The National Trust has announced that it is opening as many of its parklands and gardens as possible for free during the coronavirus outbreak. The South Downs National Park, Forestry England and others have reminded people that our forests and grasslands, woodlands and commons are open for business. With constrained options for leisure and restoration and heightened stress and anxiety levels, this is good news.

If you were in any doubt that it was OK to go outside, while keeping at least two metres away from others, the chief medical officer Chris Whitty told the BBC on Wednesday: “Being outside in the park is a very good thing to do.”

He would know. In the past decade, the scientific evidence that connection with nature has important therapeutic benefits for human mental health has mushroomed. Robust studies from disciplines across the world are demystifying what many intuitively know – that we often feel restored when we spend time in nature.

For a number of years I’ve been researching this mechanism for my book, Losing Eden. I was astounded by the variety and range of the evidence. Time spent in nature is linked to lower stress, restored attention, a balanced nervous system, increased levels of cancer-fighting “natural killer cells”, the activation of neural pathways associated with calm, and decreased levels of anxiety and depression. Phytoncides (compounds emitted from trees and plants), relaxation, stress reduction and awe are known to enhance immune function.

And there is an abundance of awe outside right now. The leaves are starting to erupt vivid lemon green. We are at the moment just before the natural world really lets rip.

Birds are busy making their nests. The baby-skin softness of an unfurling chestnut bud breaks through Bumblebees potter sleepily. The blues and pinks of lungwort are as psychedelic as a Los Angeles sunset.

In this new world of uncertainty, nature can be transportive. Get down on to the earth and you can find a new reality. Spring is legal, free LSD.

It’s also a symbol of renewal and regeneration that we need at the moment. In February Afternoon, by the poet Edward Thomas, birds symbolise constancy, a reassuring sign that the globe is still working: “When one, like me, dreamed how / A thousand years might dust lie on his brow / Yet thus would birds do between hedge and shaw.” Nature is a common element in war poetry.

Can spending time in nature help people deal with death and dying today? Over the past few years as I’ve talked to people about their psychological relationship with the Earth, I have been moved by the stories of people who have encountered desperate loss and grief and found a solace in the rest of nature.

For those faced with the spectre of the death and suffering of loved ones (and, let’s be honest, that is the fear we are living with), the natural world, with its seasons and changes and weather, reminds us of the facts: death and disease are part of life on Earth, but life goes on. On a run around my local cemetery before dusk yesterday, the sky was glowing and the trees were still winter-stark. The birds were piping up, indifferent to the quieter streets and the panic. Rabbits hopped around the daffodils. Obscene, almost, the sublime-meets-Basingstoke, but also grounding.

For the religious who are unable to meet for fellowship, or indeed for those who normally find spiritual solace in pubs, recovery meetings or therapy rooms, the natural world could provide a connection with the numinous that it has done for humans over centuries.

What about the most vulnerable in our society, the disabled and chronically ill? National Parks have been doing important work improving access to open spaces for people with limited mobility. The South Downs, for instance, is creating new routes in an aim to become the most accessible park in Britain.

And for those who can’t get outdoors at all? Studies have shown that just looking at a picture of the natural world can give stress reduction and wellbeing benefits. But those who looked through glass window at real nature saw a quicker decrease in heart rate than those who looked at a technological nature window. Pot plants, too, are no small thing. GPs in Manchester have even started to prescribe them. Much of nature is fractal – a self-repeating pattern of a shape that varies in scale, rather than repeats exactly. The leaves on a pancake plant (Pilea peperomioides), for instance, which start small and grow in size but repeat the same shape. Richard Taylor, professor of physics at the University of Oregon, found that these fractals provoked brain waves suggesting a relaxed state which could reduce stress levels.

Thankfully, the dawn chorus has started across the country. At 4.30 this morning, on the busy urban street where I live, there was a magical wall of sound. Crack open a window if you’re sleepless in the early morning, or first thing.

In the interwar years and second world war, bird song was early public sonic therapy. In 1924, the BBC recorded the cellist Beatrice Harrison playing in her garden accompanied by a nightingale. It became a cult hit, and the recording was repeated every spring until 1942. It represented something that we all “unconsciously crave and urgently need” as the BBC’s first director general, Lord Reith, wrote.

Of course, the natural world isn’t there to make us feel better. It doesn’t exist for mankind. (Nor is it going to be the panacea for our loneliness, stress and worry.) Are there ways, then, that the relationship can be reciprocal, instead of a one-way street? Perhaps by making our gardens nature-led and more habitable for other species. Supporting initiatives that improve access to nature and biodiversity. Ceremonies, rituals, gratitude. Could reconnecting with nature help us see our environment and origins with new eyes? Could we start to see the trees in our stockpiled loo roll?

In Boccaccio’s Decameron, the 14th-century novellas about Florence during the Black Death, some people lived temperately, hoping it would protect their health, secluding themselves from society. Others got plastered round the clock: “seeing death imminent they became reckless with their lives”.

But there was a third group who kept a middle course. They carried flowers or fragrant herbs, which they “frequently raised to their noses, deeming it an excellent thing thus to comfort the brain with such perfumes”. More than 600 years later, we would be wise to take a leaf out of their book, and seek joy in spring.

• Lucy Jones is a journalist and the author of Losing Eden: Why Our Minds Need the Wild