Benefitting both the body and mind, mushrooms are one of the most under-appreciated things on Earth—so much so that we’ve dedicated the week to them. Sunday’s Optimist View covered how psychedelic mushrooms can be used to resolve mental health issues, but we also want to let you know everything else there is to know about mushrooms.

For instance, did you know there are likely 1.5 million different species of fungi on earth? Or were you aware that mushrooms used to be seen as a low-calorie food with little nutritional benefit? We know more about mushrooms now than ever—and while they are indeed low in fat, sodium, and carbohydrates, they are high in vitamin D, potassium and antioxidants. In short, mushrooms are increasingly recognized as nutritional powerhouses.

Because of this, the demand for a wide variety of mushrooms has shot up. And while it’s a good thing that more people are eating mushrooms, scientists are alarmed because the demand for mushrooms is being linked to a decline in the numbers and diversity of mushroom fruiting bodies in traditional centers of high consumption, such as Europe and Japan.

This trend is a serious concern for scientists, who are continuously learning more about the important ecological roles that fungi play. Some form relationships with plant roots that sustain the growth of native forests and commercial tree plantations. As decomposers, fungi also recycle nutrients from the dead matter in many different types of habitats.

It’s concerning that mushroom diversity may be in decline, but the fact that we’re aware of this says something. It tells us that humans are finally starting to see fungi not just as commodities or as biological organisms, but also as important contributors to ecosystem function that are worthy of conservation.