Shining a light on ecosystem services

Humans rely on nature’s rich bounty for a vast array of services, from pollination, water, food, soil and air quality to materials, inspiration, medicine and wellbeing. But we reap what we sow.

These gifts for humanity – known as ecosystem services – are waning, according to an exhaustive review and synthesis of thousands of peer reviewed papers published in the journal PNAS.

Spanning the past 50 years, the paper shows a disconnect between the overwhelming declines in nature’s potential to support human wellbeing and how people are affected.

Some human rewards such as employment and income, bioenergy and health from natural medicines have grown due to technological, social and economic advances, while related resources have become depleted.

Using crops pollinated by wind rather than insects, water-filtration to offset poor water quality, mineral fertilisers to grow plants in degraded soil and aquaculture to replace wild fish are some examples. Such initiatives, the authors say, are unsustainable and mask the problem.

“This reflects how adaptable people are, and how we’re often able to use substitutes for nature in the short term, which is good,” says lead author Kate Brauman from the University of Minnesota, US. “But it bodes really poorly for the long term, because substitutes are imperfect, expensive and not uniformly available.”

Food is a good example, she notes. While we’re seeing overall improvements in nutrition, fishery declines and increased dominance of food production by monocrops like corn, wheat and rice will impact many people’s health in the long term.

The study, a culmination of four years’ work by an international team of authors assembled as part of the IPBES Global Assessment, focussed on wide-ranging trends in nature and associated impacts on people, encompassing marine and terrestrial ecosystems. It also included evidence from Indigenous and Local Knowledge Systems.

The latter makes many contributions to our understanding of nature’s resources, including “the stewardship of a large spectrum of local landraces and varieties of food plants and animals and through long-term use and management of natural medical resources”, says co-author Yildiz Aumeeruddy-Thomas, from France’s University of Montpellier.

Results showed trends are driven by declining habitats and biodiversity, with the greatest impacts on pollination, seed dispersal and pest control, and differed across regions, income streams, ethnicities and social groups.

Inequalities include millions of people suffering from hunger and malnutrition despite enough food being produced to feed everyone. More than half the world’s population relies on natural medicines which are likely to become more inaccessible.

Other highlights include the impact of habitat conversion for agriculture on much of nature’s potential contributions including climate regulation. At a less tangible end of the spectrum, growing urbanisation has driven a wedge in people’s cultural and spiritual attachment to the Earth.

“Recognising and accounting for not only the state of nature but how nature’s contributions to people are changing is critical to understanding and managing the world we are all part of in a way that will enable us to thrive into the future,” says Brauman.

“The big takeaway here is that by clearly showing these different categories and the trends in them, we’re in a much better position to identify the problems in the way we are managing nature, and that gives us a path forward to manage it better.”

The team sought to capture evidence beyond that which identifies as “ecosystem services” or “nature’s contribution to people” and draw parallels between nature’s resources and benefits. This includes, for instance, the impacts of biophysical nature research on human wellbeing such as how changes in watershed vegetation affect floods.

By disentangling nature’s potential and actual contributions, considering environmental conditions, quality of life and local and regional impacts, the authors say their paper offers a framework to help reverse these declines and their impacts on quality of life.