Experiments suggest that biodiversity is essential in enhancing the ability of ecosystems to maintain multiple functions simultaneously: such as carbon storage, productivity, litter decomposition, water infiltration and the build-up of nutrient pools. This is known as "multi-functionality". These functions can help, for instance, in controlling soil erosion or regulating CO2 exchanges between the soil and the atmosphere.

Until now, most of the work on the relationship between the diversity of plants and multi-functionality has been carried out in highly controlled laboratory conditions or small-scale field experiments. By conducting their study in 224 dryland ecosystems from 17 countries across all continents (except Antarctica), Dr Fernando T. Maestre and his team assessed this relationship at the global level for the first time. Dr Maestre emphasised that "The financial support provided by my ERC grant has been essential in allowing me to successfully carry out the field surveys and conduct the laboratory analysis of more than 2600 soil samples gathered during the global survey. Without funding of this magnitude, it would have been very difficult, if not impossible, to conduct this large-scale research."

Some past research had revealed that the loss of biodiversity may impair the functioning of natural ecosystems, and thus diminish both the number and the quality of services they provide to the environment. This new study reveals that drylands, which host many endemic plants and animal species and include about 20% of the major centres of global plant diversity and over 30% of the birds native to dryland areas, are not an exception to the rule. The research also indicates that in drylands worldwide, multi-functionality is enhanced by an increased number of plant species and is reduced by a rise in the average annual temperature.

Dr. Maestre explained that "The results of this extensive fieldwork provide empirical evidence of the importance of biodiversity in maintaining and improving ecosystem multi-functionality in drylands. Our findings also 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."

An important result of this research is that the increase in average annual temperatures predicted by climate change models will reduce the ability of dryland ecosystems to perform multiple functions related to carbon, nitrogen and phosphorous cycling, which are crucial to supporting life on Earth. Commenting on these findings, Fernando T. Maestre said that “Although it is sometimes difficult to agree on limiting the emission of greenhouse gases responsible for global warming, we can contribute to minimize its negative consequences if we take clear actions to both preserve and restore plant biodiversity." This would not only preserve the wealth of species but, as land degradation is often accompanied by the loss of soil fertility, also limit the number of areas affected by desertification.