Featured Research

from universities, journals, and other organizations

Extreme weather caused by climate change decides distribution of insects, study shows

Date:
February 20, 2014
Source:
Aarhus University
Summary:
Extreme weather caused by climate change in the coming decades is likely to have profound implications for distributions of insects and other invertebrates. This is suggested by a new study of insects in tropical and temperate regions of Australia. "Our predictions are that some species would disappear entirely in the next few decades, even when they have a fairly wide distribution that currently covers hundreds of kilometers”, the researchers conclude.

Fruit flies have been the model for a study that has shown how climate change may affect insect distribution in the future.
Credit: Ary A. Hoffmann

As climate change is progressing, the temperature of our planet increases. This is particularly important for the large group of animals that are cold-blooded (ectothermic), including insects. Their body temperature is ultimately determined by the ambient temperature, and the same therefore applies to the speed and efficiency of their vital biological processes.

Related Articles


But is it changes in average temperature or frequency of extreme temperature conditions that have the greatest impact on species distribution? This was the questions that a group of Danish and Australian researchers decided to examine in a number of insect species.

Johannes Overgaard, Department of Bioscience, Aarhus University, Denmark, Michael R. Kearney and Ary A. Hoffmann, Melbourne University, Australia, recently published the results of these studies in the journal Global Change Biology. The results demonstrate that it is especially the extreme temperature events that define the distribution of both tropical and temperate species. Thus climate change affects ectotermic animals primarily because more periods of extreme weather are expected in the future.

Fruit flies were modeled

The researchers examined 10 fruit fly species of the genus Drosophila adapted to tropical and temperate regions of Australia. First they examined the temperatures for which the species can sustain growth and reproduction, and then they found the boundaries of tolerance for hot and cold temperatures.

"This is the first time ever where we have been able to compare the effects of extremes and changes in average conditions in a rigorous manner across a group of species," mentions Ary Hoffmann.

Based on this knowledge and knowledge of the present distribution of the 10 species they then examined if distribution was correlated to the temperatures required for growth and reproduction or rather limited by their tolerance to extreme temperature conditions.

"The answer was unambiguous: it is the species' tolerance to very cold or hot days that define their present distribution," says Johannes Overgaard.

It is therefore the extreme weather events, such as heat waves or extremely cold conditions, which costs the insects their life, not an increase in average temperature.

Drastic changes in store

With this information in hand, the researchers could then model how distributions are expected to change if climate change continues for the next 100 years.

Most terrestrial animals experience temperature variation on both daily and seasonal time scale, and they are adapted to these conditions. Thus, for a species to maintain its existence under varying temperature conditions there are two simple conditions that must be met. Firstly, the temperature should occasionally be such that the species can grow and reproduce, and secondly, the temperature must never be so extreme that the population's survival is threatened.

In temperate climate for example, there are many species which are adapted to endure low temperatures in the winter, and then grow and reproduce in the summer. In warmer climates, the challenge may be just the opposite. Here, the species might endure high temperatures during the dry hot summer, while growth and reproduction mainly occurs during the mild and wet winter period.

The result was discouraging for all 10 species.

"Climate change will result in fewer cold days and nights, and thus allow species to move toward higher latitudes. However climate change also leads to a higher incidence to extremely hot days and our model therefore predicts that the distribution of these species will be reduced to less than half their present distribution"says Johannes Overgaard.

"In fact, our predictions are that some species would disappear entirely in the next few decades, even when they have a fairly wide distribution that currently covers hundreds of kilometers," adds Ary Hoffmann.

"Although none of the 10 species studied are normally perceived as either harmful or beneficial organisms for human society, the results indicate that distribution of many insect species will be changed dramatically, and it will probably also apply to many of the species that have particular social or commercial importance ," ends Johannes Overgaard.


Story Source:

The above story is based on materials provided by Aarhus University. The original article was written by Christina Troelsen and Johannes Overgaard. Note: Materials may be edited for content and length.


Journal Reference:

  1. Johannes Overgaard, Michael R. Kearney, Ary A. Hoffmann. Sensitivity to thermal extremes in AustralianDrosophilaimplies similar impacts of climate change on the distribution of widespread and tropical species. Global Change Biology, 2014; DOI: 10.1111/gcb.12521

Cite This Page:

Aarhus University. "Extreme weather caused by climate change decides distribution of insects, study shows." ScienceDaily. ScienceDaily, 20 February 2014. <www.sciencedaily.com/releases/2014/02/140220161312.htm>.
Aarhus University. (2014, February 20). Extreme weather caused by climate change decides distribution of insects, study shows. ScienceDaily. Retrieved November 26, 2014 from www.sciencedaily.com/releases/2014/02/140220161312.htm
Aarhus University. "Extreme weather caused by climate change decides distribution of insects, study shows." ScienceDaily. www.sciencedaily.com/releases/2014/02/140220161312.htm (accessed November 26, 2014).

Share This


More From ScienceDaily



More Plants & Animals News

Wednesday, November 26, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

From Popcorn To Vending Snacks: FDA Ups Calorie Count Rules

From Popcorn To Vending Snacks: FDA Ups Calorie Count Rules

Newsy (Nov. 25, 2014) The US FDA is announcing new calorie rules on Tuesday that will require everywhere from theaters to vending machines to include calorie counts. Video provided by Newsy
Powered by NewsLook.com
Feast Your Eyes: Lamb Chop Sent Into Space from UK

Feast Your Eyes: Lamb Chop Sent Into Space from UK

Reuters - Light News Video Online (Nov. 25, 2014) Take a stab at this -- stunt video shows a lamb chop's journey from an east London restaurant over 30 kilometers into space. Rough Cut (no reporter narration). Video provided by Reuters
Powered by NewsLook.com
Cambodian Capital's Only Working Elephant to Retire in Jungle

Cambodian Capital's Only Working Elephant to Retire in Jungle

AFP (Nov. 25, 2014) Phnom Penh's only working elephant was blessed by a crowd of chanting Buddhist monks Tuesday as she prepared for a life of comfortable jungle retirement after three decades of giving rides to tourists. Duration: 00:36 Video provided by AFP
Powered by NewsLook.com
Stray Dog Follows Adventure Racing Team for 6-Day Endurance Race

Stray Dog Follows Adventure Racing Team for 6-Day Endurance Race

Buzz60 (Nov. 24, 2014) A Swedish Adventure racing team travels to try and win a world title, but comes home with something way better: a stray dog that joined the team for much of the grueling 430-mile race. Jen Markham has the story. Video provided by Buzz60
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Plants & Animals

Earth & Climate

Fossils & Ruins

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins