Climate change impacts on plants and animals

Dr Lesley Hughes.

Macquarie University biologist Dr Lesley Hughes believes global climate change will wipe out some species of plants and animals, and has already caused some birds to start migrating earlier.

Hughes, a senior lecturer in the Department of Biological Sciences, has been looking at what plants and animals are doing to cope with climate change and how their interactions will change as the planet warms.

Extinction for some species

She notes that many species would have difficulty coping with climate change, particularly those that are already vulnerable.

“Certainly we are talking about extinction for some,” she says. “As climate zones shift, species won’t be protected in National Parks which have a rather static design, so examples would be species that have narrow geographic ranges or are in isolated reserves perhaps surrounded by farmland.’’

Hughes said a major part of the national discussion on climate change should include how to give those species the best possible chance of survival.

Available options

One option would be limiting stress on species by doing a better job controlling exotic pests and other environmental stresses. Another possibility would be connecting national parks in some locations or providing stepping-stones between reserves. But that may not be possible in all situations for a variety of reasons such as cost and existing human activity.

Hughes notes that in South Australia and Western Australia, some of this type of activity has already begun.

“There are a couple of programs aimed at identifying appropriate parcels of land that could be purchased to improve connectivity between protected areas,” she says.

If there is one positive change in the global warming debate in Australia, Hughes says that it has been an increase in public awareness of the changes taking place in the environment.

“People are noticing changes whether it’s trees fruiting or flowering earlier or birds migrating sooner,” she says.

Changes already occurring in some species

Hughes notes one of her students, who has been studying global warming’s impact on bird migration, has found that birds have been migrating about 3.5 days sooner each decade since the 1960s.

Hughes says such changes in behaviour are significant because every time the behaviour of one species changes, the other species with which it interacts may also be affected. For example, if birds are migrating sooner, there may not be an adequate supply of certain insects available in a given location thereby threatening the species, she says.

Hughes has been using bioclimatic modeling to try and predict how species distributions may change under altered climatic conditions in the future to assess which species might be most vulnerable to negative impacts.

Action needed

With governments and policy makers now becoming more concerned about the impacts of global warming in addition to thinking about how to reduce greenhouse gas emissions, Hughes is hoping that her work will lead to better planning and implementation of conservation strategies designed to ensure species survival.

For more information, contact Dr Lesley Hughes at lhughes@rna.bio.mq.edu

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