that we need to SAVE THE PLANET from climate change. Deny that.
5 / 5 (3) Jan 19, 2015
the simple nature of your thoughts renders your opinions meaningless, kiddies. the lone climate of this planet is not concerned with such miniscule, incomplete measurements. it will always sadden to see folks preach personal belief in the face of irrefutable data.
alchemist from bristol
3.7 / 5 (3) Jan 20, 2015
Switching to renewable, sustainable energy will stimulate the economy, create jobs, save money and clean up the environment. "For many species, including humans, the climate may be changing faster than we can keep up."
1 / 5 (2) Jan 24, 2015
Personally I really think that if every person on the planet was to vanish suddenly and stopped putting co2 in the air from industry, transportation, heating and simply breathing there are already enough feedback loops (such as permafrost melting in the far north all over the world spewing methane in increasing amounts) now operating that the climate is going to continue to slowly warm regardless. As far as animals and plants go they will either adjust, adapt or die. Not a whole lot of choices there available to them. We can't change things back to the way they were. We simply don't have the capability.

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