A “remarkable” woman who spent a huge portion of her life devoted to the organic agricultural movement has died aged 97.

Pamela Gwendolen Schiele died on June 29. Fascinated by science, she worked tirelessly in striving to conserve rare species of animal and plant. She was also co-founder of Foundation Rachel and Pamela Schiele, the UK organic farming charity she set up with her sister in 1994.

Miss Schiele was born in Buenos Aires, Argentina on February 20 1918 to farmer Herbert and his wife Winifred Rachel Schiele, nee Vernon-Harcourt.

Her father died when she was one year old and her mother spent the rest of her life dedicated to caring for her two daughters. Pamela had one sister, Rachel, who was born in 1914 and died in 2011.

As a girl, Miss Schiele grew up in Fyfield Road, Oxford, and then Brookside, Headington. She attended Runton School before studying geography at Somerville College, Oxford.

She was devoted to the organic agricultural movement and she and Rachel donated what is thought to be the first and largest organic farm in Argentina to their UK charity, called Foundation Rachel and Pamela Schiele. They had inherited the farm many years before from their father.

Conservation and education were also very important to both sisters and their work led to the survival of two semi-endangered species of bird and the survival of many species of native grass.

Her family and friends said she had a “heart of gold” and was always very keen to help those less fortunate than herself.

She volunteered in 1946 to work with Save the Children and also the UN High Commission for Refugees in Athens. During the late 1950s, she volunteered to help build houses for Greek families who had been displaced when Albania took over part of Greece.

She worked for the Red Cross in central Greece, Salonika and Thrace, sometimes vaccinating people against diphtheria. In about 1961, she moved to Yugoslavia and then to Austria to help with refugees and to work with doctors.

She was multilingual, speaking English, Spanish, Greek, French and German.

Miss Schiele never married or had children.

Her cousin Ken Murray nominated Miss Schiele for a Queen’s Honour about two months ago.

Despite not being allowed to, he read her one of the letters of support for his nomination during her last few days of consciousness, coming from a very significant American philanthropist called Douglas Tompkins, who called Miss Schiele an “inspiration”. Mr Tompkins co-founded and ran two clothing companies: the outdoor clothing company The North Face and the ESPRIT clothing company. Since leaving the business world in 1989, he then dedicated himself to environmental activism and land conservation. Along with his wife, he conserved over two million acres of wilderness in Chile and Argentina.

Miss Schiele’s funeral was held on July 17 at Oxford Crematorium.