Research suggests Autumn is ending later in the northern hemisphere

March 28, 2014
Research suggests autumn is ending later in the northern hemisphere
This is a photo of autumn leaves. Credit: University of Southampton

A study by the University of Southampton suggests that on average the end of Autumn is taking place later in the year and Spring is starting slightly earlier.

A team of researchers examined satellite imagery covering the northern hemisphere over a 25 year period (1982 - 2006), and looked for any seasonal changes in vegetation by making a measure of its 'greenness'. They examined in detail, at daily intervals, the growth cycle of the vegetation - identifying physical changes such as leaf cover, colour and growth.

The project was led by University of Southampton Professor of Geography Peter Atkinson, who worked with his colleague Dr Jadunandan Dash and in collaboration with Professor Jeganathan Chockalingam from the Department of Remote Sensing at the Birla Institute of Technology in India.

Professor Atkinson says: "There is much speculation about whether our seasons are changing and if so, whether this is linked to . Our study is another significant piece in the puzzle, which may ultimately answer this question."

The team was able to examine the data for specific vegetation types: 'mosaic' vegetation (grassland, shrubland, forest and cropland); broad-leaved deciduous forest; needle-leaved evergreen forest; needle-leaved deciduous and evergreen forest; mixed broad-leaved and needle-leaved forest; and mixed-forest, shrubland and grassland. They analysed data across all the groups, recognising that forests which have not changed size due to human intervention, for example through forestry or farming, provide the most reliable information on vegetation response to changes in our climate.

The most pronounced change found by the researchers was in the broad-leaved deciduous and needleleaved deciduous forest groups, showing that Autumn is becoming significantly later. This delay in the signs of Autumn was generally more pronounced than any evidence for an earlier onset of Spring, although there is evidence across the groups that Spring is arriving slightly earlier.

Professor Peter Atkinson comments: "Previous studies have reported trends in the start of Spring and end of Autumn, but we have studied a longer time period and controlled for loss and vegetation type, making our study more rigorous and with a greater degree of accuracy.

"Our research shows that even when we control for land cover changes across the globe a changing climate is significantly altering the vegetation growth cycles for certain types of vegetation. Such changes may have consequences for the sustainability of the plants themselves, as well as species which depend on them, and ultimately the climate through changes to the carbon cycle."

The study used the Global Inventory Modelling and Mapping Studies (GIMMS) dataset and combined with an innovative data processing method to study vegetation cycles.

Explore further: Trees invading warming Arctic will cause warming over entire region, study shows

More information: C. Jeganathan, J. Dash, P.M. Atkinson, "Remotely sensed trends in the phenology of northern high latitude terrestrial vegetation, controlling for land cover change and vegetation type," Remote Sensing of Environment, Volume 143, 5 March 2014, Pages 154–170, dx.doi.org/10.1016/j.rse.2013.11.020

Related Stories

Recommended for you

Clues from ancient Maya reveal lasting impact on environment

September 3, 2015

Evidence from the tropical lowlands of Central America reveals how Maya activity more than 2,000 years ago not only contributed to the decline of their environment but continues to influence today's environmental conditions, ...

Ice sheets may be more resilient than thought

September 3, 2015

Sea level rise poses one of the biggest threats to human systems in a globally warming world, potentially causing trillions of dollars' worth of damages to flooded cities around the world. As surface temperatures rise, ice ...

Climate ups odds of 'grey swan' superstorms

August 31, 2015

Climate change will boost the odds up to 14-fold for extremely rare, hard-to-predict tropical cyclones for parts of Australia, the United States and Dubai by 2100, researchers said Monday.

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.