Earlier this month, a report about insect extinctions suggested we’re going to find it increasingly difficult to feed ourselves, a few decades down the line. Well, here’s another warning.

This one comes from the Food and Agriculture Organization (FAO) of the United Nations, which says food security and nutrition are being put at risk by a dramatic loss of biodiversity—that is, the plants and animals that give us food, plus the organisms that support food production by pollinating plants, keeping soil fertile, and so on.

The FAO on Friday published its first report into the state of the world’s biodiversity, warning that the losses threaten our food, livelihoods, health and environment. And once that biodiversity is lost, it isn’t coming back.

“Biodiversity is critical for safeguarding global food security, underpinning healthy and nutritious diets, improving rural livelihoods, and enhancing the resilience of people and communities,” said FAO Director-General José Graziano da Silva.

There are several causes: farmers are growing less diverse crops; fish stocks are being depleted by overfishing; and, with urbanization, pollution and badly-thought-through agricultural techniques destroying natural habitats, wild food species are in decline.

On the bright side, however, conservation efforts and other biodiversity-friendly practices—such as organic agriculture—are on the rise. But, according to the FAO, countries need to do more to “strengthen enabling frameworks, create incentives and benefit-sharing measures, promote pro-biodiversity initiatives and address the core drivers of biodiversity loss.”

“We need to use biodiversity in a sustainable way, so that we can better respond to rising climate change challenges and produce food in a way that doesn’t harm our environment,” said Graziano da Silva.