A new study has found that diverse plant life may play a crucial role in buffering the negative impact of climate change and desertification in dryland ecosystems.
The findings of the multi-author study are based on samples of ecosystems in every continent except Antarctica.
The study has confirmed for the first time that the more diverse an ecosystem is, the more ecological functions it performs. It also has implications for carbon sequestration and soil health.
"This is the most extensive study of the links between function and diversity ever undertaken," said co-author Professor David Eldridge, of the UNSW School of Biological, Earth and Environmental Sciences.
According to the study, dryland ecosystems cover about 40 per cent of the Earth's land surface, support 40 per cent of its people, and are particularly vulnerable to environmental changes and desertification
"Our findings suggest that plant species richness may be particularly important for maintaining ecosystem functions linked to carbon and nitrogen cycling, which sustain carbon sequestration and soil fertility," said Eldridge.
"And because land degradation is often accompanied by the loss of soil fertility, plant species richness may also promote ecosystem resistance to desertification," he stated.
It is generally accepted that the loss of biodiversity may impair how natural ecosystems function by reducing the quality of services they provide.
Ecosystems that provide multiple services - such as carbon storage, productivity, and the build-up of nutrient supplies - are described as multi-functional.
However, the links between biodiversity and multi-functionality in dryland ecosystems have never been assessed globally.
In this study, a team of scientists from 14 countries evaluated how the diversity of perennial plants, and a range of climatic and landscape variables, were related to multi-functionality in 224 dryland ecosystems.
Researchers surveyed plots large enough to represent the main ecosystem features at each site and assessed 14 functions all related to the cycling and storage of carbon, nitrogen and phosphorus.
These functions were chosen because they deliver some of the fundamental supporting and regulating ecosystem services, and because they are used to identify the onset of desertification processes, asserted Professor Eldridge.
The study has been recently published in the journal Science.