You and Your CourseOpportunities
Research and Teaching
Our ResearchResearch Degrees
Partners and Community
Partner with JCU
- About JCUPartner with JCU
- Advanced Analytical Centre
- Association of Australian University Secretaries
- Australian Quantum & Classical Transport Physics Group
- Careers and Employability
- College of Healthcare Sciences
- College of Medicine and Dentistry
- Division of Tropical Environments and Societies
- International Students
- JCU Eduquarium
- JCU Halls of Residence
- Language and Culture Research Centre
- Marine Geophysics Laboratory
- Open Day
- Parents and Partners
- Pathways to University
- Planning and Performance
- Professional Experience Placement
- Rapid Assessment Unit
- JCU Connect
- Scholarships @ JCU
- Tropical Sustainable Design Case Studies
- VAVS Home
- Media & Comms
- Australian Institute of Tropical Health & Medicine
- About JCU
Featured News Big trees face ‘dire future’
Big trees face 'dire future'
Jan 27, 2012: - Already on the decline worldwide, big trees face a dire future according to James Cook University’s Distinguished Professor William Laurance.
Writing in New Scientist magazine, Professor Laurance said that the world’s "biggest and most magnificent" trees face a range of threats.
Reviewing research from forests around the world, he said that there was evidence of their decline due to habitat fragmentation, selective harvesting by loggers, exotic invaders, and the effects of climate change.
He said their demise will have substantial impacts on biodiversity and forest ecology, while worsening climate change.
"To persist, big trees need a safe place to live and long periods of stability," Professor Laurance said. "But time and stability are becoming very rare commodities in our modern world."
Giant trees offer critical habitat and forage for wildlife, while transpiring massive amounts of water through their leaves, contributing to local rainfall. Old trees also lock up massive amounts of carbon — in some forests they can account for more than a quarter of living biomass.
“But their ability to sequester carbon and render other ecosystem services is threatened by human activities. Some of the world's largest trees are particularly targeted by loggers. The oldest trees are among the most valuable and therefore the first to be cut in ‘virgin’ forest areas,” he said.
“Big trees are also sensitive to habitat fragmentation, which exposes them to stronger winds and drier conditions.”
Professor Laurance's own work in the Amazon has shown substantial die-off of canopy giants in small forest fragments.
“Their susceptibility seems counter-intuitive given big trees' life histories, which invariably include periods of drought and other stress,” he said.
"All around the tropics, big canopy and emergent trees are succumbing to strong droughts.
"That's been a surprise to me and many other ecologists, because big, ancient trees would have had to survive many droughts in the past."
Professor Laurance said that forest giants may suffer disproportionately from climate change.
"According to one popular theory, trees get a double-whammy when the thermometer rises. During the day, their photosynthesis shuts down when it gets too warm, and at night they use more energy because their metabolic rate increases, much as a reptile’s would do when it gets warmer.
“With less energy being produced in warmer years and more being consumed just to survive, there is less energy available for growth.
“This hypothesis, if correct, means tropical forests could shrink over time. The largest, oldest trees would progressively die off and tend not to be replaced,” Professor Laurance said.
“Alarmingly, this might trigger a positive feedback that could destabilize the climate: as older trees die, forests would release some of their stored carbon into the atmosphere, prompting a vicious circle of further warming, forest shrinkage and carbon emissions.”
Professor Laurance said that climate change was also having less direct impacts on forests, including creating conditions for exotic pathogens to thrive. For example, pathogens such as Dutch Elm Disease, introduced by trade or circumstance, have devastated trees in many parts of the world.
“All told, the outlook for big trees is not good,” he said.
"The decline of big trees foretells a different world where ancient behemoths are replaced by short-lived pioneers and generalists that can grow anywhere, where forests store less carbon and sustain fewer dependent animals.
“It’s a place where giant cathedral-like crowns could become a thing of the past."
Reference: Laurance, William F. 2012. How the mighty are fallen. New Scientist, 28 January, pp. 39-41.
For further information:
William Laurance, Distinguished Research Professor & Australian Laureate
James Cook University, Cairns, Queensland, Australia
Phone: +61-7-4038-1518 and +61-7-4042-1819
- James Cook University
- Bachelor of Advanced Science
- Bachelor of Arts
- Bachelor of Biomedical Sciences
- Bachelor of Business
- Bachelor of Business / Laws
- Bachelor of Business & Environmental Science
- Bachelor of Dental Surgery
- Bachelor of Early Childhood Education
- Bachelor of Primary Education
- Bachelor of Secondary Education
- Bachelor of Environmental Practice
- Bachelor of Geology
- Bachelor of Information Technology
- Bachelor of Laws
- Bachelor of Nursing Science (External)
- Bachelor of Midwifery
- Bachelor of Pharmacy
- Bachelor of Physiotherapy
- Bachelor of Planning
- Bachelor of Psychological Science
- Bachelor of Science
- Bachelor of Social Work
- Bachelor of Speech Pathology
- Bachelor of Sport & Exercise Science
- Bachelor of Veterinary Science
- Bachelor of Clinical Sciences (Honours)
- Bachelor of Engineering (Honours)
- Bachelor of Engineering / Science (Honours) MBA in Tourism
- Master of Public Health and Tropical Medicine
- Master of Data Science
- Bachelor of Sports Psychology
- Bachelor of Marine Science
- Bachelor of Medicine / Surgery
- Bachelor of Nursing Science [Pre-Registration]
- Bachelor of Medical Laboratory Science (Honours)
- Bachelor of Occupational Therapy (Honours)
- Bachelor of Psychology
- Master of Conflict Management & Resolution
- Graduate Certificate of Conflict Management & Resolution
- Master of Global Development
- Master of International Tourism & Hospitality Management
- Bachelor of Technology and Innovation
- Bachelor of Science & Bachelor of Laws
- Diploma of Higher Education
- Diploma of Higher Education (Business)
- Diploma of Higher Education Majoring in Business Studies
- Diploma of Higher Education Majoring in Engineering and Applied Science
- Diploma of Higher Education Majoring in General Studies
- Diploma of Higher Education Majoring in Health
- Diploma of Higher Education Majoring in Information Technology
- Diploma of Higher Education Majoring in Science
- Diploma of Higher Education, Majoring in Society and Culture