Emily Carr, Dulwich Picture Gallery

Walking into this exhibition is a bit like walking into a great forest. The dark green walls are hung all around with paintings of trees; we look up through branches that spiral dizzyingly skyward, while the upwards sweep of vast trunks seem relentlessly, tangibly full of life. Some of these paintings verge on abstraction, the forms of tree trunks simplified and reduced to an arrangement of planes, with spatial recession represented entirely through colour.

In others, a flurry of brushstrokes captures the energy of the forest, the wind in the leaves, the light breaking through to the velvety darkness beneath.

In their soulful evocation of the grandeur of nature, these late works by Canadian painter Emily Carr are the culmination of an entire career. Her love of the natural environment of British Columbia on Canada’s west coast is fused with a fascination for the native peoples of that region, whose culture and way of life was shaped by its great temperate rainforests and was, in Carr’s lifetime, threatened and marginalised as at no other time.

Her connection to this simultaneously specific and obscure location is presumably the reason why, outside Canada, no one has ever heard of Emily Carr. To Canadians, she is something of a national hero, regarded as a pioneering artist who embraced modernism and championed oppressed native cultures. But beyond her own borders, Carr's work has seemed excessively bound up with New World concerns, preoccupied with matters of identity and belonging that resonate only in a country that has been shaped by the traumas of colonial rule. (Pictured left: Tree (spiralling upward), 1932-1933)

Nevertheless, it would be a terrible error to describe Carr as provincial. Born in 1871 in Victoria, British Columbia, Carr railed against a stiflingly conventional upbringing, and was single-minded enough to attend art school in San Francisco aged 18, before coming to study in London. Later, she lived in Paris for a couple of years, where she absorbed the vivid colours and expressive brushwork of Post-Impressionism, and had two paintings accepted at the Salon d’Automne of 1911.

Having resolved a few years earlier to dedicate herself to recording the embattled native cultures of Canada’s west coast, Carr returned from Paris with a new energy. In watercolours of remote and often deserted settlements, Carr’s recent encounters with the Fauves are unmistakably evident. In Tanoo, Queen Charlotte Island, BC, 1913 (main picture), the bold, vigorous treatment of the overgrown grass and lush foliage contrast with the melancholy aesthetic of the piece. The forgotten totem poles, gradually being reclaimed by nature, are reminiscent of the picturesque ruins beloved of 19th-century English watercolourists.

For all Carr’s earnestly felt concern for Canada’s native peoples, as an artist and as a member of the colonial population, she could not help but aestheticise what she saw. Even her use of an avant garde European painting style to represent indigenous art underlines the disconnect between native and settler, a tension she acknowledged herself when she said, “I was as Canadian-born as the Indian but behind me were the Old World heredity and ancestry”.

For all their romanticising tendencies, Carr’s watercolours have an integrity that lacks in her later paintings of indigenous subjects. Disillusionment at her lack of success and dire financial necessity drove her to abandon painting altogether for an extended period, and her career only resumed when her work was included unexpectedly in a major exhibition of Canadian west coast art. As a result she was thrust into the spotlight and was introduced to American modernist painter Mark Tobey and also the Group of Seven, whose visionary paintings invest the Canadian landscape with an epic, divine presence.

Carr’s exposure to these new influences resulted in an astonishing shift in style; in her large-scale oil paintings from the late 1920s the brushwork is tight and the forms closely defined, while the cropped composition invests the totems with a strangeness and sense of menace absent from her watercolours. In Blunden Harbour, c.1930 (pictured left), the documentary purpose of her earlier paintings has gone. The carved heads and figures are almost fetishised, these unnervingly animated, humanoid figures replacing any human presence, while the surrounding landscape is reduced to an anonymous and largely featureless space. In her clinical observation and studious application of modernist ideas, Carr has lost her empathetic gaze and with it the paintings their integrity.

When at the end of her career, Carr moved away from representing indigenous art her painting transformed once again, and finally, it seems, we see the real Emily Carr.  By concentrating on the landscape she loved, Carr found that her true subject was that amazing sense of life that bursts forth from her tree pictures, and through it she found a new way to honour the indigenous people of British Columbia.

Carr herself said, "Painting is a striving to express life. If there is no movement in the painting, then it is dead paint." Ever resourceful, and due as much to poverty as artistic necessity, she developed a new technique; using white house paint coloured with pigment and thinned with petrol, she was able to paint with fast, vigorous brushstrokes, and her late work shimmers with movement, light and life.

• From the Forest to the Sea: Emily Carr in British Columbia at Dulwich Picture Gallery until 8 March, 2015