New Zealand vegetation study reveals changes to Earth's ecosystems

New Zealand scientists say they have developed a new system to map the world's vegetation, which might help track the progress of climate change in future.

The system used satellite observations of the timing and intensity of activity in large-scale vegetation formations --known as biomes -- and how it relates to temperature and soil moisture to classify the world's vegetation into 24 biome types, said the University of Otago researchers on Monday.

Several other global biome maps existed, but the new system was objective and not reliant on expert opinion or correlations between vegetation and climate, Botany Professor Steven Higgins said in a statement.

The system was important for comparing the behaviour of ecosystems in different parts of the world, which was essential for understanding the drivers of ecosystem dynamics and how ecosystems might respond to change.

They used their new classification scheme to examine change in biomes over time and found that 13 percent of the Earth's land surface changed its biome state over the last three decades.

"This suggests that substantial shifts in the character of the Earth's surface are under way," said Higgins.

"Examples include swathes of Namibia and north-central Australia transitioning into drier biome categories, and large expanses of cold limited systems shifting to more productive categories."

Global change was the likely driver of the biome shifts detected, but the system was not yet being used to establish causal links.

"Future studies could use this system to monitor biome change and attribute the causes of the change," he said. Endit